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Management of Canine position Abnormalities
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1 Management Management of of anine Position A Position Abnormalities C Canine bnormalities Prepared by: Prepared by: Dr. Mohammed Alruby Dr. Mohammed Alruby Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
2 Transmigration of canine = an impacted tooth migrates to a location some distance away from the site of its development but usually remain at the same site of the arch = migration of tooth across midline jaw without influence of any pathological entity = intra-osseous migration of tooth apparently starts during the early mixed dentition stage Left canine undergoes migration more commonly than right one Types of canine transmigration: 1-Intra-osseous: a-Favorable position: Labial of the tooth to be pulled to its ideal site in the dental arch and a symptomatic tooth so it need surgical exposure and orthodontic treatment b-Favorable position: Of the tooth for surgical removal in one piece, open apex root, and retained deciduous canine so it need auto-transplantation c-Unfavorable position: And a symptomatic tooth so it need radiographic monitoring d-Unfavorable position: And a symptomatic tooth associated with pathology or neurological pain so it need surgical removal 2-Erupted into oral cavity: a-Favorable: position of the tooth so ------ orthodontic alignment and reshaping of the tooth b-Unfavorable: transposition of the tooth ------- surgical exttaction Canine impaction ** true facts about upper canine: Crown start calcification ------ 1-year-old Crown complete formation: 6.5 years’ old Erupts: ---------------- 12 year old Root complete formation: ------ 14 years old Definition: canine that is prevented from erupting into its normal functional position by bone, tooth, or fibrous tissue. Incidence: Developmentally absent U3 is: 0.08% Impacted U3: 2% Palatally impacted 3: 61% Impacted canine in the line of the arch: 34% Impacted canine bucally: 4.5% Eruption: U3: ------ 11 – 12 years, L3: ----- 9 -10 years U3 palpable: ------ 10 years Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
3 *** early prediction of maxillary canine impaction from panoramic radiographs (Anand et al 2012 Amj) Importance of early prediction to prevent complication: 1-Needs time and more money 2-Risk of gingival recession 3-Risk of bone loss 4-Risk of detachment gingiva around the treated canine 5-Risk of development of necrotic pulp and stones 6-Risk of root resorption This study: Was made on 484 panoramic radiographs with unilateral impacted canine to compare the position of impacted canine with its antimere by using geometric measurements Geometric measurements are: 1-The vertical distance from tip of canine to the occlusal plane: Occlusal plane: a horizontal line passing through the incisal edge of central incisors and buccal cusp tip of 1st molar D1: distance from canine tip to occlusal plane on impacted canine side D0: distance from canine tip to the occlusal plane on the antimere side = beyond age 5 years there was a significant difference between the location of impacted and non-impacted canine = from the age 5 till 12 years old: the vertical distance at impacted site is 18.2m and at antimere side of un-affected canine was 3.3mm 2-Location of canine in relation to adjacent teeth: S: canine tip of impacted side N: canine tip of antimere side At 9 years: there was significant difference in location between the impacted and non-impacted side At 9 years: the cusp tip of impacted canine crosses the distal border of lateral incisors to lie between the distal border and midline of lateral incisors 3-Angle formed by long axis of canine with upper maxillary midline: The angle at impacted side called alpha and at antimere side called theta Upper maxillary midline ------- inter-maxillary suture to ANS to inter-nasal suture At 9 years of age: the mean angulation at impacted side was 28.4 degree and it may continuously increase by age and also there is significant difference with the antimere side 4-Stage of root development: Stage 0: root formation not begun Stage 1: less than ¼ of root complete Stage 2: root formation between ¼ to ½ Stage 3: root formation between ½ to ¾ Stage 4: root formation more than ¾ Stage 5: root formation is complete Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
