Dentofacial deformities affect patients' oral health-related quality of life (OHRQoL) and orthognathic surgery is commonly used to correct these skeletal deformities. Currently, few studies have compared patients with class II and class III dentofacial deformity using validated tools, with control groups and longer-term follow-up. This study evaluated OHRQoL in 94 patients with class II (n = 28) and class III (n = 66) dentofacial deformity before (baseline) and 1 (M1), 3 (M3), and 6 (M6) months after orthognathic surgery, using the Chinese version of the Orthognathic Quality of Life Questionnaire (OQLQ). A total of 118 college students without dentofacial deformity served as controls. Comparisons and longitudinal changes were analysed. Preoperatively (baseline), patients exhibited worse OQLQ scores than controls (P < 0.001). Significant improvements of OQLQ scores were observed in patients with class II and class III dentofacial deformity from baseline to M6 (P < 0.001). Patients with class II dentofacial deformity showed significantly worse OQLQ scores than those with class III dentofacial deformity in certain aspects at M6 (P < 0.05). This study provides novel evidence that while orthognathic surgery substantially improves OHRQoL, patients with class II dentofacial deformity may experience poorer OHRQoL at 6 months postoperatively compared to patients with class III dentofacial deformity.
Gender disparities in research trial leadership have been reported in nearly every medical specialty. The true extent of women's involvement as principal investigators (PIs) in oral and maxillofacial surgery (OMS) research trials remains unknown. The current study aims to address this knowledge gap through analyzing relevant trials registered on ClinicalTrials.gov in the 21st century. A validated search strategy, comprising procedure names and field-specific terms, was utilized to identify OMS research trials. The analysis was limited to trials where at least one PI was an oral and maxillofacial surgeon or an OMS department-affiliated researcher. Trial characteristics, including study type, phase, funding status, and investigator details were extracted from records. PI gender was determined using Genderize.io. Overall, men occupied 73.7% of PI positions for OMS research trials, and women 26.3%. Linear regression analysis revealed a significant yearly increase in proportion of women PIs over time. Geographically, women PI representation was highest in African (predominantly Egypt) and Asian institutions, and lowest in European and North American institutions. Relative to other phases, women PIs were significantly more likely to lead Phase 3 trials and less likely to lead Phase 2 trials compared to men PIs. While government funding patterns were similar between genders, women PIs were significantly less likely to lead industry-funded trials. Despite recent improvements, women remain underrepresented in OMS research trial leadership, especially in North American institutions. Targeted interventions and cultural shift are essential to fostering gender-based parity in this domain.
A processing model in which each stage of mastication and deglutition overlaps has recently been proposed, suggesting coordinated activity of the bucinator, pharyngeal muscles, and masticatory muscles. However, there is little anatomical evidence demonstrating structural continuity among these components. Since functional integration among these muscles likely depends on connective tissue interfaces, this study aimed to examine the distribution of the dense connective tissue layer covering bucinator and temporalis tendons and its relationship with the surrounding muscles. Twelve halves of nine adult Japanese cadaveric heads were examined: five halves were observed macroscopically and seven histologically. A dense connective tissue layer was identified between the bucinator, deep temporalis tendon, and superficial temporalis tendon. This layer was formed by the fusion of the temporal fascia and buccopharyngeal fascia, was continuous with the masseteric fascia, and received partial attachment from the medial pterygoid muscle. In addition, loose connective tissue was observed in the space between the superficial and deep temporalis tendons. The fibre orientation of the dense connective tissue layer and bucinator was consistent with that of the tendon. This dense layer formed a capsule-like structure enclosing loose connective tissue and neurovascular bundles, and was centrally located among the bucinator, temporalis, masseter, medial pterygoid muscle, and superior constrictor of the pharynx. These findings suggest that this structure may contribute to coordinated muscle activity and efficient force transmission during mastication and deglutition, providing a structural basis for future functional and imaging studies.
