Impaction

IMPACTION 14-04-2018 1 DR. SWATI SAHU MDS FELLOW DEPT. OF ORAL & MAXILLOFACIAL SURGERY

content Introduction & etymology Definition chronology Theories of tooth impaction Etiology Surgical Anatomy of 3 rd molar Indications and contraindications Mandibular 3 rd molar: classification pre–op assessment various incision removal of tooth complications Mandibular canine Mandibular 2 nd molar Mandibular premolar Mandibular incisor References 14-04-2018 2

introduction The management of impacted teeth is a basic component of most oral and maxillofacial surgery practices. Although the majority of impacted teeth are third molars , any other tooth may be impacted. The usual care for impacted third molars is removal; however, the care for impacted teeth other than third molars may include exposure (with or without attachment of an orthodontic bracket ), uprighting , transplantation, or removal. These teeth often pose challenges in treatment planning and surgical care 14-04-2018 3

etymology They are generally thought to be called wisdom teeth because they appear so late – much later than the other teeth, at an age where people are presumably "wiser" than as a child, when the other teeth erupt. The term probably came as a translation of the Latin dens sapientiae . Wisdom teeth usually appear between the ages of 17 and 25. a time of life that has been called the "Age of Wisdom”. 14-04-2018 4

Impacted tooth is a tooth which is completely or partially unerupted and is positioned against another tooth, bone or soft tissue so that its further eruption is unlikely, described according to its anatomic position. 14-04-2018 5

14-04-2018 6 Malposed tooth is tooth, unerupted / erupted which is in an abnormal position in the maxilla/mandible

14-04-2018 7 Unerupted tooth is a tooth not having perforated the oral mucosa

14-04-2018 8 Ankylosed teeth is when cementum of the tooth is fused to the alveolar bone and there is no periodontal ligament in between, a tooth is considered to be ankylosed

14-04-2018 9 Partially erupted when the tooth has failed to erupt into a normal functional position but has crossed the bone barrier and has not reached the occlusal line.

14-04-2018 10 Ectopic/displaced teeth a tooth is ectopic if malpositioned due to congenital factors or displaced by the presence of pathology.

DEFINITION BY ARCHER – “ A tooth which is completely or partially unerupted beyond its chronologic age & is positioned against another tooth, bone or soft tissue, so that further eruption is not possible is known as impaction” ANDERSSON (1997) , FONSECA (2000) ,PETERSON & LASKIN I mpaction is defined as a cessation of eruption of a tooth caused by a clinically or radio graphically detectable physical barrier in the eruption path or by an ectopic position of the tooth. SHAFER - Impacted teeth are those prevented from erupting by some physical barrier in the eruption path 14-04-2018 11

14-04-2018 12 AMERICAN SOCIETY OF ORAL SURGEONS 1971 A tooth which is completely or partially unerupted and is positioned against another tooth, bone or soft tissue so that its further eruption is unlikely, described according to its anatomic position. LYTLE : -- Impacted tooth is one that has failed to erupt into normal functional position beyond the time usually expected for such experience. Eruption is prevented by adjacent hard or soft tissue including tooth, bone, of dense soft tissues.

11 year 14 year 18 year 25 year Tooth germ -9 year Cusp mineralization -2 year later 11 year- tooth located in anterior border of ramus, occlusal surface facing anteriorly Crown formation-14 years Root-50% formed by 16 years Root formation with open apex-18 years 24 years-95% of 3 rd molars completed eruption chronology 14-04-2018 13

Theories of Impaction (ACCORDING TO DURBECK) Phylogenic Theory Mendelian Theory Endocrine Theory Orthodontic Theory Skeletal Theory Anthropological Theory 14-04-2018 14 www.indianjournals.com/%2Fijor.aspx?target=ijor:rjpt&volume=7

Phylogenic Theory Nature tries to eliminate that which is not used. Third molar occupies an abnormal position and may be considered as a vestigial organ without purpose or function Individual receives small jaw from one parent and complement of large teeth from another parent. Mendelian Theory 14-04-2018 15

Endocrine Theory Lack of growth of the jaws is due to the lack of the function of the anterior lobe of the pituitary gland with the result that sufficient amount of growth hormone is not produced to ensure the proper growth of jaws . Orthodontic Theory Constricted and narrow dental arches of early mouth breathers affect the position and alignment of permanent teeth. The third molars attempting to erupt at a time when the deformity is well established gets impacted. 14-04-2018 16

Skeletal Theory Inadequate growth of the jaws due to an improper function of the functional matrix in which it is enclosed leads to lack of space for eruption of the third molars . Anthropological Theory During the course of evolution, increase in cranial capacity occur at the cost of decreasing jaw size 14-04-2018 17

Etiology 14-04-2018 18

Etiology – Local Causes Obstruction for eruption Irregularity in position and presence of an adjacent tooth Density of overlying and surrounding bone Lack of space in dental arch Supernumerary teeth Crowding Ankylosis of primary or permanent teeth Over-retention of deciduous teeth Dilaceration of roots (trauma) Habits involving Tongue Finger Thumb Cheek Pencil Etc 14-04-2018 19

Etiology – Systemic Causes Prenatal Causes Heredity miscegenation Post Natal Causes Rickets Anemia Tuberculosis Congenital Syphilis Malnutrition Endocrinal disorders of Thyroid Parathyroid Pituitary Glands disorders like Hypothyroidism Achondroplasia etc 14-04-2018 20 Hereditary Linked disorders like Down’s Syndrome cleidocranial dysostosis Hurler’s Syndrome Osteoporosis oxycephaly Cleft Palate Etc.

cleidocranial dysostosis 14-04-2018 21

oral surg. oral med. oral pathol . 59~420-425, 1985 According to Archer impacted teeth occur in the following order of frequency. Maxillary 3 rd molars. Mandibular 3 rd molars. Maxillary cuspids . Mandibular bicuspids. Mandibular cuspids . Maxillary bicuspids. Maxillary central incisors. Maxillary lateral incisors . 14-04-2018 22 RECENT Mandibular 3 rd molars Maxillary 3 rd molars Maxillary canine Mandibular canine Mandibular premolar Maxillary premolar Maxillary central incisors Maxillary lateral incisor

INDICATIONS Sequelae of impaction Pericoronitis Caries Periapical Pathosis Focus Of Infection Anterior Crowding Retention Or Resorption Of 2 nd Molar(pathologic Resorption) Increased Risk Of Angle Fracture Cyst And Tumors Facial Pain 14-04-2018 23

Other Periodontal Consideration Orthodontic Consideration Prosthodontic Consideration Involvement In Fracture Line Retention of 2 nd Molar Orthognathic Surgery Prophylactic Removal RETENTION OF SECOND MOLAR 14-04-2018 24

PERICORONITS CARIES 14-04-2018 25

PERIAPICAL PATHOSIS PATHOLOGIC RESORPTION FORMATION OF FOLLICULAR CYST 14-04-2018 26

CONTRAINDICATIONS Deeply, embedded, asymptomatic impacted molar. Poor systemic condition of patient Poor prognosis of 2 nd molar. In case it can serve as abutment tooth. Extremes of age Question about the future status of the second molar Probable Excessive Damage to Adjacent Structures 14-04-2018 27

Surgical anatomy 14-04-2018 28

Relation with : lingual nerve long buccal nerve Inferior dental nerve 14-04-2018 29

CLASSIFICATION OF IMPACTED MANDIBULAR THIRD MOLAR 14-04-2018 30

Angulation Impacted tooth 2nd Molar Inferior alveolar canal Thickness of bone Depth of impaction 14-04-2018 31

Classification Of Impacted Mandibular 3 rd Molar Teeth Winter’s classification(1926):---Angulation 14-04-2018 32

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14-04-2018 34 G.R.OGDEN METHOD It compares the distance between the roots of 2 nd & 3 rd molars with that of 1 st & 2 nd molars

Modified Winter Classification-(Archer, 1966): 14-04-2018 35

Pell and Gregory’s classification (1933) Relationship of impacted third molar to ramus of mandible and second molar based on space available distal to second molar 14-04-2018 36

Pell and Gregory’s classification(1942) Depth :- based on relationship to the occlusal plane of impacted tooth to that of second molar 14-04-2018 37

Combined ADA and AAOMS Classification for Impacted Teeth 07220 :- overlying soft tissue (Impaction that requires incision of overlying soft tissue and the removal of the tooth ) 07230 : - partially bony impacted (Impaction that requires incision of overlying soft tissue, elevation of a flap, and either removal of bone and tooth or sectioning and removal of tooth ) 07240 : - completely bony (Impaction that requires incision of overlying soft tissue, elevation of a flap, removal of bone,and sectioning of tooth for removal ) 07241 : - completely bony, with unusual complications (Impaction that requires incision of overlying soft tissue,elevation of a tlap , removal of bone, sectioning of the tooth for removal, and/or presents unusual difficulties and circumstances ) 14-04-2018 38

1.Position & Angulation- Winter’s Classification a) Erupted b) Partly erupted c) Unerupted 3. Number & pattern of roots - Fused -Multiple -Favourable - Unfavourable 2. State of eruption -Two KILLEY & KAY’S CLASSIFICATION

Based on State of Eruption Erupted Partially Erupted Unerupted 14-04-2018 40

Based on Number of Roots Fused Roots Two Roots Multiple Roots 14-04-2018 41

Based on Type of Tissue Overlying the tooth Soft Tissue Partial Bony Complete Bony impaction 14-04-2018 42

