Two- versus three-dimensional imaging in subjects with unerupted maxillary canines

The aim of this study was to evaluate whether there is any difference in the diagnostic information provided by conventional two-dimensional (2D) images or by three-dimensional (3D) cone beam computed tomography (CBCT) in subjects with unerupted maxillary canines. Twenty-seven patients (17 females and 10 males, mean age 11.8 years) undergoing orthodontic treatment with 39 impacted or retained maxillary canines were included. For each canine, two different digital image sets were obtained: (1) A 2D image set including a panoramic radiograph, a lateral cephalogram, and the available periapical radiographs with different projections and (2) A 3D image set obtained with CBCT. Both sets of images were submitted, in a single-blind randomized order, to eight dentists. A questionnaire was used to assess the position of the canine, the presence of root resorption, the difficulty of the case, treatment choice options, and the quality of the images. Data analysis was performed using the McNemar-Bowker test for paired data, Kappa statistics, and paired t-tests. The findings demonstrated a difference in the localization of the impacted canines between the two techniques, which can be explained by factors affecting the conventional 2D radiographs such as distortion, magnification, and superimposition of anatomical structures situated in different planes of space. The increased precision in the localization of the canines and the improved estimation of the space conditions in the arch obtained with CBCT resulted in a difference in diagnosis and treatment planning towards a more clinically orientated approach.     

Management of unerupted maxillary canines where no orthodontic treatment is planned; a survey of UK consultant opinion

Abstract

Objective: To assess current consultant opinion on the management of impacted maxillary canines in patients for whom no orthodontic treatment is planned.

Design: Questionnaire survey.

Method: Questionnaires were sent to all UK consultant orthodontists identified from the Consultant Orthodontists Group database. Follow-up questionnaires were sent to those who had not replied within 6 weeks. An overall response rate of 76% was achieved.

Results: Most consultants were in favor of intervention, with removal of the unerupted canine, although a significant minority suggested a conservative approach. Of the latter group, nearly all recommended radiographic monitoring, but there was little agreement regarding the frequency and duration of this. The risk of root resorption was stated to be the most important factor justifying monitoring.

Conclusions: Significant variation was found amongst UK consultant orthodontists with regard to the management of impacted canines, where orthodontic treatment was not planned. The clinical and radiographic features, which the respondents stated would influence their decision to remove or leave the canine, were not those that existing research suggests as being the primary risk factors. It is suggested that, once the patient has passed the peak age for initiation of resorption, a more conservative approach may be appropriate.     

Orthodontic treatment of palatally impacted maxillary canines

The aim of this study was to determine the feasibility of treating children with impacted maxillary canines by orthodontic treatment alone. The subjects were 28 children (mean age: 13.5 years, range 11.4-16.1 years) with between them 32 palatally impacted canines. The overlying primary canines were extracted between 0 and 42 months before the start of appliance treatment to open space in the arches for the impacted teeth. No other surgical procedures were carried out prior to the start of appliance treatment. Appliance treatment was deferred for at least six months if an impacted canine was the main reason for treatment, otherwise treatment was commenced according to the needs of the patient. In 94% of the cases, the severity of impaction lessened following extraction of the overlying primary canines and orthodontic treatment. The deepest impactions tended to occur in the oldest children. The majority (75%) of the canines emerged following orthodontic treatment to create space for them in the arch; the remainder were surgically exposed. Appliance treatment tended to take longer in children with the deepest impactions. It is concluded that fixed appliance treatment to create space for a palatally impacted canine is an effective management option for children with impacted maxillary canines.     

Interceptive approach to treatment of impacted maxillary canines

Impaction of maxillary canines can be prevented by early intervention in the mixed dentition phase after the correct diagnosis of malocclusion, reducing the complexity of the treatment. This article reports the case of a 10-year-old patient who possessed impacted maxillary canines and, after early extraction of primary canines, had reestablished favorable permanent successors' eruption axis. This 5-year radiographic follow-up study with panoramic radiography shows that this can be used in practice and that an effective control strategy ensures the accuracy in the inclination of the impacted canines. Treatment success is related to early diagnosis and strategic interceptive treatment choice.     

Impacted permanent maxillary canines: diagnosis and treatment

Palatally impacted permanent maxillary canines are a relatively common dental anomaly of unknown etiology. Early diagnosis of these impactions and subsequent intervention reduce the risk of further complications and may even remedy the impactions. Additionally, several surgical techniques can be used to resolve the impactions when intervention is not sufficient. An understanding of effective diagnosis and treatment of these impactions is imperative to the health and well-being of the teeth and supporting periodontium.     

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 of maxillary canines

Abstract – In 79 of 124 children with bilaterally located widened follicles around non-erupted canines one of the maxillary canines was chosen by lot for surgical exposure of the tooth crown. In seven cases both maxillary canines were exposed. The remaining 38 children were radiographically controlled at certain time intervals as were the 86 cases where surgery was perfomed. The follicles removed from 52 cases were tooth. The histologic examination showed that the histologic appearance of the extirpated follicle did not correspond to the radiolographically verified width of the pericoronal space. The specimens were composed of a losely arranged fibrous connective tissue with an epithelial lining occurring in 77% of the cases. The epithelial lining consisted of reduced enamel epithelium and showed in none of the cases squamous metaplasia or keratinization. Nor was there any clinical or histologic sign of a neoplastic or cystic change of the follicle.