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Sublingual hematoma is a serious complication associated with anterior mandible surgery. It presents considerable risk due to the potential for airway obstruction, which can be life-threatening and necessitates prompt diagnosis and intervention. This case report describes the occurrence of sublingual hematoma following mandibular midline osteotomy and the subsequent management of this condition. Mandibular midline osteotomy is performed to correct skeletal or dental discrepancies in the transverse plane. Sublingual hematoma as a complication of a midline osteotomy has not been previously documented in the literature. This article provides a comprehensive review of the various etiologies associated with sublingual hematoma, along with its management modalities. [ABSTRACT FROM AUTHOR]

This paper examines the relationship between roll rotation of the jaws and changes in alar base or lip line asymmetry in the coronal plane following orthognathic correction. The study involved patients with preoperative frontal alar base and lip line asymmetries greater than 0.5° (because it corresponds to the minimum asymmetry perception threshold) and underwent bimaxillary orthognathic surgery without (Group I) or with (Group II) genioplasty. The alar base angle (ABA), lip line cant angle (LLCA), maxillary cant angle (MxCA), and mandibular cant angle (MnCA) were measured using preoperative and 12 months postoperative cone beam computed tomography (CBCT) images. Thirty-four patients were included in the study. Significant correlations were found between changes in MxCA and ABA besides between changes in MnCA and LCA in Groups I (P = 0.016, P ˂0.001, respectively) and II (P = 0.002, P ˂0.001, respectively). The mean of the change in ABA/the change in MxCA and the change in LLCA/the change in MnCA ratios for Group I were 0.59 ± 1.57 and 0.73 ± 0.94, respectively, while those for Group II were 0.46 ± 3.70 and 0.39 ± 2.00, respectively. Angular measurements from jugular and mental foramina points, aligned with the bony midline, offer a convenient tool for predicting alar base and lip symmetry during bimaxillary orthognathic surgery planning. [ABSTRACT FROM AUTHOR]

Background: Square faces, which are influenced by genetic factors and structural features, are considered undesirable among the Asian population. Surgical interventions, such as mandibular angle reduction, aim to alter these characteristics, though complications may arise. We aimed to investigate the morphology of the mandibular angle and masseter muscle thickness using computed tomography (CT) and to analyze hard and soft tissue correlations to enhance surgical outcomes for patients with square faces. Methods: This retrospective clinical study included 100 Taiwanese patients aged 18–50 years. CT was used to analyze key clinical parameters, including bilateral mandibular width, mandibular divergence angle, ramus height, distance from the mandibular angle to the inferior alveolar nerve (IAN), and the thickness of the masseter muscle. Results: Significant correlations were noted between the patients’ physical height and weight, mandibular width, ramus height, masseter thickness, and distance from the angle to the IAN. Males exhibited a significantly longer and thicker ramus height (66.48 ± 4.28 mm), greater masseter thickness (15.46 ± 2.35 mm), and greater safety range for mandibular angle reduction surgery (18.35 ± 3.19 mm) (p < 0.00008). Significant correlations were observed among all parameters, except between mandibular width and gonial angle and the distance from the angle to the IAN and between mandibular divergence and masseter muscle thickness (p > 0.1). Conclusions: Our study highlighted the complex interplay among factors that contribute to square facial morphology. Careful preoperative assessments and customized surgical planning are essential for addressing this multifaceted clinical challenge.

Background: Square faces, which are influenced by genetic factors and structural features, are considered undesirable among the Asian population. Surgical interventions, such as mandibular angle reduction, aim to alter these characteristics, though complications may arise. We aimed to investigate the morphology of the mandibular angle and masseter muscle thickness using computed tomography (CT) and to analyze hard and soft tissue correlations to enhance surgical outcomes for patients with square faces. Methods: This retrospective clinical study included 100 Taiwanese patients aged 18–50 years. CT was used to analyze key clinical parameters, including bilateral mandibular width, mandibular divergence angle, ramus height, distance from the mandibular angle to the inferior alveolar nerve (IAN), and the thickness of the masseter muscle. Results: Significant correlations were noted between the patients' physical height and weight, mandibular width, ramus height, masseter thickness, and distance from the angle to the IAN. Males exhibited a significantly longer and thicker ramus height (66.48 ± 4.28 mm), greater masseter thickness (15.46 ± 2.35 mm), and greater safety range for mandibular angle reduction surgery (18.35 ± 3.19 mm) (p < 0.00008). Significant correlations were observed among all parameters, except between mandibular width and gonial angle and the distance from the angle to the IAN and between mandibular divergence and masseter muscle thickness (p > 0.1). Conclusions: Our study highlighted the complex interplay among factors that contribute to square facial morphology. Careful preoperative assessments and customized surgical planning are essential for addressing this multifaceted clinical challenge. [ABSTRACT FROM AUTHOR]

AbstractThree different kinds of condylar inclination were manually modelled anteriorly inclined condylar neck, vertical condylar neck, and posteriorly inclined condylar neck. Three different maxillary impactions were simulated to evaluate the effect of counterclockwise rotation. The von Misses stresses of the disc, compressive stresses of the glenoid fossa, and compressive stresses of the condyle were the highest in the models with posteriorly inclined neck and lowest in the models with vertical condylar neck design. Stresses of the temporomandibular joint increase with the counterclockwise rotation of the maxilla-mandibular complex. The posteriorly inclined neck should be considered a risk factor for condylar resorption with increased counterclockwise rotation. [ABSTRACT FROM AUTHOR]