14-04-2018 43 NEW CLASSIFICATION (2013)

14-04-2018 44 J Oral Maxillofac Res . 2013 Apr-Jun; 4(2): e1

14-04-2018 45 CBCT RADIOLOGICAL CLASSIFICATION FOR MANDIBULAR 3 rd MOLARS

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PRE-OPERATIVE ASSESSMENT OF IMPACTED MANDIBULAR THIRD MOLARS 14-04-2018 50

14-04-2018 51 Assessment of impacted tooth is done 1. History 2. Clinical evaluation 3. Radiographic evaluation

history Age General medical condition 14-04-2018 52

Clinical examination Mouth opening Absence of local inflammatory conditions Determination of mobility characteristics of lips and cheeks Size and contours of the tongue Appearance of soft tissue overlying the impacted teeth 14-04-2018 53

Radiographic evaluation 14-04-2018 54

SHOWS : Position and type of impaction. Relationship of impacted tooth to adjacent teeth. Size and shape of impacted tooth. Depth of impaction in bone. Density of bone surrounding impacted tooth . Relationship of the impacted tooth to various anatomic structures. 14-04-2018 55

Radiographic evaluation A.INTRA-ORAL Periapical (IOPA) x-ray – paralleling tech./distal oblique/bisecting Bitewing x –ray Occlusal x-ray – topographical/cross-sectional/modified lateral cross- sectional Projection B.EXTRA-ORAL Lateral oblique mandible x-ray Orthopantomogram Computed tomography Cone- beam CT scan 14-04-2018 56

14-04-2018 57 PERIAPICAL RADIOGRAPHS

14-04-2018 58 According to winter (1926) An ideal periapical X-ray should include the whole third molar, its investing bone, the anterior border of ramus, the inferior alveolar canal and the adjacent second molar tooth. In a good film the lateral image of the second molar will be sharp without vertical shortening. In a poor film with incorrect angulation, the 'enamel cap' will be absent and there will be overlapping of contact points of molars. A. L. Mac Gregor, Geoffrey Hoe, Killey And Kay, Archer

14-04-2018 59 The specifications for an ideal IOPA radiograph as per G. B. Winter (Mac GREGOR) The buccal and lingual cusps of the erupted second molar must be superimposed The area of contact of first and second molar must not show overlap. The film must be far enough back in the mouth to show only the distal root of the first molar. The whole third molar should be seen. According to G.L.Howe the standard IOPA must have typical ‘enamel cap’ appearance of second molar .

A . Root morphology The number of factors considered . a ) Length of the root - Optimal time is when the roots 1/3 +2/3 formed. When this is the case, the ends of the roots are blunt and almost never fracture. If the root development is insufficient less than 1/3of the tooth, it is difficult to remove . b ) Single/conical, separate/distinct roots are noted . c ) Curvature of roots d) Total width of the roots in mesiodistal direction should be compared with the width of the tooth at the cervical line . e) Assess the periodontal ligament space. More the width the periodontal ligament space, is the easier the tooth is to remove. 14-04-2018 60

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B . Size of follicular sac More follicular space Less alveolar bone Easy removal C . Density of the surrounding bone Younger patient the bone is less dense, is more likely pliable and expands and blends somewhat, which allows the socket to be expanded by elevators/by luxation forces by itself and easier to cut with bur. Patients who are older than 35 years have dense bone and thus decreased ability to expand. In these patients surgeon must remove all interfering bone, because it is not possible to expand the bone socket. Bone cutting is difficult and bone removal process takes longer. 14-04-2018 62

14-04-2018 63 D. Contact with the 2nd molar Taken care if 2nd molar has carious/large restoration/root canal treated. Locked against second molar there is no space for elevation, then sectioning of the tooth should be planned. E. Nature of overlying tissues -is considered Soft tissue covering Soft tissue + Bone covering Bone

F . Inferior Alveolar Nerve and Vessels Are usually in true osseous canal in the ramus and body of the mandible. There may be multiple branches of Inferior Alveolar Nerve, instead of single combined structure. When Inferior Alveolar Nerve canal identified radiograhically , determine its relationship with impacted mandibular 3rd molar. Usually canal will be inferior/ buccal to the third molars, but variations are common. Blending of the structure radiographically indicates that the root surround the canal and its contents A thinning/narrowing of canal indicates displacement of the canal by the roots of the tooth. 14-04-2018 64

14-04-2018 65 Distinct lines of canal and of roots indicate an overlap without encroachment. To locate the canal, Frank suggests that a modification of tube shift method can be used to determine whether mandibular canal is medial to, lateral to/below an impacted mandibular 3rd molar. This method first described by Richards. Two films in identical position used but position of the x-ray tube changed to determine the position of impacted teeth. To accomplish this an x-ray angle must be shifted from 25 degree upwards and this 2nd film compared with the film taken with the x-ray tube parallel to occlussal plane.

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RELATIONSHIP OF INFERIOR ALVEOLAR NERVE TO THE ROOTS OF THE THIRD MOLAR. Deflected roots 14-04-2018 67

G. LINGUAL NERVE The studies by Kisselbach and Chamberlain demonstrated that the lingual nerve may be located some time slighter superior to the crest of bony ridge medial to the mandibular 3rd molar region and only 1/2mm toward midline in the lingual soft tissue. At this position lingual nerve is at risk during flap reflection. Usual location is superior and inferior to mylohyoid muscle. The nerve may be in various locations from crest of alveolar process to positions below mylohyoid muscle . More than one branch of the nerve may be present, and the position of the lingual nerve, relative to the mandibular 3rd molar may vary depending on the intersection of the body of the mandible and the ramus. The lingual nerve is relatively more superior and more directly associated with the soft tissue immediately adjacent to the mandible and hence greater chance of damage during surgery, in the class III and II relationships than in the class I . 14-04-2018 68

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H . Relationship to Body and ramus of mandible is important surgical consideration. This relationship described by Gregory and Pell . In Class III, t he ramus begins immediately posterior to 2nd molar and no space consists for the impacted tooth to erupt. In class II and class III relation there is reduced surgical access and close anatomic relationship with lingual nerve exists . I . Third molar and 2nd molar relationship The long axis of the third and 2nd molar is studied to determine whether impacted tooth is in Mesioangular / Vertical/ Distoangular /Horizontal/inverted position. The level of the crown of third molar are determined whether it is crown to crown, crown to cervix, crown to root and crown below 2nd molar. J. Buccal to lingual position of third molar If impacted 3rd molar is too lingually placed there may be chance of stretching of the lingual nerve. 14-04-2018 70

Mandibular Molar External oblique ridge Mylohoid ridge Mandibular canal Submandibular fossa a b c d d 14-04-2018 71

External oblique ridge . A continuation of the anterior border of the ramus, passing downward and forward on the buccal side of the mandible. It appears as a distinct radiopaque line which usually ends anteriorly in the area of the first molar. Serves as an attachment of the buccinator muscle. (The red arrows point to the mylohyoid ridge). facial view Facial view 14-04-2018 72

Mylohyoid ridge (internal oblique). Located on the lingual surface of the mandible, extending from the third molar area to the premolar region. Serves as the attachment of the mylohyoid muscle. lingual view 14-04-2018 73

facial view Mandibular (inferior alveolar) canal. Arises at the mandibular foramen on the lingual side of the ramus and passes downward and forward, moving from the lingual side of the mandible in the third molar region to the buccal side of the mandible in the premolar region. Contains the inferior alveolar nerve and vessels. 14-04-2018 74

lingual view Submandibular gland fossa. A depression on the lingual side of the mandible below the mylohyoid ridge. The submandibular gland is located in this region. Due to the thinness of bone, the trabecular pattern of the bone is very sparse and results in the area being very radiolucent. The fact that it occurs bilaterally helps to differentiate it from pathology. 14-04-2018 75

The external oblique ridge (red arrows) and the mylohyoid ridge (blue arrows) usually run parallel with each other, with the external oblique ridge always being higher on the film. 14-04-2018 76

The mandibular canal (red arrows identify inferior border of canal) usually runs very close to the roots of the molars, especially the third molar. This can be a problem when extracting these teeth. Note the extreme dilaceration (curving) of the roots of the third molar (green arrow) in the film at left. The film at right shows “kissing” impactions located at the superior border of the canal. 14-04-2018 77

14-04-2018 78 BITEWING RADIOGRAPHS

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14-04-2018 80 OCCLUSAL RADIOGRAPHS

DONOVAN TECHNIQUE IN OCCLUSAL RADIOGRAPHY 14-04-2018 81

14-04-2018 82 LATERAL RADIOGRAPHIC VIEW OF MANDIBLE

LATERAL RADIOGRAPHIC VIEW OF MANDIBLE 14-04-2018 83

14-04-2018 84 This is a accurate radiograph in class III horizontal impacted third molar. It is a good substitute when IOPA cannot be taken. It shows the vertical depth of the mandibular bone. It shows the bone below the buried tooth ,ectopic teeth and about any existing pathologies

14-04-2018 85 ORTHOPANTAMOGRAPH (OPG)

ORTHOPANT0MOGRAM 14-04-2018 86

14-04-2018 87 The angle between the occlusal plane or line parallel to it and the longitudinal axis of the impacted third molar, in turn, allowed objective classification of the third molars within the Winter subclasses .

14-04-2018 88 CONE BEAM COMPUTED TOMOGRAPHY (CBCT)

CT-scan 14-04-2018 89 Superior in showing tooth and root Shape, crown/root relationship, Tooth inclination and gives exact idea Of the proximity of IAN and canal to the Roots.

