Preoperative planning is crucial in orthognathic surgery, addressing both functional and aesthetic aspects in young adults. The current state-of-the-art still relies on fully manual virtual surgery planning despite the availability of detailed three-dimensional imaging. A prototype system for orthognathic surgery planning was developed that transforms manually identified landmarks into automated planning proposals by embedding established cephalometric rules, photoanalysis and clinical expert knowledge into an algorithmic framework. To evaluate the prototype, an initial retrospective study including 20 patients who underwent bimaxillary orthognathic surgery was performed. The study population was balanced for gender and skeletal class. For each case automatic planning proposals were compared with state-of-the-art virtual surgery planning. Quantitative differences between both planning approaches were analysed across all six degrees of freedom. In addition, a subgroup analysis according to skeletal class (class II vs class III) was conducted to assess potential class-specific deviations. Statistical comparisons were performed using t-tests or Mann-Whitney U-tests depending on data distribution (P < 0.05). Agreement between prototype and expert planning was assessed using Bland-Altman analysis and intra-class correlation coefficients. Results showed good agreement in most degrees of freedom. Statistically significant differences in planning results were noted in the Pitch dimension (Expert: 0.88° ± 4.46; Planning system: 5.72° ± 5.7; P = 0.0049; CI: 1.56, 8.12). The prototype generally produced clinically reasonable planning propositions within the scope of the preliminary evaluation study. Incorporating additional cephalometric analyses and optimising the algorithm will likely enhance the systems performance.
The objective was to evaluate the technical feasibility, geometric accuracy, and preliminary short-term safety of using a multimodal, image-guided, robot-assisted iodine-125 seed implantation targeting the stylomastoid foramen and high-risk perilesional regions in selected patients with parotid adenoid cystic carcinoma with facial nerve involvement. A total of 23 consecutive patients treated between January 2020 and January 2023 were reviewed. Preoperative puncture planning was conducted using fused computed tomography (CT)/magnetic resonance imaging datasets. Intraoperative percutaneous needle placement and radioactive seed implantation were performed under robotic navigation. Postoperative CT imaging was obtained within 24 h to quantify implantation accuracy by calculating the spatial deviation between planned and actual seed positions. All patients were followed for up to 3 years, during which neurological function and intracranial tumor progression were systematically evaluated using clinical assessment and imaging. All surgeries were completed successfully without intraoperative incidents or significant perioperative complications. The mean particle placement error was 1.46 ± 0.85 mm (95% confidence interval: 1.09-1.83 mm), with intraoperative blood loss of 2-3 mL. During subsequent follow-up, no further neurological deficits were observed, and serial imaging revealed stable disease in 16 patients, partial response in six, and local progression without intracranial extension in one. The employment of robot-assisted iodine-125 brachytherapy has the potential to offer a safe, accurate, and minimally invasive clinical option for focal neural-pathway irradiation in a selected group of high-risk parotid adenoid cystic carcinoma patients. However, the confirmation of long-term oncological and neurological benefits necessitates the performance of prospective controlled studies.
Cancer-associated fibroblasts (CAFs) influence the tumour microenvironment and promote tumour growth and metastasis. In recent years, the extracellular volume (ECV) fraction derived from contrast-enhanced computed tomography (CECT) has been recognized as a useful, non-invasive imaging biomarker for assessing tissue fibrosis. The aim of this study was to evaluate the clinical significance of the ECV fraction in tongue squamous cell carcinoma (TSCC) by examining its association with histopathological fibrosis. This retrospective observational cohort study analysed 63 patients with TSCC diagnosed between 2015 and 2023. CAFs and tumour microenvironment activity were assessed immunohistochemically using α-SMA, FAP, and TGF-β1. Associations among ECV fraction, fibrosis, and clinical factors were examined. ECV fraction was significantly associated with tumour size, cervical lymph node metastasis, and depth of invasion (all P < 0.001). Receiver operating characteristic curve analysis identified an optimal ECV fraction cut-off of 19.2% for predicting cervical lymph node metastasis. Kaplan-Meier analysis using this cut-off showed that a high ECV fraction was associated with significantly poorer overall survival (P = 0.032). Kaplan-Meier analysis showed that patients with a high ECV fraction experienced significantly poorer overall survival (P = 0.032). Subgroup analysis of early-stage tumours (T1/T2) demonstrated a comparable prognostic value (cut-off = 19.3%), showing a similar prognostic trend. The ECV fraction is a non-invasive imaging biomarker that reflects stromal fibrosis and is associated with tumour progression and cervical lymph node metastasis in TSCC. The ECV fraction cut-off value served as a reliable prognostic indicator, including in early-stage cases. The integration of ECV fraction with the evaluation of histological fibrosis and CAFs may facilitate personalized risk assessment and guide clinical decisions such as elective neck dissection.
