Palatally impacted canines: aetiology of impaction and the scope for interception. Report of cases outside the guidelines for interception

Patients with palatally impacted canines have an increased incidence of missing or anomalous lateral incisors adjacent to the impacted canines. Their arches are often uncrowded and this, in part, is linked to the increased incidence of missing or anomalous lateral incisors. Other teeth are also more frequently missing. The present guidelines for the relief of palatally impacted canines by extraction of the deciduous canine require that the patient is aged between 10–13 years and that normal space conditions are present. Two successful case reports are presented which were outside the recommended guidelines. The technique of relieving a palatal impaction by extraction of the deciduous canine has wide application.     

Therapeutic strategies for impacted maxillary canines

A disturbance in the normal eruption pattern of one or both of the maxillary canines is found in 1% to 2% of the teenagers aged ten to thirteen years. Frequently, dentists refer these patients to orthodontists who, in turn, seek the assistance of an oral and maxillofacial surgeon to retrieve the impacted canine, either by exposure alone or by exposure and attachment of a bracket and ligature for orthodontic extrusion. A common request in this procedure is the extraction of the persistent upper deciduous canine and/or, in case of an Angle Class II molar relationship, extraction of the upper first premolar. It has been shown, however, that on average 15% of these exposed or ligated maxillary canines fail to erupt. Therefore, one should be reluctant to extract the deciduous canine or the permanent first premolar before it is clear that the impacted maxillary canine will indeed erupt after surgical exposure and/or placing of a bracket and ligature for orthodontic extrusion.     

Eruption disturbances of mandibular permanent canines in Japanese children

Objectives. The purpose of this study was to clarify the cause and prognosis of eruption disturbance of mandibular permanent canines.
Sample and Methods. Fifteen Japanese children who visited Niigata University Dental Hospital between 1979 and 1997 with unerupted and/or impacted mandibular permanent canines were examined.
Results. All cases showed unilateral disturbances. The eruption disturbance of 6 mandibular canines was associated with a calcified obstacle such as an odontoma (5 cases) or a supernumerary tooth (1 case). After removal of the obstacle, 5 canines were aligned within the dentition. Out of 10 cases, where the permanent canine germ showed malpositioning or aberrant eruption path, 5 primary predecessors had undergone endodontic treatment. In these 10 cases, 6 canines erupted after treatment, two were extracted and the remaining two were left in their impacted position.
Conclusions. The present results suggest that it is relatively easy for the position of unerupted mandibular canines associated with calcified obstacles to be improved by removal of the obstacle, but that it is more difficult for teeth showing anomaly in the position of the canine germ to be aligned within the dentition.     

Birooted primary canines identified in 8-year-old Japanese girl – Case report

This report presents a rare case of birooted bilateral maxillary primary canines. A Japanese girl aged 8 years 10 months was referred to the Pediatric Dentistry Clinic of Osaka University Dental Hospital by an orthodontic dentist to extract maxillary bilateral primary canines. The canines appeared to be birooted in panoramic radiography and were extracted under infiltration anesthesia. Both visual observation and computed tomography findings revealed that the birooted primary canine had 2 roots for each root canal. In spite of the rareness of this condition, it should be kept in mind because of potential problems in affected patients.     

Favourable spontaneous eruption of severely displaced maxillary canines with associated follicular disturbance

Cases of severely displaced unerupted maxillary canines are presented, related to disturbance of the follicle. Removal of the deciduous predecessor produced favourable eruption of the permanent canine and should be considered as a treatment option in similar cases.     

