Management of impacted canines

Introduction
Incidence
Development of canine
Eruption of canine
Etiology of canine impaction
Sequelae of canine impaction
Classification of canine impaction
Diagnosis
Radiographic Prediction
Prognosis
Prevention of maxillary impaction
Extraction of impacted canine
Treatment alternatives
General principles of mechanotherapy
Methods of gaining space
Anchorage considerations
Surgical Methods
Surgical exposure for natural eruption
One step vs two step
Types of flaps
Attachments
Methods of traction
Mandibular canine impaction
Canine impaction and resorption
Canine impaction and periodontium
Retention
Complications of treatment
Complications of untreated impacted canine
Conclusions
References

1. Dr. Miliya Parveen MANAGEMENT OF IMPACTED CANINES

2. CONTENTS Introduction Incidence Development of canine Eruption of canine Etiology of canine impaction Sequelae of canine impaction Classification of canine impaction Diagnosis Radiographic Prediction Prognosis Prevention of maxillary impaction Extraction of impacted canine Treatment alternatives General principles of m echanotherapy Methods of gaining space Anchorage considerations Surgical Methods Surgical exposure for natural eruption One step vs two step Types of flaps Attachments Methods of traction Mandibular canine impaction Canine impaction and resorption Canine impaction and periodontium Retention Complications of treatment Complications of untreated impacted canine Conclusions References

3. INTRODUCTION An impacted tooth is defined as tooth whose roots are 2/3rd or fully developed but nevertheless expected to erupt spontaneously . According to Shafer, Hine and Levy, impacted teeth are those which are prevented from erupting by some physical barrier in the eruption path. An impacted or unerupted canine tooth is usually easy to diagnose, but the skill and expertise of the general practitioner, the pedodontist , the oral surgeon, the periodontist as well as the orthodontist are needed, to bring it, to its proper position.

4. incidence Mandibular third molar -- Maxillary canine -- mandibular second premolar. Impacted maxillary canines are seen in 2% of the population Palatal canine impaction is more common (85%) than buccal canine impaction.{Jacoby 3:1}. A ratio of twelve palatably impacted canines for one labially impacted canine ( Jaloby ) It is twice as more common in females than males. Of all patients with impacted maxillary canines, 8% have bilateral impactions. Incidence of maxillary canine impaction : 1.7 % ( Ericson) Incidence of mandibular canine impaction 0.35% ( Dachi )

5. development According to Broadbent, AO 1941- Canine develops at 4 – 5 months of age between the roots of deciduous 1st molar. Calcification of canine - around 12 months of age. Calcification takes place far above the roots of deciduous molar, allowing development of the first premolar between the deciduous molar roots.

6. ERUPTION OF CANINE Dewel (1949) stated that “no tooth is more interesting from the development point of view than the maxillary canine” Canine develops in deepest area of maxilla has the most tortuous course and longest path of eruption (22mm) during its course or eruption and has longest period of development. During their course of development, the crowns of the permanent canines are intimately related to the roots of the lateral incisors .

7. A periapical view shows the unerupted permanent canine crowns, of each side, pointing mesially towards the lateral incisor apical area - causing the apical convergence of the incisor roots and the median diastema doesn’t close completely. T he permanent canine alters its relationship as it moves downwards along the distal side of the root of the lateral incisor, uprighting the long axis of that tooth – it then becomes more vertical as it progresses and as the root of the deciduous canine becomes resorbed.

8. With the shedding of the deciduous canine, it finally erupts with a slight mesial inclination, taking up its place in the arch by moving the crowns of the incisors towards the midline, to close off the diastema completely. Throughout the period of its downward progress, the permanent canine is conspicuously palpable on the buccal side of the alveolar ridge, from as early as 2-3 yrs period to its normal eruption, which normally occurs at the age of 11-13 yrs.

9. Etiology Becker Concept: Becker (1984) hypothesized two processes in the palatal impaction of the maxillary canine - Absence of initial early guidance from an anomalous lateral incisor, and later failure of buccal movement of the canine at an unspecified age {9 years }. Moyer’s etiology of Maxillary Canine Impaction (Multifactorial ): Bishara summarised Moyer's theory that the causative factors may be - 1 . Primary (Localized) (a) Tooth size-arch length discrepancies. (b) Prolonged retention or early loss of deciduous canine. (c) Abnormal position of the tooth bud (rotation of tooth buds). (d) Trauma to the deciduous tooth bud.

10. (e) Disturbances in the tooth eruption sequence. (f) Presence of an alveolar cleft. (g) Ankylosis (h) Cystic or neoplastic formation (i) Dilaceration of the root (j) Premature root closure (k) Iatrogenic (l) Idiopathic 2 . Secondary ( Generalised ) (a) Abnormal muscle pressure (b) Febrile diseases (c) Endocrine disturbances (d) Vitamin D deficiency (e) Irradiation.

11. Berger Concept {Systemic cause of impaction}: Malnutrition Tuberculosis Syphilis Rickets Anemia Progeria Syndromes: a)      Cleidocranial dysplasia b)      Achondraplasia c) Down syndrome Vonder Heydt Concept: Total arch length of permanent teeth is initially established very early in life at the true of eruption of first permanent molars. Canine is larger and later erupting and considering like a musical chair situation it may get impacted. Reason for eruption of canine labially is arch length deficiency.

