Management of Impacted third molars

This is a presentation of management of impacted third molars from the point of view of an Maxillo-Facial Surgeon

1. IMPACTIONS PRESENTED BY DR Rayan MODERATOR DR M E Sham

2. CONTENT History Definitions Theories of impaction Etiology Indications & Contraindications for removal Classification Pre-op assessment Surgical techniques perioperative care Prophylactic Odontectotmy & Coronectomy Impacted maxillary third molars Impacted maxillary and mandibular canine Surgical side-effects and complications References

3. History The term impaction is of latin origin coming from the term ‘ impactus ’. Dr George B Winter has played a major role in the development of third molar surgery. Winter published a treatise after many years of research, which appeared in ‘Dental Items of Interest’ under the title of “Exodontia” in 1913. In the year 1926 a much enlarged second edition was printed and the title was changed to ‘The Impacted Mandibular Third Molar’

4. DEFINITIONS Impacted Tooth: 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.( American society of oral surgeons 1971) A cessation of the tooth eruption caused by a clinical or radiographically detectable physical barrier in the path or by an ectopic position of tooth.( Andreason 1997)

5. “ A tooth that has failed to erupt into the oral cavity to its functional level of occlusion, beyond the time usually expected for that tooth to erupt and is prevented by adjacent hard or soft tissue including overlying teeth or dense soft tissue”. ( Lytle 1979) “A tooth is considered to be impacted when it has failed to fully erupt in the oral cavity within its expected developmental time period and can no longer do so.” (Peterson) “ Impaction is any tooth that is prevented from reaching its normal position in the mouth by tissue or bone or another tooth”. (WHO)

6. THEORIES OF IMPACTION

7. ETIOLOGY Local causes Irregularity in the position and presence of an adjacent tooth. Density of the overlying or surrounding bone. Chronic inflammation with resultant increase in density of the overlying mucous membrane. Lack of space due to underdeveloped jaws. Long retention of the primary teeth. Premature loss of the primary teeth. Berger A. As cited by Archer, WH, Oral and Maxillofacial Surgery. Vol 1 Ed.5Philadelphai,WB, Saunders Co., 1975

8. Ankylosis of the primary or the permanent tooth Non absorbing alveolar bone Ectopic position of the tooth Dilaceration of the roots Habits involving tongue,finger,thumb,cheek .

9. Systemic causes : Prenatal causes Heredity Postnatal causes Rickets Endocrine dysfunctions Malnutrition Rare conditions Cleidocranial dysostosis Oxycephaly Achondroplasia Cleft palate

10. ORDER OF FREQUENCY OF IMPACTED TEETH

11. According to AAOMS, 1989, indications for removal of impacted teeth are : Pericoronitis Non restorable dental caries. Cyst formation. Interference with orthodontic treatment. Presence of impacted tooth in the line of fracture. Pre-irradiation. Periodontitis Pathological Resorption In edentulous ridge

12. Contraindications for removal of Impacted Teeth Possible Damage to Adjacent Structures Compromised Physical Status Prosthetic consideration Availability of adequate space Questionable future status of the second molar

13. According to Larry J. Peterson the general contraindications for removal of impacted teeth can be grouped into 3 primary areas : Patient factors Extremes of age Poor health. Surgical damage to adjacent structures. Local factors Radiotherapy Teeth in close proximity to tumour ANUG Systemic factors Uncontrolled diabetes Pregnancy Underlying bleeding disorders Patients on anticoagulants,etc .

14. IMPACTED MANDIBULAR 3 rd MOLARS

15. PRE-OP ASSESSMENT Chief complaint History of presenting illness Medical history Dental history Personal history General physical examination Maxillofacial examination TMJ examination

16. Hard tissue examination Number of teeth Occlusion Carious teeth Restored teeth Prosthesis External & internal oblique ridge Status of concerened 8 Status of 7 Status of opposing 8

17. Soft tissue examination Periodontal involvement Status of buccal mucosa Tongue Salivation and hydration

18. RADIOGRAPHIC EVALUATION To study the relation with adjoining tooth. To study the configuration of the roots & status of the crown. To know the buccoversion or linguoversion of impacted tooth. Shadow of the external oblique ridge. If vertical & anterior to the Impacted tooth – Poor access. If oblique & posterior to the Impacted tooth—Good access.