Inferior alveolar nerve (IAN) injury is the most common side effect of bilateral sagittal split ramus osteotomy (BSSRO), often caused by anatomical variability and the proximity of the nerve to the buccal cortex. This study was performed to compare functional sensory recovery (FSR) times when using cone-beam computed tomography (CBCT) vs panoramic radiographs (OPG) preoperatively to locate the IAN in patients undergoing BSSRO. A split-mouth randomized design was used. Twenty patients who underwent BSSRO in the Faculty of Dentistry, Mahidol University, between January 2023 and July 2024 were included. CBCT and OPG images were obtained preoperatively. Subjective and objective neurosensory evaluations were performed preoperatively, immediately postoperative, and at 1, 3, 6, and 9 months postoperative. The median time to FSR in the lip area was 2 days in the CBCT group and 35 days in the OPG group (P = 0.050; borderline significant difference), while in the chin area it was significantly shorter in the CBCT group (CBCT 2 days vs OPG 63 days; P = 0.026). Patients subjectively reported more neurosensory disturbances when compared to the FSR results (lip and chin region, both P < 0.001). Neither the IAN-to-buccal cortex distance nor the magnitude of the mandibular movement was significantly associated with time to FSR in either the lip or chin area (all P > 0.05). CBCT appears to be a useful modality to support safer surgical approaches, promote faster sensory recovery, and enhance patient satisfaction following BSSRO.
Artificial intelligence (AI) has advanced rapidly in healthcare, with large language models (LLMs) like ChatGPT-4o showing potential in education and clinical support. This study evaluated the performance of ChatGPT-4o on oral surgery-related questions from the Japanese National Dental Examination, focusing on how visual materials impact accuracy. Questions were categorized by type (general knowledge vs clinical practice), number of correct answers required, and presence of visual materials (e.g., radiographs, models). The comparison of correct and incorrect answers according to the number of visual materials was performed using the Mann-Whitney U-test, while logistic regression was used to assess the influence of specific visual content types. ChatGPT-4o performed well on general knowledge questions but showed lower accuracy on questions requiring clinical decision-making . The presence of multiple visual materials significantly reduced accuracy, with panoramic radiographs and dental models showing the strongest negative effects (odds ratios 0.46 and 0.45, respectively; both P = 0.002). Other visual materials, such as computed tomography/magnetic resonance imaging scans, had no significant impact. These findings highlight the strengths of ChatGPT-4o in processing structured textual data and its limitations in interpreting visual or procedural content. Enhancing AI-assisted dental education will require domain-specific training data and the development of multimodal models capable of integrating both text and images. This study informs future applications of AI in oral surgery education.
Robotic-assisted surgery has progressively expanded in head and neck diseases, providing minimally invasive alternatives to conventional transcervical approaches while improving visualization, precision, ergonomics, and cosmetic outcomes. The MiRA (Micro Robotic Access) pneumoneck technique was developed as a fully robotic subclavicular approach for lateral neck dissection. The technique combines small subclavicular ports, carbon dioxide insufflation to create a stable cervical working space, and the Asson assistant port system to optimize pressure stability and auxiliary instrument use. The MiRA pneumoneck technique was applied in a female patient with squamous cell carcinoma of the oral floor who underwent a right selective lateral neck dissection. Four subclavicular incisions were created for robotic and assistant ports. Pneumoneck was established using CO2 insufflation, and the procedure was performed with the Da Vinci Xi Surgical System. Robotic dissection enabled en-bloc clearance of cervical levels I-III while preserving major neurovascular structures. The specimen was removed through the assistant port. Postoperative recovery was uneventful, with no major complications, early mobilization, and discharge on postoperative day 4. Compared with previously described robotic neck approaches, the MiRA pneumoneck technique represents a fully remote-access strategy for lateral neck surgery without visible cervical incisions. CO2 insufflation improves visualization and instrument maneuverability, while the Asson system reduces gas leakage and enhances procedural versatility. The MiRA pneumoneck technique represents a further evolution in minimally invasive robotic neck surgery. Further studies are required to evaluate reproducibility, oncologic safety, cost-effectiveness, and long-term outcomes.