4 Factors affecting eruption of impacted teeth: 1-Initial distance between the tooth and the occlusal plane and the amount of crowding 2-Stage of development of the impacted tooth 3-Age of patient 4-Manner in which the soft tissue is laid down in the healing wound (elephantiasis gingiva) Rare complication of impaction: 1-Mobility and migration of the adjacent teeth (due to root resorption) 2-Painless bony expansion: dantigerous or radicular cyst 3-Pain and discharge: infected cyst 4-Morbidity of deciduous canine due to its short root and high susceptibility to inter-proximal caries 5-Cystic changes 6-Internal resorption Another complication: 1-Crown resorption of impacted canine and replacement of enamel by bone, if impaction not treated for 20 – 30 years 2-Resorption of permanent central and lateral incisors root 3-When a normally sizes lateral incisors is associated with an adjacent palatally impacted canine, the chances of resorption of its root are 7 times greater than if the lateral incisors is small or peg shaped. Theories of impaction: 1-Guidance theory: Impacted canine is a result of local predisposing causes including congenitally missing lateral incisors, supernumerary teeth, odontomes, transposition of teeth and other mechanical determinants that all interfere with path of eruption of the canine The guidance theory compromise five elements: a-Normal eruption: Normal development lateral incisors guide canine for eruption, buccal path of eruption is expected with tooth palpable in the buccal sulcus b-First stage impaction: Absence of guidance at critical time which lead to deflection of normal path of canine c-First stage of impaction with secondary correction: Alveolar process act to redirect the canine on a more favorable downward path, this scenario is difficult to diagnose d-Second stage of impaction: Self-correction is prevented by the presence of an anomalies and late developing of palatal incisors, re-deflecting the tooth further palatally, this may term second stage displacement e-Second stage with secondary correction: Extraction of an over-retained deciduous canine, or even the anomalies lateral incisors itself. May lead to spontaneous eruption of impacted tooth 2-Genetic theory: Palatally impacted maxillary cuspid often with other dental abnormalities, including tooth size, shape, number and structure which are linked congenitally. Several abnormalities are believed to have a common hereditary link Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
5 N: B: Cephalometry: An unerupted U3 is about 10 degree of labial tipping relative to FHP Forward tipping: 15 -25 degree require treatment Tipping: 25 – 45 degree more difficult Tipping over 45 degree is generally orthodontically untreatable How to create spaces: 1-Closing the spaces in anterior region 2-Correction of arch form: it will give 2 -3mm 3-Increasing arch form: in mild cases of crowding with using headgear 4-Extraction of premolars in severe cases of crowding 5-Open coil spring is used to push the lateral incisors mesially and 1st premolar distally 6-Heavy rectangular arch wire is used to preserve the space using open coil or stainless steel tube Orthodontic attachment: 1-Lasso wire: Developed by Hazard Lasso, it is twisted lightly around the neck of the canine Disadvantages: -Irritation of gingiva -Prevent re-attachment of the healing tissue in area of cemento-enamel junction -May produce area of external resorption & ankylosis in area of CMJ 2-Threaded pins 3-Orthodontic bands 4-Direct bonding attachment 5-Bracket or eye lets 6-Elastic thread or golden chain 7-Ligature wire 8-Spring 9-Magnets Advantages of magnets: a-Rapid, safe, and sure eruption of teeth in much less time than conventional method b-No chain, lasso, or ligatures penetrating the palatal tissue, reduces chances of inflammation, infection c-The attachment is less likely to be knocked and dislodged from the tooth d-Produce constant physiological forces (40 -60gm) over long periods of time Direction of force can be chosen by the clinician N: B: Crowding or lock of space in the arch usually results in buccal displacement. 80% of palatal impaction, there is adequate space for the eruption of canine Palatally impacted canine Prevalence: 1.7%: among Chinese 5.9%: Caucasian 1.4%: American Female: male: 2.3:1 Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
6 Congenital absence: 0.3% of upper, 0.1% of lower Theories regarding the cause of palatal displacement 1-Long path of eruption: From the days of Broadbent in 1940, the most common reason for impacted palatal canine is the long and tortuous path of eruption as it starts close to the floor of the orbit as compared with other permanent teeth 2-Crowding: Some authors considered the crowding of the dentition as the reason for palatal impacted canine 3-Non-resorption of the root of deciduous canine: Failure of the root of maxillary canine to resorb cause palatal deflection of path of eruption of maxillary canine 4-Trauma: Which lead to cessation of the development of lateral incisors root as trauma lead to movement of lateral incisors followed by movement of unerupted canine 5-Soft tissue pathology: Chronic infection or granuloma around the apex of the root of deciduous canine, may lead to deflection of unerupted maxillary canine or initiate cystic change in the follicle which alter the path of eruption 6-Guidance theory: discussed 7-Genetic theory: discussed 8-Heredity: