Purpose This study aimed to investigate the relationship between posterior occlusal plane (POP) inclination and three-dimensional (3D) facial morphology at rest and when smiling.Materials and methods Twenty orthodontic females patients (mean age, 22.5 years) were included in this study. On lateral cephalograms, POP was defined as the line connecting the midpoint between the bimaxillary second molars and that between the second premolars, calculated from their mesiodistal segments. The angle between the POP and the Frankfort horizontal (FH) plane was defined as the POP angle. Three-dimensional facial images were captured at rest and when smiling. The coordinates of the upper and lower lip points were measured. The surface area and volume of the lips were then calculated. Pearson’s correlation coefficients were used to assess the relationship between the POP angle and each variable.Results Larger POP angles tended to exhibit a more posteriorly positioned lower lip and labiomentale, and a more medially and posteriorly positioned cheilion at rest and when smiling. The POP angle showed a significantly negative correlation with the volumes of the upper and lower lips.Conclusion In resting and smiling conditions, a larger POP angle was associated with medial and posterior displacement of the bilateral oral commissures, as well as posterior positioning of the lower lip and small lip volume.
Purpose Accurate growth assessment in orthodontics requires three-dimensional (3D) methodologies. However, studies using cone-beam computed tomography (CBCT) for long-term, longitudinal 3D growth assessments remain scarce. Furthermore, few studies have utilized 3D registration based on planes traditionally used in two-dimensional (2D) cephalography, such as the Sella (S)-Nasion (N) and Basion (Ba)-N planes. This study aimed to develop a 3D registration method using the pterygoid point (PT) and Dorsum Sellae (DS) from the onset to the completion of growth.Materials and methods 12 skeletal Class I patients (6 males, 6 females) treated at Nezu Orthodontic Clinic from 2002 to 2022 were included. CBCT scans were performed at four intervals from the initial consultation to the end of treatment, classified as T1–T4. Seven measurement points (Nasion[N], anterior nasal spine [ANS], pogonion [Pog], bilateral PTs, and bilateral dorsum sellae [DSs]) were identified. PT-based and DS-based registration methods were utilized for qualitative and quantitative assessments.Results Qualitative analysis revealed PT-based registration demonstrated anteroinferior movement of the maxilla and mandible, while DS-based registration showed downward movement. Quantitatively, movement tendencies for N, ANS, and Pog were highly consistent with no significant differences across all axes and periods. Localized significant differences in 3D cumulative magnitudes were limited to only two specific landmarks.Conclusion PT-based and DS-based registrations allowed effective superimposition for evaluating 3D growth. Differences in movement trends suggest cranial base registration points facilitate quantitative assessment of growth-related changes over time.
Purpose This in vitro study evaluated the antimicrobial efficacy of different cleaning solutions used for orthodontic clear aligners.Methods Eighty-four specimens were prepared from unused orthodontic clear aligners and randomly allocated to five experimental (alcohol, toothpaste, mouthwash, detergent, and effervescent disinfectant crystals) and two control groups (sterility and biofilm growth). After contamination with Streptococcus mutans, Lactobacillus casei, and Candida albicans, the samples were treated during 5-day protocol. Microbial growth (CFU/mL), culture medium pH, and volumetric surface roughness (Sa) were statistically analysed using Kruskal-Wallis and Mann-Whitney tests (α = 0.05).Results Mouthwash showed a significantly lower bacterial growth (9.01 ± 8.18 × 106 CFU/mL), lower pH ~ 5.5 at 48 h, and Sa = 9.01 ± 8.18 µm. In contrast, alcohol showed highest microbial load (15.94 ± 12.95 × 106 CFU/mL), in a more acidic environment (pH 4.5 at 96 h), and Sa = 15.94 ± 12.95 µm. Toothpaste, detergent, and crystals showed statistically similar and moderate antimicrobial efficacy (10.83 ± 6.74 < CFU/mL < 13.03 ± 7.78 × 106). Sterility control showed no microbial growth (CFU = 0; Sa = 4.80 ± 1.76 µm), while the growth control exhibited the highest biofilm formation (7.4 × 109 CFU/mL, p < 0.005) and degradation (Sa = 42.37 ± 28.08 µm).Conclusions Transparent night-time mouthwash was the most effective cleaning solution. Alcohol was associated to increased bacterial accumulation and surface degradation. Detergent, toothpaste, and effervescent disinfectant crystals showed comparable efficacy and may serve as accessible alternatives, with neutral detergent standing out as a cost-effective daily solution.
