Journal of Orthodontics最新文献

The aetiology of impacted canines is multi-factorial. Several theories have been proposed, such as lack of space, genetic predisposition, physical barriers like supernumerary teeth, odontomas and other conditions that interfere with the eruption pathway. One of the main complications that can be generated by impacted canines is the resorption of the root of the adjacent teeth. This case report examines the importance of interdisciplinary management of maxillary incisors with root resorption caused by impacted canines in a 13-year-old male patient. Careful traction of impacted canines and proper tissue management followed by space closure and retroclination of anterior incisors with orthodontic treatment. Finally, functional and aesthetic results using dental veneers for oral rehabilitation allowed the patient to obtain favourable results.

Objective: To compare the stress distribution and total strain applied to the dentition, periodontal ligament (PDL) and cortical and trabecular bones by three Class II correctors using finite element analysis.

Design: Three-dimensional analysis of stresses and total strain of the dentition with three Class II correctors.

Setting: Computational study.

Methods: Three-dimensional finite element models of Class II elastics, the Forsus Fatigue Resistant Device (FRD) and the Carriere Motion Appliance (CMA) were constructed from a cone-beam computed tomography (CBTC) image of an orthodontic Class II patient. The distribution of stress (von Mises and principal stress) and the total strain (mm) in maxillo-mandibular dentition, PDL, cortical and trabecular bone were analysed.

Results: The highest von Mises yield and the maximum principal stress in the three models were found at the teeth, followed by the cortical bone, trabecular bone and PDL. The maximum stress and total deformation were located at the upper canines and lower molars in the Class II elastics and CMA models, in the upper first molars in the Forsus FRD and CMA, and in the lower first premolars in the Forsus FRD. In addition, stress was distributed in the anterior and posterior regions of the teeth, and the total deformation was found in the distal direction in the upper arch and in the mesial direction in the lower arch.

Conclusion: The stress concentrations in the three models were located close to the active components of each appliance, producing specific patterns of stress distribution and displacement that should be taken into account when planning the type of appliance to be used for the correction of the Class II malocclusion.

Objectives: To determine differences in the location of centre of resistance (Cres) between functional and hypofunctional teeth and to evaluate the relationship between the pulp cavity volume and locations of the Cres, using the finite element (FE) method.

Design: Retrospective cohort study.

Participants: FE models of right maxillary central incisor, derived from cone-beam computed tomography (CBCT) images of 46 participants, were divided into normal function (n = 23) and hypofunction (n = 23) groups using anterior overbite and cephalometric measurements.

Methods: Measurements of the tooth and pulp cavity volume were made from the CBCT. Cres levels were presented as percentages of the root length from the root's apex. All data were analysed and compared using the independent t-test (P < 0.05). The relationship between the location of Cres and volume ratios were evaluated statistically.

Results: The means of the pulp cavity/tooth volume and root canal/ root volume ratio of the maxillary central incisor in the anterior open bite group were significantly greater than those in the normal group. The average location of Cres in the anterior open bite group was 0.6 mm (3.7%) apically from the normal group, measured from root apex. The difference was statistically significant (P < 0.01). There was a significant correlation between root canal/root volume ratio and locations of Cres (r = -0.780, P < 0.001).

Conclusions: The Cres in the hypofunctional group was located more apical than the functional group. As the pulp cavity volume increased, the level of Cres shifted apically.

Background: Dental monitoring (DM) constitutes a recent technological advance for the remote monitoring of patients undergoing an orthodontic therapy. Especially in times of health emergency crisis, the possibility of relying on remote monitoring could be particularly useful.

Objectives: To assess the effectiveness of DM in orthodontic care.

Eligibility: Studies conducted on healthy patients undergoing orthodontic care where DM was applied, assessing a change in treatment duration, emergency appointments, in-office visits, orthodontic relapse, early detection of orthodontic emergencies and improvement of oral health status.

Information sources: PubMed, Web of Science and Scopus were searched for publications until November 2022.

Risk of bias: Quality assessment was performed with the STROBE Checklist.