There are some authors that believed that heredity is the direct cause of palatally impacted canine and dismiss others relationship as secondary Peck et al 1992: studied the maxillary canine / 1st premolar transposition and found strong heredity influence in its etiology ***** we may prefer to define the 1st premolar/canine transposition as primary tooth germ displacement Other associated clinical features: 1-Dentition with small teeth 2-Generally, the mall teeth larger than female but in case of palatally impacted -------- male is smaller than unaffected group 3-Features of missing teeth such as: third molar, U2, U5 and L5, L1 4-Late dental development and high frequency of lateral incisors anomalies 5-Infra-occluded deciduous molars Nine indicators of canine impaction: 1-Lack of bulge in the buccal vestibule after 10 years of age 2-Presence of bulge in palate 3-Deciduous canine is retained with no mobility 4-Sever crowding in arch 5-Maxillary lateral missing or tendency for small laterals especially 6-Contralateral canine has erupted, there is a gap for 6 months since into eruption 7-There is general tendency of small teeth and delayed eruption of teeth 8-Unusual rotation of maxillary lateral incisors 9-Mobility of maxillary lateral incisors Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
7 Sector classification of impacted canine: Lindaur et al Sector I: represent area distal to line tangent to distal heights of contour of lateral incisors crown and root Sector II: is mesial to sector I but distal to bisector of lateral incisor long axis Sector III: mesial to sector II but distal to mesial height of contour of lateral incisors crown and root Sector IV: include all areas mesial to sector III Complication of un-treated impacted canine: 1-Morbidity of deciduous teeth: Early morbidity of deciduous canine is more common because: -Its root may be become markedly resorb causing mobility and shedding which was difficult for restoration because of its small space -High susceptibility to inter-proximal caries (particularly distal) 2-Cystic change: Loss of vitality in early caries deciduous canine, necrosis pulp and periapical pathology may affect the follicular sac and produce dantigerous cyst OR: chronic periapical lesion on deciduous canine may itself become cystic ------ radicular cyst ----- and displace palatal canine 3-Crown resorption: = the reduced enamel epithelium surrounding the completed crown, separate the crown from the surrounding tissue = this epithelium may degenerate with age and so the crown become in contact with bone and connective tissue and osteoclastic activity lead to crown resorption = after surgical exposure of tooth will show pitted surface which is difficult to separate from the bone. So in adult persons that impacted tooth left 2 or 3 seconds, the tooth possibility for response to orthodontic force very low 4-Resorption of roots of the incisors: = the proximity of the follicular sac of unerupted tooth to the roots of deciduous predecessor initiate the process of resorption roots and this process may transmit to permanent one because histologically, there is no way to differentiate between root tissue of deciduous and permanent teeth = resorption in root of adjacent permanent tooth depend on eruptive movement of impacted tooth Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
8 Diagnosis: = unerupted maxillary canine cause some problems to patients as poor appearance of deciduous canine which has small size = the discovery of palatal impacted canine usually made by general dentist during routine examination Inspection: = the maxillary incisors are normally spaced and flared laterally at age of 10 (Broadbent ugly duckling stage) and this situation is still true till age of 11 or 12 years = care must be taken to examine size and shape of incisors = examine any anomalies affect the position of lateral incisors root and crown and in some cases there is cross bite of upper lateral incisors Palpation: = for normal development, the permanent canine is palpated bucally above the deciduous canine for 2 – 3 years before eruption =wide convex of bone indicate the canine = care should be taken not to confuse this with the narrow profile of the root of deciduous canine = test the mobility of deciduous canine if it mildly positive, this means that the permanent canine close to the normal eruptive path = when the root of lateral incisors is palatally palpated, this means the canine is displaced labially in alveolus Radiographically: 1-Periapical films: Evaluate the canine mesiodistally and superior-inferior, but to evaluate the palatal canine, second periapical film should be obtained a-Tube shift technique: Clark’s rule: change the horizontal angulation of cone in second film If canine move with cone so it is palatally If canine move opposite to cone so it is labially b-Buccal object rule: change the vertical angulation