Purpose To evaluate the effects of fixed and removable habit-breaking appliances on overbite correction in tongue-thrust-associated anterior open bites.Methods Searches were conducted in MEDLINE, Embase, CENTRAL, Scopus, Web of Science, and grey literature up to December 2025. Randomized and non-randomized controlled studies involving children and adolescents with tongue-thrust-associated anterior open bites were included. The interventions included fixed and removable habit-breaking appliances. The primary outcome was overbite change. Subgroup analyses were used to assess appliance type, age, stability, and spontaneous changes. The risk of bias was evaluated using RoB 2 and ROBINS-I, and the evidence certainty was evaluated using GRADE. Random-effects meta-analyses were performed, as appropriate.Results Eleven studies were included in this meta-analysis. The pooled analysis suggested greater overbite improvement with habit-breaking appliance therapy compared with untreated controls. Fixed and removable appliances showed comparable effects, with no significant differences between the types. Greater effects were observed in younger patients. Overbite correction was maintained during follow-up, whereas the untreated controls demonstrated spontaneous growth-related improvement. The overall evidence certainty was very low.Conclusion Habit-breaking appliances may improve overbite in patients with tongue thrust–associated anterior open bite; however, the certainty of the available evidence is very low, and the findings should be interpreted cautiously.
Purpose Malocclusion affects oral function and systemic health; however, its integrated mechanisms remain unclear. Further, previous studies have focused on anteroposterior discrepancies, and the systemic significance of lateral dentofacial abnormalities is unclear. Thus, we aimed to evaluate the relationships between dentofacial morphology and psychosomatic function in patients with malocclusion and identify factors associated with gastro-oesophageal reflux disease (GERD).Materials and methods This multicentre cross-sectional study was conducted across five Japanese universities in accordance with the Declaration of Helsinki and STROBE guidelines. Consecutive patients aged 11–65 years scheduled to initiate comprehensive orthodontic treatment with multibracket appliances between January 2023 and May 2025 were enrolled (n = 287). Psychological status, physical and oral function, general and oral health–related quality of life (QOL), and dentofacial morphology using lateral and posteroanterior cephalograms were compared between patients with and without GERD, defined as FSSG-positive GERD (FSSG score ≥ 8). Intergroup comparisons and multivariable logistic regression analyses were performed with adjustments for age and sex.Results The prevalence of FSSG-positive GERD was 33.5%. The GERD group was significantly older with greater mandibular lateral deviation, higher anxiety and daytime sleepiness, and poorer oral health–related QoL. Multivariate analysis identified mandibular lateral deviation (odds ratio [OR] 2.69, 95% confidence interval [CI] 1.36–5.35) and oral health–related QoL (OR 2.08, 95% CI 1.19–3.64) as independent factors associated with GERD.Conclusion Mandibular lateral deviation and impaired oral health–related QoL were independently associated with GERD, suggesting a close relationship between lateral dentofacial abnormalities and systemic function.
Purpose Recent evidence highlights a bidirectional relationship between oral function and systemic metabolic diseases, particularly type 2 diabetes mellitus. Although orthodontics has traditionally emphasized craniofacial aesthetics and functional occlusion, basic research increasingly links masticatory function to neuroendocrine and metabolic homoeostasis. The primary purpose of this comprehensive review is to clarify the impacts of high-fat diet (HFD) exposure and masticatory dysfunction – induced by bilateral maxillary molar extraction (BMME) – on the stomatognathic and gastrointestinal systems.Materials and methods To address this objective, we synthesized recent basic research findings from murine models, focusing on transgenerational HFD exposure, experimental T2DM models, and occlusal loss.Results Transgenerational high-fat diet exposure alters craniofacial morphology, including increased total skull length in males, and programmes high-salt taste preference through angiotensin II receptor type 1 upregulation. Type 2 diabetes mellitus is associated with time-dependent purinergic receptor upregulation and incretin receptor downregulation in submandibular glands. The combined effects of occlusal loss and type 2 diabetes mellitus further downregulate incretin receptors in the submandibular glands and reduce gastric ghrelin expression with mucosal hypertrophy.Conclusion Supported by quantitative and human epidemiological evidence, this review suggests that stable occlusion through orthodontic and prosthodontic interventions may support systemic metabolic management.