19. Localization Of Impacted Teeth: Three different methods are useful in determining the exact location of an impacted tooth with the periapical x-ray: The conventional method directing the central ray of the x-ray beam at 90° to the film surface ; The use of the periapical x-ray film to record an occlusal view as described by Donovan. The tube shift concept as described by Clark

20. PERIAPICAL X-RAYS FRANK’S TUBE SHIFT TECHNIQUE 2 2 radiographs directed at 90 degree to each other

21. RADIOLOGICAL ASSESSMENT OF AN IMPACTED MANDIBULAR THIRD MOLAR 1.Type of impaction 2.Access. 3.Existing pathology. 4.WHARFE assessment. 5.Position –WAR lines. 6.Crown of impacted tooth. 7.Root of impacted tooth. 8.Relationship with inferior alveolar canal

22. WHARFE’S ASSESSMENT Winter's classification Horizontal 2 Distoangular 2 Mesioangular 1 Vertical 0 Height of mandible 1-30mm 0 31-34mm 1 35-39mm 2

23. 3. Angulation of 2 nd molar 1- 59° 0 60 -69° 1 70 -79° 2 80 -89° 3 90° & above 4 4. Root shape- Root development Favourable curve 1 Unfavourable curve 2 Complex 3

24. 5. Follicle Normal 0 Possibly enlarged -1 (NEGATIVE) Enlarged -2 (NEGATIVE) Impaction relieved -3 (NEGATIVE) 6. Path of exit Space available 0 Distal cusp covered 1 Mesial cusp covered 2 Both covered 3

25. WINTER’S LINES OR WAR LINES. WHITE LINE It corresponds to the occlusal plane. It indicates the difference in occlusal level of second & third molars .

26. AMBER LINE. Crest of the interdental septum This line denotes the alveolar bone covering the impacted tooth & the portion of the tooth not covered by the bone.

27. RED LINE It indicates the amount of bone that will have to be removed before elevation i.e. the depth of tooth in bone & the difficulty encountered in removing the tooth. Length more than 5mm - extraction is difficult Every additional millimeter renders the removal of the Impacted tooth 3 times more difficult.

28. RELATIONSHIP WITH INFERIOR ALVEOLAR CANAL I . Root Related But Not Involving The Canal Root and canal separate – more intervening bone. Root and canal adjacent -less intervening bone. Superimposed –no intervening bone. II . Related To Change In Root Dark and bifid root – canal crosses root. Root narrow – canal involves more of root. Deflection of root – canal passing through root apex. Rood, B. A, Shehab NA; The radiological prediction of inferior alveolar nerve injury during third molar surgery; BJOMS Journal of Oral and Maxillofacial Surgery (1990) 28,204

29. III. Related With The Changes In The Canal Interrupted “tram” lines - danger sign Converging “tram” lines - hour glass appearance. Diverted “tram” lines- upward displacement of canal passing through the root.

30. Darkening of root Deflection of root Narrowing of root Dark & Bifid apex

31. Interruption of white Narrowing of canal Diversion of canal line of canal

32. Arc of rotation is drawn with the centre of circle at distal root tip and periphery at mesial cusp tip

33. CLASSIFICATIONS

34. Winters classification [1926] 1 . Mesio angular 2. Horizontal 3. Vertical 4. Disto angular 5. Lingo angular 6. Buccoangular 7. Inverted

35. Classification suggested by Pell &Gregory(1933) A. Availability of space between 2 nd molar and ramus of the mandible (horizontal plane) :  Class I- There is sufficient space between the ramus of the mandible & the distal side of the second molar for the accommodation of the mesiodistal diameter of the crown of the third molar. Br J Oral Maxillofac Surg 2000; 83:585-587

36. Class II The space between the ramus of the mandible & the distal side of the second molar is less than the mesiodistal diameter of the crown of the third molar.

37. Class III Complete or most of the third molar is located within the ramus .

38. B. Relative depth of the 3rd molar in bone (vertical plane): Position A The highest portion of the tooth is on a level with or above the occlusal plane.   Position B The highest portion of the tooth is below the occlusal plane, but above the cervical line of the second molar.   Position C The highest portion of the tooth is below the cervical line of the second molar.

39. C. Long axis of the impacted tooth in relation to the long axis of the 2nd molar : 1.      Vertical. 2.      Horizontal. 3.      Inverted. 4.      Mesioangular . 5.      Distoangular . 6.      Buccoangular . 7.      Linguoangular .

