MAXILLARY CANINE impaction techniques.pptx

maxillary canine, impaction and techniqus for surgery

1. CANINE IMPACTION

2. INTRODUCTION Impaction is defined as the failure of tooth eruption at its appropriate site in the dental arch, within its normal period of growth. The impacted maxillary canine is second only to the impacted third molar in its frequency (1.7- 2.2%). Mandibular canine impaction occurs at a much lower rate, possibly about 0.3%.

3. Prevalence of maxillary canine impaction ranges from 1.0% to 2.5%, where 8.0% to 10.0% of these cases are bilateral. Affecting female patients 2.3 to 3 times more frequently than males. Palatal impaction of the maxillary permanent canine has been reported to occur approximately 3 times more frequently than facial impaction.

4. 4 Normal Development of Maxillary Canines 4-6 months Development (calcification) begins high in the maxilla 3 Years located high in maxillary bone – mesially & lingually directed crown 6 years Crown completed 10 years Palpable high in the buccal vestibule 11-13years Eruption 14 - 15 years Root completed

5. ETIOLOGY The causes can be classified into 4 distinct groupings: local hard tissue obstruction local pathology departure from or disturbance of the normal development of the incisors hereditary or genetic factors. Etiology of maxillary canine impaction: A review (Am J Orthod Dentofacial Orthop 2015)

6. LOCAL HARD TISSUE OBSTRUCTION Lappin observed that the deciduous canines were frequently overretained , often with a long and unresorbed root. He speculated that the nonresorption of the deciduous canine was the cause of the anomaly.

7. In unilateral cases of central incisor impaction whether because of obstruction by a supernumerary tooth or an odontoma or because of dilaceration or recent trauma, there is a high frequency of eruption disturbance of the canine on the same side. The permanent central incisor (#21) is dilacerated with its crown in the area of the anterior nasal spine. The long axis of the lateral incisor (#22) is strongly tipped displacing the root end distally and into a close relationship with the canine crown (#23).

8. This investigation showed a significant increase in the prevalence and severity of displaced canines (41.3%): buccal displacement was seen in 30.2%, palatal displacement occurred in 9.5%, and canine-lateral incisor transposition in 1.6% of the patients.

9. LOCAL PATHOLOGY Overretained deciduous canines are commonly nonvital by the age of 12 years because of caries, trauma, or extreme attrition. The resulting chronic periapical granuloma,by itself, is a soft tissue inflammatory lesion that will have a potent effect on deflecting or arresting the eruption of the permanent canine.

10. A large cyst occupies much of the left side of the maxilla (approximately demarcated by the yellow ring). The lateral incisor root has been tipped mesially into contact with the central incisor root. The first premolar lies horizontally in the floor of the cyst, and the canine has been pushed upward and tipped almost horizontally. This appears to be a radicular cyst resulting from the nonvital deciduous first molar.

11. Trauma to the face can cause laceration of the soft tissues of the lips and cheek, and its force may be transmitted to the maxilla to cause displacement of the unerupted canine or dilaceration of its developing root, particularly in younger children. Pursuant to incidents of this kind, the tooth may become impacted.

12. DISTURBANCE OF NORMAL DEVELOPMENT Miller and Bass independently observed that the prevalence of palatal displacement was greater when lateral incisors were congenitally missing. They concluded that the absence of the lateral incisor denied the canine its guidance, permitting it to migrate palatally .

13. At the age of 9 to 10 years, the unerupted canine is normally found at the distal aspect of the root of the lateral incisor. In contrast to the maxillary lateral incisors, maxillary canines are ontogenically stable teeth in terms of shape, size, and developmental timing. If the lateral incisor is absent or late developing,peg shaped, or small with only the earliest degree of root development, it will be clear that the canine will not find the guidance that would enable it to descend along its normal eruption path . Thus, the tooth may move down in a more palatal path into the downward converging, V-shaped alveolar ridge until it comes close to the periosteum of the medial aspect of the alveolar process.

14. Other Local causes can be: loss of arch space ankylosis reconstructive surgery for cleft lip/palate repair thickened overlying bone or soft tissue missing adjacent lateral incisor idiopathic.