Objective: Unknown etiology. Background: Ameloblastoma is a locally aggressive, benign, odontogenic tumor. Reports suggest that the chances of recurrence of this tumor are high if treated with a conservative approach. Concordantly, surgical removal of the lesion along with the affected adjacent tissues and bone structure is recommended to reduce the chances of recurrence. Post-surgical prosthetic rehabilitation is advised to improve speech, mastication, and aesthetic appearance. This case report highlights the treatment and reconstruction challenges that maxillofacial surgeons and their teams face in managing cases of large ameloblastoma. Case Report: A 41-year-old Sudani man was referred for the management of a large ameloblastoma associated with the left border of the mandible. Management consisted of surgical removal of the affected mandible along with prosthetically preserving the mandible with grafts and screws. Histopathological, computed tomography, and incisional biopsy evaluation confirmed the presence of ameloblastoma. Postoperatively, no complications were reported. Six months postoperatively, no sign of recurrence was seen. The patient was referred to a surgeon for placement of an endosseous implant. Conclusions: When dealing with large ameloblastoma, an interdisciplinary dental team is essential for improving the treatment results. This case highlights the importance of precise and timely primary care diagnosis and a collaborative approach to treatment. By embracing advancements in digital technologies, surgeons can enhance functional and aesthetic results, improving long-term quality of life. [ABSTRACT FROM AUTHOR]

Objective To investigate the efficacy of drawer-genioplasty in correcting the long-chin deformity and preventing postoperative sagging of submental soft tissues. Methods Forty-two patients with long-chin deformity admitted to the Department of Craniomaxillofacial Surgery, Plastic Surgery Hospital from October 2020 to December 2023 were selected for this study. The modified drawer-genioplasty was performed through an intraoral incision approach, using subapical and mandibular contouring osteotomy. The osteotomy lines were designed and performed during surgery to minimize damage to the bone attachments of the anterior belly of the digastric muscle, mylohyoid muscle, and geniohyoid muscle to protect the floor-of-mouth muscles adequately. Digital technology enabled the assessment of surgical outcomes through the analysis of three-dimensional reconstruction of bone and facial scanning. Follow-up visits were conducted 6-12 months post-surgery. Results All patients achieved uncomplicated primary healing at gingiva-labial sulcus incisions, without any occurrences of hematoma, infection, or bone necrosis. The digital analysis revealed a postoperative ratio change of 1:0.86 between the chin bones and soft tissues. Measurements demonstrated an increase in R1 (the ratio of the middle and lower face) from preoperative 0.82±0.09 to postoperative values 0.92±0.11, as well as an increase in R2 (the ratio of the upper and lower lips) from preoperative 0.52±0.06 to postoperative values 0.63±0.05. However, there was an increase in the mentocervical angle from preoperative 104.90°± 8.02° to postoperative 111.50°±7.03°, this value was still within the normal range. The results above demonstrated statistically significant differences (P<0.05). Two patients experienced transient lower lip numbness postoperatively, which resolved at four months and ten months respectively. All patients expressed satisfaction with their postoperative facial contour morphology. Conclusion The modified drawergenioplasty demonstrates both safety and efficacy in correcting patients with long chin deformity, while effectively preventing postoperative sagging of the submental soft tissues, thereby exhibiting significant clinical applicability. [ABSTRACT FROM AUTHOR]

Objectives: To investigate soft-to-hard tissue response following mandibular reconstruction and to develop a predictive model for projecting soft tissue movement. Materials and methods: In this retrospective study, 18 patients receiving mandibular reconstruction using a vascularized iliac flap were enrolled. Various indicators for characterizing the movement of tissues were considered to identify the effective predictors for projecting soft tissue movements. Face-region-specific linear regression models for prediction were constructed and evaluated. Results: The arithmetic mean of hard tissue movement in an extended area had the strongest correlation with the movement of the focal soft tissue, while the arithmetic mean in a regional area (Ram) was a more effective predictor. The linear regression model using Ram, global extrema and distances between them as the predictors performed the best in the lower margin of the face, with an average error of 1.51 ± 1.38 mm. Soft tissue movement in the alveolar process was not correlated with the existence of dentition, only can be predicted by the soft tissue movement below it. The area of the masseter was strongly correlation with Ram, but no other factors. Conclusions: An accurate prediction of soft tissue movements in the lower margin and the alveolar process of the face can be achieved by considering hard tissue and adjacent soft tissue movements. No effective predictor in the masseter area was identified. Clinical relevance: We investigated the relationship between hard tissue movements and the soft tissue responses in the facial area. Through building predictive models for projecting postoperative soft tissue movements, we derive insights for the aesthetic outcome of face surgeries. Clinical trial registration: This study was registered on the Chinese Clinical Trial Registry (registration number: ChiCTR2100054103). [ABSTRACT FROM AUTHOR]

Background/Objective: With the rapid advancement in surgical technologies, new workflows for mandibular reconstruction are constantly being evaluated. Cutting guides are extensively employed for defining osteotomy planes but are prone to errors during fabrication and positioning. A virtually defined osteotomy plane and drilling holes in robotic surgery minimize potential sources of error and yield highly accurate outcomes. Methods: Ten mandibular replicas were evaluated after cutting-guided saw osteotomy and robot-guided laser osteotomy following reconstruction with patient-specific implants. The descriptive data analysis summarizes the mean, standard deviation (SD), median, minimum, maximum, and root mean square (RMS) values of the surface comparison for 3D printed models regarding trueness and precision. Results: The saw group had a median trueness RMS value of 2.0 mm (SD ± 1.7) and a precision of 1.6 mm (SD ± 1.4). The laser group had a median trueness RMS value of 1.2 mm (SD ± 1.1) and an equal precision of 1.6 mm (SD ± 1.4). These results indicate that robot-guided laser osteotomies have a comparable accuracy to cutting-guided saw osteotomies, even though there was a lack of statistical significance. Conclusions: Despite the limited sample size, this digital high-tech procedure has been shown to be potentially equivalent to the conventional osteotomy method. Robotic surgery and laser osteotomy offers enormous advantages, as they enable the seamless integration of precise virtual preoperative planning and exact execution in the human body, eliminating the need for surgical guides in the future. [ABSTRACT FROM AUTHOR]