12. MC Bridge Concept: Canine formed at high in the anterior wall at antrum , below the floor of orbit, its long tortous path of eruption is the reason for impaction. Peck and Peck Concept: Characteristics of palatally impacted canines include, 1) Occurrence of other dental anomalies - occurs in combination with tooth agenesis, tooth size reduction, supernumery tooth and other ectopically positioned tooth. 2) Bilaterally occuring Phenomenon (17%) 3) Females affected more than males (1:3.2) 4) Familial occurence They concluded palatally impacted canine as dental anomaly of genetic origin.

13. Guidance Theory – Miller: Canines usually have a more mesial development path , which is guided downwards apparently along the distal and aspect of the lateral incisor roots . - First stage Impaction : If there is a loss of guidance due to missing lateral incisors or late developing laterals, canines will have a mesial and palatal path of eruption . In this event there is no vertical movement of canine into the alveolar process , resulting in a more horizontal impaction. First stage impaction and secondary correction : Once it has reached the palatal alveolar process , canine is redirected to a more favorable path of eruption . - Second stage Impaction : Self correction is prevented by, late developing lateral incisors (peg laterals) which re-deflect the tooth further palatally . Second stage Impaction and secondary correction : Extraction of deciduous canine or even extraction of lateral incisors leads to spontaneous eruption of the impacted tooth.

14. LABIAL CANINE IMPACTION In Arch length deficiency, Canine will have contact with crown or root at lateral incisors, first premolar and deciduous canine. Canine is surrounded by anterior wall of maxillary sinus, and nasal cavity. So it is impossible for canine to jump in to or behind tooth or penetrating to nasial cavity or sinus - impacted labially . PALATAL CANINE IMPACTION Canine can be palatally positioned if extra space available in maxillary bone space due to, Excessive growth in the base of maxillary bone Agencies of lateral incisors Peg shaped lateral incisors Stimulated eruption of lateral incisors or 1 st premolars.

15. Sequelae of impaction The normal sized and early developing lateral incisor root obstructs the deviated eruption path of canine - damaged by resorption . Anomalous lateral incisors (peg shaped & or small mesiodistal crown width ) have small and late developing roots - more easily bypassed

16. Classification Impacted canine Maxillary canine Mandibular canine Buccal Palatal Lingual Buccal

17. IMPACTED CANINE Horizontally Vertically Palatal Above Labial Mid- alveolar Below ( With respect to the arch) (With respect to the apex) ( JCO 1979 DEC) Classification by ACKERMAN and FIELDS (1935) -

18. Class I: Impacted cuspids located in palate. a)      Horizontal b)      Vertical c)      SemiVertical Class II: Impacted cuspids located in Labial or buccal surface of maxilla a)      Horizontal b)      Vertical c) SemiVertical Archer’s canine impaction classification -

19. Class III: Impacted cuspids located in palatine and maxillary bone e.g . crown is on the palate and root passes through the root of the adjacent teeth and ends in the labial or buccal surface of maxilla. Class IV: Impacted cuspids located in the alveolar process, usually vertically between incisor and first bicuspids Class V: Edentulous maxilla Class VI: Aberrant position

20. Classification of palatally impacted canine Based on two variables : (1 ) Transverse relationship of the crown of the tooth to the line of dental arch which may be - (a) Close (b) Distant (nearer the midline ) (2 ) Height of the crown of the teeth in relation to the occlusal plane which may be (a) High (b) Low

21. Group 1 Proximity to the line of arch – close. Position in the maxilla – low . Group 2 Proximity to the line of arch – close. Position in the maxilla – forward , low & mesial to the lateral incisor root.

22. Group 3 Proximity to the line of arch – close . Position in the maxilla – high . Group 4 Proximity to the line of arch – distant . Position in the maxilla – high.

23. Group 5 Canine root apex mesial to that of lateral incisor or distal to that of first premolar . Group 6 Erupting in the line of arch in place and resorbing the roots of incisors.

24. Diagnosis IMPACTED OR PREMATURLEY ERUPTED? Gron (1962) stated that under normal circumstances a tooth erupts with a developing root and with approx. three quarters of its final root length. The mandibular central incisors and first molars have marginally less root development and mandibular canines and second molars marginally more when they erupt . Thus should an erupted tooth have less root development, it would be appropriate to label it as prematurely erupted. At the opp. end of the scale, we find the un-erupted tooth that exhibits a more completed developed roots, the normal eruption process of this tooth must be presumed to be impeded .

25. CLINICAL EVALUATION:   The following signs might be indicative of canine impaction . Delayed eruption of the permanent canine or prolonged retention of the deciduous canine beyond 14 to 15 years of age. Absence of a normal labial canine bulge. Presence of a palatal bulge. Delayed eruption, distal tipping or migration(splaying ) of the lateral incisor.