of second film by 28 degree If canine move opposite to cone so it buccal If canine move with cone so it is palatal 2-Occlusal film: Help to determine the bucco-lingual position of impacted canine with periapical film 3-Lateral cephalometric 4-P.A cephalometric 5-Panoramic C.T Preventive treatment and its timing 1-Extraction of deciduous canine: as prevention: Extraction of deciduous canine at age 11 years offers a good prognosis for the natural eruption of canine The following conditions should be met before extraction: 1-Diagnosis of palatal displacement made as possible early 2-Patient must be at 10 – 13 range of age 3-Accurate identification at root apex to be in the line of arch 4-Medial overlap of unerupted canine should be less than half way a cross the root of lateral incisors on panorama 5-The angulation of long axis should be less than 55 degree to mid sagittal plane Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
9 2-Extraction of 1st premolar: as prevention: In cases of extraction of 1st or 2nd premolars because of crowding give a good chance for good prognosis in impacted canine especially if the tooth extracted is close to impacted canine 3-Extraction of lateral incisors: as preventive: = many of impacted cases associated with anomalous lateral incisors and at the end of treatment it necessary to alter its shape, if extraction is need to overall treatment so extraction of lateral incisors as an alternative way = some cases lateral incisor may form barrier in the way of canine, so it is second stage impaction, logically extraction of lateral incisors improves natural eruption of impacted canine --- second stage impaction with secondary correction = extraction of lateral incisors is not suitable for each cases because this depend on: Position of canine Position of lateral incisor Relation between canine and lateral 4-Orthodontic space opening: Which involve extraction of deciduous canine, extraction of premolar, extraction of lateral incisors, when this is done the unerupted tooth may improves their position in the dental arch and spontaneously eruption 5-Rapid maxillary expansion: Skeletal mid palatal suture splitting expansion provide space allow spontaneous eruption of impacted tooth Some studies show the increase the incidence of spontaneous eruption after expansion to 60% of cases Treatment options of impacted canine: 1-Interceptive removal of deciduous canine 2-No treatment, but with periodic evaluation of pathologic change 3-Surgical removal and prosthetic replacement of impacted canine 4-Surgical exposure of canine and orthodontic alignment 5-Auto-transplantation of canine All of these options depend on: -Patient age -General dental health and oral hygiene -Whether space is available in the arch or can be made available for alignment of canine -The suitability of 1st premolar to replace the permanent canine -Patient motivation for orthodontic appliance -Medical contraindication for surgery Cases for canine removal: 1-If it is ankylosed and cannot be transplanted 2-If it is undergoing external or internal root resorption 3-If root is severely dilacerated 4-If impaction is severe as canine is positioned between the roots of central and lateral incisors and orthodontic movement may affect these teeth Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
10 5-If the occlusion is acceptable, with the 1st premolar in the position of canine with aligned teeth 6-If there is a pathologic changes as cystic formation or infection 7-If the crown tip at or apical the apical 1/3 of incisors 8-If its root apex is distal to second premolar Interceptive treatment of impacted canine = in class I non-crowded situation where permanent maxillary canine is impacted or erupting bucally or palatally, so extract the primary cuspid at patient age 10 -13 year, this resolve about 63% of cases = however extraction of primary canine does not guarantee correction of problem, in some cases surgical correction indicated = when the degree of overlap between the permanent canine and lateral incisor exceed half width of incisor root, the chance for complete recovery are poor Mechanotherapy: Timing of mechanotherapy: = the patient is generally in the full permanent dentition stage, with the exception of the deciduous canine on the affected side = although a minor degree of local tooth malalignment may often be seen as: collapsed arch form, space loss in immediate area, some crowding is occurring in 15% of cases General principle of mechanotherapy: Diagnosis of over-all malocclusion needs to be made and problem list set out, the principles should adapt to the new circumstances: 1-The appliance should align all erupted teeth with controlled crown and root movements, open adequate space to accommodate the impacted tooth 2-Maximize the anchorage by using heavy arch wire 3-Surgical exposure of the crown of impacted tooth in a manner that will achieve good