Neoplasms of the mandibular ascending ramus and condyle cause facial asymmetry, trismus, malocclusion, swelling in the temporomandibular joint area, and pain. Conventional surgeries require an external incision, with a risk of facial nerve injury and leaving a scar. This study aimed to establish a minimally invasive approach for mandibular ramus-condyle tumour resection, using intraoperative navigation and endoscopes. The safety and feasibility were assessed by cadaveric dissection. Nine patients with osteomas or osteochondromas occurring from the mandibular ascending ramus and condyle were included in this study. All patients underwent navigation-assisted transoral endoscopic resection of the tumours. Cadaveric dissection demonstrated how the transoral endoscopic approach to the mandibular ramus-condyle unit was established and enabled analysis of the anatomical structures. Mandibular tumours were successfully resected in all the patients, with a low incidence of postoperative complications, and the morphologies and functions of the mandible were satisfactorily preserved. The results indicate that navigation-assisted transoral endoscopic surgeries for the mandibular ramus-condyle tumours are feasible and effective in a preliminary clinical setting. Studies with larger sample sizes and further assessment of the navigation system are required to confirm the accuracy of the surgeries.
Large language models have shown remarkable performance on medical examinations, but their application in oral and maxillofacial surgery remains under-investigated. This study evaluated whether general-purpose models outperform domain-specific retrieval-augmented generation (RAG) models in specialized medical assessments. Five AI models were tested on official Phase A board examinations (2017-2024, 788 questions): three general-purpose models (Gemini 2.5, ChatGPT-5, Claude Sonnet 4) and two GPT-4o variants (non-tuned baseline and RAG-augmented with complete access to official examination materials). Gemini 2.5 achieved 83.8% accuracy, ChatGPT-5 73.2%, Claude Sonnet 4 72.3%, GPT-4o non-tuned 51.4%, and GPT-4o with RAG 50.9%. Pairwise McNemar's tests showed significant differences between Gemini 2.5 and both ChatGPT-5 (P < 0.001) and Claude Sonnet 4 (P < 0.001), while ChatGPT-5 and Claude Sonnet 4 did not differ (P = 0.609). All general-purpose models significantly outperformed both GPT-4o variants (all P < 0.001). Direct comparison between GPT-4o variants revealed no difference (P = 0.788), indicating that RAG with direct access to examination materials provided no benefit over baseline architecture. Error analysis revealed complementary failure patterns: humans struggled with factual recall, while AI struggled with contextual integration within regional medical curricula. Gemini 2.5 significantly exceeded the 70% passing threshold (P < 0.001); ChatGPT-5 marginally exceeded it (P = 0.048); Claude Sonnet 4 achieved a passing score without statistically exceeding the threshold (P = 0.153). Architectural sophistication, rather than domain-specific knowledge augmentation, emerged as the primary performance determinant. These findings reflect examination performance on text-based multiple-choice questions and should not be extrapolated to real clinical decision-making.
The aim of this systematic review and meta-analysis was to estimate the prevalence of temporal bone pneumatization (TBP), including pneumatization of the articular tubercle (PAT) and glenoid fossa (PGF), based on cone-beam computed tomography (CBCT) studies. The laterality, pattern, and extension of the TBP, as well as the sex distribution and age range of the patients are also described. A systematic search was performed in the PubMed, Embase, Scopus, Web of Science, and Google Scholar databases up to May 2025 . Studies reporting TBP prevalence on CBCT were included. The data extraction followed the PRISMA guidelines, and risk of bias was assessed using the JBI checklist for prevalence studies. Meta-analyses were performed using a random-effects model to calculate pooled prevalence rates. The pooled prevalence of TBP was 62.5% (95% confidence interval (CI) 53.6-70.7%), while the prevalence rates of PAT and PGF were 26.1% (95% CI 15.4-40.6%) and 28.6% (95% CI 18.7-41.2%), respectively. Multilocular patterns predominated over unilocular, and grade 2 extension (pneumatization between the glenoid fossa and crest of the articular eminence) was the most frequent extension type in PAT. In conclusion, due to the anatomical risks associated with TBP, CBCT assessment is recommended before surgical procedures involving the temporomandibular joint to reduce the risk of complications, such as perforation of the middle cranial fossa.