26. RADIOGRAPHIC EVALUATION:    Periapical films : The first, simplest and most informative X-ray. - Advantages, 1) Root development , pattern and integrity 2) Crown resorption 3) Root resorption of adjacent tooth 4) Minimun of surrounding tissue is exposed which increases accuracy and resolution . 5) Minimal radiation exposure - Disadvantages, Two dimensional representation which gives no information regarding buccolingual plane Overlapping structures cannot be differentiated as to which is lingual and which buccal .

27. Tube Shift Technique - Two periapical films are taken of the same area with the horizontal angulation of the cone changed when the second film is taken. If the object in question moves in the same direction as the cone - lingually positioned. If the object moves in the opposite direction it is situated closed to the source of radiation - buccally located . - Disadvantage : In cases when canine is highly placed, and periapical film shows no superimposition of canine with the roots of erupted tooth or when superimposition is only in the periapical region, the result may be misleading.  

28. b) Buccal Object rule If the vertical angulation of the cone is changed by approximately 20 o in two successive periapical films, the buccal object will move in the direction opposite to the source of radiation. On the other hand, the lingual object will move in the same direction as the source of radiation. The basic principle of this technique deals with the foreshortening and elongation of the images of the films.

29. Occlusal films   - To determine the buccolingual position of the impacted canine (provided the image of the impacted canine is not superimposed on the other teeth ) - In this view the central ray of X-ray beam runs parallel to long axis of central incisors . Exposure is done through the vertex i.e 110º to the occlusal plane . - When the radiograph is viewed the anteriors are seen as small tiny concentric circles. If the impacted tooth is not parallel to neighbouring tooth, depend on angulation of long axis of the tooth it will be elliptical or oblique in cross section. - If tooth is horizontal, its full length will be seen.

30. Extra Oral films :   - Frontal and lateral cephalograms for determining the position of the impacted canine, particularly its relationship to other facial structures ( eg . Maxillary sinus and the floor of the nose ) - Panoramic films to localize impacted teeth in all 3 planes of space (much the same as with 2 periapical films in the tube shift method, with the understanding that the source of radiation come from behind the patient , thus the movements are reversed for position )

31. - In OPG, when mesiodistal width of canine crown was 1.5 times larger (i.e. 15% larger) than the adjacent central incisor, then the canine is palatally placed. - This is only true in cases where canine should not be at a higher level. [ Reliability of a method for localisation of displaced maxillary canines using a single panoramic radiograph. Chaushu et al; clin orthod res 1999; 2: 194-9]

32. CT Scanning: - Clear radiograph can taken at graduated depth in any part of the human body . By viewing serial radiograph slices of the maxilla, the relationship of the impacted tooth to adjacent teeth in all the three plane of space can be accurately assessed . - Root resorption can be assessed. - Superimposition of structures doesn’t obscure the image. Disadvantage : Expensive, large dose of radiation to be justified.

33. 5. Rapid prototyping: - Comprises several technologies that use data from computer-aided design files to produce physical models and devices by a process of material addition. - This made possible the fabrication of an attachment for forced canine eruption. - Rapid prototyping dental modeling might become the diagnostic procedure of choice in the evaluation of impacted maxillary canines

34. Ericson and Kurol in EJO 1988 defined number of sectors to denote different types of impaction - i. Sector 1: if the cusp tip of the canine is between the interincisor median line and the long axis of the central incisor; ii. Sector 2: if the peak of the cuspid of the canine is between the major axes of the lateral and central; iii. Sector 3: if the peak of the cuspid of the canine is between the major axis of the lateral and the first premolar. RADIOGRAPHIC PREDICTION

35. They used angle “ α ” to represent the angle formed between the interincisor midline and long axis of canine. The risk of resorption of the root of the lateral incisor increases by 50% if the cusp of the canine belongs to sector 1 or 2 and if α angle is greater than 25°. The duration of treatment is longer if the canine is found in sector 1, shorter if it belongs to sector 3, with respect to sector 2. The necessity of treatment and the degree of treatment difficulty increases as this angle increases.

36. Modification of Ericson & Kurol’s definition of sectors used: Sector I: Located distal to a tangent to the distal crown & root of the lateral incisor. Sector II: The area from the tangent on the distal surface to a midline bisector of the lateral incisor tooth. Sector III: The area from the midline bisector to a tangent to the mesial surface of the lateral incisor crown & root. Sector IV: All areas mesial to sector III . Steven Lindauer et al. JADA March 1992 . Canine Impaction identified early with Panoramic Radiographs

37. Study done by Stivaros and Mandall to investigate the radiographic factors that influence the orthodontists decision to expose align or remove an impacted tooth panoramic radiographs. (JO 2000)

38. 1 . Canine angulation to the midline - Grade 1: 0–15° - Grade 2: 16–30° - Grade 3: >31° 2. Vertical Canine Crown Height - Grade 1: Below the level of the CEJ - Grade 2: Above the CEJ, but less than half way up the root. - Grade 3: More than half way up the root, but less than the full root length. - Grade 4: Above the full length of the root .