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DIFFICULTY INDICES 14-04-2018 91 PELL & GREGORY DIFFICULTY INDEX WAR LINES PEDERSON’S DIFFICULTY INDEX MODIFIED PARANT’S DIFFICULTY INDEX YAUSA ET.AL. DIFFICULTY INDEX WHARFE’S ASSESSMENT INDEX PREDICTING RISK FOR PERIODONTAL DEFECTS – KUGELBERG 1990 DIFFICULTY INDEX BASED ON CLINICAL AND RADIOLOGICAL PARAMETERS

14-04-2018 92 PELL & GREGORY DIFFICULTY INDEX

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14-04-2018 94 WINTERS W.A.R. LINES

WAR lines Line extension significance W-white line Drawn along the occlusal surface of the erupted mandibular molar and extends posteriorly over the third region Depth of the tooth within the mandible relationship of occlusal surface of impacted tooth within the erupted molars A-amber line Drawn from surface of the bone distal to the third molar to the crest of the interdental septum between the first and second molars The height of the margins of the alveolar bone enclosing the tooth Amount of vertical bone that requires removal for the extraction of 3 rd molar R-red line Perpendicular line drawn for the ambar line to the imaginary point of application for the elevator Longer the line more difficult the extraction <5 mm-less difficult For every 1 mm increase after 5 mm difficulty increases by 3 times >5 mm-advised under GA ≥9 mm-very difficult,denuding of distal of second molar may mandate the removal of second molar also 14-04-2018 95

Another method of judging the depth of the 3rd molar is to divide the root of the 2nd molar into thirds. A horizontal line is drawn from the point of application for an elevator to the 2nd molar. If the point of application is adjacent to the coronal, middle or apical root third, then the tooth extraction is assessed as easy, moderate or difficult respectively.

14-04-2018 97 PEDERSON’S SCALE

Difficulty Index : T he index for predicting the difficulty in the removal of mandibular third molar Classification . Value Spatial relationship Mesioangular 1 Horizontal/transverse 2 Vertical 3 Distoangular 4 Depth Level A 1 Level B 2 Level C 3 Ramus relationship/space available Class I 1 Class II 2 Class III 3 Index 7-10(very difficult), 5-6(moderately difficult),3-4(minimally difficult) Pederson Scale(1988) 14-04-2018 98

MODIFIED PARANT'S DIFFICULTY INDEX 14-04-2018 99

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14-04-2018 101 YAUSA et al DIFFICULTY INDEX

14-04-2018 102 Yuasa H, Kawai T, Sugiura M. Classiﬁcation of surgical difﬁculty in extracting impacted third molars. Br J Oral Maxillofac Surg 2002;40:26–31.

14-04-2018 103 WHARFE’S ASSESSMENT – MACGREGOR 1985

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14-04-2018 105 INDEX PREDICTING RISK FOR PERIODONTAL DEFECTS – KUGELBERG 1990

14-04-2018 106 Variable name Classification Value Preop plaque index (distal to 2M ) Not visible Visible 1 Preop probing depth (distal to 2M) ≤ 6mm > 6mm 1 Preop intrabony defect ( distal to 2M) ≤ 3mm > 3mm 1 Sagittal inclination of 3 rd molar ≤ 50˚ > 50˚ 1

14-04-2018 107 Contact area 2 nd and 3 rd molar Small contact Large contact 1 Resorption distal root of 2 nd molar No Yes 1 Pathologically widened follicle of 3 rd molar No or Distal Mesial ≥ 2.5 mm 1 Smoking habits Non-smoker Smoker 1 CONTD…..

14-04-2018 108 Level of risk indicated by RISK INDEX M3 - Kugelberg Risk index M3 Index Score No risk ≤1 Low risk 2 Moderate risk 3 High risk ≥ 4 Risk index M3 Predicted IBD (mm) 0-2 2.0-3.0 3-4 3.5-4.0 ≥ 5 >4.0 IBD – intrabony defect

14-04-2018 109 DIFFICULTY INDEX BASED ON CLINICAL AND RADIOLOGICAL PARAMETERS

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14-04-2018 111 J. Maxillofac . Oral Surg. DEC 2014

14-04-2018 112 SURGICAL ANATOMY

14-04-2018 113 LOCATION: L ower 3 rd molar is situated at the distal end of the body of the mandible where it meets a relatively thin ramus. Embedded b/w thick buccal alv bone buttressed by external oblique ridge & the narrow inner cortical plate. Ramus offset by 20° Retro Molar triangle- depressed roughned area post. to 3 rd molar

14-04-2018 114 MUSCLES:  Vestibule is formed by the attachment of buccinator buccally and mylohyoid lingually .  Along the anterior border of the ramus - tendinous insertion of temporalis Excessive stripping of these muscle will cause hematoma, pain and trismus .  Lingual pouch – perforation of roots along the lingual cortical plate. - may cause # of lingual cortical plate - displacement of fractured root fragments below the mylohyoid

14-04-2018 115 ARTERIES • Facial artery & facial vein run in close approximation with lower 2 nd molar near the anterior border of masseter. • Mandibular vessels in retro molar triangle which supply temporalis tendon . • Hemorrhage can occur during surgical removal of impacted tooth if distal incision is not taken laterally towards cheek.

14-04-2018 116 INFERIOR ALVEOLAR NERVE • Lies just below the roots of mandibular molars but slightly buccally placed in inferior dental canal. • In case of deep seated impaction special care should be taken to protect this neurovascular bundle during bone drilling & tooth sectioning . • Calcification of inferior alveolar canal is completed before the roots of 3 rd molar are formed. Thus growing roots may impinge upon the canal or get deflected. So blind elevation is not advisable .

14-04-2018 117 ARMAMENTARIUM FOR THIRD MOLAR SURGERY

14-04-2018 118 General Technique of Third Molar Removal Oral Maxillofacial Surg Clin N Am 19 (2007 ) 23–43

14-04-2018 119 The instruments used for surgical removal of impacted teeth are essentially a combination of instruments used for transalveolar extraction and soft tissue surgery in the mouth. There are only a few special instruments that are required. Very often the selection of instruments is a matter of personal preference. It is essential that the bare minimum instruments are used depending on the case with provision to meet exigencies. This is because a large collection of unfamiliar instruments and an elaborate tray set-up will cause embarrassment for both the patient as well the operator and interfere with efficient progress of the surgery k. George Varghese, Killey & Kay, Archer, Geoffrey L. Howe

14-04-2018 120 SURGICAL TECHNIQUE FOR REMOVAL OF IMPACTED TOOTH

14-04-2018 121 PATIENT POSITIONING The dental chair is adjusted in such a manner which is comfortable for the patient and at the same time enables the operator and the assistant to have a clear view of the surgical site. Generally, for operative procedures in mandible the occlusal plane of lower teeth should be parallel to the floor and for the maxillary teeth the occlusal plane of the upper teeth at 45° angles to the floor

14-04-2018 122 The instruments are arranged in a rational order of their intended use (not cluttered) on a sterile towel placed over the instrument tray of the dental chair or more preferably on a separate instrument trolley. If there is delay in starting the surgery, the instruments should be covered with another towel to avoid contamination and to maintain the sterility of the instruments . The surgeon and the assistant then wear cap and face mask. This is followed by scrubbing the hands After scrubbing a sterile gown is worn by the surgeon and the assistant.

14-04-2018 123 Preparation of the surgical site: Before preparing the intraoral surgical site it is always desirable to wipe the patient's face with an antiseptic solution like povidoneiodine ( Betadine ). The third molar area is then swabbed with 0.5% solution of chlorhexidine or betadine . Alternatively the patient can be given a mouth wash of the above antiseptic. This is followed by the administration of local anesthetic injection.

14-04-2018 124 Draping the patient: Ideally the head and the front part of the body of the patient should be draped, thus exposing only the face. For this the patient's head is covered with a sterile towel, the edge of which is brought under the chin and fixed with towel clip. This ensures that the head, neck and shoulders are covered and only the face is exposed.

14-04-2018 125 Palpation of Anatomical Landmarks Before starting the surgical procedure, palpation of the region and locating the anatomical landmarks is essential. The pterygomandibular fold covering the pterygomandibular raphe is usually very prominent when the mouth is opened wide. The external oblique ridge is then located. Next, the anterior part of the ramus with the coronoid notch and medially the retromolar fossa should be identified followed by the medial tendon of temporalis. The lingual shelf is palpated. Locating the anatomical landmarks will give information regarding the underlying bone and will help the operator as to where the incision is to be given.

14-04-2018 126 The standard operative plan can be divided into the following stages: 1. Incision to gain access to the area 2. Removal of adequate amount of bone 3. Sectioning and delivery of tooth from the socket 4. Debridement 5. Closure of the incision

14-04-2018 127 INCISIONS & FLAP DESIGN

14-04-2018 128 Incision – 3 parts: Anterior, posterior & intermediate limb Not to be extended too distally- Bleeding from buccal vessels & other arteries Postoperative trismus – temporalis muscle damage Herniation of buccal fat pad Damage to lingual nerve (lingual extention )

14-04-2018 129 The first step in removing the impacted tooth is to reflect a mucoperiosteal flap. The flap should be Of adequate size to permit access, & exposure of operative site. Allow adequate visibility It should have wide base to assure good blood supply to the soft tissue it should be large enough so that soft tissue surrounding the operative site is not traumatized during the operation and so that when the flap is replaced, the edges rest on wide shelf of bone Ensure unhindered healing without periodontal pocket formation distal to second molar Archer, Killey & Kay, Alling And Alling

14-04-2018 130 The most important factor in designing the flap is the position of the third molar which in turn dictates the amount of bone removal required and the need for tooth sectioning. More over, due consideration should be given for the lingual nerve, buccinator muscle and the periodontium distal to second molar while designing the flap.