Dental anxiety is a common problem in oral surgery practices. Recently, interest has increased in non-pharmacological methods to reduce anxiety, such as auditory stimulation. This randomized controlled trial evaluated the effects of binaural beats (BB) and isochronic tones (IT), two forms of auditory stimulation, on dental anxiety and physiological parameters during impacted mandibular third molar surgery. Ninety patients were assigned equally to BB, IT, and control (no intraoperative auditory stimulation) groups. Anxiety levels were assessed using the MDAS, DFS, STAI-S, and a visual analogue scale pre- and postoperatively. The BB and IT group patients also completed a satisfaction questionnaire. Physiological parameters (respiratory rate, pulse rate, blood pressure [SBP, DBP], oxygen saturation) were recorded at eight surgical stages. No significant between-group differences were observed in the pre- or postoperative anxiety questionnaire scores. Isolated between-group differences in physiological parameters were observed: mean SBP at incision was lowest in the BB group (P = 0.041), while mean respiratory rate at anaesthesia was lowest in the IT group (P = 0.015). The majority of BB and IT group patients (78.3%) reported that they would prefer auditory stimulation in future dental treatments. The findings indicate that BB and IT have a limited effect on reducing dental anxiety during impacted mandibular third molar surgery and do not support a definitive anxiolytic benefit. Auditory stimulation may transiently influence certain stress-related physiological responses; however, further studies using objective neurophysiological measures and standardized protocols are required to clarify their role in oral surgery.
This systematic review and meta-analysis evaluated the impact of platelet-rich fibrin (PRF) and its derivatives on postoperative complications following mandibular third molar extraction, drawing from 28 randomized controlled trials. Outcomes assessed included pain, swelling, trismus, alveolar osteitis (AO), soft tissue healing, bone healing, and probing depth, with meta-analyses performed for individual postoperative days or follow-up intervals. PRF was associated with a significant reduction in pain on postoperative days 2, 3, and 7. There was significantly less swelling in the PRF group on days 1-3 using the two-line measurement method and on day 2 using the three-line method. Mouth opening (trismus) was significantly better in the PRF group on day 1, while no significant improvements were shown on subsequent days. The odds of developing AO were significantly higher in the control group compared to the PRF group (odds ratio 2.69, 95% confidence interval 1.55-4.68, P < 0.001; I2 = 0.00%). PRF did not have a significant effect on soft tissue or bone healing. While there was no significant difference in probing depth at 1 week, there were statistically significant improvements at 3 and 6 months in favor of PRF. The analysis identified positive effects of PRF on pain and trismus, although the certainty of the evidence was moderate for trismus and low for pain. Overall, PRF may offer benefits for pain, swelling, trismus, and AO, and may improve probing depth at longer follow-up intervals, while its impacts on soft tissue and bone healing remain uncertain.
The superficial circumflex iliac artery (SCIA) perforator flap is supplied by the SCIA, which consists of superficial and deep branches. In this study, the feasibility of using a flap based solely on the superficial branch of the SCIA for reconstruction surgery in the head and neck region was explored. During flap harvesting, the deep branch of the SCIA was discarded, and the superficial branch was dissected as the vascular pedicle; this technique is referred to as the 'simplified SCIA flap. This simplified SCIA flap was used to repair head and neck defects in 16 patients, all of whom were followed up for at least 3 months postoperatively. The superficial branch of the SCIA was successfully identified in all 16 patients. The mean pedicle length of the superficial branch of the artery was 7.2 cm (range 6.2-8.2 cm). The mean diameter of the superficial branch of the artery was 0.7 mm (range 0.6-0.9 mm), while the mean diameter of the accompanying vein was 1.2 mm (range 1.0-1.3 mm). The reconstruction was successful in 15 of the 16 patients. The remaining patient ultimately underwent reconstruction with a left radial forearm free flap. In this case, the skin paddle of the simplified SCIA flap was used as a full thickness skin graft to repair the defect in the forearm donor site. All patients completed speech and swallowing assessments during postoperative follow-up. Compared with the traditional SCIA flap, the simplified SCIA flap is easier to harvest, offers lower donor site morbidity, and results in a well-concealed scar in the iliac region. This flap warrants clinical promotion.