Background and Aim Estimation of skeletal maturity is essential for orthodontic treatment planning and time of intervention. Spheno Occipital Synchondrosis (SOS) plays an important role in cranial base growth and during adolescence it plays a cardinal role in the ontogeny of the human skull. The study was aimed at correlating the fusion stages of SOS with the Middle Phalanx of the Third Finger (MP3), Cervical Vertebral Maturation staging (CVMI) and chronological age in the Dravidian population.Materials and Methods Records of 80 subjects (males 34, females 46) in the age range of 10–16 years were examined. These consisted of Full Skull CBCT and Radiovisiography (RVG) images of the MP3 of either hand, taken not more than a month apart as a part of orthodontic diagnostic records. SOS and CVMI were scored from CBCTs and MP3 staging from RVG images. Statistical analysis was done using SPSS software, Spearman’s correlation test was done.Results The correlation of MP3 and SOS staging was strong (r = 0.88). Similarly, a moderate correlation was observed between SOS staging and chronological age (r = 0.59 overall, r = 0.57 for females and r = 0.54 for males). Also, correlation of CVMI with SOS was high (r = 0.78) (p < 0.01).Conclusion Skeletal maturity in the Dravidian population can be assessed using SOS fusion staging as it correlates well with both MP3 and CVMI staging.
Objective To systematically review studies assessing the variations in levels of different biomarkers in saliva involved in bone remodelling during Orthodontic tooth movement (OTM).Search Methods A comprehensive search of databases for studies from January 2003 up to April 2025 and a revised search for studies from January 2001 to June 2025, including PubMed, Web of Science, Scopus, and Google Scholar, was conducted, limited to the English language.Selection Criteria Observational studies aligning with the PECO question were included, and their risk of bias was assessed using the Revised JBI tool for cohort studies.Data Collection and Analysis Data were collected using Covidence software, and a meta-analysis was conducted with a random-effects model and Standardized Mean Difference (SMD) by STATA 19.5 software. The primary outcome was changes in the levels of salivary biomarkers during different phases of OTM.Results Twenty-five studies were reviewed, and fourteen were included in the meta-analysis. Although many studies had a low overall risk of bias, concerns remained regarding confounding factors, classification of exposure and statistical analysis. Timepoints were grouped into baseline, initial phase, lag phase and post-lag phase to standardize comparisons. The certainty of evidence from these results is very low. IL-1β, TNF-α and PGE2 showed an early transient rise, peaking during the initial phase before declining, with inconsistent long-term changes. Bone remodelling markers showed phase-specific changes during OTM with considerable clinical and methodological heterogeneity.Conclusions MMP-8, MMP-9 and Myeloperoxidase showed statistically significant increases between baseline and initial phase, but the certainty of evidence is very low, with limited clinical applicability of these findings.PROSPERO CRD420251012590
Introduction & Aim Attachments are used in clear aligner therapy (CAT) to improve efficiency of tooth movement. This study was done to assess the surface wear and adhesive failure of conventional and optimized attachments used in CAT.Materials & Methods This prospective study recruited 13 participants with 211 resin attachments. Seventy-five teeth with conventional attachments (3 mm, 4 mm rectangular, ellipsoid) and 136 teeth with optimized attachments were scanned with iTero scanner. Meshmixer 3.5 was used to superimpose teeth bearing attachments initially (T1) with 3 month follow up scans (T2) based on best-fit registration. Deviation incidences were recorded. Adhesive failure of the attachments was also evaluated among the attachments.Statistical Analysis Shapiro-Wilk normality test, the Intraclass Correlation Coefficient (ICC), and Mann-Whitney test were employed.Conclusion Both attachment types showed no significant difference in wear after 3 months of CAT. A higher frequency of adhesive failure was observed in conventional attachments and in the upper molar region. However, given the observational study design, limited sample size and limitations pertaining to unit-of-analysis, these findings should be considered preliminary. The clinical significance of the observed wear patterns remains uncertain since treatment outcomes were not directly assessed.Results Deviations between samples were computed at 0.1 mm to 0.4 mm levels and revealed that both attachment types experienced similar amounts of wear after 3 months of aligner therapy. A higher frequency of adhesive failure was observed in conventional attachments and in the upper molar region. Surface wear was most frequently observed in upper anterior attachments.