Data extraction: Data were extracted independently by two reviewers, and discrepancies were resolved with a third reviewer.

Included studies: Out of 6887 records screened, 11 studies were included.

Synthesis of results: DM implemented to the standard orthodontic care was found to significantly decrease the number of in-office visits by 1.68-3.5 visits and showed a possible trend towards improvement of aligner fit. Conversely, evidence does not support a reduction of treatment duration and emergency appointments. The assessment of the remaining variables did not allow any qualitative synthesis.

Conclusions: This review highlighted that DM implemented to standard orthodontic care can significantly decrease the number of in-office visits and may potentially result in an improved aligner fit. Due to the low quality of most of the included studies and the heterogeneity of the orthodontic system where DM was applied, studies with different investigation team and rigorous methodology are advocated.

Introduction: This survey was undertaken as a second part to 'Barriers to Post-CCST training in orthodontics: A survey of trainee perceptions'. Recruitment of Post-CCST trainees in certain areas of the country has attracted concerns as it has become increasingly difficult. This survey was undertaken to assess trainee satisfaction with Post-CCST training and to look at possible ways to improve trainee satisfaction and make Post-CCST training more desirable.

Methods: The Training Grades Group (TGG) committee of the British Orthodontic Society (BOS) produced an online survey that was sent to all TGG members and newly qualified consultants in May 2021. All Post-CCSTs who entered training between February 2017 and October 2020, were asked to complete the survey.

Results: There were 37 respondents, which gave a response rate of 62%. While 61% of respondents were satisfied with their Post-CCST training, 17% were 'neither satisfied or dissatisfied' and 6% were either 'dissatisfied' or 'very dissatisfied'. Of the 37 respondents, 25 (67%) would apply for Post-CCST training again, 6 (16%) would not and 6 (16%) did not answer this question. When asked for possible suggestions for improvements to Post-CCST training to encourage greater satisfaction, the responses could be grouped into the following themes: Part-time training; Teaching; Time commitment; Salary; and Experience.

Conclusion: In general, respondents were satisfied with Post-CCST training. There was a significant range of positive and negative responses to various aspects of training including multidisciplinary team clinic preparation, support, supervision and management experience. Suggestions for improvements echo the barriers to Post-CCST training survey.

A 16-year-old female patient presented to the orthodontic department with a 2-week history of painful oral lesions that were affecting her ability to eat. Clinical examination revealed widespread oral ulceration, crusted bleeding from the lips with evidence of a herpes simplex infection in the region of the right buccal commissure. A diagnosis of oral erythema multiforme (EM) was made after a detailed clinical history and examination by the oral and maxillofacial team. Supportive care was provided alongside management with topical corticosteroids. Within 6 weeks of initial presentation, complete resolution of the lesions had occurred and the patient was able to resume active orthodontic treatment.

Introduction: Orthodontic discrepancies are a common finding in patients with supernumerary teeth (ST). The presence of a ST can cause a number of orthodontic discrepancies, including delayed eruption or retention of adjacent teeth, crowding, spacing, and abnormal root formation. The aim of the present study was to assess the effect of extraction of an anterior supernumerary tooth on the underlying orthodontic discrepancies without additional treatment for a 6-month period.

Methods: This was a prospective, longitudinal, observational, study. It included 40 participants with orthodontic malocclusions due to maxillary anterior supernumeraries. We examined the changes in the crowding and excessive space in the anterior and posterior segments on cast models.

Results: In the group that presented with crowding, a statistically significant decrease of 0.95 ± 0.17 mm (P < 0.001) was found between T0 and T1. Of the participants, three exhibited full self-correction. The excessive space at T0 (3.06 mm) decreased by 1.78 ± 0.19 mm to T1 (1.28 mm) in the anterior segment. Seven participants showed full self-correction of the diastemas after the 6-month observation period.

Conclusion: The results imply that orthodontic treatment can be postponed for at least 6 months after the extraction of the supernumerary tooth as potential self-correction can be expected. This natural alleviation of the malocclusions may make the orthodontic treatment simpler, shorten the treatment time and decrease overall appliance wear time.