The study aimed to evaluate the prevalence and associations of body dysmorphic disorder (BDD) in East Asian patients undergoing orthognathic surgery, and the applicability of current BDD screening tools for these patients. A prospective cohort study was conducted involving patients presenting for orthognathic surgery. Data on their preoperative and postoperative complaints, age, gender, psychiatric history, skeletal classification, overjet and overbite were collected. Patients completed three questionnaires as part of their BDD screening: Body Dysmorphic Disorder Questionnaire (BDDQ), Appearance Anxiety Inventory (AAI), and Oral Health Impact Profile-14 (OHIP-14). Patients screening positive were referred for formal psychiatric diagnosis. Analyses were conducted to evaluate for associations between clinical variables and a positive or negative BDD screen. One hundred patients were included in the study, of whom 10% screened positive with the BDDQ. A positive screen was associated with female sex (P < 0.0001) and patients with higher AAI scores (P < 0.0001). No significant associations were found between a positive screen and age, psychiatric history, skeletal relationship, overjet, overbite, or OHIP-14 scores. Of the patients referred for formal psychiatric evaluation, none was ultimately diagnosed with BDD. No postoperative aesthetic complaints were reported. The BDDQ yielded a positive screen of 10% in this study, with only sex being significantly associated with a positive screen. While BDD screening tools may identify patients with a heightened sense of aesthetics, the applicability of these tools in this population is limited, as none of the patients who screened BDD positive were ultimately diagnosed with BDD.
The aim of this study was to evaluate the prevalence of spin and associated factors in randomized controlled trials (RCTs) assessing quality of life after third molar extraction. This meta-research followed meta-epidemiological guidelines and included RCTs reporting quality of life outcomes after third molar surgery, regardless of statistical significance. Searches were conducted in 11 databases up to March 2025. Spin was assessed in abstracts, main texts, and conclusions, and categorized as low (<25%), moderate (25-75%), or high (>75%). Of 4093 citations, 42 articles met inclusion criteria. Most reported statistically significant results. Overall, spin was infrequent, occurring in 9.5% of abstracts and full texts. The omission of adverse events was the most common pattern, observed in 85.7% of abstracts and 47.6% of full texts, potentially leading readers to overestimate the benefits of treatment and underestimate associated risks. This underreporting, particularly in abstracts, may misinform clinical decision-making and patient counselling. Spin was highly prevalent in the results sections of abstracts (88.1%). No significant associations were found between spin, CONSORT adherence, or study and journal characteristics (P ≥ 0.05). Spin was uncommon in RCTs evaluating quality of life after third molar extraction, especially in conclusions. However, when present, it was often substantial, highlighting the need for improved transparency in scientific reporting.
Maxillary segmentation is often necessary to achieve optimal occlusion in orthognathic surgery, and although virtual surgical planning provides improved diagnostic precision and workflow efficiency, many surgeons continue to rely on conventional model surgery for establishing occlusion in segmented cases, with limited evidence directly comparing these approaches. This in-vitro study evaluated archived, de-identified preoperative intraoral scans of patients who underwent segmental maxillary orthognathic surgery at the University of Texas Health Science Center at San Antonio, including only cases requiring a three-piece maxillary osteotomy and excluding patients with partial edentulism or cleft palate. The method used to obtain the occlusion-either physical model surgery performed on digitally fabricated models or virtual model surgery-served as the predictor variable, and the primary outcome was equivalence of the final occlusal result. Two surgeons independently performed both techniques in 20 cases, generating a total of 80 final occlusions. Dimensional analysis using surface-based best-fit registration demonstrated a mean three-dimensional occlusal deviation of 0.03 mm between workflows, which was well below the predefined tolerance threshold of 0.3 mm. Parametric statistical analysis showed no significant differences between occlusal outcomes produced by the two methods. These findings indicate that virtual model surgery is clinically feasible and produces occlusal results equivalent to conventional model surgery in segmental maxillary procedures, supporting its use as a reliable alternative for preoperative planning.