39. 3. Position of Canine Root Apex Antero-posteriorly - Grade 1: Above the region of the canine position . - Grade 2: Above the upper first premolar region . - Grade 3: Above the upper second premolar region. The vertical height from canine tip to the occlusal plane (  > 15mm - poor prognosis). 4. Canine Overlap of the Adjacent Incisor Root - Grade 1: No horizontal overlap. - Grade 2: Less than half the root width. - Grade 3: More than half, but less than the whole root width. - Grade 4: Complete overlap of root width or more.

40. PROGNOSIS B efore the treatment decision was made, a number of diagnostic patient and radiographic factors would have to be considered including : Patient age - The upper age limits suggested for successful alignment of an ectopic canine include 16 ( McSherry , 1996) and 20 ( Nordenram , 1987) years of age. General dental health and oral hygiene Whether space is available in the arch or can be made available for alignment of the permanent canine - In 85 per cent of subjects with palatal displacement of a canine there is adequate space in the arch (Jacoby, 1983), whilst in crowded arches the canine is more likely to erupt in a buccal position (Oliver  et al ., 1989).

41. (4) S uitability of the first premolar to replace a permanent canine (5) P atient motivation for orthodontic appliances (6) Medical contra-indications for surgery . (7) Position of canine – As canine angulation to the midline increases so does the likelihood of removal rather than attempted alignment. Palatally impacted canines more likely to be exposed, and those in the line of the arch or buccally positioned more likely to be removed (increased problems of managing the attached gingivae) Higher above the occlusal plane the canine is positioned, the poorer the prognosis for alignment 

42. PREVENTION OF MAXILLARY CANINE IMPACTION When the clinician detects early signs of ectopic eruption of the canines, an attempt should be made to prevent their impaction and its potential sequelae . Selective extraction of the deciduous canines as early as 8 or 9 years of age has been suggested by Williams as an interceptive approach to canine impaction in Class I uncrowded cases. Ericson and Kurol suggested that removal of the deciduous canine before the age of 11 years will normalize the position of the ectopically erupting permanent canines in 91% of the cases if the canine crown is distal to the axis of the lateral incisor. S uccess rate is only 64% if the canine crown is mesial to the midline of the lateral incisors.

43. Vertical canine angulation exceeding 31° relative to the midline decreased success rates significantly. After extraction of the primary canines only 65% of the palatally displaced canines have been found spontaneously erupted. The success rate would improve to 88% by the addition of forces to prevent mesial migration of the maxillary posterior teeth after extraction, i.e., the use of cervical-pull headgear.

44. ( 1) If it is ankylosed and cannot be transplanted (2) If it is undergoing external or internal root resorption (3) If its root is severely dilacerated, (4) If the impaction is severe ( e.g., The canine is lodged between the roots of the central and lateral incisors and orthodontic movement will jeopardize these teeth) (5) If the occlusion is acceptable, with the first premolar in the position of the canine and with an otherwise functional occlusion with well-aligned teeth (6) there are pathologic changes ( e.g., c ystic formation , infection), and the patient does not desire orthodontic treatment. Extraction of impacted canines

45. TREATMENT ALTERNATIVES No treatment if the patient does not desire it . In such a case, the clinician should periodically evaluate the impacted tooth for any pathologic changes but long term prognosis for retaining the deciduous canine is poor, regardless of its present root length and the esthetic acceptability of its crown. Auto transplantation of the canine . Due to a high possibility of pulp necrosis, endodontic treatment of fully developed transplanted teeth should be undertaken. Recipient socket should be prepared to a size that is slightly larger than the root of the donor tooth. Extraction of the impacted canine and movement of a first premolar in its position.

46. Extraction of the canine and posterior segmental osteotomy to move the buccal segment mesially to close the residual space, which is a tedious surgical procedure. Prosthetic replacement of the canine , not amenable for juvenile patients. T ransalveolar transplantation of maxillary canines was reported by Soren Sagne et al., in AJODO ’86 - during this procedure it is important to minimize trauma to the tooth, remove a great amount of bone, to loosen the tooth gently from its impacted positions and not to force it into its new site with hard bone contact. Surgical exposure of the canine with/without orthodontic treatment to bring the tooth into the line of occlusion - most desirable approach.

47. GENERAL PRINCIPLES OF MECHANO-THERAPY Leveling and Alignment of the erupted teeth. Creating enough space for the impacted canine and maintaining it. Conversion of the arch into a rigid anchorage unit . Surgical exposure of the crown of the impacted canine and attachment bonding. Application of low force (60gm) traction from r igid anchorage unit.

48. Method of creating space A) Existing incisor space - Becker showed incisor spacing was due to failure of completion of ugly duckling stage of development . During final stage these existing spaces will be closed by mesial movement of lateral incisor . B) Improving arch form - I mproving arch form after extraction of deciduous canine will add 2-3 mm of space.

49. C) Increasing arch length - In mild crowding cases distalization of molar is recommended which increases the arch length. D) Extraction as means of prevention (Mixed dentition period) - D eciduous canine P atient with age of 10-13 years with delayed dental age , palatal displacement of canine with apex confirmed in line of arch requires extraction of deciduous canine for good prognosis for eruption of permanent canine.