periodontal diagnosis. An attachment is bonded to it with fully covered flap 4-Using auxiliary means of traction, gentle and continuous force is applied to erupt the impacted tooth in a path free from any obstacle 5-Finally detailing of erupted tooth ** In cases of class 2 and class 3 skeletal components, these cases require special treatment with the use of orthopedic /functional appliance, there are several factors that affect the treatment: a-The result in orthopedic / functional treatment are best realized during growth period b-Maxillary canine impaction is much more frequent in females who complete their growth earlier than male c-Patient with palatally canine impaction exhibit an overall late dental development d-The resolution of impacted canine takes considerable time and not dependent on further growth may be expected ** The treatment of skeletal problem is achieved first and treatment of canine start after case with normal class I, but there is exception about this as: a-In case of canine cause resorption in the adjacent root b-If there is no enough space for erupting of tooth to align Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
11 Classification of palatally impacted canine The classification that is offered here is based on two variables: a-The transverse relationship of the crown of the tooth to the line of the arch, which may be close or distant (nearer to midline) b-The height of the crown of the tooth in relation to the occlusal plane, which may define as high or low Group Proximity to the line of the arch 1 Close 2 Close Position in maxilla Low Forward, low, mesial to lateral root High High Transposed 3 4 5 6 Close Distant Root apex mesial to lateral or distal to premolar Erupting in the line of the arch in place of resorbed incisor root Group 1: = proximity to the line of arch (bucco-lingual): close = position in maxilla (occlusal plane): low = it represents the by far the most common form of palatal impaction in which: -Canine opposite the space and is not rotated -The root apex is in normal position -Root movement is rarely necessary Prognosis: Good prognosis Surgery: = approach from occluso-buccal, little bone removal is needed after reflection of the palatal flap = after suturing, the peg tail ligature is drawn through the sutured edge in the direction of the arch wire Ortho: = some extrusion with buccal tipping movements = direct force applied between peg tail and arch wire Problems: As the tooth moves bucally it gather a gingival tissues a head of it, if oral hygiene is not excellent so the soft tissue become inflamed and impinge on the bracket, wider exposure will eliminate this Complications: 1-Rotations: = Mesio-palatal so the buccal surface of the canine faced the distal surface of the lateral root = The eyelet should be positioned on the anatomic labial surface of the canine to help in correction of rotation = the elastic traction will rotate the canine along its long axis in a corrective mesio-distal direction = A good alternative involves the use of slingshot elastic which is elastic modules, placed between the bracket of lateral incisor and 1st premolar, it stretched towards the canine and tied into the buccal eyelet (the steel tube in arch wire maintain the space) Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
12 OR: elastic thread tied between the eyelet and cut length of stainless tube that has been threaded on to the main arch wire 2-Mesial crown displacement: It is very common problem, the area of the buccal surface of canine is too small to receive brackets, so using of eyelets is the only solution The elastic thread is tied toward the premolar bracket, to enhance the rotation correction AVOID: placing an attachment on the palatal surface of the impacted canine as you can, very difficult to correct later and will significantly added to the amount of mechanotherapy manipulation that tooth will undergo 3-Palatal displacement of root: When palatal surface of the crown bulges inferiorly while the labial surface tips superiorly This type needs more torque in the fixed orthodontic appliance after the tooth has been aligned N: B: The heavy arch wire is now needed to serve as the base arch to the labial root- torqueing auxiliary. The heavy base arch provides the fulcrum about which the auxiliary will bucally rotate the root apex Group 2 = proximity to the line of arch: close = position in maxilla: forward, low, tilted mesially, mesial to the root of lateral incisor Root apex is in correct place in the line of the arch = the crown is in close association with palatal aspect of the lateral incisor root = often it is sited between the roots of central and lateral incisors = the tooth is not palpable on the palatal side Surgery: The surgery is complicated by exposure of the incisor roots Avoid wide exposure The peg tail wire is drawn through slit in the flap made by electro-cautery to avoid bleeding