Surgical resection of the pterygoid plate is technically demanding, with risks of inadequate margins and complications. This preclinical study evaluated the accuracy of two novel technologies for improving pterygoid plate osteotomy: a real-time navigated piezo-electric system (RNPS) and a custom surgical guide. An optical navigation system was integrated with a piezo-electric instrument (RNPS), and a patient-specific surgical guide was three-dimensionally printed. The positional and rotational accuracy of both systems was evaluated by performing pterygoid plate resections on 20 phantom models and compared against a conventional freehand technique. Both technologies demonstrated significantly higher accuracy than the conventional approach. The RNPS group showed a mean positional error of 0.92 ± 0.59 mm, significantly lower than the control mean of 2.65 ± 1.07 mm (P < 0.05), and achieved better rotational accuracy. The surgical guide also resulted in a significantly lower mean positional error compared to the control group (1.18 ± 0.95 mm vs 2.75 ± 0.92 mm; P < 0.05). In this preclinical setting, both the RNPS and the custom surgical guide significantly improved the accuracy of pterygoid plate resection. These technologies show strong potential to enhance surgical precision and safety, which may lead to improved oncological outcomes in complex maxillofacial surgery.
External apical root resorption (EARR) is a recognized adverse outcome of orthodontic treatment that may also be influenced by orthognathic surgery. However, the body of evidence on this combined effect is nascent and has not been mapped. The aim of this scoping review was to systematically map and characterize the available literature on EARR measured using cone-beam computed tomography (CBCT) in surgical versus non-surgical jaws in orthognathic patients, and to identify key methodological and knowledge gaps to guide future research. The PRISMA-ScR guidelines were followed. Five electronic databases were searched, to December 2025. Two reviewers independently performed the study selection and data extraction, followed by a synthesis to map the evidence. The review identified four retrospective cohort studies involving 250 patients and over 2300 teeth. Three of the four included studies (75%) originated from a single research group. All studies assessed EARR using CBCT-derived measurements of root length and volume .Three of the studies reported greater EARR in surgical jaws, particularly involving the maxillary incisors, canines, and premolars . Volumetric analysis showed more pronounced changes than analysis of linear measurements . All studies were judged to have a moderate risk of bias, and substantial methodological heterogeneity was observed. In conclusion, this scoping review maps a limited evidence base that preliminarily reports an association between orthognathic surgery and increased EARR. The certainty of the evidence is low, and independent validation is absent. Well-designed prospective studies with standardized protocols are required to clarify clinical significance.
Patients with head and neck cancer (HNC) frequently experience psychosocial distress, yet its trajectory across the surgical pathway is insufficiently understood. The National Comprehensive Cancer Network (NCCN) Distress Thermometer (DT) is a rapid screening tool, though its longitudinal behavior and predictive value in surgical HNC care require further study. This prospective study assessed perioperative distress trajectories, explored predictors of elevated distress, and evaluated the feasibility of serial inpatient assessment. Forty-eight patients undergoing curative surgery for primary HNC at a tertiary center were enrolled. Distress was measured using the DT and Problem Checklist at five timepoints: staging admission (ePOS), preoperative (DT1), early postoperative (DT2), approximately day 7 (DT3), and pre-discharge (DTE). Socio-demographic, clinical, and symptom-burden variables were collected. Analyses were descriptive statistics, paired comparisons, subgroup analyses, and correlations (α = 0.05). Mean DT scores were 6.4 (ePOS), 5.7 (DT1), 6.4 (DT2), 5.4 (DT3), and 5.1 (DTE). Clinically relevant distress (DT ≥5) occurred in 59-85%. Higher distress was associated with younger age, lower educational attainment, comorbidity, and greater physical symptom burden. Distress increased more strongly in patients without nicotine or alcohol use. Patients requesting psycho-oncological support at baseline showed greater distress reduction between ePOS and DT2. Completion rates exceeded 90%, and patients rated serial assessment as acceptable. Distress remains elevated during inpatient surgical treatment, with peaks at diagnosis and early postoperative recovery. Serial distress assessment is feasible and may help identify high-risk subgroups. Integrating repeated screening and timely psychosocial support into surgical pathways could improve patient-centered care in HNC.