The objective was to evaluate the accuracy of patient-specific surgical cutting chin guides, patient-specific implant (PSI) chin plates, and β-tricalcium phosphate (β-TCP) gap patient-specific implants used in chin osteotomy by comparing their planned and postoperative positions. In addition, the reproducibility of the measurement method was assessed using intraclass correlation coefficients. Orthognathic patients requiring a chin osteotomy were included in the study. Preoperative virtual surgical planning was fused with postoperative cone-beam computed tomography imaging obtained 4 weeks after surgery. The planned and postoperative positions of the bony chin, PSI chin plate, and β-TCP gap-PSI were compared in terms of translational and rotational deviations. Reproducibility was assessed by two observers who repeated all measurements in two separate sessions. Ten patients were included in this pilot validation study. The mean deviation of the repositioned bony chin segment, the PSI chin plate, and β-TCP gap-PSI was <0.5 mm in the anteroposterior, vertical, and left-right directions. Rotational discrepancies were <1° for pitch, yaw, and roll, except for the pitch deviation of the β-TCP gap-PSI, which was 1.7°. Reliability ranged from moderate to excellent. The combination of patient-specific cutting guides, PSI chin plates, and β-TCP gap-PSIs allowed transfer of the virtual genioplasty plan with limited positional deviation in this pilot study. Further studies with larger samples and longer follow-up are required to assess β-TCP graft integration and clinical outcomes.
Oral squamous cell carcinoma (OSCC) continues to be associated with a poor prognosis despite recent advances in surgical and adjuvant treatment. Although a variety of experimental models are available, no widely accepted or practical framework has combined cell lines, patient-derived organoids, and in vivo transplantation models in translational OSCC research. This review summarizes the main preclinical models used in OSCC research and discusses how they can be used together in a stepwise manner for drug development. A narrative review of the literature was conducted focusing on OSCC research cell lines, organoids, and transplantation smodels, as well as studies that have applied artificial intelligence (AI) and multi-omics analyses. Cell lines are useful for reproducible mechanistic studies and initial drug screening. Organoids better preserve tumour heterogeneity and allow patient-specific testing. Orthotopic transplantation models reproduce local invasion, metastatic spread, and interactions with the tumour microenvironment. When data from these platforms are analysed together and, where appropriate, supported by AI-based imaging and molecular profiling, their translational relevance may be enhanced. Combining cell lines, organoids, and in vivo models in a planned, stepwise approach provides a practical framework for OSCC research. This approach may help bridge the gap between experimental studies and clinical practice, particularly in oral and maxillofacial surgery.
Parapharyngeal space tumors present significant clinical challenges due to their deep anatomical location, diverse pathological types, and proximity to critical neurovascular structures, including cranial nerves and the internal carotid artery. While surgical resection is the primary treatment, it is associated with substantial risks of damaging these adjacent structures. Therefore, careful surgical planning and meticulous intraoperative technique are essential to minimize complications. A retrospective review was conducted on 106 patients with parapharyngeal space tumors treated at the Affiliated Hospital of Qingdao University from 2014 to 2024. This study evaluated parapharyngeal space (PPS) tumors in terms of clinicopathological features, preoperative imaging findings, surgical approach selection, perioperative complications and long-term recurrence patterns. Among 106 patients (61 males, 45 females; median age: 36.8 years), neck swelling was the most common symptom. Salivary gland tumors (45.3%) and neurogenic tumors (42.5%) predominated. Malignant tumors were found in 9.4% of cases. The transcervical-transparotid approach was most frequently employed (50.9%). For larger or deeper tumors, vertical ramus osteotomy provided enhanced exposure with minimal morbidity. Surgical resection remains the cornerstone of treatment for PPS tumors, achieving favorable outcomes with low recurrence and mortality rates. The selection of surgical approach depends on several factors including tumor size, precise location, proximity to major vessels, and suspicion of malignancy. While the transcervical-transparotid approach is the most common technique for benign lesions, it is imperative that surgical strategy is adapted to the individual patient's anatomy, and surgeon expertise is paramount for a successful outcome.