Elective mandibular surgical osteotomies are commonly used to correct craniofacial discrepancies. Since the modifications proposed by Obwegeser, Dal Pont, and Hunsuck, no effective variations have been proposed to improve the biomechanical results of these mandibular osteotomies. With technological developments and the use of three-dimensional images from CT scans of patients, much has been done to plan and predict outcomes with greater precision and control. To date, 3D imaging and additive manufacturing technologies have not been used to their full potential to create innovative mandibular osteotomies. The use of 3D digital images obtained from CT scans as DICOM files, which were then converted to STL files, proved to be an efficient method of developing an innovative mandibular ramus beveled osteotomy technique. The new mandibular osteotomy is designed to reduce the likelihood of vasculo-nervous damage to the mandible, reduce the time and ease of surgery, and reduce post-operative complications. The proposed osteotomy does not affect traditional osteotomies. Anatomical structures such as the inferior alveolar nerve and intraoral surgical access were preserved and maintained, respectively. The results obtained from the digital images were validated on an additively manufactured 3D synthetic bone model. [ABSTRACT FROM AUTHOR]

This systematic review aimed to investigate the factors that may contribute to the development of OSA after orthognathic surgery in patients with skeletal class III. Electronic searches of PubMed, Embase, Web of Science, and Cochrane databases were conducted up to December 10, 2022. In total, 277 studies were retrieved and screened according to the inclusion and exclusion criteria, and 14 were finally selected. All studies were of medium quality (moderate risk of bias). The occurrence of OSA after orthognathic surgery in patients with class III skeletal relationships depends on surgical factors and patient self-factors. Surgical factors include surgery type, amount of maxillary and mandibular movement, and the patient's postoperative swelling. Patient self-factors include weight, age, gender, and hypertrophy of the soft palate, tonsils, and tongue. According to information in the 14 selected articles, the incidences of OSA after Le Fort I impaction and BSSO setback, BSSO setback, and Le Fort I advancement and BSSO setback were 19.2%, 8.57%, and 0.7%, respectively, mostly accompanied with greater amounts of mandibular recession. However, no clear evidence exists to confirm that orthognathic surgery is a causative factor for postoperative sleep breathing disorders in patients with mandibular prognathism. The wider upper airway in patients with class III skeletal might be the reason for the rare occurrence of OSA after surgery. In addition, obesity and advanced age may lead to sleep apnea after orthognathic surgery. Obese patients should be advised to lose weight preoperatively. [ABSTRACT FROM AUTHOR]

The aim of the present study was to propose and validate FAST3D: a fully automatic three-dimensional (3D) assessment of the surgical accuracy and the long-term skeletal stability of orthognathic surgery. To validate FAST3D, the agreement between FAST3D and a validated state-of-the-art semi-automatic method was calculated by intra-class correlation coefficients (ICC) at a 95 % confidence interval. A one-sided hypothesis test was performed to evaluate whether the absolute discrepancy between the measurements produced by the two methods was statistically significantly below a clinically relevant error margin of 0.5 mm. Ten subjects (six male, four female; mean age 24.4 years), class II and III, who underwent a combined three-piece Le Fort I osteotomy, bilateral sagittal split osteotomy and genioplasty, were included in the validation study. The agreement between the two methods was excellent for all measurements, ICC range (0.85–1.00), and fair for the rotational stability of the chin, ICC = 0.54. The absolute discrepancy for all measurements was statistically significantly lower than the clinical relevant error margin (p < 0.008). Within the limitations of the present validation study, FAST3D demonstrated to be reliable and may be adopted whenever appropriate in order to reduce the work load of the medical staff. [ABSTRACT FROM AUTHOR]

ObjectiveThe objective of this study was to assess characteristics of patients with mandibular osteoradionecrosis (ORN) of severity necessitating segmental mandibulectomy and osteocutaneous free flap reconstruction.Study designThis study is a retrospective review of patients who underwent free flap reconstruction of the mandible at the UCLA Medical Center between January 2016 and February 2020 secondary to ORN.ResultsTwenty-nine charts with detailed dental and medical records were identified. Hypertension was reported in 14 of 29 patients, diabetes in 2 of 29, osteoporosis in 2 of 29, antiresorptive use in 3 of 29, tobacco use in 15 of 29, and alcohol use in 19 of 29. Twenty-three patients initially had stage III-IV cancer. The median radiation dose was 68 Gy and median time to ORN was 5.2 years. Chemotherapy was given in 21 patients and 4 had previous mandibular surgery. Twelve of 29 patients had surgical procedures identified as the causative factor and 17 of 29 occurred spontaneously. Median decayed, missing, and filled teeth score was 17 and 17 of 29 patients had grade II-IV periodontitis. Periodontitis was present in 8 of 17 of spontaneous and 1 of 12 of surgery cases. Twenty-five of 29 cases occurred in the same oral sextant as the tumor.ConclusionSevere ORN occurred at doses >60 Gy in most cases. Location of the primary tumor was predictive of site of ORN and only molars were involved when precipitated by tooth extraction. Risk of ORN persists indefinitely.