40. Archer (1975) & Kruger (1984) Angulation : Mesio angular Horizontal Vertical Disto angular Lingo angular Buccoangular Inverted

41. Based on the nature of overlying tissue - [Peterson] Soft tissue impaction Partial bony impaction Bony impaction

42. Killey & Kay's classification- Angulation and position Vertical Mesioangular Distoangular Horizontal Transverse Buccoangular , Lingoangular Inverted Aberrant position

43. B. State of eruption- - Erupted - Partially erupted - Unerupted – soft tissue impaction - Complete bony impaction C. Number of roots- Unfavorable impaction- Mesial curvature of roots - Multiple roots Favorable impaction- Fused roots - Distal curvature of roots

44. G.R. Ogden Method: A simple method of determining the type of impaction involves comparing the distance between the roots of 3rd and 2nd molars, with the distance between the roots of the 2nd and 1st molars.

45. a>b : mesioangular a=b: vertical a<b: distoangular

46. SUPERIOR-INFERIOR POSITION OF THE 3 RD MOLAR: Crown to crown Crown to cervix Crown to root

47. ADA code on procedures and nomenclature: The American Dental Association (ADA) Code describes the amount of soft and hard tissues over the coronal surface of an impacted tooth. These are described as: Soft tissue impactions, Partial bony impactions, Completely bony impactions Completely bony impactions with unusual surgical complications.

48. Combined ADA and AAOMS classifications : The AAOMS published the ADA coding with explanations from the AAOMS procedural terminology, in parentheses, as follows: 07220 : Removal of impacted tooth – (overlying) soft tissue (Impaction that requires incision of overlying soft tissue and the removal of the tooth). 07230 : Removal of impacted tooth – 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 : Removal of impacted tooth – completely bony (Impaction that requires incision of overlying soft tissue, elevation of a flap, removal of bone, and sectioning of tooth for removal). 07241 : Removal of impacted tooth – completely bony, with unusual surgical complications (Impaction that requires incision of overlying soft tissue, elevation of a flap, removal of bone, sectioning of the tooth for removal, and/or presents unusual difficulties and circumstances.

49. PEDERSON SCALE OF DIFFICULTY INDEX FOR REMOVAL OF IMPACTED LOWER 3 RD MOLARS Class I – 1 Class II – 2 Class III- 3   Mesioangular - 1 Horizontal – 2 Vertical - 3 Distoangular - 4   Pederson GW. Oral Surgery. Philadelphia: WB Saunders, 1988. The removal of impacted third molars –principles and procedures. Dent Clin North Am 1994; 38: 261

50. Position A - 1 Position B - 2 Position C - 3 INTERPRETATION: Relatively difficult: 3-4 Moderately difficult: 5-7 Very Difficult : 7-10

51. According to Pogrel According to Holzle and Wolfe SURGICAL ANATOMY

52. Third molar is situated in the distal end of the body of the mandible. It is embedded between a thick buccal bone and thin lingual cortical plate

53. IMPORTANT CONSIDERATIONS On average, the buccal aspect of the canal is 4.9 mm from the buccal cortical margin of the mandible. The superior aspect of the IAN canal is 17.4 mm inferior from the alveolar crest The mean distance from root of the erupted mandibular third molar teeth to the inferior alveolar canal is 0.88 mm. The lingual nerve lies 0.5 mm lingual to the lingual cortex and 2mm apical to the alveolar crest in the third molar region. Levine M H, Goddard A L , Dodson TB, Journal of Oral and Maxillofacial Surgery Volume 65, Issue 3, March 2007, 470-474 Relationship of lingual nerve to mandibular third molar region. Journal of oral and maxillofacial surgery 53:1178-1181, 1995

54. Distance from superior border of the canal to the most apical aspect of the tooth Mesioangular (0.97 mm), Vertical (0.61 mm), Distoangular (0.31 mm), Horizontal (0.24 mm). Inferior alveolar vein lies superior to the nerve and the artery appears to be solitary and lies on the lingual side of the nerve, slightly above the horizontal position. Radiographic proximity of the mandibular third molar to the inferior alveolar canal;Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;100:545-9 The Anatomic Structure of the InferiorAlveolar Neurovascular Bundle in the Third Molar Region; J Oral Maxillofac Surg 67:2452-2454, 2009