14-04-2018 131 Flap designs A small artery, the buccal artery, is sometimes encountered while giving the releasing incision, the injury of which will lead to mild bleeding. The incision should not be continued posteriorly in a straight line, because the mandible diverges laterally. If the incision is extended straight, the blade will enter the sublingual space and is likely to damage the lingual nerve. The lateral extension also avoids small vessels emerging from the retromolar fossa.

The base of the flap should be larger than the apex. Essentially, the releasing incision(s ) should be divergent in relation to the site of exposure so as to not undermine the blood supply of the raised flap. • The flap should be raised and released in such a manner as to prevent tearing of the flap . Tearing might lead to a compromised blood supply and necrosis. • The ratio between the height of releasing incision(s ) and length of base should not exceed 2:1 . The type of flap used in third molar surgery is classified as full thickness, which describes an incision that is made from the epithelial surface to the underlying bone Basic principles of flap 14-04-2018 132

14-04-2018 133 GROOVE’S & MOORE INCISION ARCHER’S APPROACH ENVELOP FLAP L-SHAPED INCISION BAYONET SHAPED INCISION TRAINGULAR SHAPED INCISION LINGUAL BASED TRIANGULAR INCISION WARD’S INCISION MODIFIED WARD’S INCISION NAGESHWAR COMMA SHAPED INCISION MODIFIED SZMYD INCISION BERWICK’S TONGUE SHAPED FLAP BUCCAL EXTENSION FLAP

ENVELOPe FLAPS 14-04-2018 134 The most commonly used flap is the envelope flap, which extends from just posterior to the position of the impacted tooth anteriorly to the level of the first molar. The posterior end of the incision is directed buccally along the external oblique ridge . SZYMD FLAP

14-04-2018 135 Incision is made horizontally along the crest of the ridge or in the buccal gingival crevice. Has no vertical incision. For shallow or superficial impactions

14-04-2018 136 Most common approach . ADVANTAGES: Generous visibility. Mesial extension possible. The osseous defect can be safely covered . Blood supply up to the margins is adequate . DISADVANTAGES: The distal component can cut across the insertion of the temporalis tendon. The flap margins lies over the bony defect so formed. Wound dehiscence at the distofacial edge of the preceding second molar is frequent.

Modification of the envelope flap described by Szmyd (1971). 14-04-2018 137 Free buccal gingival tissue around first and second molars is spared. Minimal reflected periosteum . Broad-based blood supply to the flap. Adequate exposure and visibility. Good bony support for the soft tissue flap. Closure can be effected with a single suture and the distal aspect of the third molar socket. ADVANTAGES OF MODIFIED FLAP

14-04-2018 138 TRIANGULAR FLAP A small ‘V’ shaped incision, made with one point at distobuccal line angle of the second molar. One vertical limb followed the external oblique ridge, and the other avoided the gingival sulcus and extended down to the mucogingival junction , doen’t involve papilla of mandibular 2 nd molar .

14-04-2018 139 ARCHER’S APPROACH

14-04-2018 140 Standard incision(Ward’s incision,1968)

14-04-2018 141 PARTS OF INCISION

14-04-2018 142 Limb C - not to be extended too distally Bleeding from buccal vessels & other arteries Postoperative trismus – temporalis muscle damage Herniation of buccal fat pad Damage to lingual nerve (lingual extention ) In case of unerupted tooth ,intermediate incision is not needed.The limb A is extended upto the middle of the distal surface of the 2 nd molar

14-04-2018 143 This incision is started from a point approximately 6.4 mm (1\4 in)down in the buccal sulcus appox at the junction of posterior and middle thirds of second molar; the line passes upwards to distobucaal angle of second molar at gingival margin. The incision now passes cervically behind the tooth to middle of its posterior surface if third molar is unerupted . It is then extended posteriorly and laterally along the anterior border of the ramus for a maximum of 25.4 mm Extension of the incision further posteriorly may result in prolapse of buccal pad of fat or lead to marked trismus and swelling postoperatively .

14-04-2018 144 MODIFIED Ward’s incision Anterior incision is commenced at t he distobuccal corner of the crown of m andibular 1 st molar instead of 2 nd molar

BAYONET FLAPS S imilar to the molar sulcus incision The incision is similar to the second molar sulcus incision with the addition of an oblique vestibular extension in the sulcus area which is angled forward. However , oblique vestibular extension is made in the sul c us region . This extension should be angled forward to facilitate suturing and to optimize blood supply to the anterior part of the flap . This type of incision gives excellent buccal visibility. A variant of this incision is to limit the sul c us in c ision buccal to the second molar only to the distobuccal part of the gingiva . This flap offers limited visibility and should only be used for superficially and buccally placed third molars. 14-04-2018 145

‘L’ SHAPED FLAP L flap is similar to the bayonet flap only difference being that the incision is made a couple of millimeters away from the marginal gingiva. It optimizes marginal attachment healing next to the second molar. Vertical relieving incision is given at 45˚ angle to the long axis of the 2 nd molar and runs straight anteriorly and downwards. This procedure optimizes marginal attachment healing next to the second molar but requires that the main surgical approach to the third molar is at a distance from the second molar. 14-04-2018 146

LINGUAL FLAP This flap is used with a lingual approach for third molar removal. The incision starts on the ascending ramus aiming at the distobuccal corner of the second molar, follows the distal surface of the second molar as a sulcular incision, and then continues lingually to the first molar region. A sulcular incision is also made along the buccal aspect of the second molar 14-04-2018 147

14-04-2018 148 BUCCAL EXTENSION FLAP

14-04-2018 149 VESTIBULAR TONGUE SHAPED FLAP BY BERWICK’S (1966)

14-04-2018 150 Extended onto the buccal shelf of the mandible Incision line did not lie over the bony defect created by the removal of the impacted teeth Its base at the distolingual aspect of the second molar

14-04-2018 151 GROOVE & MOORE In the year 1970 they designed three flaps Produced an apparent decrease in pocketing distal to 2 nd molar A collar of tissue was preserved around the 2 nd molar hence decreasing pocket formation A lingual extension of the incision allowed for exposure of the lingual aspect as well

14-04-2018 152 NAGESHWAR’S COMMA SHAPED INCISION (2002)

14-04-2018 153 Begins at a point distal to the second molar, smoothly curved up to meet the gingival crest at the distobuccal line angle of the second molar. The incision is continued as a crevicular incision around the distal aspect of the second molar. Allows reflection of a distolingually based flap adequately exposing the entire third molar area. The incision and flap design seems best suited to cases in which the third molar is completely covered with soft tissues. In cases in which part of the impacted tooth is visible in the mouth, a small modification is made.

14-04-2018 154 Advantages No part of wound lies on resultant bone defect Less postoperative pain and swelling

FLAP ELEVATION Distolingual spur 14-04-2018 155

14-04-2018 156 The sharp end of the periosteal elevator is inserted in the region of vertical incision to ensure that the incision has reached up to bone. If not, the sharp tip of the instrument is employed to sever the remaining attachment. The blunt end of the instrument is then passed beneath the mucoperiosteum to reflect the soft tissue in the correct plane. Care should be taken not to strip the periosteum from the mucosa while reflecting.

14-04-2018 157 The mucoperiosteal flap is then reflected laterally to the external oblique ridge with a periosteal elevator and held in this position with an retractor (third molar retractor). The flap reflection should be limited to external oblique ridge laterally, because reflecting beyond this area leads to increased dead space resulting in more edema postoperatively.

14-04-2018 158 BONE REMOVAL

14-04-2018 159 The next major step is to remove the bone around the impacted tooth. The amount of bone removal varies with the depth of impaction. This can be accomplished either by use of bur, or chisel and mallet or a combination of the two methods. Whatever may the method used (which may be of individual preference), the aim is to remove sufficient amount of bone to free the tooth from obstruction and to provide a point of application for the elevator.

14-04-2018 160 If adequate amount of bone covering the tooth has been removed, an attempt can be made to elevate the tooth from the socket. Application of a great amount of force without adequate bone removal can result either in fracture of the tooth or fracture of the mandible. Due to the above risk dental extraction forceps and elevators with great mechanical efficiency like cross bar elevators are contraindicated for the removal of impacted third molar.

14-04-2018 161 Once the obstructing bone has been removed, only a slight amount of force alone is needed to deliver the tooth. Elevators with less mechanical efficiency like Warwick James elevator (straight and curved type) and Coupland chisels are recommended for this purpose. The # 301, Crane pick and Cogswell B elevators also serve this function well.

14-04-2018 162 It is a common practice to use a broad elevator between the buccal surface of the impacted tooth and the external oblique ridge in order to elevate a tooth or root fragment. This technique places the external oblique ridge, one of the buttresses of the mandible and the lingual plate at risk of fracture. If such a fracture is unrecognized, a substantial late presenting sequestrum or immediate lingual nerve injury is possible ( Farish and Bouloux , 2007).

14-04-2018 163 At the time of elevating the tooth, the index finger of the operator's left hand should rest on the occlusal surface of the wisdom tooth to judge its movement and the other fingers support the mandible. Because the impacted tooth has never sustained occlusal force, their periodontal ligament space is wider and less tenacious and they can be easily displaced if adequate bone is removed and elevation forces are applied in a proper direction.