15. Generalized tooth impaction has been associated with certain host systemic disorders, including (1) endocrine disorders (2) febrile illness (3) irradiation (4) Gardener syndrome (5) Cleidocranial dysostosis

16. CLASSIFICATION Classification helps much in the diagnosis and treatment planning. Archer (1975) Class I : Impacted canines in the palate 1: Horizontal 2: Vertical 3: Semivertical Class II: Impacted canines located on the labial surface 1: Horizontal 2: Vertical 3: Semivertical Class III: Impacted canine located labially and palatally - crown on one side and the root on the other side

17. Class IV: Impacted canine located within the alveolar process - usually vertically between the incisor and first premolar Class V: Impacted canine in edentulous maxilla. Impacted canine can be in unusual positions like inverted position

18. CLASSIFICATION USING OPG type I — vertically impacted canines, with the tooth axis being almost perpendicular to the occlusal plane, and located between the lateral incisor and first premolar. A tooth situated in close relation to the lateral incisor is also included in this classification. • type II — impacted canines inclined mesially against the occlusal plane • type III — impacted canines inclined distally against the occlusal plane. A New Classification of Impacted Canines and Second Premolars Using Orthopantomography Asian J Oral Maxillofac Surg Vol 15, No 1, 2003

19. • type IV — horizontally impacted canines with the crown directed mesially • type V — horizontally impacted canines with the crown directed distally • type VI — inversely impacted canines • type VII — labio -lingual (palatal) impaction and ectopic impaction.

20. Classification for surgical approach Chapokas AR et al. The impacted maxillary canine: a proposed classification for surgical exposure. OOOO 2012:222-28.

21. For mandibular canine LABIAL ABBERANT VERTICAL AT INFERIOR BORDER OBLIQUE ON OPPOSITE SIDE HORIZONTAL CLASSIFICATION OF MANDIBULAR CANINE IMPACTION

22. SEQUELAE OF CANINE IMPACTION Resorption of the adjacent teeth— Resorption of the lateral incisor is more common than the central incisor. Females are more likely to be affected than males.

23. Proclination of lateral incisor — Due to pressure effect from erupting cuspid , instead of resorption of root of lateral incisor, there may be proclination of the lateral incisor.

24. Cyst formation Development of dentigerous cyst in relation to impacted cuspid is not uncommon. Miscellaneous complications —Marginal breakdown of supporting bone around adjacent teeth

25. LOCALIZATION OF IMPACTED CANINE Localization of the canine is a key factor in the comprehensive assessment of the impacted canine. The position of the impacted canine is important when deciding management options for patients. Localization requires inspection, palpation, and radiographic evaluation.

26. INSPECTION AND PALPATION The position of the lateral incisor can give a clue to the canine position. The crown of the lateral root may be proclined if the canine is lying labial to the lateral incisor. Occasionally the impacted canine can be palpated on the labial or palatal aspect.

27. RADIOGRAPHIC EVALUATION Helps to supplement the findings of inspection and palpation. An ideal radiographic examination of an impacted maxillary canine should reveal not only the shape and position of the root apex, but also the position of the crown, vertical inclination of the canine, presence of any follicular cyst, and above all root resorption of the adjacent permanent teeth.

28. RADIOGRAPHIC CLUES Long axis of the canine is angled more than 10 ° to the vertical plane. The greater the angle the more likely a problem. 25° - impaction The most frequently used projection for the maxillary canine localization is the true occlusal view .

29. Accurate methods like computerized axial tomography, and 3D CAT elaboration such as 3D imaging; in addition to which real 3D stereo-lithographic models can also be generated. The second group is the less accurate methods, which include plain radiographs like panoramic radiography, occlusal radiography, anteroposterior and lateral radiographic views, which are based on image magnification and superimposition.

30. Several studies have shown that properly calibrated panoramic radiographs may be helpful in determining the buccal or palatal position of impacted maxillary canines. This is predicated on the impacted tooth size relative to the contralateral side. If the tooth is farther from the film, it will appear larger Oral Maxillofacial Surg Clin N Am 14 (2002) 187–199

31. CLARK’S RULE – HORIZONTAL CHANGE SLOB rule or buccal object rule The lingual object moves in the same direction as the x-ray source. The buccal object moves in the opposite direction of the x-ray source because it is farther away from the film than the root of the lateral incisor. When the movement is not apparent, consideration should be given to midalveolar placement of the tooth. 34 Oral Maxillofacial Surg Clin N Am 14 (2002) 187–199

32. PRECISE LOCATION CT scan is a precise method of radiographic localization. Computer-assisted tomography; particularly CBCT provides high resolution images with superior quality.

