Cone-beam computed tomography evaluation of impacted and transmigrated mandibular canines: a retrospective study

Association of mandibular canine impaction and anatomical factors: A multicentre retrospective panoramic study in Latin America

INTRODUCTION

Mandibular canine impaction is infrequent in dental eruption anomalies and treatment is very challenging. The aim of this multicenter retrospective panoramic study in Latin America was to evaluate panoramic radiographic imaging characteristics of mandibular canine impaction (impaction area, mandibular base contact, transmigration, impaction height and sex) and their associations.

MATERIAL AND METHODS

This cross-sectional study evaluated 212 digital panoramic radiographs from three radiological centres in Tingo Maria (Peru), Bogota and Tunja (Colombia). The study included children of both sexes with impacted mandibular canines. Mandibular alpha angle, contact with mandibular basal bone (MBB), impacted sector according to 10 sectors with an adaptation of the Ericson and Kurol method, presence of transmigration and the impacted height were measured and the relationship among these measures was analyzed. Fisher's exact test, Chi-square and binary logistic regression were used. (P<0.05).

RESULTS

The mandibular canine impaction showed contact with the MBB (32.08%), dental transmigration (36.79%), mainly located at an apical (40.09%) and sub-apical (36.79%) level. Transmigration mainly occurred in sectors 6 (33.30%) and 10 (25.60%) (P<0.001). It was found that for each year of increase in age, the possibility of contact with the MBB decreased (β=0.89, P=0.010), and as the alpha angle increased by one degree the probability of contact with the MBB decreased (β=0.97, P=0.001) and the probability of transmigration increased (β=1.05, P<0.001).

CONCLUSIONS

One third of the impacted canines were in contact with the MBB, while another third presented dental transmigration and were mainly located apically and subapically of the incisor roots. These imaging features should be taken into account when planning orthodontic treatment.

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.

Evaluation of children's oral diagnosis and treatment using imaging examination using AI based Internet of Things

BACKGROUND

Although cone beam computed tomography (CBCT) plays an important role in the diagnosis and treatment of oral diseases, its image segmentation method needs to be further improved, and there are still objections about the clinical application effect of general anesthesia (GA) on children's dental fear (CDF).

OBJECTIVE

This study aimed to investigate the application value of CBCT based on intelligent computer segmentation model in oral diagnosis and treatment of children in the context of biomedical signals, and to analyze the alleviating effect of GA on CDF.

METHODS

Based on the regional level set (CV) algorithm, the local binary fitting (LBF) model was introduced to optimize it, and the tooth CBCT image segmentation model CV-LBF was established to compare the segmentation accuracy (SA), maximum symmetric surface distance (MSSD), average symmetric surface distance (ASSD), over segmentation rate (OR), and under segmentation rate (UR) between these model and other algorithms. 82 children with CDF were divided into general anesthesia group (GAG) (n= 38) and controls (n= 44) according to the voluntary principle of their families. Children in GAG were treated with GA and controls with protective fixed intervention. Children's fear survey schedule-dental subscale (CFSS-DS) and Venham scores were counted before intervention in the two groups. CFSS-DS scores were recorded at 2 hours after intervention and after recovery in children in GAG. CFSS-DS and Venham scores were performed in all children 1 week after surgery.

RESULTS

The results showed that the S⁢A value of CV-LBF algorithm was higher than that of region growing algorithm (P< 0.05). OR, UR, MSSD, and ASSD values of CV-LBF algorithm were evidently lower than those of other algorithms (P< 0.05). CFSS-DS scores were lower in GAG than in controls 2 hours after intervention and at return visits after 1 week of intervention (P< 0.001), and Venham scores were lower in GAG than in controls after intervention (P< 0.001). After intervention, the proportion of children with Venham grade 0, 1, 2, and 3 was obviously higher in GAG than in controls (P< 0.001), while the proportion of children with Venham grade 4 and 5 was clearly higher in controls than in GAG (P< 0.001).

CONCLUSION

The results revealed that the computer intelligent segmentation model CV-LBF has potential application value in CBCT image segmentation of children's teeth, and GA can effectively alleviate anxiety of children with CDF and can be used as biomedical signals.

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.

The findings of impacted and transmigrated maxillary and mandibular canines: a retrospective cone beam computed tomography study

BACKGROUND

The aim of this study was to examine and evaluate the maxillary and mandibular impacted and transmigrant canines, their relationship with neighboring tissues and pathology with cone beam computed tomography (CBCT).

METHODS

CBCT data of 217 patients, between January 2018 and December 2019, with a total of 293 impacted canines were retrospectively reviewed. Clinical records were also evaluated. Maxillary or mandibular localization, angulations, transmigration, lateral and premolar tooth resorption, apical dilacerations, pathological formations, presence of persistent deciduous canines and treatment methods were investigated.

RESULTS

For 293 impacted canines, 237 were in the maxilla and 56 in the mandible, with this difference being statistically significant (P<0.05). Among the 293 impacted canines, 14 (4.8%) transmigrated canines were detected. From the 14 transmigrant canines, 13 were in the mandible and 1 was in the maxilla. This difference was found statistically significant (P<0.05). Eighteen dentigerous cysts (10 maxilla, 8 mandible) and 4 odontomas (3 maxilla, 1 mandible) were found in impacted canines. For a total of 293 impacted canines, 57 were extracted, 13 were referred to orthodontics and a follow-up decision was made for 223 teeth.

CONCLUSIONS

Transmigration incidence is statistically significant, on a higher area of the lower jaw, compared to the upper jaw (P<0.05). In patients with impacted canines, taking CBCT together with a detailed clinical examination is effective in correct treatment planning and in minimizing complications that may occur during surgical extraction.

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 implant placement in the area of ectopic and impacted teeth]

The paper presents two clinical cases demonstrating the effectiveness of using surgical templates for the installation of dental implants in the areas of ectopic and impacted teeth in case of patient's disagreement on their removal or other methods of treatment.

Craniofacial Fibrous Dysplasia Involvements of Mccune-Albright Syndrome: A Review with an Additional Case

BACKGROUND

McCune-Albright Syndrome (MAS) is a genetic disorder with a triad of endocrine diseases, café-au-lait macules and fibrous dysplasias. Craniofacial fibrous dysplasia is a term that is used to describe the fibrous dysplasia, which was localized at the craniofacial skeleton and is common in MAS patients.

OBJECTIVE

The objective of this review is to determine the involvement frequency of cranial and facial bones in patients with MAS and CFD.

METHODS

Articles in PubMed was searched with the following details "(mccune[Title/Abstract] OR albright[Title/Abstract]) OR ("craniofacial fibrous dysplasia"[MeSH Terms] OR ("craniofacial"[ All Fields] AND "fibrous"[All Fields] AND "dysplasia"[All Fields]) OR "craniofacial fibrous dysplasia"[All Fields])". The articles in which the authors did not state the involved bones or did not add any radiographic images were excluded from the study.

RESULTS

26 cases in 25 articles met the inclusion criteria. Among the 26 cases and our case, sphenoid and frontal bones were involved in 17 cases, parietal and occipital bones were involved in 15 cases, mandible and ethmoid bone were involved in 14 cases, maxilla-zygoma-temporal and palate was involved in 13, 11, 6 and 3 cases, respectively. Palate was involved in cases where maxilla was also involved. Our case was the only case that was evaluated with CBCT.

CONCLUSION

Routine follow-ups are important since new CFDs can occur in different cranial or facial bones. 2D imaging techniques may not be able to demonstrate early CFDs; thus, an advanced imaging technique should be used after MAS diagnosis.