55. Lingual Nerve Lingual nerve lies on the medial aspect of third molar. Lingual nerve may course submucosally in contact with periosteum covering the lingual wall of the third molar socket Studies done by Keisselbach (1984) Pogrel (1995) Holzle (2001) conclude that Lingual nerve was found to be at the crest of the lingual plate in 4.6 to 17.7% of cases Direct contact of lingual nerve with lingual plate was seen in 22.3% - 62% Horizontal distance from lingual nerve to lingual plate was 0 to 7mm ( avg 0.6mm) Vertical distance from the lingual nerve to the crest of the lingual plate ranged from 2mm above to 14mm below (average 2.3mm)

56. Pogrel MA, Goldman KE. Lingual flap retraction for third molar removal. J Oral Maxillofac Surg. 2004;62:1125–30 Hölzle FW, Wolff KD. Anatomic position of the lingual nerve in the mandibular third molar region with special consideration of an atrophied mandibular crest: an anatomical study. Int J Oral Maxillofac Surg. 2001 Aug;30(4):333-8.

57. Mylohyoid nerve Mylohyoid nerve leaves the inferior alveolar nerve just before the latter enters the mandibular foramen It then penetrates the sphenomandibular ligament and proceeds in the mylohyoid groove The nerve maybe damaged during lingual approach . Long buccal nerve It emerges through the buccinators and passes anteriorly on its outer surface Rarely injury to the nerve can occur when the posterior part of incision is placed too laterally If injured results in sensory deficit in buccal mucosa adjacent to lower molar teeth

58. Musculature Buccinator Musculature of the cheek During extraction deeply impacted third molars attachment may get severed resulting in marked pain and edema Temporalis During buccal approach the outer tendon maybe sectioned to enable reflection of flap This will facilitate adequate bone removal bucally and distally Medial pterygoid Not directly involved in 3 rd molar surgery While using a lingual approach post op edema may result in trismus due secondary involvement

59. Prophylactic O dontectomy It is the removal of the third molars before its complete development . Done by lateral trephination technique Described by Bowdler henry in 1969 Best time to perform it is when the radiograph of the tooth shows the roots of the third molar to be half to two third formed. If prophylactic odontectomy is done, generally all the four 3 rd molars are removed . Advantages Good bone healing Alveolar height is maintained No pocket formation distal to 2 nd molar

60. Timing : 6-9 yrs: by enucleation before the beginning of mineralization or before the calcified cusp have united. 10-16 yrs: by lateral trephination when only the crown is formed.

61. Coronectomy is a surgical procedure, first proposed in 1984 by Ecuyer and Debien , designed to avoid the risk of iatrogenic neuro -logical injury to the inferior alveolar nerve (IAN) by removal of the anatomical crown only, leaving root fragments LT Nicole Yates ;Guidelines for Surgical Coronectomies ; Clinical Update Naval Postgraduate Dental School

62. M. Anthony Pogrel , Coronectomy: A Technique to Protect the Inferior Alveolar Nerve; J Oral Maxillofac Surg 62:1447-1452, 2004

63. Complications of Coronectomy Mobalized root fragment Heamorrage Damage to adjacent tooth Alveolar osteitis Migration or eruption of roots

64. GENERAL STEPS IN SURGERY Thorough case history Radiological assessment . Patient preparation with aseptic technique Anaesthesia . Incision and reflection of mucoperiosteal flap. Removal of bone. Removal of tooth. Wound debridement. Wound closure.

65. ARMAMENTARIUM Disposable hole towel Towel clip Rampley sponge holder Fraser suction tip Mckesson mouth props Mouth mirror and probe

66. Incision and mouth opening devices scalpel-no 3 blade Markel mouth prop Molt’s mouth prop Blade- no 15 Mouth gags with Ferguson ratchet Mckesson mouth props

67. Retractors Austin retractor Minnesota retractor Seldin retractor Henahan retractor Kilner cheek retractor

68. Bone cutting instruments Straight handpiece No 702 straight fissure bur No 6 round bur French’s pattern chiesel Osteotome Weiss pattern mallet

69. Elevators Straight Cryer elevator Milller elevator Potts elevator Warwick james Heid Brink apex elevator

70. ARMAMENTARIUM Miller 52 pattern bone file London college pliers Rongeur forceps(ash’s no 3) Weider’s tongue retractor Lucas curette