50. First Premolar I) Crowding of maxillary arch II) B imaxillary protrusion III) Class II relation L ateral Incisor Peg shaped or severely malformed lateral incisor (dens invaginatus ) can be extracted instead o f healthy premolars. Central Incisor When there is advanced resorption of central incisor roots more than 2\3rd and canine erupting close to the long axis of the incisor, extraction of incisor is indicated.

51. Micro implant anchorage - The microscrew should be placed in the labial cortical alveolar bone, at an angle of 10-20° to the bone surface and as parallel to the tooth's long axis as possible. - This keeps the apex of the microscrew on the buccal side and reduces the likelihood of its contacting the root. - The head of the microscrew should be located as incisally as possible to maximize the vertical component of force.

52. Anchorage consideration and space maintenance Use of full dimension stainless steel rectangular wire in edgewise brackets. Use of 0.022 / 0.020 wires with uprighting springs or torquing springs to act as brakes if necessary in beggs and tip-edge appliance .

53. Mandibular Anchorage - Lingual arch is fabricated with 0.036 inch SS wire - Vertical hooks (5-6mm in length) - Elastic force should not exceed 40-60 gm Advantages - Simplicity in appliance design and application - Reduced overall treatment time

54. Surgical methods The goal is to choose a technique that exposes the canine within the zone of keratinized mucosa without involvement of CEJ. Surgical exposure with spontaneous eruption Surgical exposure with packing only – prevent rehealing in deep impaction cases predicting spontaneous eruption Surgical exposure with packing and delayed bonding of an auxiliary – when spontaneous eruption fails, attachment can be bonded under direct vision after 1 week post-op (2-step technique) Open eruption technique Closed eruption technique

55. Surgical exposure to allow natural eruption U seful when the canine has a correct axial inclination and does not need to be uprighted during its eruption. Clark recommended that a polycarbonate crown be placed over the impacted tooth after its surgical exposure. The crown should be made long enough to extend through a window cut in the palatal tissue. Often , 6 months to 1 year may elapse before the impacted tooth has erupted sufficiently to permit removal of the polycarbonate crown and its replacement with an orthodontic attachment. If the tooth fails to erupt, clark recommends the removal of any tissue surrounding the crown. Clark D. The management of impacted canines: free physiologic eruption. J Am Dent Assoc 1971;82:836-40.

56. One step vs two step Two approaches are generally recommended with regard to the timing of placing the attachment. 1. T wo-step approach: Canine is surgically uncovered and the area is packed with a surgical dressing to avoid the filling in of tissues around the tooth. After 3 to 6 weeks, the pack is removed, and an attachment is placed on the impacted tooth.

57. 2. One-step approach: attachment is placed on the tooth at the time of surgical exposure and a periodontal pack placed. The pack minimizes patient discomfort and prevents the granulation tissues from covering the attachment. Recommended for palatably impacted teeth. Advantages - the clinician is able to visualize the crown of the tooth and to have better control over the direction of tooth movement, prevents moving the impacted tooth into the roots of the neighboring teeth.

58. Types of Flaps for Impacted Canine Labially impacted tooth A circular incision - done by removing mucosa over the crown to expose the impacted tooth .

59. Advantages: a ) Easy to perform   b ) Suitable access can be provided for bonding of the attachment c ) Reduction of impaction is rapid. Disadvantages: a ) Tooth will be invested on labial side with thin oral mucosa rather than attached gingiva. b) Typical soft tissue contour aggravates plaque accumulation which leads to gingivitis . Inflammation will prevent regeneration of the periodontal ligament which leads to apical movement of the epithelial attachment .

60. Apically repositioned surgical flap – A split thickness pedicle reflected from the edentulous area. I ncisions extend vertically into the vestibule and split thickness flap is reflected. Bone covering the enamel is removed. Two thirds of the crown exposed, and the connective tissue follicle, curetted from the periphery of the exposed portion of the crown. The flap is sutured to the periosteum , leaving one half to two thirds of the crown uncovered. A surgical dressing is placed on the enamel to prevent overgrowth of the adjacent tissue. The dressing is removed 1 week, post operatively and the attachment placed on the uncovered tooth.

61. Advantages : a ) Maintain the width of attached gingiva b ) Easy access for bonding of the attachment c ) Tooth can be visualized from the time of exposure till it comes to occlusion Disadvantages : a ) Uneven and unesthetic gingival margin b ) Increased Clinical crown length c) Some degree of attachment and bone loss on the labial surface , which was considered as possibly related to an increased potential for plaque accumulation.

62. Full flap closure – - A full buccal surgical flap is raised to expose the canine, an attachment is bonded to the tooth and the flap is sutured back to its former place itself. - A twisted thread is tied to the bonded tooth and then drawn inferiorly and through the sutured ends of the replaced flap, through the crest of the ridge or through the socket vacated by the extracted deciduous canine.

