Three-Dimensional Analysis of Impacted Maxillary and Mandibular Canines and Evaluation of Factors Associated With Transmigration on Cone-Beam Computed Tomography Images

Local factors relating to mandibular canine impaction: A retrospective study

INTRODUCTION

This study aimed to investigate the characteristics of impacted and transmigrated mandibular canines and the association existing between them and some local factors, such as degrees of axial inclination of mandibular incisors, skeletal Class, and mandibular symphysis width.

METHODS

A retrospective observational study was performed on the medical records and radiographic examination (panoramic radiographs and lateral cephalograms) of 102 orthodontic patients divided into a study group, with at least 1 impacted mandibular canine (51 subjects) and a control group, without mandibular impaction (51 subjects). A chi-square test, t test, and analysis of variance test analysis were used to analyze the data.

RESULTS

Unilateral and buccal impaction and the presence of the deciduous canine were the more prevalent characteristics of impacted canines, whereas 39.2% presented transmigration. Furthermore, the persistence of the deciduous canine on the impaction side (P <0.0001) and the mesial axial inclination of the impacted canine (P <0.0001) were found to be statistically significant characteristics. A statistically significant association was found between the impaction of the mandibular canine and mandibular incisor to the mandibular plane angle (IMPA) (IMPA, 95.8°; P = 0.009). An additional statistically significant association was found with transmigrated canines (IMPA, 96.8°; P = 0.024).

CONCLUSIONS

The mesialization of the canine cusp and the persistence of the mandibular deciduous canine are characteristics frequently found in the impaction of the mandibular canine. An accentuated vestibular inclination of the mandibular incisors is significantly associated with mandibular canine impaction.

Prevalence, etiology, clinical features and management associated with impacted and transmigrated mandibular canines: a systematic review

BACKGROUND

The occurrence of mandibular canine impaction and/ or transmigration is a rare clinical entity but diagnosis and treatment planning is of clinical significance. The associated etiological factors and the clinical guidelines for the management are still not clear. The aim of this systematic review was to summarize the available data to report the prevalence and identify the etiological factors, clinical features, and various treatment outcomes in patients with mandibular canine impaction and/or transmigration.

METHODS

The review protocol was registered in PROSPERO (CRD42021222566) and was conducted and reported according to the PRISMA and Cochrane Handbook / Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. A computerized search of studies published up to April 30, 2023, was conducted using the following databases: Medline, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and Latin American and Caribbean Health Sciences Literature. A manual search of the reference and citation lists of eligible articles and existing systematic reviews for any additions were also conducted. The Newcastle-Ottawa Scale quality assessment tool was used to assess the studies' quality.

RESULTS

After removing 6 duplicates, 3700 articles were identified. For the final analysis, 19 studies published between 1985 and 2023 met all the eligibility criteria and were included. A total of 7 studies presented as good and 12 studies presented as satisfactory. Patients were screened in ten studies and diagnostic records from archives were retrieved in nine studies. The total number of diagnostic records screened was 138.394, and the total number of patients from the included studies was 43.127.

CONCLUSIONS

Based on the findings from this systematic review, the prevalence of mandibular canine impaction ranged from 0.008% to 1.29% while canine transmigration from 0.12% to 0.98%. Crowding of the mandibular arch, the presence of a retained deciduous canine, and odontoma or cyst are the etiological factors more commonly associated with mandibular canine impaction and or transmigration. Surgical extraction and surgical exposure followed by orthodontic traction are the two most frequently carried out treatment modalities in the management of mandibular canine impaction and or transmigration.

Treatment of Mandibular Impacted Canine in a Patient with Class II Division 1 Malocclusion with "Reverse Pin": A Case Report

This case report presents an orthodontic treatment conducted on a 13-year-old girl with bilateral Class II malocclusion and a mandibular impacted canine. The presence of an impacted tooth necessitates careful consideration of the timing of orthodontic treatment, the appropriate surgical procedure to expose the tooth, the specific orthodontic mechanics involved, and the potential problems that may arise, all of which depend on the type and location of the canine impaction in the jaw. The treatment plan included a surgical procedure to expose the impacted tooth and orthodontic traction to guide it into position. Correction of the Class II Division 1 malocclusion utilized a specialized technique called the "reverse pin", reducing vertical side effects. The revised version maintains clarity and key information about the case report and treatment.