The purpose of the present study was to compare the precision and reliability of voxel- and surface-based registration for computer-assisted assessment of the surgical accuracy and postoperative stability of segmental bimaxillary surgery. Three-dimensional translational and rotational measurements were performed by two observers using voxel- and surface-based registration. The precision and reliability of the measurements were calculated by the mean absolute differences (MAD) and intraclass correlation coefficients (ICC) at 95 % confidence intervals. A paired t-test or the non-parametric equivalent, Wilcoxon signed-rank test, was applied to statistically evaluate whether the precision of voxel- and surface-based registration was statistically significantly different (p

Objectives: To reveal the change patterns of the facial soft tissue after applying mandibular reconstruction. Materials and Methods: 16 Patients with mandibular benign tumor were recruited in this retrospective study. For all patients, segmental mandibular osteotomy and concurrent reconstruction using vascularized iliac flap were conducted. The soft tissue thickness of patients' lower face was measured with CT scans before surgery, 1 week, 6 months and 1 year after surgery. The time-dependent changes of tissue thickness were analyzed. Results: The most significant tissue swelling was 28.86%, at 1 week after the surgery. The average increase of tissue thickness was 4.78 ± 5.30 mm across patient. After 1 year of the surgery, tissue thickness decreased to the level before operation or the level of the healthy side. The thickness of the low-density tissue fluctuated mildly, while the thickness of the high-density tissue fluctuated significantly. The disuse atrophy of the masseter occurred 1 week after the surgery, and was reversed after 1 year. The removal of the submandibular gland caused depression in submandibular area, which intensified over time. Conclusion: Across patients, soft tissue thickness in the lower face after mandibular osteotomy and reconstruction increased significantly 1 week after the surgery, and decreased over time. After 1 year, tissue thickness went back to the pre-surgery level, where matched up with the healthy side. Clinical relevance: We documented the change patterns of the facial soft tissue after mandibular reconstruction. These results can help improve the planning of virtual surgeries and the timing for aesthetic assessment. Trial Registration: ClinicalTrials.gov Identifier: ChiCTR2100054103. [ABSTRACT FROM AUTHOR]

A clinical trial was performed to assess the analgesic efficacy of adding ropivacaine pre-extubation for pain management after bimaxillary osteotomy. Forty-eight patients were assigned to receive general anaesthesia followed by either a single pre-incisional infiltration with lidocaine (control group, n = 24) or the same pre-incisional infiltration with lidocaine and an additional second infiltration with ropivacaine before awakening (test group, n = 24). Postoperative pain was assessed subjectively using a visual analogue scale and objectively based on the frequency of postoperative rescue opioid consumption. The dose of opioids (methadone) consumed and frequency of postoperative-nausea-vomiting were also recorded. Patients who received the two infiltrations of local anaesthetic had better results in terms of lesser pain during the first 8 hours postoperative (P <0.001 at 2 and 4 hours; P = 0.028 at 8 h), a lesser need for rescue opioids (P = 0.020) and lower doses of rescue opioids (P = 0.011), and consequently a lesser incidence of postoperative-nausea-vomiting (0–4 hours postoperative, P <0.03). The results obtained suggest that the infiltration of an additional dose of local anaesthetic is a simple strategy for reducing pain perception and opioid use, and for ensuring greater patient comfort after bimaxillary osteotomy. [ABSTRACT FROM AUTHOR]

This study aimed to assess preoperative radiological and clinical examinations for identifying bone status and to evaluate survival outcomes in patients undergoing marginal mandibulectomy for the primary treatment of oral squamous cell carcinoma. The medical records, enhanced computed tomography (CT) scans, and pathological specimens of these patients were reviewed. Disease-free (DFS), local recurrence-free (LRFS), and osteoradionecrosis-free (ORNFS) survival were analysed. The study included 104 patients. The preoperative CT and clinical examinations achieved a sensitivity of 45.8% and specificity of 100% for judging bone condition. LRFS was 79.6% and DFS was 68.8%. Pathological bone invasion in significantly affected DFS (P = 0.597), while DFS was significantly higher for those with a lower clinical tumour stage (1/2 vs 3/4; P = 0.005) and postoperative radiotherapy (P = 0.011). Among 39 patients receiving postoperative radiotherapy, ORNFS was 75.2%. Postoperative chemotherapy significantly decreased ORNFS (P = 0.009). Tumour subsite (P = 0.003) and the resection site (P = 0.035) significantly affected the remaining bone height. The results indicate that CT and clinical examinations cannot precisely identify superficial bone damage, but work well in selecting patients for marginal resection. Adhering to current indications, this resection approach can guarantee safe bone margins in terms of survival outcomes. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the virtually planned position to the postoperative position of the maxilla, having performed the maxilla-first sequence or mandible-first sequence orthognathic surgery. An audit of 64 patients who underwent bimaxillary surgery between 2017 and 2020 was performed. Thirty patients had maxilla-first surgery and 34 had mandible-first surgery. The planned and post-surgical positions were analyzed using specific skeletal landmarks. Differences were calculated and the two-sample t -test was used to compare the groups. Measured differences between the planned and postoperative results differed significantly between the mandible-first and maxillary-first surgery groups (P < 0.001). The maxillary central incisors were under-advanced in the anterior–posterior direction in both groups. Most data points showed deviation from the surgical plan ≤ 2 mm and ≤ 4°. Secondarily, maxillary under-advancement in the mandible-first cohort was evaluated; these patients were subdivided into rigid and non-rigid fixation groups. The non-rigid fixation group showed less accuracy compared to the rigid fixation group, which was statistically significant (P = 0.014). The findings of this study demonstrate that virtual surgical planning can be less accurate in predicting the maxillary incisor position when performing mandible-first surgery, but this inaccuracy is within the acceptable range and can be mitigated by rigid fixation of the mandible. [ABSTRACT FROM AUTHOR]