DIFFERENCES BETWEEN BUR & CHISEL TECHNIQUE Sl.No Criteria. Chisel&Mallet Bur 1. Technique Difficult Easy. 2. Controll over bone cutting Uncntrolled&chances of fracture is more. Controlled. 3. Patient acceptance. Not tolerated in L.A. Well tolerated in L.A. 4. Healing of bone. Good Delayed Healing 5. Postoperative edema Less More. 6. Dry socket. Less. More. 7. Postoperative Infection. Less. More. 14-04-2018 164

BONE REMOVAL WITH BUR (MOORE & GILBE COLLAR TECHNIQUE) 14-04-2018 165 No. 7 or 8 round bur can be used in the range of 5000-10,000 rpm. Use of bur should always be done with copious saline irrigation to prevent thermal injury. Bone should be removed from t he occlusal surface of the tooth . A channel is formed in the bone lateral and posterior to the impacted third molar to the cervical level of the crown contour .  Adequate amount of trough should be created to remove any bony obstruction for exposure and delivery of the tooth .  Careful bone removal should be done around the distal and distolingual aspect of the tooth without damaging the lingual nerve which lies in the vicinity of the lingual plate adjacent to the third molar

14-04-2018 166

14-04-2018 167 Conventional tech of using bur. Rosehead round bur no.3 is used to create a gutter along the buccal side & distal aspect of tooth. A point of elevation is created with bur. Amount of bone sacrificed is less. Can be used in old patient. Convenient for patient.

14-04-2018 168 Lateral trephination technique ( Bowdler Henry; 1969) Indicated for removal of unerupted third molars in the age group of 9 to 18 years. A extented S shaped incision is made from the retro molar fossa across external oblique ridge. Such an incision leaves behind 5mm cuff of attached mucosa at the distobuccal region of second molar.

14-04-2018 169 A round toller bone bur is used to trephine the crypts of third molar. After anterior posterior length of crypt has been determined, a vertical cut is made through external plate A second cut is made through the outer plate at the posterior end of crypt at an angle of 45̊ from the row of trephine bur. A chisel is applied in vertical direction to out fracture outerplate

14-04-2018 170 Complications:- A transient anaesthesia in post-operative period Buccal vessel may be cut during the incision. Damage to 2 nd molar roots F racture of mandible during bone cutting Bleeding Advantages Bone healing is excellent without any loss of alveolar bone around 2 nd molar. Local anaesthesia preferred over general anaesthesia

14-04-2018 171 Split Bone / Lingual Split Technique / Sir William Kelsey Fry(1933) Described by Sir William Kelsey Fry (1933). Later popularized by Terence G ward(1956) Specially for lingually placed tooth. Modified by Dr. Davis in 1960 & Lewis in 1980

14-04-2018 172 The technique involves the use of a chisel and mallet to remove or displace the lingual plate of bone adjacent to lower third molar teeth. A small amount of buccal bone is often removed to facilitate exposure of the crown and provide a point of application for a dental elevator. Although tooth division is usually not required, it usually can be achieved with the chisel. Although the lingual split technique is well suited to patients receiving sedation or general anesthesia , it is generally not well suited to surgery conducted purely under local anesthesia .

14-04-2018 173 ARMAMENTARIUM -

14-04-2018 174 An incision is made from the retromolar area to the mesial aspect of the first molar or the distal aspect of the second molar, depending on whether an envelope incision or a triangular flap is used. The latter approach involves a vertical buccal relieving incision on the distal aspect of the second molar and is preferred by the author (GFB) because it allows better retraction and improved visibility. The buccal flap is raised in a subperiosteal plane using a # 9 periosteal elevator. The flap should be extended just slightly beyond the external oblique ridge to prevent excessive dead space beneath the flap. A 2-0 silk retraction suture is placed through the apex of the triangular flap. The suture should be clamped with a heavy hemostat 6 to 8 inches from the flap, which is then allowed to rest on skin of the cheek, where it serves to keep the flap retracted .

14-04-2018 175 The flap should be raised along a broad length before proceeding deeper. This latter approach reduces the tension placed on the lingual nerve , which adheres to the periosteum . The flap should extend from the mesial of the second molar to the lingual aspect of the anterior ramus. The inferior aspect of the pterygomandibular raphe and superior constrictor muscle together with a small portion of the mylohyoid muscle are included in this flap. The lingual nerve enters the sublingual space by passing between the superior constrictor and mylohyoid muscles; at this location the nerve is immediately beneath the periosteum and at risk from trauma.

14-04-2018 176 After lingual flap elevation, a left or right Hovell’s retractor (depending on which side of the mandible is being operated) is placed beneath the flap and allowed to sit passively. The buccal flap , previously secured with the silk suture, is retracted in part from the weight of the heavy hemostat . The first finger and thumb grasp the 3-mm chisel while the second or third finger is placed on the first molar or alveolus to stabilize the instrument. The blade of the chisel is kept vertical , with the bevel facing posteriorly, and a vertical cut is made at the mesial aspect of the third molar.

14-04-2018 177 A 5-mm chisel is then used to create a horizontal cut from the inferior aspect of the previously made vertical cut to the distobuccal aspect of the third molar

14-04-2018 178 The bevel should be kept facing superiorly for this osteotomy cut . The superior aspect of the buccal cortex adjacent to the third molar is delivered and exposes a portion of the third molar crown and provides a mesial or buccal point of elevation/access

14-04-2018 179 After completion of the buccal osteotomies, the crown of the impacted tooth is completely visible, with good access for application of elevators.

14-04-2018 180 The most difficult and crucial aspect of the lingual split follows. The 5-mm chisel is then positioned with the edge of the blade located just posterior to the distolingual aspect of the crown of the third molar. The chisel edge should lie just lateral to the lingual cortex, and the cutting edge should be kept parallel to the sagittal plane

14-04-2018 181 The handle of the chisel should be approximately 45 to the horizontal. Positioning the chisel meticulously helps ensure that when the chisel is struck with the mallet, the cutting edge penetrates the superior aspect of the alveolus just inside the lingual cortex and results in displacement of the cortex lingually .

14-04-2018 182 The anterior aspect of the fractured lingual cortex usually extends as far as the mesial of the third molar, whereas the posterior aspect may extend up to 1 cm distally . The posterior extent of the fracture is limited by the natural bony lingual concavity behind the third molar. When the chisel blade is originally positioned for the osteotomy, the cutting edge can be rotated from parallel to the sagittal plane to shorten the posterior extent of the fracture . The inferior extent of the fracture typically involves the mylohyoid ridge

14-04-2018 183 (A ) With vertical mandibular impactions (Pell and Gregory classes B and C) it is necessary to remove bone overlying the occlusal surface of the tooth. This procedure may be completed before or after removal of the buccal cortex. (B) The thin overlying bone has been removed with a chisel after the buccal osteotomy was completed, which often can be completed without the mallet using hand pressure alone.

14-04-2018 184 (A) With mesioangular mandibular impactions a variable amount of overlying bone must be removed . (B) The overlying bone has been removed with a chisel after the buccal osteotomy has been completed. Note that the inferior extent of the buccal osteotomy does not have to extend to the inferior extent of the tooth but only as far as is needed to obtain a buccal point of application for luxation before displacing the tooth lingually .

14-04-2018 185 (A) With horizontal impactions a significant amount of overlying bone may need to be removed. This approach occasionally may necessitate the use of a bur. ( B) Adequate removal of buccal and occlusal bone provides a point of elevation and exposes the distolingual aspect of the tooth.

14-04-2018 186 Coupland #1 or straight Warwick James used to engage mesial aspect and provide initial mobility . Occlusal view illustrates use of a Coupland elevator buccally to displace the tooth lingually .

14-04-2018 187 Occlusal view illustrates displacement of the tooth lingually for easy retrieval.

INCISION VERTICAL STOP CUT HORIZONTAL CUT SPLIT OF DISTOLINGUAL BONE REMOVAL OF PENINSULA BETWEEN BUCCAL & DISTOLINGUAL BONE ELEVATION REMOVAL OF DISTOLINGUAL BONE CLOSURE Split Bone / Lingual Split Technique Sir William Kelsey Fry(1933)

14-04-2018 189 ADVANTAGES Faster tooth removal. Less risk of inferior alveolar nerve damage. Reduces the size of residual blood clot by means of saucerization of the socket . Decreased risk of damage to the periodontium of the second molar. Decreased risk of socket healing problems.

14-04-2018 190 DRAWBACKS Risk of damage to the lingual nerve. The incidence of lingual nerve and inferior alveolar nerve damage has been reported as 1-6.6% . Increased risk of postoperative infection Patient discomfort due to the use of a chisel and mallet for lingual bone removal or fracturing. Only suitable for young patients with elastic bone

14-04-2018 191 Davis's technique mentions not to separate the mucoperiosteom from lingual area of bone. The bone was released in segments to allow tactile control of osteotome to prevent penetration of the osteotome into soft tissue. More than one osteotome per impaction was usually used to ensure sharp cutting edge. Wedging the osteotome between tooth and bone should be avoided to prevent fracture of the mandible. Lewis technique : Lewis (1980) modified the lingual split-bone technique by minimizing periosteal reflection and buccal bone removal and by preserving the fractured lingual plate. He claims that these modifications reduce the possibility of lingual nerve damage, minimize periodontal pocket formation, and improve the chances for primary wound healings. Modified distolingual bone splitting technique

14-04-2018 192 TOOTH SECTIONING

14-04-2018 193 Rationale of tooth sectioning is to create a space into which impacted tooth can be displaced & thence removed. Indication: Multi-rooted teeth with different lines of withdrawal Tooth division may be done using a bur, an osteotome or tooth-splitting forceps (tooth shear forceps). Tooth Sectioning Bone belongs to the patient and the tooth belongs to the surgeon

14-04-2018 194 Mesioangular mandibular impaction removal. Buccal and distal trough created and tooth elevated distally with a #301 elevator or a purchase point and a Cogswell B elevator. ( B) Distal portion of crown sectioned and removed followed by elevation of the mesial crown segment and roots. ( C) Sectioning the roots with elevation of the distal segment followed by elevation of the mesial segment.