Purpose: The study aims to compare the changes in nasolabial fold appearance after four first bicuspid extractions in female patients above and below 30 years. Materials and methods: The study evaluated retrospective photographs of 47 female patients, divided into two: Group A (<30 years) and Group B (>30 years). All participants underwent extraction of all four first bicuspids as a part of their orthodontic management. Standardized pre-treatment and post-treatment extraoral photographs were evaluated by seven calibrated orthodontists using the Modified Fitzpatrick Wrinkle Scale (MFWS), Wrinkle Severity Assessment Scale (WSRS) and Global Aesthetic Improvement Scales (GAIS). The Wilcoxon signed-rank test was used to compare pre-trey atment and post-treatment MFWS and WSRS scores within each age group. The Mann-Whitney U test was applied to compare the scores between the groups. One way Analusis of Covariance (ANCOVA) and ordinal logistic regression was used to analyse the impact of age on the GAIS scores. Results: Group A showed minimal, non-significant change in the NLF severity (MFWS change: +0.036, p = 0.403; WSRS change: +0.146, p = 0.332). Group B demonstrated significant improvement in NLF appearance (MFWS change: -0.457, p < 0.001; WSRS change: -0.761, p < 0.001). About 83% of Group B showed aesthetic improvement compared to 50% in Group A. Ordinal logistic regression indicated that Group B patients were approximately five times more likely to show improved or stable NLF appearance (OR = 5.04). Conclusion: Significant age-related differences exist in NLF response to extraction therapy. Older adult females (>30 years) with bidental proclination are more likely to experience improvement in NLF appearance following four first bicuspid extractions compared to younger adults.
Purpose This study evaluated how facial height affects perceptions of mandibular asymmetry in individuals with short and long faces, as viewed by three groups of raters. Materials and methodsLong-face and short-face models were selected based on the facial index. Symmetrical frontal-view photographs of the models were altered with mandibular rotations of 0-6 degrees. Seventy laypeople, 24 orthodontists, and 24 oral and maxillofacial surgeons rated the images for aesthetics using a 0-100 visual analogue scale (VAS) and assessed treatment needs. Data were analysed using ANOVA, LSD, Tukey's HSD and Spearman correlation, with a significance set at p < 0.05. ResultsThe treatment need threshold for the long-face model was identified at 4, 4 and 5 degrees by orthodontists, surgeons and laypeople, respectively. In contrast, for the short-face model, it was 6 degrees according to orthodontists and surgeons; laypeople did not perceive a need for treatment even at 6 degrees. All groups detected 1-degree rotations in the long-face model. Still, in the short-face model, laypeople and orthodontists noticed 1-degree rotations, while surgeons did not show significant differences for 0-, 1- and 2-degree rotations but were better at detecting higher degrees. ConclusionAll raters identified a 1-degree detection threshold for mandibular rotation in the long-face model. In the short-face model, orthodontists and laypeople noted 1 degree, while surgeons noticed 3 degrees. The long-face model needed treatment for a lower degree of rotation based on all three rater groups. Specialists generally require lower degrees of asymmetry to determine treatment needs compared to laypeople.
BackgroundTo develop and internally validate a clinically applicable risk-prediction model for estimating the progression of mandibular anterior crowding in mixed dentition.Materials and methodsThis prospective longitudinal study included 450 children aged 7-9 years, followed by approximately four years. Mandibular anterior crowding progression was defined as an increase of >= 2 mm in the Little's Irregularity Index. Twelve dental, cephalometric, and soft tissue variables were evaluated. Penalized logistic regression (LASSO) was used for model development, and a simplified clinical scoring system was derived. Model performance was assessed using discrimination, calibration, and internal bootstrap validations.ResultsCrowding progression was observed in 36% of the participants. Six predictors are retained in the final model. The model demonstrated a good discriminative ability (AUC = 0.87) and satisfactory calibration. The derived scoring system showed a reliable diagnostic performance with minimal optimism after internal validation.ConclusionMandibular anterior crowding progression is influenced by a combination of spatial, dentofacial, and soft tissue factors. The proposed scoring system provides a practical tool for early risk stratification; however, external validation is required before its routine clinical application.