Elective mandibular surgical osteotomies are commonly used to correct craniofacial discrepancies. Since the modifications proposed by Obwegeser, Dal Pont, and Hunsuck, no effective variations have been proposed to improve the biomechanical results of these mandibular osteotomies. With technological developments and the use of three-dimensional images from CT scans of patients, much has been done to plan and predict outcomes with greater precision and control. To date, 3D imaging and additive manufacturing technologies have not been used to their full potential to create innovative mandibular osteotomies. The use of 3D digital images obtained from CT scans as DICOM files, which were then converted to STL files, proved to be an efficient method of developing an innovative mandibular ramus beveled osteotomy technique. The new mandibular osteotomy is designed to reduce the likelihood of vasculo-nervous damage to the mandible, reduce the time and ease of surgery, and reduce post-operative complications. The proposed osteotomy does not affect traditional osteotomies. Anatomical structures such as the inferior alveolar nerve and intraoral surgical access were preserved and maintained, respectively. The results obtained from the digital images were validated on an additively manufactured 3D synthetic bone model.

Introduction: Orthognathic surgery involves the manipulation of facial bone architecture through osteotomies to restore form and function, correcting malocclusion, maxillomandibular disproportions, and facial asymmetries. Virtual planning in orthognathic surgery is carried out with the help of software that uses real measurements of the craniofacial skeleton and records of the patient’s occlusion through 3D analysis. Method: 18 patients with dentofacial deformities were evaluated, according to Angle’s classification, who underwent orthognathic surgery using virtual planning between 2018 and 2019. The inclusion criteria were patients between 16 and 60 years old with maxylo-mandibular disproportions in which orthodontic treatment alone was not sufficient. Exclusion criteria were the presence of cystic or tumoral lesions in the jaw and clinical comorbidities that contraindicated surgery. Virtual planning was carried out on all patients, using Dolphin® Imaging 11 software and surgical guides made with a 3D printer. Results: The intermediate surgical guide presented perfect adaptation on the occlusal surfaces, promoting great stability for the repositioning and fixation of the maxilla in intermediate occlusion. The 18 operated patients responded as “completely satisfied” in relation to the aesthetic-functional result in this series studied. A very great similarity was found between the position of the maxillofacial skeleton in the pre-operative virtual planning and that obtained post-operatively through the evaluation of teleradiography. Conclusion: Virtual planning in craniomaxillofacial surgery has numerous advantages, such as reduced pre-operative laboratory time, greater precision in the creation of surgical guides, and better reproducibility of simulated results.

Background: Mandibular angle osteotomy (MAO) is a frequently described technique in Eastern females. The success hinges on the precise positioning of the osteotomy line. The geometric mathematical method is viable. Therefore, we explored the impact of mandibular angle osteotomy using aesthetic standards and printed digital osteotomy templates (DOTs) on the aesthetic osteotomy line. Methods: This retrospective observational study included female patients with prominent mandibular angle (PMA) who underwent MAO at our hospital between January 2020 and March 2021. Thirty-three female patients were included, 22 in the DOTs group using new DOTs, and 11 in the traditional group using traditional free-hand techniques. Results: Regarding the width of the excised bone, the postoperative deviation from the preoperative plan was not significant in the DOTs group (0.5 ± 0.3 mm, P > 0.05), while the deviation was significant for the traditional group (2.5 ± 1.2 mm, P<0.05). The preparation time was longer in the DOTs group than in the traditional group (82 ± 11 vs. 53±4 min, P < 0.001). The osteotomy time and the operation time were shorter in the DOTs group than in the traditional group (osteotomy: 54 ± 5 vs. 73 ± 6 min; preparation: 124 ± 10 vs. 169 ± 13 min; both P < 0.001). The Likert (4.0 ± 0.5 vs. 1.0 ± 0.6, P = 0.006) and FACE-Q scores (17.5 ± 1.7 vs. 15.6 ± 1.3, P = 0.029) were higher in the DOTs group. Conclusions: The new method of positioning the new aesthetic osteotomy line based on geometric analysis might provide a possible osteotomy method that strongly suggests effectiveness, safety, individualization, and accuracy, with a shorter operation and higher patient satisfaction. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the changes in the upper airway following mandibular setback surgery. Methods: The patients underwent mandibular setback surgery and cone‐beam computed tomography scan data obtained at four time points: before surgery, immediately after surgery, short‐ and long‐term follow‐up. Upper airway geometries were segmented and extracted at each time point. Time‐averaged airflow through the upper airway was evaluated at each time point. The measurements of airway volume and minimum cross‐sectional areas were obtained at four time points. Results: The airway volume and cross‐sectional areas of airway significantly decreased immediately after surgery (p = 0.013 for airway volume and 0.016 for cross‐sectional area). At short‐term follow‐up, the decreased airway volume and cross‐sectional areas still showed statistically significant difference to original dimension (p = 0.017 for airway volume and 0.006 for cross‐sectional area). At long‐term follow‐up, although there were no statistical significances (p = 0.859 for airway volume and 0.721 for cross‐sectional area), the airway volume and cross‐sectional areas had increased slightly compared to those at short‐term follow‐up. Conclusions: Although the airflow and dimensional parameters of the upper airway worsened following mandibular setback surgery, there was a tendency to gradually recover during long‐term follow‐up. [ABSTRACT FROM AUTHOR]