14-04-2018 195 Horizontal mandibular impaction removal. ( A) The crown is sectioned from root and removed as a unit or may need to be sectioned longitudinally for removal. ( B) Elevation of roots with a purchase point and a Cogswell B elevator. Roots may need to be sectioned into two pieces and removed separately, with upper followed by lower.

14-04-2018 196 Vertical mandibular impaction removal. ( A) Buccal and distal trough created and purchase point placed and elevation with a #301 elevator or a Cogswell B elevator. ( B) Distal crown segment sectioned and removed followed by a purchase point in the roots for elevation with a Cogswell B or a #301 elevator. C ) Tooth and root units split and removed distal followed by mesial with purchase points for Cogswell B and #301 elevators as required. ( D) Crown removed horizontally and roots split for removal distal followed by mesial with purchase points for Cogswell B and # 301 elevators as required.

14-04-2018 197 Distoangular mandibular impaction removal. ( A) Buccal and distal trough created and distal portion of crown sectioned followed by a purchase point in the mesial of the remaining tooth structure followed by elevation. ( B) Crown sectioned horizontally and removed followed by sectioning of the remaining roots and elevation of each root independently .

14-04-2018 198 (A) Elevation of a remaining root fragment with a Cryer - or Winter-type elevator in a distal direction removes intraseptal bone but forces the root against the intact distal socket wall, where it resists removal. ( B) A well-placed purchase point in the distal of the root fragment allows a Cogswell B or Heidbrink elevator to guide the root mesially , where it meets no resistance to removal.

BUR TECHNIQUE MESIO-ANGULAR IMPACTION Luxation of the mesial segment of an impacted tooth using a straight elevator. a Diagrammatic illustration. b Clinical photograph 14-04-2018 199

BUR TECHNIQUE MESIO-ANGULAR IMPACTION Segments of tooth after removal Empty socket after extraction of tooth 14-04-2018 200

BUR TECHNIQUE MESIO-ANGULAR IMPACTION a Removal of follicle using a hemostat and periapical curette. b Surgical field after placement of sutures 14-04-2018 201

BUR TECHNIQUE DISTO-ANGULAR IMPACTION a Radiograph showing impacted mandibular third molar (partial bone impaction) with a distoangular position. b Clinical photograph of the area of impaction 14-04-2018 202

BUR TECHNIQUE DISTO-ANGULAR IMPACTION The horizontal incision extends as far as the mesial aspect of the first molar. a Diagrammatic illustration. b Clinical photograph 14-04-2018 203

BUR TECHNIQUE DISTO-ANGULAR IMPACTION Diagrammatic illustration ( a ) and clinical photograph ( b ) showing the horizontal incision upon completion 14-04-2018 204

BUR TECHNIQUE DISTO-ANGULAR IMPACTION Reflection of the mucoperiosteal flap, and partial exposure of the crown of the impacted tooth. a Diagrammatic illustration. b Clinical photograph 14-04-2018 205

BUR TECHNIQUE DISTO-ANGULAR IMPACTION Removal of bone on the buccal and distal aspects of the crown of the tooth. The groove is created to facilitate luxation. a Diagrammatic illustration. b Clinical photograph 14-04-2018 206

BUR TECHNIQUE DISTO-ANGULAR IMPACTION Sectioning of the distal portion of the crown of the impacted tooth using a fissure bur. a Diagrammatic illustration. b Clinical photograph 14-04-2018 207

BUR TECHNIQUE DISTO-ANGULAR IMPACTION Removal of the distal part of the crown using a straight elevator. a Diagrammatic illustration. b Clinical photograph 14-04-2018 208

BUR TECHNIQUE DISTO-ANGULAR IMPACTION Luxation of the impacted tooth in the distal direction, after creating a pathway for removal. a Diagrammatic illustration. b Clinical photograph 14-04-2018 209

BUR TECHNIQUE DISTO-ANGULAR IMPACTION Tooth after removal Surgical field after suturing 14-04-2018 210

14-04-2018 211

BUR TECHNIQUE HORIZONTAL IMPACTION a Radiograph showing impacted mandibular thirdmolar in the horizontal position. b Clinical photograph of the area of the impacted tooth. 14-04-2018 212

BUR TECHNIQUE HORIZONTAL IMPACTION Horizontal incision using a scalpelwith a no. 15 blade. a Diagrammatic illustration. b Clinical photograph 14-04-2018 213

BUR TECHNIQUE HORIZONTAL IMPACTION Reflection of flap and retraction with the broad end of a periosteal elevator. a Diagrammatic illustration b Clinical photograph 14-04-2018 214

BUR TECHNIQUE HORIZONTAL IMPACTION Removal of bone using a round bur, to expose the crown of the impacted tooth. 14-04-2018 215

BUR TECHNIQUE HORIZONTAL IMPACTION Sectioning of tooth at the cervical line using a fissure bur. The diagrammatic illustration ( a ) shows the position beyond which the bur must not proceed, to avoid injury of the inferior alveolar nerve 14-04-2018 216

BUR TECHNIQUE HORIZONTAL IMPACTION Separation of crown from the root, with rotation of the elevator in a groove created on the impacted tooth 14-04-2018 217

BUR TECHNIQUE HORIZONTAL IMPACTION Diagrammatic illustration ( a ) and clinical photograph ( b ) showing removal of the crown of the tooth using a straight elevator 14-04-2018 218

BUR TECHNIQUE HORIZONTAL IMPACTION Luxation of the root of using an elevator. 14-04-2018 219

BUR TECHNIQUE HORIZONTAL IMPACTION a Operation site after removal of tooth. b Surgical field after suturing 14-04-2018 220

14-04-2018 221

Buccal Corticotomy Used in deeply impacted mandibular teeth. in this tech a trapezoidal flap is raised in mandibular molar regions, and rectangular window is made over deeply to impacted tooth using a narrow fissure bur, with the mesial and distal cuts almost reaching the inferior border of mandible. the buccal cortictomy window is removed. Deeply molar is exposed, divided a bur and removed the molar. Bony fragments removed at buccal corticotomy is replaced and secured with wires or plates and screw at mesial and distal edges, and wound is sutured. 14-04-2018 222

14-04-2018 223 DEBRIDEMENT & CLOSURE

14-04-2018 224 Once the impacted tooth is delivered from the alveolar process the surgeon must pay strict attention to debriding the wound of all particular bone chips and other debris. This is best accomplished by mechanically debriding the socket and the area under the flap with a periapical curette. A bone file is used to smooth any rough and sharp edges of the bone. Instead an acrylic trimmer on a handpiece also can be used. DEBRIDEMENT

14-04-2018 225 A mosquito hemostat is employed to remove any remnant of the dental follicle in order to prevent the formation of a cyst later on. Fractured interdental septum or large pieces of bone is also removed using a hemostat . In certain instances a fractured portion of lingual plate may remain. Using a hemostat it is palpated to determine whether it is mobile. If it is having adequate attachment it may be left as such.

14-04-2018 226 If the vitality of the fractured piece is doubtful it may be detached gently from the periosteum without causing injury to lingual nerve which may be lying nearby. Finally the socket and the wound margins (including under surface of mucoperiosteum ) is irrigated with saline to remove bone and tooth debris. It has been observed that, the more irrigation is used, the less likely the patient is to develop a dry socket, delayed healing, or other complications.

14-04-2018 227 Wound Closure Bleeding from the socket is completely arrested before attempting closure. Troublesome bleeding from the socket can be controlled using bone wax, surgicel or gelfoam . The flap is then returned to its original position and the initial suture placed just distal to the second molar. It is opined that this suture reduces the possibility of the development of periodontal pocket distal to the second molar.

14-04-2018 228 In cases where the anterior vertical incision has been carried forwards up to the mesial aspect of second molar, the wound is closed with two sutures. Here the first suture is placed between the first and second molar by passing the needle from lingual to buccal side through the interdental space between the two. After this the second suture is placed in the usual position distal to second molar.

14-04-2018 229 If the flap is not repositioned properly and sutured correctly it may be heaped up over the crown of the second molar. This will lead to its ulceration due to impingement of the upper teeth during closure of the mouth and final breakdown of the wound. The patient is then asked to bite firmly on a gauze piece for 30 mts. to one hour or till the bleeding stops. Following the procedure oral and written postoperative instructions can greatly help the patient and also ensure better patient compliance.

GOOD MORNING 14-04-2018 230

14-04-2018 231 POST – OPERATIVE CARE

14-04-2018 232 The patient and the by stander should be informed that unnecessary pain and complications like infection, bleeding and swelling can be minimized if the instructions are followed carefully.