The two-part flap is sutured back into place Orthodontic plane: = The mesio-palatal rotation of canine that is usually present in these cases, places the labial surface completely in an in-accessible position, so the attachment is bonded to the palatal surface = Different approach is needed to free the tooth from incisor roots, draw it down ward and then in labial direction ------- then the tooth has clear path in the arch without interposing adjacent roots and group 2 canine will have been converted to group 1 canine = Three type of maxillary auxiliary spring may be used to allow desired movements: a-Ballista: Unilateral spring with rectangular wire, which is tried into one of the rectangular molar tubes It proceeds forward until it is opposite the canine space At this point it is bent vertically downward toward the lower jaws and terminate in small loop, with light finger, the vertical portion is turned upward and inward to attached with peg tail ligature to close to the mucosa of palate The elasticity of Ballista allows to apply extrusive force to the unerupted tooth b-Active palatal arch: Consists of fine (0.6mm) palatal arch wire carrying an omega loop on each side, the wire is slotted into a soldered horizontal tube on the palatal side of maxillary molar Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
13 c-Light auxiliary labial arch: 0.014 or 0.016 inch in diameter round wire forming vertical loop in the area of impacted canine, loop has small terminal helix. - the auxiliary is tied into all bracket of the arch in piggy back style over a heavy main arch - the activation of the auxiliary from its curved arch form which does not transfer torque to the molar - this method is useful in bilateral impaction, when two different loops will need to be inserted into the arch form - in the construction of Ballista and auxiliary labial wire it is important to calculate the length of active arm in advance Problems: The palatal tissue is very resistant and bulges more and more so, surgical super-facial removal of the mucosa immediately over the crown of the tooth Complications: The internal location of the tooth may be complicated by one of the following: 1-Rotation: Mesio-lingual rotation will be corrected during traction from the second eyelet to the arch wire 2-Palatally displaced root: It requires more buccal root torque with mesio-distal root uprighting Revision: We have to apply 5 orthodontic movements: 1-Vertical extrusion from the palate 2-Buccal tipping to the line of the arch 3-Rotation 4-Mesio-distal root uprighting 5-Buccal root torque N: B: ** heavy force can lead to loss of anchorage, cross bite of lateral incisor, and damaged of its root with midline shift To avoid this position, try to push the impacted canine toward the tongue not toward the arch wire ** to avoid rotation during traction the direct traction to the arch wire should only be performed from an attachment sited in the mid buccal position of the tooth Group 3 Criteria: Close proximity to line of the arch High position in maxilla The root apex is very high in the maxilla Crown is high, mild displaced palatally Not palpable No rotation No ectopic root apex Surgical and orthodontic strategy: Access palatal or buccal, with considerable bone removal is needed orthodontic movements: -Extrusion with buccal tipping Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
14 -Orthodontic traction should be applied in 2 stages as in group 2 after palatal approach which leaves the tooth with good amount of bone and healthy periodontium Buccal approach: The tooth is approached as far as buccal impaction Apical re-positional flap appears to be a good approach to allow application of orthodontic force direct to the arch This method is not suitable for superior position canine palatally Post-surgical discomfort with this method is more severe and more prolonged than with closed exposure method By this method there is: -Unacceptably reduced bone support -Poor gingival contour -Poorer periodontal prognosis -Long clinical crown -Deficient interdental papilla This approach was recommended by Johnston 1972 Tunnel approach: An excellent approach in which the buccal plate of bone is preserved while the impacted tooth is drawn through a tunnel in bone provided by the vacated socket of the simultaneously extracted deciduous canine Preservation of buccal plate inferior to the tooth Fine wire is extended through socket of deciduous canine. By this method there are: -Good bony profile -Good periodontal result similar to normal eruption Palatal approach: If the canine is more palatally displaced, surgery from buccal side more radical, so palatal approach is preferred Many surgeons will remove a part of the flap in order to leave the impacted tooth in visual contact and will place a pack to cover the open area New eyelets were bonded and traction was applied in buccal direction Auxiliary arch wire in active mode used for vertical eruption N: B: Tunnel method may be the best way to go with the promise of a superior periodontal outcome Group 4 Criteria: Proximity to line of arch: distant Position in maxilla: high Not palpable in palate Root apex is normal Surgery: The tooth is at some distance from the adjacent teeth. Little bone is needed to be removed, but the roots of adjacent teeth are in danger Orthodontic strategy: Downward tipping movement will be achieved with the same vertical direction approach as for group 2 and 3 with the use of auxiliaries Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