63. Advantages: a ) Tooth can be erupted towards and through the attached gingiva which maintains the width of the attached gingiva b ) No gingival scarring and good periodontal attachment is established c ) No vertical relapse d )  Conservative bone removal e )  Immediate traction possible f) Less discomfort and good post operative haemostasis

64. Disadvantage: a) Placement of the bonding attachment is necessary at the time of exposure b)  If there is a bond failure it needs re-exposure c)  Difficulty in gaining dry field d) Buttonholing: due to buccal prominence of the tooth, lack of buccal bone and relative tightness of the replaced flap, damage to the mucogingival tissue is due to the bulk of wide and high profile bracket, which may leads to a breakdown of the overlying tissue causing dehiscence

65. Palatally impacted tooth Closed technique – The canine was surgically uncovered with a full-thickness mucoperiosteal flap dissected off the bone. The bone covering the canine was removed with a punch or bur; NaCl irrigation. Attachment with a chain was bonded to the exposed tooth. Swab gauze 1.5  ×  1.5  cm and tranexamic acid ( Cyklokapron 5%) could be used to get a dry operation field. The palatal flap was repositioned and sutured back with the chain extending through an incision in the palatal flap.

66. Open technique – The canine is surgically uncovered with a full-thickness mucoperiosteal flap dissected off the bone. The bone covering the canine i s removed with a punch or bur; NaCl irrigation. Polyacrylic acid and then conventional, light cured glass ionomer cement are applied on the surface of the crown of the impacted canine, to the level of intact mucosa. Swab gauze 1.5 × 1.5 cm and tranexamic acid ( Cyklokapron 5%) could be used to get a dry operation field. The palatal flap i s repositioned and sutured back, and a window of mucoperiosteal tissue overlying the tooth was removed with a punch or a scalpel.

67. attachments Lasso wires:   It is twisted lightly around the neck of the canine. Disadvantages :   Irritation of the gingiva Poor control over direction ofm extrusion   Prevents reattachments of the healing tissues in area of CEJ ( cemento -enamel junction).   May produce areas of external resorption & ankylosis in areas of CEJ. So , it is rarely used now.

68. 2. Threaded Pins: Provides the attachment for an impacted tooth . Disadvantages : - Dentaly invasive. - Requires a subsequent restoration. - Difficult to place along the long axis of the tooth because of smaller surgical exposure. - The drilled hole may inadvertently enter the pulp( unerupted teeth may have large pulp chambers). Also rarely used.

69. 3. Orthodontic bands: They largely replaced the lasso wires & threaded pins . Advantage : They are compatible with the health of periodontal tissues . Disadvantage : Large surgical field required. Requires extensive bone removal -   Inadequate moisture control may hamper with the cement-band bond .     

70. 4. Standard orthodontic brackets: Any edge-wise, Begg’s , PAE brackets can be used with composite. Disadvantages : - As the bracket base is wide, it is difficult to adapt to any other tooth surface except for the buccal surface. - The bracket’s shear bulk creates irritation as the tooth is drawn the soft tissues . - Interferes with the investing tissues & leads to inflammation & periodontal damage.  - As the impacted tooth advances into the arch the exuberant gingival tissues bunches in front of it & causes punching between the bracket & tissues.

71. 5. A simple eyelet: Advantages : - An eyelet welded to band material with a mesh backing is soft & easy to contour - adaptation to bonding surface more accurate - superior retentive properties. - Because of small size they can be placed in more awkwardly placed teeth. -    Less irritating to the surrounding tissues.   

72. 6. Elastic ties and modules: Advantages Application of light forces Good range of action Easier to tie Disadvantages Tends to loosen High degree of force decay

73. 7 . Magnets : It is made up of rare earth lanthanide alloys . Disadvantage - corrosion . 8 . Cast Canine Cap: Requires extensive crown preparation 9. Lingual button with ligature chain or gold chain: Most commonly used.

74. Methods of traction 1. Active palatal arch (Becker1978 ) • It consists of a fine 0.020 inch removable palatal arch wire carrying an omega loop on each side . • End of the wire is doubled for frictionless fit in lingual sheath. • It is activated by downward activation of palatal arch wire and hooking the pigtail ligature around it.

75. 2. Light Auxiliary Labial Arch (Kornhauser1996 ) • Fabricated with a 0.014" round SS, formed in a archform with a loop having a small helix. • Wire is tied with the basal arch wire in piggyback fashion. • If a basal arch wire is not used it will leads to extrusion of adjacent tooth and cause alteration of occlusal plane.

76. 3. TMA Box Loop • TMA .017 X .025 wire used. • Produces sagittal and horizontal corrections while continuing vertical eruption . • Used in select cases. Alignment of Impacted Canines with Cantilevers and Box Loops; Surendra Patel; JCO 1999 volume 33 : 2 : 82-85

77. 4. Cantilever Spring • TMA .017 X .025 wire used • Initial extrusion mechanics with a cantilever. • Use of a box loop to continue canine extrusion and to make 1st- and 2nd-order corrections. • Incorporation of the canine into a continuous archwire for finishing. • The reactionary force and the moment are dissipated on the molar, which can be controlled by using a palatal arch and or ligating the molar to the rest of the arch.

78. 5. Australian Helical Archwire • Made in special plus . 016” arch wire • Activation by twisting the steel ligature wire every two w eeks . • The Australian wire is bent with helices that serve as stops against the brackets of the adjacent teeth to maintain space for the erupting canine. • An additional incisal helix increases the resilience of the system and anchors the SS ligature running to the canine attachment. • The force vector for canine can be altered by changing the transverse position of the incisal helix.