71. ARMAMENTARIUM (Suturing instruments) Adson forceps Stillies forceps Gillies rat tooth forceps Spencer wells hemostat Mayo hegar (6 inch)NH Kilners NH Lane’s suture needle 4 ½ inch SCS

72. SURGICAL TECHNIQUE GENERAL PRINCIPLES FOR SURGICAL TECHNIQUE OF IMPACTION REMOVAL Reflect mucoperiosteal flap to obtain good visual access. Remove buccal bone with high speed surgical drill using round or cross-cut bur. Expose crown of impaction upto CEJ and make room to allow for elevator placement. Attempt to gently evaluate for motility with elevator. Section crown with handpiece . Care should be taken to protect the lingual soft tissue and depth of surgical cut should not be too much.

73. Straight elevator should be used to separate crown from tooth. Deliver roots with root tip elevators. Inspect bony crypt for loose debris and any bleeding problems and smooth bone margins with bone file. Carefully remove follicular soft tissue and tease it out from surrounding mucosa. Copious irrigation of socket and beneath soft tissue

74. Reapproximate soft tissue flap and close with 3-0 or 4-0 chromic or black silk sutures. Consider intraoral injection of steroids if extensive bone surgery has been performed. Evaluate for post surgical bleeding prior to flap closure .

75. INCISIONS ENVELOPE FLAP It begins on the ascending ramus following the centre of 3 rd molar shelf to distobuccal surface of second molar Then extends as a sulcular incision to the mesiobuccal corner of the 2 nd molar

76. WARDS INCISION Begins 6.4 mm in the buccal sulcus At the junction of middle and posterior Junction of 2 nd molar Passed upward to distobuccal angle of 2 nd molar Cervically behind tooth to midline of its posterior surface Finally penetrates to mucosa of cheek, 2-3mm Total average 25.4mm MODIFIED WARDS INCISION Anterior incision is commenced at the distobuccal corner of the mandibular 1 st molar instead of 2 nd molar

77. L- SHAPED INCISION Incision is a few mm away from the marginal gingiva. Helps in an intact marginal attachment distal to 2 nd molar

78. BAYONET - SHAPED INCISION

79. COMMA INCISION

80. Starting from a point at the depth of stretched vestibular reflection posterior to the distal aspect of the preceding second molar, the incision is made in an anterior direction. The incision is made to a point below the second molar, from where it is 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 2nd molar. A llows reflection of a distolingually based flap adequately exposing the entire 3rd molar area.

81. Vestibular Tongue shaped Flap Berwick in 1986 designed a vestibular tongue shaped flap. Extended into the buccal shelf of the mandible.

82. SZMYD DESIGN THREE CORNERED FLAP

83. Principles of flap Accessibility Vascularity Base wider than apex Rest on sound bone Full thickness flap Should not extend too far distally FLAPS

84. REFLECTION OF FLAP Reflection of the flap begins at the papilla. The end of the no. 9 periosteal elevator is used . Once the flap reflection is started, the broad end of the periosteal elevator is inserted at the middle corner of the flap, and the dissection is carried out with a pushing stroke, posteriorly and apically.

85. TRIANGULAR FLAP

86. BONE REMOVAL Aim: To expose the crown by removing the bone overlying it. To remove the bone obstructing the pathway for removal of the impacted tooth. To prepare a fulcrum for support of an elevator. Types: By consecutive sweeping action of bur (in layers). By chisel or osteotomy cut (in sections).

87. Bone should be removed till we reach below the height of contour, or its greatest circumference where we can apply the elevator. Extensive bone removal can be minimized by tooth sectioning. The amber line determines the amount of bone covering the impacted tooth which has to be removed for applying elevator to remove the tooth. When the entire crown lies above and in front of the amber line, there is no necessity to remove the bone. In other cases, bone can be removed with the help of chisel or burs. How much bone has to be removed?

88. BUR TECHNIQUE The crown of the impacted tooth should be exposed (CEJ) by removal of surrounding bone: Mesially – to create a point of application. Buccally – cutting a trough or gutter around the tooth to the root furcation . Distolingually – lingual plate should not be breached to protect the lingual nerve.