14-04-2018 233 Immediately Following Surgery Bite on the gauze pad placed over the surgical site for an hour. After this time, the gauze pad should be removed and discarded. It may be replaced by another gauze pad if there is bleeding. • Avoid vigorous mouth rinsing or touching the wound area following surgery. This may initiate bleeding by dislodging the blood clot that has formed. • To minimize swelling, place ice packs to the side of the face where surgery was performed.

14-04-2018 234 Take the prescribed pain medications as soon as possible so that it is digested before the local anesthetic effect has worn off. Avoid taking medications in empty stomach to avoid nausea and gastritis. Restrict activities on the day of surgery and resume normal activity when one is comfortable. Excessive physical activity may initiate bleeding. Do not smoke under any circumstances.

14-04-2018 235 Bleeding A certain amount of bleeding is to be expected following surgery. Slight bleeding or oozing causing redness in the saliva is very common. For this reason, the gauze will always appear red when it is removed. Excessive bleeding may be controlled by first gently rinsing with ice cold water or wiping any old clots from the mouth and then placing a gauze pad over the area and biting firmly for sixty minutes. Repeat as necessary.

14-04-2018 236 • If bleeding continues, bite on a moistened tea bag for thirty minutes. The tannic acid in the tea bag helps to form a clot by contracting the bleeding vessels. This can be repeated several times. • To minimize further bleeding, sit upright, maintain constant pressure on the gauze (no talking or chewing) and avoid exercise. • If bleeding does not subside after 6-8 hours, inform the doctor.

14-04-2018 237 Swelling The swelling that is normally expected is usually proportional to the surgery involved. Simple tooth extraction generally do not produce much swelling. However, if there was a fair amount of cheek retraction and bone removal involved with the surgical procedure, mild to moderate swelling can be expected on the affected side.

14-04-2018 238 The swelling will not become apparent until the evening or the day following surgery. It will reach its maximum on the second or the third day postoperatively. The swelling may be minimized by the immediate application of ice bag following the procedure to the side of the face where surgery was performed. If ice bag is not available sealed plastic bag filled with crushed ice may be used. The ice bag should be applied for 20 minutes on and five minutes off for the afternoon and evening following the surgery. After 24 hours, ice has no beneficial effect. Warm mouth washes and vigorous swishing should be avoided for 12 to 24 hours following surgery since it may interfere with formation of blood clot. This eventually results in postsurgical bleeding.

14-04-2018 239 Once, the initial oozing of blood has stopped (i.e. after 12 to 24 hours) warm saline mouth washes (half teaspoon salt in a glass of water) may be used fourth hourly. The mouth should be filled with normal saline as hot as the patient can tolerate and the head is held to one side in such a way the fluid lies over the area of surgery. When the fluid cools it should be expectorated and the process repeated. Regular use of mouth wash markedly relieves the pain and edema.

14-04-2018 240 Pain • Postoperative pain is only mild or moderate and is controlled easily by the use of mild analgesics like aspirin , paracetamol , ibuprofen or combinations of aspirin , phenacetin and codeine. • Pain or discomfort following surgery is expected to last 4 to 5 days. For many patients, on the third and fourth day require more pain medicine than on the first and second days. Following the fourth day pain should subside more and more everyday. • If the pain is very severe it indicates the possibility of something going wrong and the most likely cause is the development of infection. In such an instance the doctor should be contacted.

14-04-2018 241 Antibiotics • Antibiotics are not given as a routine procedure after oral surgery. The over use of antibiotics leading to the development of resistant bacteria is well documented. So careful consideration is given to each circumstance when deciding whether antibiotics are necessary. In specific circumstances, antibiotics will be given to help prevent infection or treat an existing infection.

14-04-2018 242 Diet • Drink plenty of fluids. Try to drink 5 to 6 glasses on the first day. • Drink from a glass or a cup and do not use a straw. The sucking motion will suck out the healing blood clot and start the bleeding again. • Avoid hot liquids or food till the anesthesia effect wears off. Otherwise, it can result in burning/scalding of lips and tongue. • Soft food and liquids can be eaten on the day of surgery. The act of chewing does not damage anything, but should avoid chewing sharp or hard objects at the surgical site for a week. • Return to a normal diet as soon as possible unless otherwise directed. Eating multiple small meals is easier than three regular meals for the first few days.

14-04-2018 243 Oral Hygiene • Good oral hygiene is essential to proper healing of any oral surgery site. • Brushing of teeth can be resumed from the night of surgery onwards. Avoid disturbing the surgical site so as not to loosen or remove the blood clot. • Mouthwashes have an alcohol base and it may irritate fresh oral wounds. After a few days, dilute the mouthwash with water and rinse the mouth.

14-04-2018 244 Stiffness of Jaw ( Trismus ) • Perform active jaw opening from the next day of surgery to prevent development of jaw stiffness. This will not cause tearing of the suture. • If the muscles of the jaw become stiff, chewing gum at intervals will help to relax the muscles. Use of warm, moist heat to the outside of the face over these muscles also will help to relieve this.

14-04-2018 245 Activity • Keep physical activities to a minimum for 6-12 hours following surgery. Suture Removal • Sutures should be left in place for about seven days.

14-04-2018 246 Summary of Instructions to Patient Following Surgical Removal of Impacted Tooth 1. Remove the gauze pack after 30 mts to one hour. 2. Apply ice (ice cubes taken in a polythene bag) on the face for the first 24 hours. 3. For the first day take cold liquids or semisolids. 4. Avoid warm saline gargle in the first 24 hours. 5. There may be mild to moderate swelling on the side of the face for three to four days.

14-04-2018 247 6. Mild bleeding/oozing of blood can be there from the surgical site for one to two days. In the event of excessive bleeding bite on a fresh piece of sterile gauze and inform the doctor . 7. In the first few days difficulty may be experienced in opening the mouth. To avoid this, from the next day of surgery onwards try to open the mouth forcefully.

14-04-2018 248 8. From the next day onwards after surgery or once the oozing of blood has completely stopped, warm saline mouth-baths can be used at fourth hourly intervals. Avoid application of dry heat on the face . 9. Tooth brushing have to be done from the next day on wards . 10. Take the drugs prescribed by the doctor at regular intervals . 11. Avoid alcohol, smoking, physical exercise and long journey for the next few days . 12. Report for review to the doctor as suggested for suture removal.

14-04-2018 249 COMPLICATIONS

14-04-2018 250 INTRA – OPERATIVE COMPLICATIONS

During incision Bleeding from retromolar vessels Bleeding from facial vessels Damage to lingual nerve 14-04-2018 251

DURING BONE REMOVAL USE OF BURS Accidental burns Injury to IAC Injury to adjacent tooth Injury to lingual nerve Laceration of soft tissue Necrosis of bone Emphysema USE OF CHISEL Splintering of bone Fracture of mandible Displacement of tooth into lingual pouch Injury to lingual nerve Injury to adjacent tooth Soft tissue injury 252

COMPLICATION DURING SECTIONING OF TOOTH USING BUR Incorrect line of sectioning of tooth Injury to mandibular canal Breakage of bur USING OSTEOTOME Fracture of mandible 253

14-04-2018 254 Fracture of root/tooth Luxation of neighboring tooth/ fractured restoration Soft tissue injury due to slipping of elevator Injury to inferior alveolar neurovascular bundle Fracture of mandible Forcing tooth root into submandibular space or inferior alveolar nerve canal Breakage of instruments TMJ Dislocation – careful history DURING ELEVATION OR TOOTH REMOVAL

14-04-2018 255 POST – OPERATIVE COMPLICATIONS

14-04-2018 256 Post-operative Complications IMMEDIATE - Hemorrhage - Pain - Edema - Trismus DELAYED - Alveolitis - Infection - Trismus - Nerve injury IAN LINGUAL NERVE

14-04-2018 257 HAEMORRHAGE

14-04-2018 258 TOPICAL HAEMOSTATIC AGENTS MECHANICAL AGENTS- bone wax (non- resorbable ) CHEMICAL AGENTS- styptics Vasoconstrictor- epinephrine Ferric sulphate BIOLOGIC AGENTS Thrombin ABSORBABLE MECHANICAL HAEMOSTATIC AGENTS Intrinsic action agents Gelatin- gelfoam ; spongostan Absorbable collagen- collatape ; actifoam Microfibillar collagen hemostats- avitene Extrinsic action agents surgicel

Swelling :- T his is an expected squeal of 3 rd molar surgery. P atients with round puffy face frequently develop more swelling. P arenteral administration of corticosteroids is found to be extremely useful to minimize postoperative edema. The role of ice pack applied intermittently for first 24 hours. 14-04-2018 259

Trismus Is defined as prolonged, tetanic spasm of the jaw muscles by which the normal opening of the mouth is restricted. Problem Acute phase – Pain is produced by haemorrhage Chronic phase – Hypomobility is due to organization of haematoma with subsequent fibrosis and scaring 14-04-2018 260

Management Heat therapy – 20 min every hour Warm saline rinse Analgesic Muscle relaxant Physiotherapy If Condition does not improve in 48 – 72 hr suspect infection Antibiotics 14-04-2018 261

Infection : Infection after 3 rd molar surgery have been reported to vary from 0.8 to 4.2%. It may develop either in the early or in the late postoperative period. 14-04-2018 262

14-04-2018 263 DRY SOCKET DEFINITION “postoperative pain in and around the extraction site, which increases in severity at any time between 1 and 3 days after the extraction accompanied by a partially or totally disintegrated blood clot within the alveolar socket with or without halitosis .” First described by CRAWFORD in 1876 SYNONYMS alveolar osteitis (AO) alveolitis localized osteitis alveolitis sicca dolorosa localized alveolar osteitis fibrinolytic alveolitis septic socket necrotic socket alveolalgia