79. 6. Two Archwire Technique Surgical procedure involves apically positioned flap for superficial impaction and full thickness mucoperiosteal flap with a crestal incision for deeper impactions. Orthodontic procedure consists of placement of preadjusted 0.022 x 0.028 brackets. An 0.014" NITI arch wire is cut so that it passes through 2 or 5 brackets on either side of impacted tooth. Eyelet chain activated every 4 - 6 weeks.

80. 7. Piggy-back technique: Consists of double wires (auxiliary and base wire ), the auxiliary wire - segmented or continuous . Rigid stainless steel base archwires with significantly higher elastic modulus, e.g. 0.018-inch or 0.019X0.025- inch SSW, are preferred to limit unwanted effects on anchor units and an auxiliary super elastic NiTi (including thermal NiTi ) archwire of 0.012- inch or 0.014-inch to continue the eruptive process of tooth.

81. Advantages - Relatively constant, light force with high flexibility and range allowing engagement of significantly displaced teeth. Realigning of the teeth avoided . Reciprocal forces reduced – single archwire affects the other teeth in the arch - an iatrogenic open bite, canted occlusal plane, crossbite , etc . Disadvantage - Increased friction due to the doubled archwires .

82. 8 . The K-9 Spring • Designed by Dr.Varun Kalra • The K-9 is made of 0.017" x 0.025" TMA • The TMA can be activated twice as far as stainless steel before it undergoes permanent deformation, while producing less than half the force. • Designed on the principle of reciprocal torqueing. • To activate the spring after it is engaged in the b uccal s egment , the vertical arm is swung upward and ligated to the bonded attachment on the canine. • The force needed to distalize the canine is achieved by inching the spring back about 2mm after it has been ligated to the canine.

83. 9 . Ballista Spring (Jacoby 1979 ) • A ballista loop is a simple, convenient, unobtrusive method of applying a vertical vector of force to a palatally impacted tooth to erupt the crown into the center of the alveolus. • Exposure of the crown facilitates attachment of an elastomeric chain directed toward the center of the edentulous alveolar ridge to gradually guide the canine crown into the dental arch.

84. 0.018-inch continuous SS archwire used to form the spring. The impacted tooth is retracted by a spring that accumulates a continuous force from being twisted on its long axis . With this technique, the crown typically erupts into the center of the alveolar ridge, similar to a naturally erupting tooth.

85. 10. Kilroy Spring (2003) A constant force module of .016SS that delivers slow and continuous force on a rectangular archwire . In the passive state, the vertical loop of the Kilroy Spring extends perpendicularly from the occlusal plane . To activate the spring, a stainless steel ligature is guided through the helix at the apex of the vertical loop, and the loop is directed toward the impacted tooth. The ligature is then tied to an attachment that has been direct-bonded to the surgically exposed tooth

86. The amount of force generated by the Kilroy Spring can be increased or decreased by bending the vertical loop toward or away from the impacted tooth. The direction of force is also adjustable. Because of the inherent flexibility in its design, the Kilroy Spring will typically fit the available arch space whether the final destination of the impacted tooth is wider or narrower than the tooth itself. T he vertical loop of the Kilroy Spring can be adjusted to produce a light force to assist in closing, maintaining, or opening space.

87. 11. Kilroy II Spring Designed to produce more vertical than lateral eruptive forces for eruption of buccally impacted teeth. Its multiple helices increase its flexibility, but also increase the likelihood of impingement on the soft tissue. M ore frequent progress checks are recommended

88. 12. Modified Kilroy Spring The modified Kilroy I Spring that can be applied without removal of the deciduous canine, thus improving the patient’s esthetic appearance and helping to maintain the canine space. 13. The Monkey Hook • It is a simple auxiliary with an open loop on each end for the attachment of intra oral elastic or elastomeric chain or for connecting to a bondable loop button. • A combination of monkey hooks and bondable loop-buttons allows the production of a variety of different direction force such as

89. 14. Tunnel - Traction of Infraosseous Impacted Maxillary Canines Deep infraosseous canines associated with persistent deliduous teeth may be successfully and safely treated by repositioned flap and tunnel traction toward the center of the alveolar Ridge. Cortical bone removed to provide access to crown and button bonded with ligature chain. The chain passes through the bone tunnel and emerges from the socket of the deciduous tooth. Traction phase started after one week when sutures are removed and directed to the center of the alveolar ridge. Advantages - No attachment loss and no recession are observed at the end of active therapy or 3 years later.