Purpose To synthesize the comparative effects of mini-implant assisted rapid palatal expansion (MARPE) and surgically assisted rapid palatal expansion (SARPE) on upper airway, skeletal, and dentoalveolar dimensions in patients with maxillary transverse deficiency, and to assess certainty of evidence for each outcome using GRADE approach.Materials and methods A hybrid evidence synthesis was undertaken, combining a FRISBEE-based overview of systematic reviews with a de novo random-effects meta-analysis of primary studies identified from those reviews. Analyses were done in RevMan Web, and certainty of evidence was assessed with GRADEpro. Prespecified outcomes were anterior nasal width, posterior nasal width, upper first molar inter-cusp distance, posterior maxillary basal width, and posterior nasal floor width.Results Two systematic reviews comprising three primary studies (84 participants) were included. Certainty of evidence was very low for all outcomes according to GRADE. Although point estimates showed numerical differences between techniques, with trends favouring MARPE for posterior nasal width and posterior nasal floor width and SARPE for upper first molar inter-cusp distance, these findings were highly uncertain and did not support reliable comparative inferences. No definitive conclusions could be drawn from the available evidence.Conclusions MARPE and SARPE seem to produce measurable skeletal and nasal dimensional changes, but the available evidence is of very low certainty and does not include functional respiratory outcomes. Current data are more consistent with possible clinical equivalence than with superiority of either technique. High-quality randomized trials incorporating functional respiratory outcomes and stratification by age and skeletal maturity are needed.
Purpose To evaluate and compare the efficacy of fluoridated bioactive-glass varnish, silver diamine fluoride (SDF) and resin infiltration technique in the management of artificially induced initial enamel lesions by assessing surface microhardness, surface topography using scanning electron microscopy (SEM), and calcium-to-phosphate (Ca/P) ratios using energy-dispersive X-ray spectroscopy (EDX).Materials and methods Seventy-five extracted premolars were divided into five groups: sound enamel, demineralized enamel, bioactive-glass fluoride varnish, the SDF, and resin infiltration groups. A controlled demineralization protocol was used to create artificial initial enamel lesions followed by remineralization procedures. Surface microhardness was assessed using the Vickers microhardness tester, while SEM-EDX was used to evaluate surface changes and Ca/P ratio. Statistical analysis was performed using one-way ANOVA and Tukey’s post-hoc test (p < 0.05).Results Sound enamel showed the highest surface microhardness values, while demineralized enamel showed the lowest. Among the intervention groups, bioactive-glass-containing fluoride varnish demonstrated higher surface microhardness, followed by SDF and resin infiltration, respectively. SEM analysis revealed a dense mineralized layer in the bioactive-glass group, silver deposits in the SDF group, and resin-filled micro-porosities in the resin infiltration group. The fluoridated bioactive-glass varnish showed the highest Ca/P ratio, comparable to sound enamel.Conclusion Within the limitations of this study, it was found that fluoridated bioactive-glass varnish exhibited a greater improvement in surface hardness, Ca/P ratio and surface morphology compared to other groups. These findings suggest that fluoridated bioactive-glass varnish may function as a promising non-invasive strategy for the management of initial enamel lesions associated with orthodontic treatment.