89. CHISEL TECHNIQUE

90. IRRIGATION The various solutions which can be used as irrigants are: Saline Sterile water Ringer’s lactate 1% Povidone iodine

91. SECTIONING OF THE TOOTH “Bone belongs to the patient and the tooth belongs to the surgeon.” Pell and Gregory stated the following advantages of splitting technique: Amount of bone to be removed is reduced. The time of operation is reduced. The field of operation is small and therefore damage to adjacent teeth and bone is reduced. Risk of jaw fracture is reduced. Risk of damage to the inferior alveolar nerve is reduced Disadvantages : In elderly patients, splitting of the tooth is possible due to the sclerosis of the tooth structure. Sometimes due to the presence of shallow grooves on the tooth structure, splitting is difficult.

92. Mesioangular impaction Sectioning of the tooth based on the type of impaction:

93. Horizontal impaction

94. Vertical impaction

95. Distoangular impaction

96. WOUND TOILET It is important to irrigate the surgical site, with particular attention paid to the space directly underneath the buccal flap where loose debris may accumulate and cause a buccal space infection. Adequate haemostasis is also important prior to wound closure to minimize the risk of persistent postoperative oozing and haematoma formation.

97. CLOSURE The most important suture is the one placed immediately behind the second molar, ensuring there is accurate apposition of wound edges . It is also useful to place a suture across the distal incision where the soft tissue thickness and potential bleeding source is greatest. Primary closure of the wound should not be attempted unless – atleast 5mm of a band of buccal attached mucoperiosteum is present.

98. SOFT TISSUE IMPACTIONS

99. TECHNIQUES FOR REMOVAL OF DIFFERENT TYPES OF MANDIBULAR 3 rd MOLAR IMPACTIONS

100. Lateral Trepanation Technique

101. ADVANTAGE Partially formed unerupted 3rd molar can be removed. Can be preformed under general or regional anesthesia with sedation. Bone healing i s goodand there is no loss of alveolar bone around the 2nd molar . DISADVANTAGE Virtually every patient has some post operative buccal swelling for 2-3 days after surgery

102. Vertical stop cut Distal cut Elevation Horizontal cut Removal of distal & buccal bone Removal of tooth Incision Closure Lingual Split Bone Technique (Kelsey Fry , T. Ward)

103. 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. 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. Lingual Split Bone Technique

104. MODIFIED LINGUAL SPLIT TECHNIQUE FOR REMOVAL OF MANDIBULAR THIRD MOLAR ( Dr.DAVIS 1979) DISTAL CUT VERTICAL STOP CUT INCISION

105. CLOSURE TOOTH ELEVATION

106. Sagittal Split Ramus Osteotomy First advocated by Amin (1995) and Toffanin (2003) Indication – 3 rd molars are placed deeply or in intimate relation with inferior alveolar nerve Drawbacks of using conventional technique Extensive bone removal Limited visibility Nerve damage Fracture of mandible Advantages of sagittal split ramus osteotomy Preserves bone Avoids chances of nerve injury

107. Disavantages of saggital split osteotomy Unfavourable splits Derrangements of occlusion Amin M, Haria S, Bounds G. Surgical access to an impacted lower third molar by sagittal splitting of the mandible: A case report. Dent Update 1995;22:206-208

108. Buccal corticotomy First reported by Tay (2007) Indications 3 rd molars are placed deeply or in intimate relation with inferior alveolar nerve Surgical technique Trapazoidal mucoperiosteal flap is raised Using bur, rectangular window is made. Imapcted molar is exposed, sectioned and extracted The buccal cortical place is fixed using plats and screws Closure is done Tay Andrews BG. Buccal corticotomy for removal of deeply impacted mandibular molars. Br J Oral Maxillofac Surg 2007;45:83-84

109. MOORE/GILLBE COLLAR TECHNIQUE A mucoperiosted flap of standard design is elevated exposing the underlying bone. A rose-head bur (no.3) is used to create a ‘gutter’ along the buccal side and distal surface of the tooth. The lingual soft tissue is protected with a periosteal elevator during the removal of the distolingual spur of bone

110. A mesial point of application is created with the bur, and a straight elevator is used to deliver the tooth. After delivery of the tooth has been effected, the sharp bone edges are smoothed with a vulcanite bur, and the cavity is irrigated. The wound is closed with sutures

111. Sl.No Criteria. Chisel&Mallet Bur 1. Technique Difficult Easy 2. Controll over bone cutting Uncontrolled 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         CHISEL VS BUR

112. BUCCAL VS LINGUAL APPROACH Criteria Buccal Lingual Access Relatively easy in the conscious patient Relatively difficult Instruments Chisel and mallet or bur Only chisel and mallet Procedure Tedious Easy Operating time Time consuming Less time consuming Technique Easy to perform, hence traditionally popular Technically difficult, hence not popular Bone removal Thick buccal plate Thin lingual plate Postoperative pain Less More due to the damage of lingual periosteum Postoperative edema More Less Dry socket Incidence is high due to the damage of external oblique ridge Incidence is negligible since socket is eliminated.