Segmental mandibular advancement (SMA) consists of a combination of bilateral sagittal split osteotomy, anterior subapical osteotomy with extraction of the first premolars, and genioplasty, to allow an extended advancement of the mandible for the improvement of tongue base obstruction in moderate-to-severe obstructive sleep apnoea (OSA) and to minimize any unfavourable aesthetic change due to the large jaw advancement. The aim of this pilot study was to evaluate the surgical outcomes and complications following SMA in OSA patients. Twelve patients (nine male, three female) underwent SMA as part or whole of their skeletal advancement procedure for OSA. The apnoea–hypopnoea index (AHI) improved from a mean± standard deviation 42.4 ± 22.0/hour preoperatively to 9.0 ± 17.4/hour at 1 year postoperative. Surgical success (50% reduction in AHI) was achieved in 11 of the 12 patients (91.7%) at 1 year postoperative, while seven patients (58.3%) attained surgical cure (AHI<5/hour). The lowest oxygen saturation (LSAT) increased from a mean 73.3% preoperatively to 78.7% at 1 year postoperative. The airway volume increased from a mean 2.4 ± 1.7 cm3 at baseline to 6.7 ± 3.5 cm3 at 1 year postoperative (P < 0.001). No major complication occurred. This pilot study showed that SMA appears to be safe and effective as part or whole of the skeletal advancement surgery for moderate-to-severe OSA. [ABSTRACT FROM AUTHOR]

With the advancement of digital technology over the last few decades, the use of virtual surgical planning and fabrication of surgical guides have tremendously improved the outcomes of various maxillofacial surgical procedures. The intraoral vertical ramus osteotomy (IVRO) is an orthognathic surgical procedure largely employed for mandibular setback in correcting dentofacial deformities. This study describes the design and application of a surgical cutting guide for IVRO. The guide can also be used to facilitate the placement of miniplate fixation. The initial experience at the authors' centre suggests that the guide has allowed the osteotomy to be performed with increased precision and confidence. Furthermore, the use of miniplate fixation decreased the period of maxillomandibular fixation. However, a larger series is required to evaluate the utility of this system more thoroughly. [ABSTRACT FROM AUTHOR]

Background Craniofacial fibrous dysplasia (CFD) is an uncommon benign condition in which a bone is replaced by fibrous tissue. An adequate clinical characterization considering the number of affected bones and functional impairment is important to determine the most effective surgical intervention for its management. This study aims to present our institution's experience in the evaluation and management of CFD. Methods This was a retrospective study that included patients with CFD managed at our institution. Data included demographic characteristics, afflicted bones, surgical procedures performed, and recurrence. Results are presented as mean and percentages. Recurrence-free years and association between the type of surgery and recurrence was evaluated. Results Eighteen patients were included (11 females, 61%). The zygomatic, maxillary, and frontal bones were the most commonly affected with eight (18%) cases each. The most common procedure was bone burring, with 36 procedures. Recurrence was more prevalent after burring (58.3%) and occurred earlier than in the bone resection group (13 vs. 15 years, p > 0.05). Conclusion Surgery continues to be the cornerstone of CFD treatment. Bone burring is effective for debulking and contouring but increases the risk for recurrence. An individualized approach should be tailored according to the anatomical location of the disease, type of CFD, behavior of the lesion, and accompanying clinical complaints.

Objectives: The mechanisms of regional acceleratory phenomenon (RAP) induced by orthognathic osteotomy are unclear. It was not known if locally hypoxic microenvironment changes were involved in this phenomenon. Methods: Hypoxia‐induced factor‐1α knockout mice harboring Cathepsin K (CTSK) Cre were used to investigate the effect of hypoxia‐driven osteoclasts on alveolar bone remodeling. RAW264.7 cells were induced by CoCl2 to observe the effects of dendritic cell‐specific transmembrane protein (DC‐STAMP) on the fusion and differentiation of osteoclasts. Results: We found mandibular osteotomy of C57 mice induced active alveolar osteoclasts and increased hypoxia‐induced factor‐1α (HIF‐1α) positive staining areas. Alveolar bone density of the 10‐week‐old HIF‐1α conditional knockout (CKO) mouse was increased at 10 and 14 days after bilateral mandibular osteotomy. Moreover, decreased numbers of osteoclasts and matrix metalloproteinase 9 (MMP‐9)‐positive cells were observed on the surface of bone resorption lacunae in the CKO group. HIF‐1α could increase the expression level of DC‐STAMP to enhance osteoclastogenesis and cell fusion in active RAW264.7 cells. Conclusion: Our data considered hypoxia‐driven osteoclasts resorption to be an adaptive mechanism to permit alveolar bone loss after bilateral mandibular osteotomy of mice. [ABSTRACT FROM AUTHOR]

This study was performed to present a single operator's experience of in-office (outside of a hospital setting) outpatient orthognathic surgery over a period of 12 years. A total of 254 surgeries were performed during this period. Average procedure times were comparable with published results from studies of similar material. The mean operating time for bimaxillary surgery (n = 21) was 3 hours and 11 minutes. Regarding single-jaw procedures, the mean operating time for Le Fort I osteotomy (n = 115) was 2 hours and 14 minutes and for bilateral sagittal split osteotomy (n = 118) was 2 hours and 1 minute. All patients were discharged from the office the same day, except one patient who was transported to the hospital after surgery due to an anaesthetic complication. This patient was discharged from the hospital later the same day. In this setting, outpatient orthognathic surgery is both safe and practical when careful attention is given to patient preparation and selection. Emergency phone contact with the surgeon in case of complications is important to avoid unnecessary hospitalization. [ABSTRACT FROM AUTHOR]