90. Not much is present in literature about mandibular canines as its occurrence is a rare condition. For lingually placed canine, attachment has to be bonded on buccal surface only, buccal surgical exposure preferred. Mandibular Canine Impaction

91. Root resorption and canine impaction Resorption of roots stops when canine impaction has been solved. • Subsequent orthodontic movement of resorption affected teeth does not generate further resorption . • Incisors with severely resorbed roots have high survival rate. • Teeth remain vital, and retain their color , and appearance. • Teeth show very low degree of mobility and an improvement in periodontal bone support following post treatment retention. • Splinting is not usually necessary. Long-term follow-up of severely resorbed maxillary incisors after resolution of an etiologically associated impacted canine. Adrian Becker; AJODO 2005;127:650-4

92. Impacted Canine and Periodontium A study was done to evaluate the periodontal health and tooth vitality of palatally impacted and buccal ectopic maxillary canines after completion of orthodontic treatment . Conclusion : All ectopic canines had increased plaque and gingival bleeding index, greater pocket depths, reduced attached gingival width, higher gingival levels , increased crown lengths, higher electric pulp testing scores, and reduced bone levels compared to their contralaterals . Periodontal status of ectopic canines after orthodontic treatment. AO 2014 Aysegu lDalkılıc ¸ Evrena S¸ I rin Nevzatog , Tulin Arunc Ahu

93. retention To minimize rotational relapse, options available are - 1. Fiberotomy 2. Bonded fixed retainer Clark’s suggestion for palatally impacted canine: Lingual drifting can be prevented by removal of half moon-shaped wedge of tissue from lingual aspect of canine . Becker et al. evaluated the posttreatment alignment of the impacted canines in patients who had completed their orthodontic treatment. They observed an increased incidence of rotations or spacings on the "impacted" side in 17.4% of the cases, whereas on the control side the incidence was only 8.7%. The control side had ideal alignment twice as often as did the impacted side.

94. Devitalization , ankylosis or loss of vitality, recurrent pain, cystic degeneration, invasive servical root resorption , external root resorption of the canine and adjacent teeth may be seen. Loss of periodontal bone support, gingival recession, sensitivity problems or combinations of these factors may be observed. N o movement of the impacted canine is observed, inappropriate positional diagnosis of the impacted teeth and its relationship with the roots of the adjacent teeth a lack of considerably anchorage requirement will lead to inefficient mechanotherapy and unnecassarily longer treatment anyklosis might have afflicted the impacted tooth either a priori or as the result of the earlier surgical or the orthodontic maneuers . scar tissue might have blocked the wire chain Complications of treatment

95. COMPLICATIONs OF UNTREATED IMPACTED CANINE 1) Crown resorption followed by replacement resorption - resorption of enamel and its replacement by bone 2 ) Labial or lingual malposition of impacted tooth 3) Migration of neighboring teeth and loss of arch length 4 ) Internal resorption of impacted tooth 5 ) Cyst formation ( Dentigerous cyst ) - Potential complications of dentigerous cyst, a) ameloblastoma b) Epidermoid Carcinoma c) MucoEpidermoid carcinoma 6 ) Resorption of lateral incisor root

96. conclusion The management of impacted canines is important in terms of esthetics and function and, requires a qualified experience of a number of clinicians . Various surgical and orthodontic techniques may be used to uncover impacted maxillary canines related to its position. Accurate localization, conservative management of the soft tissues, selection of appropriate surgical approach, rigid anchorage unit, and the direction of the orthodontic traction are the important factors for the successful management of impacted canines.

97. Adrain Becker, Orthodontic treatment of Impacted Teeth, Third edition Kumar , S. (2015).  Localization of Impacted Canines. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH . Stivaros , N., & Mandall , N. A. (2000).  Radiographic Factors Affecting the Management of Impacted Upper Permanent Canines. Journal of Orthodontics, 27(2), 169–173.   Reliability of a method for localisation of displaced maxillary canines using a single panoramic radiograph. Chaushu et al; clin orthodres 1999; 2: 194-9 Early treatment of palatally erupting maxillary canines by extraction of the primary canines. Ericson S. & Kurol J.; European Journal of 161 Orthodontics 1988;10: 283-295 Prediction of maxillary canine impaction using sectors and angular measurement. Warford J. Jr et al AJO-DO 2003; 124(6): 651-655 Localization of Impacted Canines: A Review. Kumar S. Journal of Clinical and Diagnostic Research 2015; 9(1) Vishnoi P, Keshubhai KJ, Surendra SS, Bandi N, Jingar J, Rutvik T. Maxillary Canine Impactions: Orthodontic and Surgical Management. Ann. Int. Med. Den. Res. 2016;2(3):2-10 . Clark D. The management of impacted canines: free physiologic eruption. J Am Dent Assoc 1971;82:836-40 . Uncovering labially impacted teeth: apically positioned flap and closed eruption technique. Vermette et al; AO 1995; 65: 23-32. Shapira Y, Kuftinec MM. Treatment of impacted cuspids : the hazard lasso. Angle Orthod 1981; 51 : 203–207 . Alignment of Impacted Canines with Cantilevers and Box Loops; Surendra Patel; JCO 1999 Incisor Root Resorption Due to Ectopic Maxillary Canines A Long-Term Radiographic Follow-Up Babak Falahat ; Sune Ericson; Rozmary Mak D’Amico ; Krister Bjerklin Angle Orthodontist, Vol 78 , No 5, 2008 Periodontal status of ectopic canines after orthodontic treatment. AO 2014. Ays¸egu ¨ l Dalkılıc ¸ Evrena ; S¸ irin Nevzatog ˘ lub ; Tu ¨ lin Arunc ; Ahu Acard REFERENCES

98. Thank you