Prevalence of impacted teeth and supernumerary teeth by radiographic evaluation in three Latin American countries: A cross-sectional 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.

Mixed reality-based technology to visualize and facilitate treatment planning of impacted teeth: Proof of concept

OBJECTIVE

We propose a method utilizing mixed reality (MR) goggles (HoloLens 2, Microsoft) to facilitate impacted canine alignment, as planning the traction direction and force delivery could benefit from 3D data visualization using mixed reality (MR).

METHODS

Cone-beam CT scans featuring isometric resolution and low noise-to-signal ratio were semi-automatically segmented in Inobitec software. The exported 3D mesh (OBJ file) was then optimized for the HoloLens 2. Using the Unreal Engine environment, we developed an application for the HoloLens 2, implementing HoloLens SDK and UX Tools. Adjustable pointers were added for planning attachment placement, traction direction, and point of force application. The visualization was presented to participants of a course on impacted teeth treatment, followed by a 10-question survey addressing potential advantages (5-point scale: 1 = totally agree, 5 = totally disagree).

RESULTS

Out of 38 respondents, 44.7% were orthodontists, 34.2% dentists, 15.8% dental students, and 5.3% dental technicians. Most respondents (44.7%) were between 35 and 44 years old, and only 1 (2.6%) respondent was 55-64 years old. Median answers for six questions were 'totally agree' (25th percentile 1, 75th percentile 2) and for four questions 'agree' (25th percentile 1, 75th percentile 2). No correlation was found between age, profession, and responses.

CONCLUSION

Our method generated substantial interest among clinicians. The initial responses affirm the potential benefits, supporting the continued exploration of MR-based techniques for the treatment of impacted teeth. However, the recommendation for widespread use awaits validation through clinical trials.

General dentists' awareness of orthodontic treatment needs of patients and their referral practices

Background

Since general dentists (GDs) usually act as the primary referral source for the patients in need of orthodontic treatments, having the proper knowledge and understanding of the accurate diagnosis of clinical situations is very important. The aim of this study was to assess GDs about the identification of orthodontic treatment needs and their referral practices.

Materials and Methods

This descriptive and analytical cross-sectional study was carried out in Iran 2020. A questionnaire consisting of three main parts was designed and distributed electronically among GDs. The first section included 11 image and scenario-based questions meant to assess the ability of GDs to correctly diagnose the orthodontic treatment needs of the patients. The next two parts were to assess the dentists' knowledge of the necessity of referral to an orthodontist with 11 questions, and the proper timing of orthodontic treatments with 8 questions. Data were analyzed using SPSS 26, by conducting Mann-Whitney, Kruskal-Wallis, and correlation tests α = 0.05.

Results

Among 384 participated dentists, 50.3% (193) were female. The mean score of knowledge was 17.3 ± 3.5 out of 30. The highest percentage of good knowledge (70% of range) was related to the diagnosis of orthodontic problems, while the lowest one belonged to the referring pattern. There was a weak positive correlation between the working experience and the proper timing of referral (R = 0.15, P = 0.004 (. Kruskal-Wallis test also showed a significant difference between the total knowledge scores (P = 0.04) and the knowledge of the proper timing of treatment (P = 0.04) based on the age groups of participants. Eighty-seven percentage (n = 334) reported that they would refer the patients in need of orthodontic treatment.

Conclusion

The knowledge level of orthodontic treatment needs among GDs was moderate, thus emphasizing the importance of planning more educational courses for them to improve their knowledge, thus reducing the possible detriments of postponed or inaccurate treatments.

Detection and characteristics of the gubernacular tract in supernumerary teeth on cone beam computed tomography

OBJECTIVES

The aim of this study was to evaluate the prevalence and visualization of supernumerary teeth (ST) and imaging characteristics of their gubernacular tract (GT) using cone beam computed tomography (CBCT).

METHODS

Presence and visualization of ST were retrospectively evaluated using 960 CBCT images. The imaging characteristics of GT were analyzed to determine various presentations of GT according to type, shape, and orientation of ST.

RESULTS

ST were radiographically detected in 93 patients, for a prevalence of 9.7%. Premolar shaped ST were more common (p = 0.003). GT was detected in 104 (77.2%) of impacted ST and mostly found straight in shape (49.0%). It was most frequently observed in peridens (n = 51, 49.0%) followed by mesiodens (n = 41, 39.4%) and more frequently seen in premolar-like ST (n = 44, 42.3%). The mean length of the GT in mandible was 2.8 mm, the mean length of the GT in maxilla was 1.0 mm (p < 0.001). The mean angle of the GT in mandible was 17.0, and the mean angle of the GT in maxilla was 43.0 (p = 0.004).

CONCLUSIONS

CBCT can be used for evaluations in dental practice to provide comprehensive information about ST and their GT characteristics. Clinicians should be able to identify the characteristics of GTs on CBCT for dental treatments, especially traction and extraction of ST.