Postoperative nasal changes after Le Fort I osteotomy are common but incompletely explained. Inconsistencies in the anatomical descriptions of the depressor septi nasi (DSN), incisivus labii superioris (ILS) and nasalis may contribute to this uncertainty. This study investigated the structural continuity of the perinasal-labial musculature using gross and histological analysis. Thirty-eight sides from 19 formalin-fixed adult cadaveric heads were examined. Thirteen heads underwent gross dissection using bidirectional flip-flap and inside-out techniques to preserve muscular continuity. Six heads were processed for sagittal and axial histological sections. The relationships among the orbicularis oris (OOr), ILS, DSN, and nasalis were analyzed. The perinasal-labial musculature demonstrated continuous, multilayered architecture rather than discrete muscular units. The superior portion of the OOr extended toward the medial crus and dermis of the philtrum without direct septal cartilage insertion. The ILS originated from the anterior maxilla and was divided into inferior fibers blending with the OOr and superior fibers corresponding to the alar and transverse nasalis. No distinct borders were observed among these components. The DSN, ILS, and nasalis form a structurally continuous incisive muscle-OOr complex. Recognition of this continuity refines anatomical understanding and may clarify the morphological basis of nasal changes after Le Fort I osteotomy.
The objective of this study was to compare the behaviour of two biomaterials (Bonefill and Bio-Oss) and autogenous bone in human maxillary sinus grafting, through histometric and immunohistochemical analysis. Eighteen patients were divided into three equal groups: Bonefill, Bio-Oss, and Autogenous (control). After 6 months, biopsies were performed at the implant placement site. Histometry showed significantly greater bone formation for Bonefill (mean 61.90%) compared to Bio-Oss (mean 34.09%) (P = 0.002), and significantly greater percentage of remaining biomaterial for Bio-Oss (mean 14.30%) compared to Bonefill (mean 2.17%) (P = 0.017). Immunohistochemistry showed an improved maturation pattern for Bonefill in relation to Bio-Oss. It was concluded that Bonefill presented a greater amount of neoformed bone and a smaller amount of medullary connective tissue in relation to Bio-Oss.
Accurate control of maxillary vertical repositioning remains challenging in splint-based orthognathic surgery when large anteroposterior movements introduce a triangulation-related measurement effect. This technical note describes a virtual surgical planning (VSP)-based method to calculate the triangulation-adjusted change in the medial canthus-incisor distance and transfer it to the operating room. The distance is measured in VSP before and after the planned movements using identical landmarks, and the difference is used as the intraoperative caliper adjustment target during maxillary repositioning. This workflow provides a practical way to reduce measurement bias and improve fidelity between planning and execution.
Rehabilitation of the severely atrophic maxillae remains one of the most demanding challenges in implant dentistry. Zygomatic implants provide a graftless alternative that reduces morbidity and treatment time. However, long-term data exceeding a decade and including patient-reported outcomes remain limited. A retrospective cohort study was conducted on patients who received zygomatic implants from the year 2007 to 2024 at Rajan Dental Institute, Chennai, India. Data collected from digital archives were evaluated to calculate the cumulative survival rates of zygomatic implants. Patient-reported outcome measures (PROMs) on comfort, speech, esthetics, self-confidence, and overall satisfaction were assessed using a Likert-scale questionnaire. A total of 449 patients were rehabilitated with 945 zygomatic implants. Of these, 382 patients rehabilitated with 801 zygomatic implants were included in the study who met the inclusion criteria. The mean follow-up was 8.6 ± 4.1 years. Twenty implants failed in 14 patients, yielding a cumulative implant survival of 97.5% and patient-based survival of 96.3%. Statistical analysis demonstrated sustained survival beyond 15 years, with rates of 97.9% (4 years), 97% (8 years), 91.2% (12 years), and 81.7% (>15 years). PROMs indicated high satisfaction: >90% of respondents reported maximal improvement across all domains. This single-center analysis, with survival rates exceeding 97% over 17 years and excellent patient-reported outcomes, suggests that zygomatic implants provide a predictable and durable solution for severely resorbed maxillae. The integration of PROMs and survival modeling highlights the importance of both biological and psychosocial parameters in defining long-term success.