The accessory parotid gland (APG) is a common anatomical variant, situated adjacent to Stensen's duct and anatomically separate from the main body of the parotid gland. While often healthy, this tissue can give rise to neoplasms. This retrospective cohort analysis investigated the diagnostic features and therapeutic management of these rare tumours. The records of 647 patients with parotid gland disease treated at a single Maxillofacial Surgery Unit from 1988 to 2023 were analysed, selecting 17 patients with confirmed APG tumours for detailed analysis. The mean age of the included patients was 52 years, with a slight female predominance (58.8%). The malignancy rate was notably high at 41.1%. Benign tumours were histologically confirmed as pleomorphic adenomas, while malignant diagnoses included adenocarcinoma, adenoid cystic carcinoma, carcinoma ex pleomorphic adenoma, and non-Hodgkin lymphoma. Importantly, some malignancies were initially misdiagnosed as benign or indeterminate by fine needle aspiration cytology. Surgical management varied, with total parotidectomy reserved for all confirmed malignant tumours. For benign and indeterminate cases, excision of the APG with associated partial parotidectomy was preferred over more conservative techniques. The most common complications (temporary facial palsy and salivary fistula) occurred in patients who underwent partial parotidectomy. The conclusions of this research emphasize that due to the substantially elevated malignancy risk and the limited reliability of preoperative cytology, a cautious, high-index-of-suspicion approach is necessary for all mid-cheek masses, and a more radical surgical approach is often warranted to ensure adequate tumour clearance.
This retrospective study aimed to determine the morphology of the upper airway of craniofacial microsomia (CFM) patients with obstructive sleep apnoea (OSA) both pre- and post-mandibular distraction osteogenesis (MDO), and to compare differences in airway changes according to the therapeutic efficacy for OSA. The CFM patients with OSA were divided into 'effective' and 'ineffective' groups based on the therapeutic efficacy of MDO for OSA. Pre- and post-MDO craniofacial CT data were imported into Mimics software for three-dimensional upper airway reconstruction, which was further segmented into the nasal cavity, nasopharynx, velopharynx, glossopharynx, and laryngopharynx. The volume, surface area, length, mean cross-sectional area, and minimum cross-sectional area (minCSA) were measured. Intra-group comparisons of pre- and post-MDO data were performed, and the percentage changes (pre- to post-MDO) were compared between the two groups. Twenty-five patients were included, 10 in the ineffective group and 15 in the effective group. In both groups, the minCSA (P = 0.002, P = 0.015) and volumes of the nasopharynx (P = 0.018, P = 0.018), velopharynx (P = 0.006, P = 0.012), and glossopharynx (P = 0.007, P = 0.004) increased significantly after MDO. There were no statistically significant differences in the percentage changes in upper airway measurements between the two groups (all P > 0.05). The upper airway of CFM patients with OSA increased post-MDO, but the difference in therapeutic efficacy of MDO for OSA was not solely due to differences in the changes in morphology of the upper airway.