OBJECTIVE:To evaluate and quantify the kinematic behavior of canine mandibles before and after bilateral rostral or unilateral segmental mandibulectomy as well as after mandibular reconstruction with a locking reconstruction plate in ex vivo conditions. SAMPLE:Head specimens from cadavers of 16 dogs (range in body weight, 30 to 35 kg). PROCEDURE:Specimens were assigned to undergo unilateral segmental (n = 8) or bilateral rostral (8) mandibulectomy and then mandibular reconstruction by internal fixation with locking plates. Kinematic markers were attached to each specimen in a custom-built load frame. Markers were tracked in 3-D space during standardized loading conditions, and mandibular motions were quantified. Differences in mandibular range of motion among 3 experimental conditions (before mandibulectomy [ie, with mandibles intact], after mandibulectomy, and after reconstruction) were assessed by means of repeated-measures ANOVA. RESULTS:Both unilateral segmental and bilateral rostral mandibulectomy resulted in significantly greater mandibular motion and instability, compared with results for intact mandibles. No significant differences in motion were detected between mandibles reconstructed after unilateral segmental mandibulectomy and intact mandibles. Similarly, the motion of mandibles reconstructed after rostral mandibulectomy was no different from that of intact mandibles, except in the lateral direction. CONCLUSIONS AND CLINICAL RELEVANCE:Mandibular kinematics in head specimens from canine cadavers were significantly altered after unilateral segmental and bilateral rostral mandibulectomy. These alterations were corrected after mandibular reconstruction with locking reconstruction plates. Findings reinforced the clinical observations of the beneficial effect of reconstruction on mandibular function and the need for reconstructive surgery after mandibulectomy in dogs.

Background Craniofacial fibrous dysplasia (CFD) is an uncommon benign condition in which a bone is replaced by fibrous tissue. An adequate clinical characterization considering the number of affected bones and functional impairment is important to determine the most effective surgical intervention for its management. This study aims to present our institution's experience in the evaluation and management of CFD. Methods This was a retrospective study that included patients with CFD managed at our institution. Data included demographic characteristics, afflicted bones, surgical procedures performed, and recurrence. Results are presented as mean and percentages. Recurrence-free years and association between the type of surgery and recurrence was evaluated. Results Eighteen patients were included (11 females, 61%). The zygomatic, maxillary, and frontal bones were the most commonly affected with eight (18%) cases each. The most common procedure was bone burring, with 36 procedures. Recurrence was more prevalent after burring (58.3%) and occurred earlier than in the bone resection group (13 vs. 15 years, p > 0.05). Conclusion Surgery continues to be the cornerstone of CFD treatment. Bone burring is effective for debulking and contouring but increases the risk for recurrence. An individualized approach should be tailored according to the anatomical location of the disease, type of CFD, behavior of the lesion, and accompanying clinical complaints. [ABSTRACT FROM AUTHOR]

Introduction: The bilateral sagittal split ramus osteotomy (BSSRO) is the technique in vogue which is used for correction of a range of mandibular corpus deformity involving the dentoalveolar segment. The surgical technique has been subjected to a variety of modifications ever since its inception in the 1950s. One of the operative objectives which has been advocated sacrosanct has been the visual identification of lingula during the exposure of the medial aspect of the ramus. Materials and Method: BSSRO was successfully carried out in 45 cases operated over a period of eight years for correction of different kinds of skeletal mandibular deformity. The medial subperiosteal dissection did not involve a visual identification of the lingula. Conclusion: In our experience, the visual identification of the lingula is not essential to carry out a safe BSSRO procedure. [ABSTRACT FROM AUTHOR]

Objective: To investigate the stability and complications of mandibular anterior subapical osteotomy (ASO) in the treatment of bimaxillary dentoalveolar protrusion by way of a retrospective study. Materials and methods: One hundred and twenty patients who received orthognathic surgery at a single center between 2008 and 2017 were included. Relapse was assessed by serial tracings of lateral cephalograms which were obtained pre-operatively (T1), within 6 weeks after surgery (T2) and at 2 years after surgery. The changes between T2 and T3 represented stability and were tested using the paired t test. The relationship between the extents of surgical repositioning (T2–T1) and relapse (T3–T2) was investigated using the Pearson correlation coefficient. The associations between the variables and the occurrence of relapse and complications identified the risk factors and were evaluated using the χ2 test or Fisher's exact test. When r > 0.80, clinical correlation was considered significant; and statistical significance was set at P < 0.05, while confidence interval was set at 95%. Results: There was a mean uprighting of L1-MP by 12.7°. At 2 years after surgery, 96.7% of the patients experienced a mean relapse of L1-MP by 2.9°. The extent of surgical repositioning was only weakly correlated with that of relapse and no specific factor that increased the risk of relapse could be identified. The most frequent complications were blood loss requiring transfusion, wound dehiscence or infection, gingival recession, and periodontal bone loss, involving 25.8 to 43.3% of the patients. The remaining complications included tooth root damage, fixation hardware exposure or infection, lingual mucosal laceration, and tooth devitalization. There were no cases of avascular necrosis or nonunion. Conclusions: Although relapse occurred in most of the patients after 2 years, the actual extent was small (2.9°) which was not likely to be clinically significant. Trial registration: HKUCTR-2964 Clinical relevance: Although ASO may be valuable in correcting mandibular dentoalveolar protrusion, the procedure brings with it risks and complications and should be reserved for severe deformities. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was to provide a structured overview of three-dimensional airway volume changes in relation to various orthognathic surgeries. Clinical human studies performing pre- and postoperative three-dimensional airway volume assessments to investigate volumetric changes of the airway after orthognathic surgery were included. Pre-determined inclusion and exclusion criteria were applied in an extensive search of the PubMed, Embase, and Web of Science electronic databases. The cut-off date was set to January 1, 2022. Forty-one articles reporting retrospective and prospective case–control and case series studies were included. All studies were determined to be of medium quality (moderate risk of bias). The included studies were categorized by type of intervention. Pre- and postoperative volumes were extracted from the available data, and volume changes as a percentage of the preoperative levels were calculated. Isolated mandibular setback surgery generally decreased the airway volume. Isolated maxillary or mandibular advancement, bimaxillary advancement, and surgically assisted maxillary expansion generally increased the airway volume in the total airway and oropharynx, among which the effect of bimaxillary advancement surgery appeared most significant. High heterogeneity exists in the terminology and definitions of the airway and its segments. A more uniform methodology for airway volume measurement is needed to provide an insight into the impact on the airway of specific types of surgical intervention. In conclusion, airway volumes are affected after orthognathic surgery, which may be of clinical significance, especially in patients who are predisposed to obstructive sleep apnoea. [ABSTRACT FROM AUTHOR]