Conservative Treatment of Bilateral Impacted Mandibular Canines Traction

The objectives of the treatment of impacted canines differ according to the characteristics of dental malocclusion. Traction of the tooth is a conservative and viable alternative, which allows for maintaining stability and occlusal function. The following case report describes the treatment of an 11.6-year-old female patient, who presented bilateral impaction of mandibular canines in contact with the midline, mixed dentition in the inter-transitional period, class I angle malocclusion, with light crowding teeth. The treatment comprised three phases. The first phase, verticalization of the mandibular canines in mixed dentition, was performed to pull the impacted bilateral mandibular canines towards the dental arch to achieve their verticalization, maintaining the molar relationship, and the position of the upper and lower incisors. In the second phase, osteogenic rest was planned to relieve post-traction stress while awaiting the replacement of the mixed dentition. Finally, the third phase in permanent dentition was to align and level canines within the arch after extraction of the deciduous canines. For the viability of the permanent mandibular canines in the dental arch, orthosurgical traction was implemented, with a traction system with closed nickel-titanium coil springs with a transitory rigid dental-mucous-supported anchorage device, which allowed control and protection of the adjacent teeth and movements with helical forces of a controlled three-dimensional range. The results of the treatment were adequate, achieving consolidated molar and canine relationships, overjet, overbite, and optimal facial balance.

Orthodontic repositioning of a lingually positioned transmigrated mandibular canine

This case report presents the successful orthodontic repositioning of a transmigrated and lingually positioned mandibular canine with conventional mechanics. Treatment began with the aim of creating space for the four permanent canines that had not yet erupted. Cervical headgear, mesial slice, and extraction of the deciduous teeth were executed, but only the right canines erupted; moreover, the mandibular left canine had become lingually transmigrated. Multibracket therapy was performed with the orthodontic repositioning of both left canines in 2 steps. They were repositioned, and good alignment was obtained. To our knowledge, this is the first case report describing the orthodontic repositioning of a lingually transmigrated canine with conventional double-arch mechanics. This treatment was successful and without significant complications, even though this approach can be challenging and time-consuming.

Dental Transmigration: An Observational Retrospective Study OF52 Mandibular Canines

The aim of this study was to analyze the prevalence of transmigrated canines in a Spanish population by evaluating their clinical and radiological characteristics. The descriptive observational study obtained 6840 orthopantomographs from all patients seeking dental care in the years 2017-21 via the Patient Reception Service and Dentistry Service at the Faculty of Dentistry at the Complutense University of Madrid and the Central Hospital of the Red Cross of Madrid (Spain). In total, 52 patients presented transmigrated canines, establishing a prevalence of 0.76%. This sample comprised 28 women and 24 men. Whenever a transmigrated canine was identified, a CBCT scan was obtained and used to evaluate the clinical and radiological variables associated with canine transmigration. The predominant side of the transmigration was the left (57.69%) compared to the right side (42.30%). The position of the canine, in order of frequency, according to the Mupparapu classification, corresponded to type IV (42.30%), type II (36.53%), type I (15.38%), and type V (5.76%), with no type III transmigrations found. Clinical manifestations were only recorded in 17.30% of cases, and 11.53% of the radiological findings showed the presence of tooth cysts that were confirmed by histopathological studies. Other impactions, in addition to the transmigrated canine, were found in five patients (9.61%), with the majority being the presence of third molars.

Radiographical characteristics and traction duration of impacted maxillary canine requiring surgical exposure and orthodontic traction: a cross-sectional study

This cross-sectional study aimed to classify the radiographical characteristics of impacted maxillary canines that were surgically exposed following orthodontic traction and to find out which factor is most closely related to traction duration. This study enrolled 74 patients with 87 maxillary canines. Cone-beam computed tomography images, panoramic radiographs, and medical records were analyzed. Cystic-appearing lesion and resorption of adjacent roots were observed in 26.4% and 23.0% of cases, respectively. Impacted maxillary canines were mostly distributed in the lateral incisor area. The mean (± standard deviation) traction duration for the 47 teeth that met the study criteria was 13.9 (± 8.9) months. Impacted maxillary canines treated with surgical exposure and orthodontic traction showed increasing possibilities of palatal impaction and resorption of the adjacent root as they were located mesially (p < 0.05). The distance from the occlusal plane to the impacted maxillary canine showed the strongest positive correlation with traction duration (r = 0.519, p < 0.01). When establishing treatment plans for patients with impacted maxillary canines, distance from the occlusal plane to the impacted canines, rather than the angle, should be considered in predicting the duration of treatment.