Radiographic examination of ectopically erupting maxillary canines

This study analyzes the need for and possibility of obtaining further information from different radiographic procedures in 125 children with potential ectopic eruption of the maxillary canines. After clinical examination of 3,000 10 to 15-year-old children, it was found that 7% needed radiographic examinations for determination of the canine position. Eighty-four children (2.8%), with a total of 125 potential ectopically erupting maxillary canines diagnosed clinically and by means of periapical radiographs, were selected and a stepwise extended radiographic diagnostic procedure was used. Most canines in ectopic eruption were positioned palatally; the positions could be assessed with sufficient accuracy from conventional periapical films in 92% of the cases. Only in 37% of the cases, however, could the lateral incisor be projected free from the ectopic canine by the intraoral technique. The lamina dura of the lateral incisor facing the canine was often found to be interrupted. For 29% of the ectopic canines, the lateral incisors could neither be projected free nor judged free from resorptions and a supplementary polytomographic investigation was believed to be necessary. The number of resorbed teeth was doubled by polytomography and altogether 12.5% of the ectopic canines caused resorptions. A stepwise radiographic procedure including polytomography is described and recommended in cases of ectopic eruption of maxillary canines for determining the correct position and ruling out or confirming resorptions on incisors, thereby optimizing the orthodontic treatment planning.     

A diagnostic proposal to support early treatment of ectopically erupting maxillary canines

Although early diagnosis is essential for the correction of ectopically erupting canines, it is difficult to determine whether the condition of a canine is within acceptable normal limits, particularly in children aged 10 years or younger. The purpose of the present study was to ascertain the appropriate time for a preventive procedures, such as extraction of the predecessor, in order to avert impaction of maxillary canines. Orthopantomograms of 225 normal children without dental anomalies were examined to compare the eruption stages of mandibular and maxillary canines. Sixty-four patients with 68 unerupted and/or impacted maxillary canines were examined. In normal children, mandibular canines exhibited earlier movement toward oral emergence than maxillary canines on the same side. This tendency was particularly prominent after exfoliation of the mandibular primary canine. In contrast, nearly half of the patients with anomalies were treated before oral emergence of the mandibular canine through simple procedures such as extraction of the primary canine or exposure of the affected canine. The present findings may provide a useful supplemental rule for early diagnosis and aid in decisions whether to treat ectopically erupting maxillary canines, particularly when the anomaly is obscure.     

Spontaneous improvement in position of canines from apparently hopeless positions

Summary. Two cases are presented, each with both unerupted maxillary canines so badly positioned that eruption seemed unlikely. However, over a period of approximately three years, three out of the four initially displaced canines did erupt; the improvements in position being unrelated to whether or not the associated primary canine was extracted. Three out of four primary canines were removed. These cases highlight the difficulties in predicting canine eruption for individual patients.     

Delayed diagnosis of displaced and impacted canines – a prospective longitudinal study

Abstract

Objectives: To assess the frequency and reasons for delayed diagnoses of displaced/impacted canines and to determine to what extent this causes complications. In addition, to assess whether any preventive measures were taken.

Materials and methods: Patients with displaced/impacted canines that were diagnosed late; i.e. at an age ≥12 years, were consecutively collected during September 2015 to September 2018 in the County Region of Halland, Sweden. Additionally, patients who had undergone surgical exposure or extraction of an impacted canine during the same time period were identified.

Results: Eighty-four individuals (58% girls, 42% boys, mean age: 13.75?±?1.53?years) with 114 impacted canines were detected among 33,488 adolescents aged 12–20?years, resulting in a low-frequency rate: 84 cases per 100,000 persons. Eighty-six percent of the delayed canines were in the maxilla, the rest in the mandible. Deciduous canines were present in 80% of the cases. Most patients had a dental examination at 9–11 years of age but the position of the canine was not documented in many cases. Root resorption of adjacent teeth was noticed in 13% of the patients. No new clinical procedures or guidelines were developed.

Conclusions: The frequency of delayed diagnoses of displaced/impacted canines was low. To minimize the frequency even more, documentation of the canine position during the dental examination should not be forgotten at ages 9–11. Presence of the deciduous canine can be used as a clinical indicator that the position of the permanent canine needs to be investigated.     

Prediction of breadth of permanent canines and premolars in the mixed dentition.

