Journal of Orthodontics最新文献

Patients with hypodontia often undergo orthodontic treatment, with single tooth pontics often used to replace missing teeth. However, single tooth pontics can often rotate on the archwire, leading to compromised stability. 'Blocks of pontics' can provide prosthetic replacement during orthodontic treatment for hypodontia patients, overcoming common issues with large edentulous spans. After impression taking, blocks of pontics can be waxed up and finished in acrylic, and can then be ligated to the archwire intraorally. Blocks of pontics can be life-changing, restoring adequate aesthetics and function, before multidisciplinary restorative management.

Objective: To investigate the impact of appliance removal on oral microbial diversity, composition, and abundance using metagenomic sequencing. It aims to identify the core microbiome and assess changes between mid-treatment and 2 weeks after debonding to better understand the relationship between orthodontic therapy and oral health.

Methods: This longitudinal cohort study recruited 26 patients undergoing fixed orthodontic treatment between January 2022 and June 2023. Saliva samples were collected at two predefined time points: mid-treatment (T0, defined as before appliance removal) and 2 weeks after debonding (T1). Microbial DNA was extracted and the V1-V3 hypervariable regions of the 16S rRNA gene were sequenced using Illumina NovaSeq. Bioinformatics analysis was performed using QIIME and the SILVA database to evaluate microbial diversity and composition at T0 and T1. Beta diversity metrics and statistical tests, including PERMANOVA and Wilcoxon signed-rank tests, were applied to identify significant differences (P < 0.05). Effect sizes with 95% confidence intervals (CIs) were reported.

Results: The analysis revealed significant shifts in microbial diversity and composition between T0 and T1. A total of 189 species across 63 genera were identified, with Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Fusobacteria as dominant phyla. Genera such as Fusobacterium periodonticum (↑ 12.4%, 95% CI = 10.1-14.7) and Veillonella parvula (↑ 9.8%, 95% CI = 7.6-11.3) increased after debonding, while Prevotella melaninogenica (↓ 10.2%, 95% CI = 8.1-12.0) and Rothia dentocariosa (↓ 7.9%, 95% CI = 6.3-9.2) decreased. Beta diversity analysis confirmed a statistically significant microbial community shift (P < 0.05).

Conclusion: This study demonstrated significant microbial shifts between mid-treatment and 2 weeks after debonding, including increases in potentially pathogenic genera and alterations in the core microbiome. These findings indicate microbial changes persist for at least 2 weeks after appliance removal. Further research with pre-treatment baselines and extended follow-up is required to better define the long-term trajectory of these changes.

Objective: To compare the quality of orthodontic clinical photographs taken with a mirrorless camera and a smartphone compared with those taken with a digital single lens reflex (DSLR) camera.

Methods: This cross-sectional study involved six participants (models), each of whom had five extra-oral and five intra-oral photographs taken using a DSLR (Canon 70D), a mirrorless camera (Canon RP) and a smartphone (iPhone 14 Pro), resulting in a total of 180 photographs. Four orthodontists served as assessors, evaluating the quality of each photograph based on image clarity, colour accuracy and lighting. They categorised the photographs as 'good' (no errors), 'acceptable' (some errors) or 'unacceptable', while also noting any specific errors observed. Statistical analysis was conducted using Fisher's exact test and Pearson's chi-square test. All statistical tests were interpreted at a significance level of 5%.

Results: Compared to the DSLR camera, the photographs taken with the mirrorless camera were of identical quality, with 100% of photographs rated as good for each camera. For the smartphone camera, 41.7% were assessed as good and 58.3% as acceptable, which was significantly less (P < 0.001) than for the DSLR (100% good). For smartphone intra-oral photographs, the majority of 'upper occlusal' and 'lower occlusal' photographs were classified as 'good' (62.5%), while the remaining 37.5% were rated as 'acceptable'. In contrast, for 'right buccal' and 'left buccal' photographs, the majority of photographs (87.5%) were categorised as 'acceptable', with only 12.5% rated as 'good'.

Conclusion: In conclusion, although DSLR and mirrorless cameras consistently produce high-quality orthodontic photographs suitable for all clinical and professional purposes, smartphone cameras fall short in photographic quality. Given their lower resolution and pixel count, smartphone-captured photographs may be adequate for clinical records but are not recommended for large-format applications.