14-04-2018 264 ONSET AND DURATION Mostly 1-3 days after extraction Unlikely –before first operative day Because the blood contains anti-plasmin that must be consumed before clot disintegration can take place. The duration of AO varies depending on the severity of disease ,but it usually ranges from 5-10 days The incidence of alveolitis was 2.7 times greater among females than among males

14-04-2018 265 SIGNS AND SYMPTOMS The denuded alveolar bone is painful and tender Some patients may also complain of intense continuous pain radiating to the ipsilateral ear, temporal region or the eye Regional lymphadenopathy(occasionally) Unpleasant taste(occasionally) but foul order Trismus Confirmation by probing

14-04-2018 266 Alveolar osteitis is a condition in which the blood clot disintegrates. At first the clot has a dirty grey appearance, and then it falls out leaving a bony socket bare of granulation tissue. Suppuration is absent, but a foul odour is present, and severe neuralgic pain persists for days. The condition is also known as “dry socket.” The symptoms generally set in on the second or third day after the extraction of the tooth, and last from 10 to 40 days Thoma

14-04-2018 267 The diagnosis is confirmed by passing a small curette into the extraction wound; in dry socket, bare bone is encountered which is extremely sensitive. The socket is not always open; it may contain necrotic granulation tissue not as yet expelled, or the orifice may be covered by a flap of tissue so that detection is difficult. On account of the extreme radiating pain of prolonged duration, this complication is without doubt one of the most distressing postoperative sequelae to extraction. It occurs in spite of the most careful aseptic procedure, and regardless of the ability and judgment of the surgeon Thoma

14-04-2018 268 Theories of aetiology Catellani (1989) Stated that the pyrogens secreted by the bacteria are in direct activators of the fibrinolysis in vivo. Simpson (1969) Demonstrated through microscopic studies on the monkey that the fragments are commonly observed in any extraction and do not necessarily cause problems although they might cause inflammation and some delay in chronology of alveolar repair.

14-04-2018 269 Nitizans (1978) Demonstrated a possible relationship between the presence of aerobic microorganism and aetiology of dry socket. They also reported high Fibrinolytic activity in the cultures of anaerobic Treponema Denticola found in the periodontal disease. Mitchell (1986) Identified periodontal pathogen bacteria that produce enzymes with Fibrinolytic activity such as porphyromonas gingivalis , fusobacterium nucleatum . Hedstrom and Sjogren (2007) Concluded that local treatment with tetracyclines and chlorhexidine 0.12% mouthwash (Preoperatively and postoperatively 7 days) was clinically significant in preventing dry socket in mandibular 3 rd molar extraction.

14-04-2018 270 Tjernberg 1979-Existing infection around apex of the tooth Lehner 1958- effect of epinephrine- dec bleeding Traumatic extraction Excessive irrigation or curettage of the alveolous after extraction Physical dislodgement of the clot Local blood perfusion and anaesthesia Oral contraceptives- estrogens , like pyrogens , will activate the fibrinolytic system indirectly

14-04-2018 271 Birn theory (1973) Suggested that trauma and infection cause inflammation of bone marrow with the resultant release of tissue activators that convert the plasminogen in clot to plasmin. The Fibrinolytic agent then dissolves the blood clot and at same time release kinins or kinogens , which is also in the clot dissolution, leading to severe pain. Birn considered that the trauma resulting from extraction as well as aggressive curettage might harm the alveolar cells causing inflammation of the alveolar osseous medulla and release of all mediators to the alveolus where they cause fibrinolysis activity increasing the risk of dry socket.

14-04-2018 272 PATHOGENESIS BIRN FIBRINOLYTIC THEORY

14-04-2018 273

14-04-2018 274 RISK FACTORS Previous experience of AO Deeply impacted mandibular third molar (risk factor is directly proportional to increasing severity of impaction) Poor oral hygiene of patient Active or recent history of acute ulcerative gingivitis or pericoronitis associated with the tooth to be extracted Smoking (especially >20 cigarettes per day) Use of oral contraceptives Immunocompromised individuals

14-04-2018 275 MANAGEMENT The degenerated and lost blood clot in the tooth socket must be replaced. With the loss of the protective blanket of a healthy, organizing blood clot, the denuded bony socket walls are exposed to the various irritants of the oral milieu—bacteria, saliva, food debris, and atmospheric air. After a protective dressing is inserted into the affected socket The dressing should serve not only as a covering mantle for the denuded bone but also as a vehicle whereby appropriate anodynes can be brought into close contact with the alveolar and thus obtund the pain emanating from exposed nerve endings.

14-04-2018 276 Oil of cloves is probably the original material, but eugenol , guaiacol , benzocaine, polyethylene glycol, lignocaine, domiphen bromide, zinc oxide, whitehead’s varnish, thymol iodide, and many other substances have been used. An agent that has proven topical anodyne properties and is not unduly irritating or caustic to the oral tissues is all that is needed. The agent need not be complicated, and, as is so often the case, the simpler the method, the better, so long as it is effective.

14-04-2018 277 A common formula that has been used with much success is as follows : Eugenol 46% Balsam of Peru 46% Chlorobutanol 4% Benzocaine 4%

14-04-2018 278 ALVOGYL most widely used palliative treatment. The alvogyl contains Butamben – 25.7gm Idoform – 15.8gm Eugenol - 13.7 gm Phenqhwer - 3.5 gm Eugenol inhibits the inflammatory process and provide analgesic effects by inhibiting the actions of prostaglandins.

14-04-2018 279 NERVE INJURIES 0.6-5% of all the third molar surgeries are involved with nerve damages of which 0.2% are irreversible IAN: immediate disturbance - 4-5% (1.3-7.8%) permanent disturbances - <1% (0-2.2%) Lingual N: immediate - 0.2-22% permanent - 0-2% 96% IAN injuries show spontaneous recovery within 9 months, better than lingual nerve which is about 87% Beyond 2yrs recovery is unlikely

14-04-2018 280 The incidence of neurologic injuries from third molar surgery may be related to multiple factors such as: a. Experience of the surgeon b. Proximity of tooth to the inferior alveolar nerve (IAN) c. Deep horizontal and distoangular impactions d. Surgery performed under general anesthesia (GA)- e. Patients age over 35 years f. Completely formed roots g. Depth of impaction h. Use of rotary instruments i . Surgical sectioning of tooth

14-04-2018 281

14-04-2018 282 IANI-RISK REDUCING PROCEDURES

14-04-2018 283 CORONECTOMY A method of removing the crown of a tooth but leaving the roots untouched, which may be intimately related with the inferior alveolar nerve, so that the possibility of nerve injury is reduced. first proposed in 1984 by Ecuyer and Debien . Also known as intentional partial odontoectomy , partial root removal and deliberate vital root retention BASIS FOR CORONECTOMY It is common practice for broken fragments of the root of vital teeth to be left in place and most heal uneventfully. Renton et al.and Leung et al. (randomised clinical trial), Hatano et al. (case control study) and O’Riordan (retrospective study) provided evidence that coronectomy decreases the risk of IDNI when compared to traditional extraction of MTMs

14-04-2018 284 Coronectomy:A , cutting crown below cement-enamel junction (arrow); B, trimming cutted surface to less than 3 to 4 mm below alveolar crest.

14-04-2018 285

14-04-2018 286 FATE AFTER CORONECTOMY Bone formation over the retained root fragment. Root migration is more in distoangular impactions and in older individuals Dry socket can be treated in the conventional manner with irrigation and dressing, if it occurs. There does not appear to be any need to treat the exposed pulp of the tooth.

14-04-2018 287 PREOPERATIVELY 1 WEEK POSTOPERATIVELY 36 MONTHS POSTOPERATIVELY

14-04-2018 288 CASES TO AVOID Teeth with associated infection, particularly infection involving the root portion Teeth that are mobile Teeth that are horizontally impacted along the course of the inferior alveolar nerve DRAWBACKS OF CORONECTOMY Root walk out during surgery(FAILED CORONECTOMY) deep periodontal pockets on the distal of the second molar, delayed postoperative root migration with the possible need of a second procedure postoperative pain dry socket infection

14-04-2018 289 RESISTANCE TO THE ACCEPTANCE BECAUSE concern about leaving a large section of root in the mandible. Retained root may develop a radicular cyst leading to further surgery and morbidity. post-operative infections root eruption leading to reoperation

14-04-2018 290 ORTHODONTIC EXTRUSION Risk of direct trauma to IAN is eliminated A potential problem with this technique is soft tissue damage from impingement on the mucosa of the cheek and the gingva . Difficult in working in this area because the action of the masseter muscle leads to cheek compression against the orthodontic appliances no value in case of ankylosed teeth. It is time consuming and not always successful

14-04-2018 291 PERICORONAL OSTECTOMY The removal of the overlying bone to allow for the tooth to erupt away from the IAN, in cases of incomplete root formation in younger patients 14 to 18 years old

14-04-2018 292 ACCIDENTAL DISPLACEMENT OF THIRD MOLARS CAUSES Excessive apical force during the use of elevators . incorrect surgical technique. In mandibular third molar, the thinness of the lingual cortical bone predisposes to displacement in a lingual direction. Distolingual angulation of the tooth predisposes to the displacement.

14-04-2018 293 THANK YOU

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