Objective Solid stainless steel archwires exhibit excessively high torsional stiffness, while Ni-Ti and TMA wires of equivalent dimensions demonstrate less than half of that stiffness, often resulting in inadequate torque transmission to teeth. Conversely, using smaller stainless steel wires in a 0.022-inch slot increases play, thereby compromising torque expression. This finite element analysis (FEA) study aims to evaluate a novel archwire geometry designed to reduce the torsional stiffness of full-size stainless steel archwires without increasing play. Methods Two groups of stainless steel archwires were modelled and analysed. The first group comprised solid 0.019 & times; 0.025, 0.021 & times; 0.025, and 0.021 & times; 0.028-inch stainless steel wires, while the second included 0.021 & times; 0.025 and 0.021 & times; 0.028-inch stainless steel wires modified with the proposed geometry design. The FEA setup was calibrated to yield results consistent with existing experimental data. As the 0.019 & times; 0.025-inch wire demonstrated torque values within the clinically effective range, its performance guided the optimization of the new geometry cut dimensions. The wires with the optimized geometry were subsequently tested for comparison. Results The 0.021 & times; 0.025 and 0.021 & times; 0.028-inch stainless steel archwires incorporating the new geometry exhibited significantly reduced torsional stiffness compared to conventional solid stainless steel wires of the same sizes. Their torque values remained within the clinically effective range of 5-20 N & centerdot;mm. Conclusions The new geometry offers an effective modification for stainless steel archwires, achieving optimal torque expression with reduced torsional stiffness and minimal torque loss; however, further experimental validation is required.
Purpose Thepurpose of this study was to investigate and compare the effectiveness ofanterior segmental maxillary osteotomy (ASMO) with that of surgical mandibular advancement (SMA) in improving the softtissue profiles of Japanese patients with mandibularretrognathia.Materials and methods In total, 24 Japanese patients (12 SMA and 12 ASMO) were included in this study. Cephalometric radiographs taken before (T0) and after (T1) surgical orthodontic treatment were used to measure the angular and linear measurements of hard and soft tissues. Between-group differences at T0 and T1 and correlations between soft and hard tissue measurements for each group were calculated.Results AtT0, there were no significant between-group differences in any parameter exceptupper lip protrusion, which wassignificantly greater in the ASMO group. From T0 to T1, retractive movement ofthe lower nose and upper and lower lips was observed in the ASMO group, while retractivemovement of upper lip and protrusive movement of the chin were observed in theSMA group. Consequently, facial convexity, Z-angle, and upper lip protrusion,which represent the convexity of the lateral profile, were improved in bothgroups, with no significant differences at T1.Conclusion In Japanese patients with mandibularretrognathia, although the region of soft tissue changes differed between ASMO and SMA, the lateral profile convexity was significantly improved in both groups. Thus, both procedures can result in favourable outcomes.
Purpose: Although aesthetic motivations for orthodontic treatment are well recognized, limited evidence exists regarding associations with employment status and occupational background. This study investigated the association between occupational characteristics and orthodontic concerns (aesthetic, occlusal, and speech) among Japanese workers. Materials and methods: A cross-sectional internet-based survey was conducted in 2016 among 2,341 working adults in Japan (1,867 men, 474 women; mean age 43.3 +/- 9.2 years). Participants reported concerns across three domains: dental aesthetics, occlusion, and speech. The total concern score (range: 0-3) was calculated by summing the affirmative responses. Sociodemographic and occupational variables were recorded. Associations were analysed using chi-squared tests, logistic regression for individual concerns, and Poisson regression for total concern scores. Results: Aesthetic, occlusal, and speech concerns were reported by 24.6% (n = 577), 21.3% (n = 500), and 8.8% (n = 208), respectively. Logistic regression analysis showed that aesthetic concerns were significantly more frequent among service/clerical and blue-collar workers than among professionals. Occlusal concerns were more prevalent among night-shift workers and non-regular employees. Speech concerns were significantly less common among individuals with higher incomes. Poisson regression analysis indicated that lower income, female sex, night-shift work, and blue-collar occupation were associated with higher total concern scores. Conclusion: The findings suggest that occupational and socioeconomic backgrounds are associated with self-perceived orthodontic concerns among Japanese workers. Recognizing these differences may help improve patient communication and inform future research on access to orthodontic care.