Ectopic eruption of the first permanent molar is prevalent in children, with a reported prevalence of up to 6%. Treatment options usually range from passive observation to active correction with orthodontic appliances like separators or distalising devices. This study outlines the step-by-step procedure for creating a 'pistol spring' system, which delivers a consistent, sustained force, reducing the need for frequent reactivation. The system is easy to fabricate, well-tolerated and enhances treatment efficiency, improving patient compliance and reducing chair-side time. The 'pistol spring' offers a cost-effective, time-efficient solution for managing ectopic first molars, particularly in paediatric patients with limited appointment availability.

Objective: To develop a protocol for locating the Xi point using three-dimensional (3D) cone-beam computed tomography (CBCT) and to evaluate the linear distance between the Xi point and the mandibular foramen on the CBCT image.

Study design: A retrospective cross-sectional study.

Study setting: The study was conducted on standardised CBCT records of 35 patients aged >18 years (13 men, 22 women). The CBCT scans were analysed using Dolphin 3D 11.9 software.

Methods: The Xi point was constructed on the right and left lateral views of the ramus using the four points R1, R2, R3 and R4 based on Ricketts' analysis. The mandibular foramina were located on CBCT and the linear distance from the mandibular foramen to the Xi points were recorded.

Results: The 3D Xi point was located on the lateral surface of the mandibular ramus superior and distal to mandibular foramen. The mean distance of the Xi point from the mandibular foramen was 2.3 ± 1.46 mm on right side and 2.3 ± 1.53 mm on left side.

Conclusion: The study identified the accuracy of Xi point construction and its linear relation to the mandibular foramen. Xi point validation in relation to the mandibular foramen serves as a guide for inferior alveolar nerve course identification. The results of the study also find applications in bone screw placement and growth prediction.

Objective: To examine the palatal bone thickness in a cohort of Portuguese patients representing various age groups to identify optimal insertion sites for enhancing the stability of orthodontic micro implants (MIs). To ascertain whether there are any age- or sex-related variations in palatal bone thickness.

Design: Retrospective observational study.

Method: A total of 50 cone-beam computed tomography (CBCT) scans of patients aged 12-51 years (23 boys/men and 27 girls/women) were analysed. The CBCT scans were grouped according to age and sex. The palatal bone thickness was measured at five points: 4, 8, 12, 16 and 20 mm posterior to the incisive foramen (IF) and at 3, 6 and 9 mm lateral to the midpalatal suture (MPS). A total of 750 regions of interest were evaluated (15 for each of 50 patients). Two-way analysis of variance (ANOVA) and Student's t-tests were employed for data analysis, with a significance level of P < 0.05.

Results: The greatest thickness of palatal bone was found to be at 4 mm posterior to the ІF and 9 mm lateral to the MPS in all investigated groups, with a mean thickness of 12.29 ± 2.00 mm for girls/women and 13.59 ± 2.31 mm for boys/men; 13.30 ± 2.38 mm for adolescents and young adults, and 12.27 ± 2.03 mm for adults. Significant statistical differences were identified between male and female individuals and between different age groups (ANOVA, P < 0.05).

Conclusion: Palatal bone thickness varied with sex and age; thus, these factors must be considered when selecting the appropriate length of MIs. In general, girls/women had a thinner palatal bone than boys/men. The palatal bone was significantly thicker in the adolescent and young adult age group (12-25 years) than in the adult age group (27-51 years). In addition, bone thickness decreased posteriorly within each sagittal section.

Objectives: To establish how orthodontics is currently co-delivered by orthodontic therapists (OTs) and supervising clinicians (SCs), and to explore both sets of clinicians' perceptions of these working arrangements.

Design and setting: Cross-sectional survey using an online questionnaire.

Participants: General Dental Council (GDC)-registered OTs and specialist or non-specialist dentists who supervise OTs and work in the UK.

Methods: A link to the online questionnaire was emailed to all members of the British Orthodontic Society and Orthodontic National Group and was posted in two Facebook groups. Reminder emails and Facebook posts were sent.

Results: A total of 161 responses were received from 89 SCs and 72 OTs. Most worked in primary care as their main clinical role. Most OTs in primary care provided a mix of NHS and private care. Appointments with OTs were most likely to be supervised every other visit, with more frequent supervision reported by SCs, and by clinicians in secondary care. Remote supervision of some kind was reported by 63% of OTs. Different barriers and enablers to effective working practices were suggested by OTs and SCs. OTs reported improved patient satisfaction as the main consequence of their utilisation in the orthodontic workforce while SCs described improved clinical efficiency.

Conclusions: OTs reported improved patient satisfaction as the main consequence of their utilisation, whereas SCs described improved clinical efficiency. Some OTs felt that SCs should be more readily available and that OTs should have more autonomy. SCs would prefer more time to supervise and provide prescriptions.