Multiple stepwise regression was used in the selection of mixed dentition variables capable of predicting the total breadth of the unerupted permanent canine and premolars. The material consisted of 77 children. Stone casts were made before and after eruption of the canine and premolars. At the first examination when the children were, on the average, 10 years old, intraoral roentgenograms were obtained of the canine and the premolars. To predict the total breadth of the upper canine and premolars the buccolingual breadth of the upper first permanent molar and measurements on roentgenograms of the breadths of the upper canine and premolars proved most useful. In the prediction of the total breadth of the lower canine and premolars the best results were obtained with measurement of the breadths of the teeth in the roentgenograms. The breadth of the incisors proved less useful as a predictor of the breadths of unerupted canines and premolars.     

Transmigrant mandibular canines.

PURPOSE: The aim of the present study was to investigate the patterns of transmigrant mandibular canines, the incidence and classification of transmigrant canines, and the associated pathology of these teeth. PATIENTS AND METHODS: This retrospective cohort study was composed of 4,500 panoramic radiographs of patients who presented to our Oral and Maxillofacial Surgery Services from January 1998 to December 2005. Panoramic radiographs were reviewed. Observations were made on the status of missing permanent mandibular canines, retained deciduous canines, side and number of transmigrant canines, gender and age of patients, and any other associated pathology. RESULTS: In the present study, a total of 15 patients had transmigrated canines-6 females (ages 13-33 years) and 9 males (ages 13-57 years). All transmigrant canines were unilateral. Two canines were impacted in the mandible enveloped in cystic lesions. The rest of the transmigrated canines were in varying stages of intraosseous travel and positioning within the mandible, with no pathological entity. CONCLUSION: The use of a panoramic radiograph is imperative and is recommended for discovering such rare malpositions. If the mandibular canine that has migrated across the mandible is associated with pathology, it may be removed. Otherwise, it should be kept under observation.     

A clinical and radiologic study of autotransplanted impacted canines

The aim of the present study was to evaluate the clinical and radiologic results of 20 autotransplantations of impacted canines performed in the Orthodontic and Pedodontic Department of the University of Geneva between 1979 and 1988. The sample, divided into two different age groups (group A: 13–20 years; group B: 20–48 years), demonstrated persistence of pulp vitality in 80% of the cases in group A, whereas routine endodontic treatment was instituted in all cases of group B. Periodontal healing was noted in 90% of the cases in group A, and in 70% of the cases in group B. The present clinical and radiologic data indicate that impacted canines can be transplanted at any age with good prognosis and are an alternative to orthodontic repositioning in selected cases of canine impaction.     

A case of supernumerary primary and permanent canines

A case of supernumerary primary and permanent canines is presented. A 9Y4M-old boy was referred to our clinic for consultation regarding a maxillary supernumerary primary canine. An oral examination showed 2 primary canines with a similar morphology between the maxillary left lateral incisor and first primary molar. The primary canine in the opposite quadrant had the appearance of a fused-tooth, with composite resin restoration seen in the border. Orthopantomography revealed that permanent successors were present for each primary tooth in the maxillary left region, whereas only a single permanent canine was developing in the opposite quadrant. The 2 primary canines in the maxillary left region were extracted at 9Y4M. The mesially located permanent canine emerged into the oral cavity at 10Y1M and was extracted at 10Y9M. At 12Y2M, the other permanent canine located in the distal position had nearly reached the occlusal plane and the maxillary right permanent canine had arrived at the occlusal plane. Dental age was evaluated by assessing the tooth formation stages in 4 orthopantomographs taken between 8Y5M and 12Y2M, and found to be nearly the same as chronological age. However, the dental ages of the maxillary left permanent canine that had erupted earlier than the one located distally and of the left permanent canine were approximately 1 year behind chronological age. In addition, the dental age of the left permanent canine located distally was 2.5 years behind until the patient reached the age of 10Y9M, after which tooth development was accelerated following extraction of the mesially located permanent tooth.     