Purpose: This study aimed to assess and compare the morphology of the mandibular symphysis among individuals with orthognathic, retrognathic, and prognathic mandibles, in both male and female individuals. Materials and Methods: A comparative study was conducted using 204 lateral cephalograms. Individuals were categorized into three groups based on N perpendicular to B distance, with 68 samples in each group. Group 1(control group), group 2, and group 3 consisted of individuals with an orthognathic mandible, retrognathic mandible, and a prognathic mandible, respectively. Each group was further subdivided by gender (male and female), with 34 samples in each subgroup. Mandibular symphyseal width, height, and inclination were measured manually by trained orthodontists. The data were analysed using one-way ANOVA to compare the three main groups and unpaired t-tests to assess gender differences. A p-value of <0.05 was considered statistically significant. Results: Mandibular symphysis width exhibited statistically significant differences among the three groups. Mandibular symphysis height and mandibular symphysis inclination didn't show any statistically significant differences among the three different groups. Mandibular symphysis width didn't exhibit a statistically significant difference between males and females whereas, mandibular symphysis height (p = 0.005) and mandibular symphysis inclination (p = 0.05) show a statistically significant difference among males and females Conclusion: The morphology of the mandibular symphysis exhibited notable variations across orthognathic, retrognathic, and prognathic mandibles, as well as between male and female subjects.
Purpose: Myofunctional therapy (MFT) may improve obstructive sleep apnoea (OSA). Nonetheless, adherence is often limited by inconsistent techniques and limited engagement. We aimed to evaluate whether a novel sheet-shaped gummy could facilitate MFT and improve tongue function and OSA severity. Materials and methods: In this prospective, interventional pilot study, 10 patients with OSA underwent 12 weeks of MFT using a sheet-shaped gummy attached to the hard palate to guide tongue positioning and promote elevation exercises. Adherence, tongue pressure (maximum and sustained), genioglossus muscle (GM) activity, resting tongue position, respiratory event index (REI), and pharyngeal obstruction (VOTE classification) were evaluated pre-and post-intervention. Results: Participants completed the training programme at an 83.4% average rate. Maximum tongue pressure did not change significantly, but sustained pressure and GM electromyographic activity improved post-MFT. Seven participants exhibited improved tongue posture. Based on a >= 100% increase in the integral value of sustained tongue pressure > 20 kPa, participants were divided into improvement (n = 6) and non-improvement (n = 4) groups, with the former exhibiting a significantly lower post-treatment REI. Endoscopic findings demonstrated reduced velum and oropharyngeal wall obstructions in the improvement group. Sustained tongue pressure negatively correlated with post-MFT REI (r = -0.700, p = 0.043). Conclusion: In this pilot study, MFT using a sheet-shaped gummy was associated with improved tongue pressure endurance, muscle activity, and pharyngeal patency, particularly in participants with greater tongue pressure gains, while promoting adherence through a practical guide. This method may serve as a promising adjunct non-invasive therapy for OSA.
Purpose To evaluate the accuracy of clear aligner therapy in maxillary first premolar extraction cases by comparing virtual and clinically achieved tooth movements for maxillary incisors, canines, premolars, and molars.Materials and methods A systematic search of PubMed, Embase, Scopus, and Google Scholar was performed up to August 2025 following PRISMA guidelines. Nine retrospective studies (Invisalign®) that directly compared virtual and actual tooth movement using three-dimensional measurements were included. Data on 3 linear (mesiodistal, vertical, buccolingual) and 3 angular (tipping, torque, rotation) movements were screened. Meta-analyses were performed using either fixed or random effects models based on the heterogeneity. Publication bias was assessed using funnel plots and Egger’s test, with sensitivity analyses assessed using the trim-and-fill method.Results Maxillary incisors appeared to show underexpression of bodily retraction and root control, with greater-than-planned lingual tipping and extrusion. Canine distalization showed considerable variability and limited predictability, with reduced tipping control. Posterior teeth suggest a tendency towards anchorage loss, characterized by mesialization and mesial tipping of the maxillary second premolar and first molar, sometimes accompanied by unexpected molar intrusion. Movements requiring bodily translation, torque expression, and anchorage preservation appeared to have the lowest predictability. Substantial heterogeneity (I2 often > 50%) likely reflects variation in clinical protocols and measurement methods, although sensitivity analyses did not change the direction of the observed effects.Conclusion Although clear aligner therapy (CAT) can achieve space closure in premolar extraction cases, bodily movement, root control, and anchorage maintenance seem to be less consistently achieved than predicted in aligner-based extraction mechanics.