33. CT scan shows 13 and 23 erupting buccally to 12 and 22 pathological examination to rule out development of a dentigerous cyst respectively. The follicles have caused the buccal plate of the alveolar bone to bulge (yellow arrows) and extend asymmetrically into the cancellous bone (white arrows). There are contacts between the impacted canines and the adjacent roots of the incisors; but with no root resorption of the latter (black arrow)

34. CT scans showing the canine 13 cusp Tip in contact with root of 12 (white arrow) CT scans showing the canine 23 in contact with 22 (yellow arrow)

35. Coronal CT showing the tip of the root is seen projecting into the right maxillary antrum (yellow arrow and the tooth lies in an oblique fashion, (F) Axial CT showing a follicle is seen surrounding the crown of the impacted tooth and anteriorly the crown is covered only by a thin buccal cortical plate

36. CBCT

37. 3-D CBCT images of impacted maxillary canine—Lateral and ¾ lateral views

38. The location of the cusp tip of the canine and its relationship to the adjacent lateral incisor was divided into specific sectors : Sector I represents the area distal to a line tangent to the distal heights of contour of lateral incisor crown and root; sector II is mesial to sector I, but distal to the bisector of the lateral incisor’s long axis;

39. sector III is mesial to sector II, but distal to the mesial heights of contour of the lateral incisor crown and root; sector IV includes all areas mesial to sector III

40. As shown by the predictive values for sector location alone—(I) 0.06, (II) 0.38, (III) 0.87, and (IV) 0.99—the more mesial the cusp tip location, the greater the likelihood of impaction. The overall incidence of impaction was 82%, if the canine cusp tip was in sections II, III, or IV.

41. Ericson also showed that the position of the crown of the canine in relationship to the root of the lateral incisor is a key determinant in the potential for eruption or impaction of the maxillary canine after primary canine extraction.

42. If the crown of the canine was distal to the midline of the lateral incisor root, the canine erupted 92% of the time, whereas if it was mesial to the midline of the root, eruption occurred in 64% of the cases after primary canine extraction.

43. TREATMENT Treatment options include (1) no treatment except monitoring, (2) interceptive removal of primary canine, (3) surgical removal of the impacted canine, (4) surgical exposure with orthodontic alignment, (5) autotransplantation of the canine. Oral Maxillofacial Surg Clin N Am 19 (2007) 59–68

44. NO TREATMENT WITH PERIODIC RADIOGRAPHIC EVALUATION If the canine is in good position and without contact with the lateral incisor and first premolar. If there is no evidence of pathology or root resorption of the adjacent teeth or the patient refuses treatment, the patient can be monitored periodically. If the impacted canine is severely displaced and remote from the anterior teeth and is difficult to remove or expose, a decision can be made to monitor the patient radiographically . Oral Maxillofacial Surg Clin N Am 19 (2007) 59–68

45. INTERCEPTIVE REMOVAL OF PRIMARY CANINE Extraction of the primary canine is recommend if the patient is between 10 and 13 years, the maxillary canine is not palpable, and localization confirms a palatal position. If the canine position does not improve over a 12-month period, alternative treatment is indicated. Radiographic evaluation should be at 6-month intervals. Oral Maxillofacial Surg Clin N Am 19 (2007) 59–68

46. Oral Maxillofacial Surg Clin N Am 19 (2007) 59–68

47. AUTOTRANSPLANTATION OF THE CANINE. When the degree of malposition is too great to make successful orthodontic alignment or interceptive measures failed. Canine transplantation should be planned as early as possible when the root is 50% to 75% formed. The transplanted tooth must be held in place for 2 to 3 months with an orthodontic appliance. If endodontic treatment is necessary, it should be performed when the immobilization device is removed. Oral Maxillofacial Surg Clin N Am 19 (2007) 59–68

48. SURGICAL EXPOSURE OF MAXILLARY CANINE Options are management of impacted canines include surgical exposure followed by orthodontic forced eruption, replacement using fixed prosthodontics with and without dental implants, and removable prosthodontics . The impacted maxillary canine: a proposed classification for surgical exposure (Oral Surg Oral Med Oral Pathol Oral Radiol 2012 )

49. Class I A Class I impacted maxillary canine is located palatally . For this category of impacted canines, a surgical approach with gingivectomy is recommended.