Transmigrant impacted mandibular canines: a retrospective study of 15 cases

BACKGROUND: Transmigration of mandibular canines across the midline is rare. The authors describe the clinical and radiologic characteristics of patients with transmigrant impacted mandibular canines. METHODS: The authors conducted a retrospective observational study of 14 patients with transmigrant canines. They diagnosed transmigrant canines in all of the patients on the basis of the clinical and radiological findings, and they obtained the data from the patients' case histories and panoramic radiographs. They considered a canine to be transmigrant when one-half or more of its length crossed the mandibular midline. RESULTS: There were 15 transmigrated canines in 14 patients aged 16 to 60 years. Primary canines were present in 10 cases. One case involved a pericoronal infection, two involved supernumerary teeth, one was associated with an odontoma, and in two a pericoronal radiolucency was seen that was compatible with a follicular cyst. Treatment consisted of surgical extraction for eight patients, and periodic clinical and radiologic follow-up visits for six patients. CONCLUSIONS: Radiographic examination is necessary to diagnose impacted transmigrant canines, among other anomalies. Surgical extraction is the treatment of choice for patients with transmigrant canines involving associated pathology. In some cases, the management of asymptomatic impaction can be limited to periodic clinical and follow-up visits. CLINICAL IMPLICATIONS: The absence of the permanent canine within the arch beyond the normal time of eruption suggests the presence of an impacted canine. A transmigrant canine may develop an associated pathology.     

Two interceptive approaches to palatally displaced canines: a prospective longitudinal study

This study evaluated the effectiveness of two interceptive approaches to palatally displaced canines (PDCs), ie, extraction of the deciduous canines alone and in association with the use of a cervical pull headgear. The prospective longitudinal design of the investigation included 46 subjects with PDC (62 maxillary canines) who were randomly assigned to one of three groups (1) a group that underwent the extraction of the deciduous canine only, (2) a group that received in addition the use of a cervical pull headgear, and (3) an untreated control group. Panoramic radiographs were evaluated at initial observation (T1) and after an average period of 18 months (T2). Cervical vertebral maturation was assessed on lateral cephalograms at T1. Successful or unsuccessful canine eruption was assessed 48 months after T1. The between-group statistical comparisons were performed on the T1-T2 changes in the diagnostic parameters on panoramic radiographs, the prevalence rates of successful canine eruption, and the amount of time for canine eruption. The removal of the deciduous canine as an isolated measure to intercept palatal displacement of maxillary canines showed a prevalence rate of 50% success, which was not significantly greater than the success rate in untreated controls. The use of a headgear in addition to the extraction of the deciduous canine induced successful eruption in 80% of the cases, with a significant improvement in the measures for intraosseous canine position. There was no significant difference between the two interceptive approaches in the time required for canine eruption.     

Association between the inclination of the lateral incisors and the position of the erupting canines on panoramic radiographs

OBJECTIVE. To analyze correlations between the inclination of the permanent maxillary lateral incisors and the intraosseous position of the erupting permanent maxillary canines on panoramic radiographs. MATERIAL AND METHODS. The inclination of the lateral incisor to the midline, the mesiodistal position of the crown of the canine, and the inclination of the canine to the midline and to the long axis of the adjacent incisor were measured on panoramic radiographs of 1013 subjects aged 8-11 years. RESULTS. The distal inclination of the lateral incisor crown increased until 10 years, after which no significant changes occurred. The canine erupted with increasing mesial inclination of the crown until 9 years, after which it began to progressively right itself. As a result, inclination of the canine to the adjacent incisor increased between 8 and 9 years and decreased between 10 and 11 years. Until the children reached 9 years of age, the more mesial the crown of the unerupted canine, the greater the decrease in the distal inclination of the lateral incisor crown. CONCLUSIONS. The inclination of the crown of the lateral incisor varies during eruption of the canine, increasing distally until 10 years as a physiological stage in the mixed dentition. The inclination of the lateral incisor is also associated with the mesiodistal position of the canine crown. The mesial intraosseous location of the canine crown results in righting of the lateral incisor.     