Recently, nutritional status has been reported to be associated with the prognosis of various diseases. Methods to assess nutritional status using common blood-testing parameters include the prognostic nutritional index (PNI), hemoglobin-albumin-lymphocyte-platelet (HALP) score, and controlling nutritional status (CONUT) score. This study aimed to clarify the utility of these scores in patients with locally advanced oral cancer. A total of 106 patients with stage 3 or 4 oral squamous cell carcinoma, who underwent surgery between June 2007 and January 2020, were included. Preoperative PNI, HALP, and CONUT scores were calculated, and cut-off values were set using time-dependent receiver operating characteristic curves. The patients were divided into two arms. Cox proportional hazards analysis was used to identify the factors associated with disease-specific 5-year survival rates. Among the three preoperative scores (PNI, HALP, and CONUT), only PNI showed a significant difference between the preoperative score and disease-specific 5-year survival. The PNI score of 46.5 was set as the cut-off value, and the disease-specific 5-year survival rate was 62.0% in the PNI-low group and 76.0% in the PNI-high group (P = 0.027). In the Cox proportional hazards analysis with PNI-high/low and cancer cell differentiation as variables, the hazard ratio for PNI-high/low was 0.41 (95% confidence interval: 0.19-0.94, P = 0.034). The preoperative PNI score was correlated with disease-specific survival rates and was considered a prognostic factor in patients with locally advanced oral cancer. This suggests the usefulness of nutritional assessment using the PNI in patients with oral cancer.
Open reduction and internal fixation (ORIF) is the standard treatment for displaced mandibular condyle fractures, yet postoperative condylar remodelling remains insufficiently characterized. The aims of this study were to quantify the three-dimensional condylar remodelling postoperative by analysing immediate postoperative and 6-month computed tomography scans and to assess whether the magnitude of remodelling is associated with surgical or patient-related variables. This retrospective cohort study included 42 adults treated for isolated unilateral condylar fractures. Mandibular models were segmented and superimposed using standardized ramus-based registration. Remodelling was quantified using unsigned surface distance mapping and regional Euclidean distances across five anatomical subregions. Postoperative remodelling was observed consistently across the cohort and was statistically significant (median mean surface distance 0.60 mm; P < 0.001). However, remodelling remained modest in magnitude (mean 0.75 ± 0.53 mm; root mean square 0.94 ± 0.66 mm) with occasional focal deviations. Regional analysis demonstrated heterogeneous patterns, with greater displacement in the superior, medial, and lateral regions and smaller changes posteriorly. No statistically significant associations were identified for surgical approach, fixation plate, age, or sex, suggesting that postoperative adaptation may reflect intrinsic biological and functional processes rather than modifiable technical variables. Clinical outcomes were favourable; complications (predominantly mild and self-limiting) occurred in 28.6% of patients. Events were observed in both endoscope-assisted and open approaches. In conclusion, postoperative condylar remodelling after ORIF is significant, region-dependent, and modest in magnitude, and appears independent of surgical or demographic factors. Three-dimensional surface mapping provides a robust and reproducible method for evaluating postoperative condylar adaptation.
This study was performed to explore the use of statistical shape modelling (SSM) to predict the centre of rotation (CR) in patients undergoing total temporomandibular joint replacement (TMJ-TJR), in order to facilitate more accurate prosthesis design. In this retrospective study, a SSM of mandible halves was constructed using preoperative segmented three-dimensional models from cone-beam computed tomography scans, split into 388 mandible halves. The model was evaluated through compactness and generalization curves and by examining the principal components (PCs) of shape variations. A dataset of 40 mandible halves with four-dimensional optical tracking-derived CR measurements was fit to the SSM. Ridge regression was applied to predict patient-specific CR locations from SSM-derived PC scores. The predictions were evaluated using the root mean square error (RMSE) by comparing them to the true CR values. The SSM explained 71% of the total variation with the first five PCs. Increasing the number of PCs improved model accuracy. The regression model for predicting patient-specific CRs achieved a mean RMSE of 11.63 ± 11.01 mm, outperforming a naïve model as used in clinical practice that assumes a fixed CR location, which resulted in an RMSE of 31.88 ± 21.31 mm. A SSM of mandible halves to predict patient-specific CRs, capturing a significant portion of side-specific anatomical variability, was successfully developed. The regression analysis demonstrated a strong relationship between mandible shape, CR location, and corresponding PCs, laying a solid foundation for advancing the precision of TMJ-TJR procedures.