50. Immediately after exposure of the impacted tooth, a fixed attachment appliance should be connected . Advantages of this approach include relative simplicity of the procedure and potential for spontaneous eruption following surgical exposure.

51. According to Schmidt and Kokich , most palatally impacted canines will spontaneously erupt with simple surgical excision of the overlying palatal tissue. Conversely, Ferguson and Parvizi showed that 5.1% of impacted canines exposed with gingivectomy required a second surgical procedure because of lack of spontaneous eruption.

52. Class II A Class II impacted maxillary canine is located in the center of the alveolar crest or labial to the alveolar crest, but not superimposed labially to the root of the adjacent lateral incisor.

53. The crestal incision should be made with 3mm of keratinized gingiva labial to its location. Afterward,the flap is returned to its original position and sutured. The wire or chain will exit the flap and labial keratinized gingiva is totally preserved

54. The primary advantages of this technique include less postoperative discomfort compared with gingivectomy,as well as management of forced eruption through a zone of keratinized gingiva . Disadvantages include increased technique sensitivity, related to proper soft tissue flap management, and increased length of surgical treatment time.

55. Class III A Class III impacted maxillary canine is located labial to the root of the adjacent lateral incisor. The radiographic evaluation of an orthopantomogram will reveal a canine with its cusp tip over the root of the lateral incisor, whereas the tooth bud will be palpable labially .

56. For impacted canines in a Class III position, an apically positioned flap (window flap)is indicated. A partial thickness dissection,including 2 to 3 mm of the coronally attached gingiva is carried out. The flap is then apically positioned using 2 parallel, vertical releasing incisions.

57. Following this technique,the width of the keratinized gingiva will increase during orthodontic forced eruption. Hence, increase in the visibility of tooth orientation and preservation of keratinized gingiva are the primary advantages of this approach. Disadvantages of the window flap include its higher level of technique sensitivity compared with gingivectomy and repositioned flap previously described.

58. PALATAL CANINE AND OPEN EXPOSURE TECHNIQUE After this procedure, the canine must be left exposed to the oral environment and care taken to ensure that healing of the adjacent soft tissues will not recover the tooth and again make it inaccessible. This may be done by clearing a broad area of soft tissue, including the entire dental follicle, oral mucosa and bone, down to the cementoenamel junction (CEJ) and placing a surgical pack to cover the area . This pack would normally be left for 2 to 3 weeks in the hope that the tooth remains visible when the pack is removed, and to provide access for later bonding of an attachment.

59. PALATAL CANINE AND CLOSED EXPOSURE TECHNIQUE Alternatively, the orthodontic attachment may be bonded as an integral part of the surgical procedure in the office of the oral and maxillofacial surgeon. This method demands a less radical surgical procedure, eliminating the need for exposure down to the CEJ and leaving the deeper part of the dental follicle intact. This is because contact with and control of the tooth may be maintained through the ligature wire that is tied to the attachment. This is the thinking involved in the closed exposure procedure.

60. Labial canine and window technique To expose the tooth by opening a semilunar window in the oral mucosa directly over it . However, this will result in the tooth being drawn down with no attached gingiva on its labial side and with only this thin, mobile, and easily traumatized covering for its long-term protection . The only time that this is acceptable is when there is a broad band of attached gingiva within which the incision is made, leaving a portion of the thicker tissue above the cut. This will then become the labial gingiva when the tooth is brought into alignment.

61. LABIAL CANINE AND APICALLY REPOSITIONED FLAP TECHNIQUE The first is the apically repositioned flap, which is only suitable for the canine which is not displaced mesially or distally from its normal location in the arch. It involves raising a flap from the keratinized gingiva at the crest of the ridge or from the gingival margin of the retained deciduous canine. It is elevated above the height of the labial canine and to reveal the follicle of the canine. The follicle is opened over its labial surface only and the flap sutured tightly to the cervical half of the crown of the tooth, leaving the coronal half exposed.

62. LABIAL CANINE AND CLOSED EXPOSURE TECHNIQUE The second alternative is appropriate even in cases where the labial canine is displaced in the mesiodistal plane, making the technique more universally applicable. The same partial thickness flap is raised from within the keratinized gingiva of the crest of the ridge, as with the apically repositioned flap technique.

63. The follicle of the canine is opened to a very minimal extent over the middle of the crown, with an aperture only large enough to accommodate a small, preferably, eyelet attachment, yet large enough for hemostasis to be secured, because bonding must be performed immediately. The remainder of the follicle is left intact. The attachment is bonded and the gold chain or twisted steel pigtail ligature is drawn downwards and held in place by the sutured edge of the flap.