15 Problems: = torque cannot be useful until the crown of the tooth reached its place = cingulum area of palatal aspect of the crown is very important and is likely to interfere with the occlusion = in some cases there is cross bite tendency in buccal side which can treated by using cross elastics from the buccal side of arch to the lingual side of other arch There is some loss of bone support at affected side compared with the unaffected group Group 5 Criteria: = canine root apex is mesial to that of lateral incisor or distal to that of first premolar = This is transposed position = canine 1st premolar transposition must be considered as, three dimensional phenomenon -Premolar erupt in its normal location in arch -Strong mesial displacement of 1st premolar root -Bucally: there is a bulge which clearly indicated the position of canine = canine- lateral incisor transposition, position of crown reversed, but there is no buccal-lingual displacement from the lone of the arch = lateral incisor is more tipped palatally and distally Examination: From frontal: Canine not palpable on labial or palatal side Lateral incisor root exhibit distal displacement From occlusal: Long axis of lateral has posterior displacement in apical direction Outline of the root may be bulge beneath the palatal tissue Pair of periapical view: Canine crown is palatal to the root of the central incisors on which it is superimposed Panoramic view: Canine over lateral incisor Canine root apex above or distal to that of incisor but more superiorly located Surgery: Many transposed canines are partially erupted and need surgery to expose the crown Apical repositioned flap makes the tooth accessible In some cases, palatal exposure gives more accessibility Orthodontic strategy: there are four possible lines of treatment: 1-Resolve the transposition to ideal relationship 2-To move the premolar mesially (or the incisor distally) and align the canine between the premolar 3-Use the canine for auto-transportation into prepared socket 4-Extract the severely displaced canine Complications: 1-Loss of bone height 2-Biomechanics is difficult 3-Root proximity may occur during treatment 4-Root resorption 5-Some loss of gingival attachment Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
16 Group 6 Criteria: Erupting in the line of arch, resorping root of incisors Canine not palpable and its root apex is close to its ideal position in the line of the arch The cusp tip is located against and within the resorbed distal side of incisors root Orthodontics: = once the surgeon exposed the distal part of canine and the attachment has been placed, the distal and buccal tipping of the tooth toward the arch wire is required = un-treated canines will lead to total resorption and extraction of one or more of the incisors and it will erupt in their place. This resorption is un-accepted from esthetic point of view = orthodontic traction is applied in distal direction toward the molars without any vertical movement = after eruption through palatal mucosa, eyelet is bonded on the buccal surface with downward traction Problems: If more than ½ of incisor root has been resorbed, this incisor should be removed and canine will take its place with mesial uprighting of its root and reshaping of the crown Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
17 Angulation of the impacted canine to the midsagittal plane: (A) Score 1—less than 30 degrees (B) Score 2—between 30 and 45 degrees (C) Score 3—more than 45 degrees Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
18 Apex position: (A) score 1—in the area of canine apex, (B) score 2—in the area of the first premolar apex (C) score 3—in the area of the second premolar apex. Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby
19 Vertical position of the impacted canine: (A) Score 1: canine cusp tip at the level of the cemento-enamel junction of the adjacent incisor, (B) Score 2: canine cusp tip at the middle of the root of the adjacent incisor, (C) Score 3: canine cusp tip within the apical third of the root of the adjacent incisor, (D) Score 4: canine cusp tip above the apical third of the root of the adjacent incisor. Management of Canine Positions Abnormalities Management of Canine Positions Abnormalities Dr. Mohammed Alruby Dr. Mohammed Alruby