Temporomandibular joint (TMJ) internal derangements with anterior disc displacement without reduction can be treated arthroscopically. However, traditional arthroscopic disc repositioning and suturing techniques are technically demanding and associated with a steep learning curve. This technical note describes a modification of Yang's level III TMJ arthroscopy in which the suture passage is performed using a single access point through the cartilage of the external auditory canal, avoiding the need for a fourth portal. The modification aims to simplify the operative sequence by reducing the number of access points required for suture management.
Postoperative narrowing of the pharyngeal airway is a well‑recognized consequence of mandibular setback surgery, yet whether this functional compromise actually drives skeletal relapse has not been definitively shown. In this retrospective cohort study, records of 41 patients with angle class III malocclusion who underwent orthognathic surgery were analyzed to clarify this relationship. Serial lateral cephalograms and three‑dimensional scans obtained preoperatively, immediately postoperatively, and at follow‑up (mean 1.4 years) were used to quantify total and regional pharyngeal airway volume changes and mandibular relapse, defined as sagittal point B displacement. Demographic characteristics, surgical movements including setback magnitude and SN-MP rotation, osteotomy type, genioplasty, treatment approach, and baseline airway dimensions were incorporated as covariates. Correlation analyses and multivariable linear regression assessed associations between airway changes and relapse while controlling for potential confounders. The mean mandibular surgical movement was -6.32 ± 8.72 mm. There was no significant reduction in total airway volume immediately after surgery or at follow-up, and no significant mandibular relapse occurred. Also, no significant correlation was detected between airway changes and relapse in either immediate postoperative period or follow-up period, whereas greater mandibular setback independently predicted forward relapse (β = -0.64, P < 0.001). These results do not support the notion that compromised airway mechanics precipitate skeletal instability, and instead suggest that airway preservation and mandibular stability may be better conceived as parallel but independent treatment considerations.
Neurosensory disturbances in the infraorbital nerve territory are recognized sequelae of Le Fort I osteotomies; however, the operative factors contributing to their occurrence remain insufficiently defined. The authors retrospectively analyzed 102 skeletally mature patients with class II or III malocclusion who underwent Le Fort I combined with bilateral sagittal split ramus osteotomy. Using the preoperative and 1-week postoperative computed tomography scans, the anterior nasal spine displacement, maxillary molar impaction, maxillary advancement, shortest distance from the infraorbital foramen to the maxillary osteotomy line, and infraorbital foramen-to-fixation plate distance were quantified. Trigeminal somatosensory evoked potentials were recorded preoperatively, immediately postoperatively, and 6 months postoperatively to objectively assess infraorbital nerve function. Neurosensory disturbances were defined as postoperative prolongation of infraorbital nerve latency relative to each patient’s preoperative baseline. Immediate postoperative neurosensory disturbances were observed in of 49 out of 102 patients (48.0%). Compared with the non-neurosensory disturbance group, the neurosensory disturbance group exhibited greater maxillary molar impaction (P = 0.012) and shorter infraorbital foramen-to-fixation plate distances (P < 0.0001); significant differences were also noted in the trigeminal somatosensory evoked potential-derived sensory threshold (P = 0.042), N45 latency (P < 0.0001), and stimulation intensity (P < 0.0001). Stimulation intensity negatively correlated with the infraorbital foramen-to-fixation plate distance (R2 = 0.344; P < 0.0001). All neurosensory disturbances resolved completely within 6 months. A shorter infraorbital foramen-to-fixation plate distance and larger maxillary impaction were associated with immediate postoperative infraorbital nerve neurosensory disturbances. Accurate preoperative estimation of planned movements and plate positioning that maximizes clearance from the infraorbital foramen may help reduce the risk of neurosensory disturbances after Le Fort I osteotomy.