64. MIDALVEOLAR CANINE AND TUNNEL (CLOSED EXPOSURE) TECHNIQUE Generally considered together with the labial canines because surgical access to it is performed on the labial side of the alveolar process, the midalveolar impaction is often the result of a mesioangular canine impacting against the distal aspect of the lateral incisor. In these cases, exposing the crown of the tooth in the usual manner will require the removal of a relatively large area of overlying labial plate of bone, which will result in the erupted tooth exhibiting a long, unaesthetic , clinical crown, and reduced bone support on the labial side. Crescini’s tunnel technique is an excellent method of limiting these complications insofar as it erupts the canine down through the evacuated socket of the extracted deciduous canine, leaving the labial part of the socket wall intact.

65. Removal of palatally impacted canine: If unilateral: 1 . Reflection of flap from mesial of central incisor to distal of first molar. The flap is better to be envelop. 2 . Bone removal by post stamp technique. 3 . Decapitation  removal of the crown. 4 . A cryer elevator is used to push the root to the empty space then remove it. SURGICAL REMOVAL OF IMPACTED MAXILLARY CANINES

66. If bilateral: The flap will result in cutting of nasopalatine vessels & nerves leading to hemorrhage & numbness in order. However , regeneration of the nerve fibers will occur later. Another solution is to make the flap crossing around the incisive papilla to avoid injury to the neurovasculature Upon suturing a palatal flap always place the knots buccally to prevent irritation of the tongue.

67. Removal of labially impacted canine : Easier since the buccal plate of bone is thinner & better accessibility. A pyramidal flap is preferred , followed by similar steps as before..

68. LABIALLY PLACED CANINE

69. Removal of impacted canine from intermediate position Usually open the flap in the area where the crown is present (mostly buccally ),so a buccal flap is reflected first. The type of the flap differs according to the height of the impacted tooth e.g. if the tooth is very high, do semilunar flap or pyramidal. After opening a buccal flap, decapitate & remove the crown, follower them by the root .

70. Open the buccal flap finding the root  remove it first then do a palatal flap & remove the crown. If the other half of the tooth can't be reached, push it from the buccal side to the palatal side or vice versa until it can be held & removed

71. Removal of impacted canine in edentulous ridge : The problem here is the pneumatization of the maxillary sinus & should be in mind while doing such impaction . If the tooth need the buccal side, do buccal flap . If the tooth need the palatal side do palatal flap.  

72. MANAGEMENT OF MANDIBULAR CANINES Management of impacted mandibular canines includes the following treatment options: No treatment with clinical and radiographic observation Surgical extraction Surgical exposure to aid eruption Surgical exposure with orthodontic guidance Transplantation

73. No treatment, only observation- If the impacted mandibular canine is below the apices of the teeth and without pathology, it can be observed periodically. Surgical extraction- If the impacted mandibular canine is not in an upright position, extraction should be considered. Surgical extraction is accomplished by using a labial or lingual mucoperiosteal flap with possible releasing incisions. The removal of bone over the crown is achieved with a round bur. The tooth can be luxated and removed with an elevator. If this approach is unsuccessful, the crown is sectioned and the crown and root are removed. If the mandibular canine is lingual, the extraction is more difficult because of poor access

74. Surgical exposure to aid eruption If the mandibular canine impaction is caused by an overlying impediment, the impediment can be removed surgically. Then a bony pathway for eruption can be created. Surgical exposure with orthodontic guidance types of incisions can be used for exposing the impacted mandibular canine : the labial gingival crevice incision, free mucosal incision, lingual gingival crevice incision.

75. Transplantation Transplantation of the mandibular canine can be successful if the apex of its root has not closed. The canine can be transplanted to its correct position in the dental arch or even to a different site. The difficulty is in removing the tooth without damaging the root surface or apical end. The canine must be firmly immobilized for at least 2 months.

76. COMPLICATIONS Infection Paresthesia Noneruption Loss of soft tissue flap/dehiscence Lack of attached gingiva Devitalization of the pulp Pain Fracture of large segment of bone. Traumatization or dislodgement of adjacent teeth. Injury to the soft tissues from the instruments. Forcing a tooth into the maxillary sinus. Opening into the nasal cavity  oro -nasal communication.

77. THANX