Objectives: To evaluate the reliability and measurement agreement of two smartphone-based facial scanning applications—Qlone (iOS) and Magiscan (Android)—with direct anthropometry following scale factor calibration, and to assess intra- and inter-examiner reliability. Methods: A total of 22 orthodontic patients were enrolled in this prospective study. Nine soft tissue landmarks (midsagittal and bilateral) were marked using 2.5 mm stickers and three vertical and six transverse linear distances were measured using digital vernier calliper (resolution 0.01 mm, accuracy ±0.02 mm) for direct anthropometry and MeshLab software following .obj export and scaling for both applications. Reliability was assessed in 10 randomly selected patients after 15 days. Results: Repeated-measures ANOVA (F-statistic, 2 and 42 degrees of freedom) showed no statistically significant differences between Qlone, Magiscan, and direct anthropometry for 8/9 parameters (p range 0.165–0.988; η 2 p range 0.001–0.082). A statistically significant difference was found for Exo Left–N (p = 0.041; η 2 p = 0.141; mean difference 0.55 mm), not considered clinically significant. Bland–Altman analysis confirmed clinically acceptable agreement (mean bias ⩽ 0.55 mm across all comparisons). Intraclass correlation coefficients (two-way mixed model, absolute agreement) were excellent for all parameters (intra-examiner 0.998–1.000, inter-examiner 0.994–0.999), with relative TEM ⩽ 0.79% and reliability coefficient R ⩾ 0.994. Conclusion: Following scale factor calibration, smartphone-based 3D facial scanning application demonstrate high reliability, precision, and clinically acceptable agreement with direct anthropometry. These applications offer a portable and cost-effective option for facial assessment in orthodontic practice, pending independent accuracy validation using a non-circular reference standard.
Aim: This study aimed to evaluate the potential risk of caries in patients who underwent interproximal enamel reduction (IPER) in the maxillary and mandibular teeth during clear aligner orthodontic treatment. Methods: A total of 344 patients treated with clear aligners were included. Samples were categorised into four groups based on IPER site: maxillary posterior (MxP), maxillary anterior (MxA), mandibular posterior (MdP) and mandibular anterior (MdA). The amount of IPER was classified according to the total reduction performed at each interproximal contact area involving two adjacent tooth surfaces, rather than per individual tooth surface, into four subgroups: (1) 0.1–0.3 mm, (2) 0.4–0.5 mm, (3) 0.6–0.8 mm and (4) 0.9–1.0 mm. Clinical and radiographic caries assessments were performed, and longitudinal data were analysed using Generalised Estimating Equations (GEE) models at the proximal tooth-surface level, with clustering of surfaces within patients taken into account. Results: A total of 4800 proximal surfaces were evaluated, with caries detected on 66 surfaces in 36 patients. Overall incidence remained low across all groups. Site- and amount-related differences were observed in the GEE analysis; however, these findings should be interpreted cautiously because of the low absolute event rate and limited number of carious surfaces. Conclusion: Within this low-risk, highly compliant cohort, IPER up to 1.0 mm (0.5 mm per tooth surface) was associated with a very low observed incidence of caries when combined with proper polishing, oral hygiene and follow-up care. However, this study does not show that IPER increases caries compared with untreated teeth.
Aim: To explore changes in salivary biomarkers and rate of tooth movement during en-masse retraction into recent and healed extraction sites. Methods: A total of 20 patients with prominent anterior maxillary teeth requiring en-masse retraction were randomly allocated into two groups. First premolar extractions were carried out either at the start of orthodontic treatment (healed extraction group) or immediately before the commencement of en-masse retraction (recent extraction group). Unstimulated saliva samples and study models were collected at five time points: before the start of orthodontic treatment; after alignment and levelling; and at 2, 8 and 12 weeks after the initiation of retraction. Changes in concentrations of salivary biomarkers were assessed as primary outcomes. Rate of tooth movement was evaluated as a secondary outcome. A mixed analysis of variance was used to evaluate changes in salivary biomarker concentrations over time and between groups. The rate of tooth movement was compared between groups using an independent t -test. Results: Both groups demonstrated an increase in salivary receptor activator of nuclear factor kappa-B ligand (RANKL) levels and a decrease in osteoprotegerin (OPG) levels during the 12-week retraction period. Significant time and group interaction was observed for the RANKL:OPG ratio ( P < 0.05). Between-group differences at individual time points were not statistically significant after correction for multiple comparisons. A statistically significantly higher rate of tooth movement was found in the recent extraction group (mean difference: 0.07 mm/week, 95% confidence interval 0.04–0.09; P < 0.05), although this difference is probably not clinically significant. Conclusions: The RANKL:OPG ratio may reflect the biological activity during orthodontic tooth movement better than individual biomarker concentrations and extraction timing may influence the rate of space closure. Trial registry: Trial was prospectively registered with the Clinical Trials Registry India ( https://ctri.nic.in/Clinicaltrials ) CTRI/2020/12/029660 and approved by the Institutional Ethics Committee of All India Institute of Medical Sciences, Jodhpur (AIIMS/IEC/2019-20/977), Rajasthan, India.