Longitudinal study and analysis of clinical supervision of maxillary canine eruption

In 505 Swedish schoolchildren, the need to supervise the eruption of the maxillary canines was assessed by digital palpation and related to occlusal development and somatic maturity. The aim was to judge the extent to which clinical methods should be supplemented with radiographic methods. The 505 children, aged 8-12 yr, were clinically investigated and the eruption was followed over a 3-yr period. The age of the child was found not to be a valid criterion for radiographic investigation of the canine position. The investigation showed that 29% of 10-yr-old children had non-palpable canines bilaterally. In 11-yr-old children, the corresponding figure was 5%. A palpable buccal bulge in the primary canine apical area was found to signify a favorable eruption position. The prevalence of non-palpable or unerupted canines was 3% in the age group 11-15 yr. Indications for radiographic examination of canine position were present in altogether 7% of the children over 10 yr of age according to the clinical diagnostic criteria used.     

Unerupted canine without median diastema

summary The eruption of the canine is known to be a factor for diastema closure. In this study the relative changes in the orientation of the unerupted canine were assessed using the orthopantomographs of 9854 patients who sought consultation between April 1984 and March 1993. A total of 38 canines in 32 patients, all aged 11 years or older, were identified as unerupted canines. The features of the patients with unerupted canine showed no significant relation to diastema closure status, but some patients had unerupted horizontal or inverted canine without diastema even in the absence of a history of orthodontic treatment, suggesting the presence of a mechanical force due to some phenomenon other than canine eruption as a factor in diastema closure.     

Orthodontic screws to extrude impacted maxillary canines

Objective

The impaction of maxillary canines is a frequently encountered clinical problem in orthodontic practice. Patients?? refusal to participate in long-term treatment or ankylosis of the impacted tooth result in various treatment difficulties. The aim of this study was to evaluate the possible role of mini-screws in the management of unerupted upper canines.

Patients and methods

In a series of 63 consecutive patients (27 males and 36 females, age range 14?C49?years, mean 22.7?years) with a total of 69 impacted maxillary canines, each impacted tooth was surgically exposed and an attachment bonded. An intraosseous screw with an endosseous body and intraoral neck section was inserted into the premolar?Cmolar interradicular space. Following soft tissue healing, orthodontic traction was initiated. After correction of the canine angulation, the mini-screw was removed and conventional orthodontic therapy completed.

Results

Of the 69?canines, 61 (88.41%) were extruded successfully. In the 7?cases that failed, skeletal anchorage spared both patients and clinicians the disappointment of customary long-term, unsuccessful orthodontic therapy. In one patient, the mini-screw was removed because of inflammation and pain before initiating orthodontic traction.

Conclusion

Our results demonstrate that mini-screw anchorage should be taken into consideration when extrusion of an impacted canine is planned.     

A treatment difficulty index for unerupted maxillary canines

The aim of this study was to produce a treatment difficulty index (TDI) for unerupted maxillary canines. Thirty treated cases, each with an unerupted unilateral maxillary canine, were graded by 14 consultant orthodontists in terms of perceived alignment difficulty, and the four main factors which had contributed to each grade were listed in order of importance. The relationship between the grade and the contributory factors was then examined using regression analysis, and weightings were derived. These were applied to each factor, in order to derive a difficulty score total for each case. Linear regression analysis of difficulty scores against consultant grades produced an R2 value of 54.7 per cent using the original equation and an R2 of 52.3 per cent using values rounded to the nearest half. Both indicated a moderate level of agreement between allocated difficulty grade and calculated difficulty scores. The index provides a useful treatment planning aid for the management of impacted maxillary canines.