113. CLASSIFICATION OF IMPACTED MAXILLARY MOLARS

114. CLASSIFICATION OF MAXILLARY THIRD MOLAR Archer’s (1975) On anatomic basis similar to mandibular 3 rd molar Pell & Gregory Based on relative depth in relation to 2 nd molar Based On Relation Of Max 3 rd Molar To Max Sinus Floor Sinus approximation- no bone / thin partition present No sinus approximation – 2mm or more bone is present

115. Techniques For Maxillary Third Molar Impactions

116. Flap design: Envelope flap is most commonly used. Armamentarium are same as used for mandibular impactions except forceps and elevators. Millers and Potts elevators are commonly used because of their curved blades.

117. Fracture of the maxillary tuberosity is most commonly associated with manipulation of the mesioangular impactions. Displacement of the tooth in the infratemporal fossa occurs most frequently with the distoangular impactions.

118. CLASSIFICATION OF MAXILLARY AND MANDIBULAR CANINE IMPACTION

119. Etiology The origin of impaction is unclear but most likely is multifactorial. Because the maxillary canine has the longest path of eruption in the permanent dentition, alteration in position of the central and lateral incisor may be a factor. Arch length discrepancy and space deficiency may result in the canine becoming labially impacted.

120. MAXILLARY CANINE LABIAL POSITION Crown in intimate relationship with incisors Crown well above apices of incisors PALATAL POSITION Crown near surface in close relation to roots of incisors Crown deeply embedded in close relation to apices of incisors INTERMEDIATE POSITION Crown between lateral incisor & 1 st premolar root Crown above lateral incisor & 1 st premolar with crown labially placed and root palatally placed or vice versa UNUSUAL POSITION In nasal or antral wall In infraorbital region FIELD & ACKERMAN (1935)

121. CLASS I : PALATALLY PLACED MAXILLARY CANINE A) HORIZONTAL B) VERTICAL C) SEMIVERTICAL CLASS II: LABIALLY OR BUCCALLY PLACED MAXILLARY CANINE A) HORIZONTAL B) VERTICAL C) SEMIVERTICAL CLASS III: INVOLVING BOTH BUCCAL AND PALATAL BONE CLASS IV: IMPACTED IN THE ALVEOLAR PROCESS BETWEEN THE INCISORS AND FIRST PREMOLAR CLASS V: IMPACTED IN EDENTULOUS MAXILLA

122. CLASSIFICATION FOR IMPACTED MANDIBULAR CANINE Labial : vertical, oblique , horizontal Aberrant : at inferior border or On the opposite side

123. Treatment options No treatment with periodic radiographic evaluation. Interceptive removal of primary canine.

124. Surgical removal and prosthetic replacement. Surgical extraction of the impacted canine is indicated when there is poor position for orthodontic alignment, there is early evidence of resorption of adjacent teeth, the patient is too old for exposure, and the degree of displacement does not allow for surgical reposition or transplantation.

125. Surgical exposure Surgical exposure is the conventional treatment for impacted canines. open surgical exposure. surgical exposure with packing and delayed bonding of the orthodontic bracket. surgical exposure and bonding of orthodontic bracket intraoperatively.

126. SURGICAL SIDE-EFFECTS AND COMPLICATIONS Perioperative Complications.: Fracture of the crown of the adjacent tooth or luxation of the adjacent tooth Soft tissue injuries Fracture of the alveolar process Fracture of the mandible Broken instrument in tissues Dislocation of the temporomandibular joint Subcutaneous emphysema Hemorrhage Displacement of the root or root tip into soft tissues Nerve injury

127. Postoperative Complications: Trismus Hematoma Ecchymosis Edema Post extraction granuloma Dry socket Infection of wound

128. CONCLUSION Surgical removal of an impacted mandibular third molar is one of the most frequently performed minor oral surgical procedures and demands sound understanding of surgical principles to perform it as atraumatically as possible.

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