Condylar hyperplasia is one of the causes of facial asymmetry and malocclusion, characterized by enlargement of the lower jaw due to excessive condyle growth activity. The aim of this study was to use micro-computed tomography (micro-CT) to evaluate the bone architecture of the condylar head and determine whether there are differences between patients with various forms of unilateral condylar hyperplasia (UCH): hemimandibular hyperplasia, elongation, and mixed form. The cohort consisted of 28 patients with a mean age of 21.9 years. All patients underwent surgical treatment (condylar shaving) for active pathological growth activity. The portion of the condylar head removed was imaged by micro-CT and subsequently evaluated. Micro-CT imaging and semiquantitative and quantitative evaluation of the bone structure (percentage bone volume, surface density, trabecular thickness, trabecular separation, degree of anisotropy, and porosity of the subchondral bone) did not reveal significant differences between the individual types of condylar hyperplasia (P > 0.05). There were no significant differences in bone structure between the anterior and posterior portions of the condylar head. No statistically significant differences between individual groups of UCH were found in the micro-CT evaluation of the condylar head bone architecture. [ABSTRACT FROM AUTHOR]

Parapharyngeal space tumors have poor subjective symptoms and often grow until diagnosed; therefore, mandibular transection may be needed to obtain a wider field of view during surgery. However, if a median lower lip incision is performed for the mandibular transection, esthetic problems occur after surgery. Here, we report two cases of parapharyngeal space tumors that were removed with a mandibular lateral segment‐osteotomy technique without median lower lip incision to avoid esthetic problems. Case 1 was a 49‐year‐old woman. She was aware of a right tonsillar swelling, and an imaging test revealed a tumor lesion 60 mm in size in the right parapharyngeal space. Case 2 was a 40‐year‐old woman with an abnormal position of the uvula, and an imaging test showed the left parapharyngeal space tumor lesion 45 mm in size. Both cases were diagnosed as a pleomorphic adenoma, and surgery under general anesthesia was performed jointly with otolaryngology and oral surgery. The incision was performed from the lower part of the right auricle to the anterior part of the submandibular area. After the tumor resection, the mandible was repositioned, fixed by plates, and the intermaxillary fixation was performed with a surgical stent. In both cases, slight paralysis of the mandibular branch of the facial nerve and the mental nerve was observed after the operation, but they were improved immediately. One year after the operation, the plates were removed. There have been no recurrences until now. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the indications and outcomes of the total inferior border ostectomy and T-shape genioplasty. A retrospective study was conducted using the clinical notes and records of patients who underwent total inferior border ostectomy (group 1, n = 42) and T-shape genioplasty (group 2, n = 60). The outcomes were evaluated by assessment of computed tomography images combined with medical records and photographs. Lower facial height, chin width, chin symmetry, and facial proportions, as well as patient satisfaction and complications were investigated. The data were collected preoperatively and 6–24 months postoperatively. All 102 patients showed an improved lower facial contour. No severe complications were observed during the follow-up period. Although the postoperative lower to midfacial height ratios were similar in the two groups (P = 0.080), both the preoperative and postoperative chin width to lower facial height ratios were lower in group 1 (both P < 0.001). A larger amount of chin narrowing, as well as better chin symmetry were observed in group 1 (P < 0.001). In conclusion, compared to the T-shape genioplasty, the total inferior border ostectomy is well suited for a longer, wider, and more asymmetrical chin. The surgical options should be considered and chosen quantitatively to achieve aesthetically pleasing results. [ABSTRACT FROM AUTHOR]

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Antegonial notching can occur after bilateral sagittal split osteotomy (BSSO) and may lead to unpleasant aesthetic outcomes in both young and older patients. This clinical study presents a new concept to potentially overcome this problem and describes the workflow. Beta-tricalcium phosphate patient-specific gap implants (β-TCP gap-PSIs) are biocompatible and resorbable bone grafts that are placed in the space of the osteotomy gap during orthognathic procedures; they are virtually planned and printed in 3D. Between July 9, 2017 and July 31, 2018, 14 patients received bilateral β-TCP gap-PSIs during BSSO procedures. Nine were female (64.3%) and five were male (35.7%); mean age at surgery was 32.4 ± 12.7 years and the mean sagittal advancement gap was 9.4 ± 1.74 mm. The immediate postoperative position of the β-TCP implants, as well as early and long-term complications were evaluated; the clinical follow-up was 5 years. Intraoperative placement of the β-TCP implants was achieved without early complications, and the mandibular border contour was rated as very good or good in 82.1% of sides. Two minor long-term complications occurred, resulting in a total grafting success rate of 92.9%. In conclusion, this initial study (part 1) showed the potential of the β-TCP gap-PSI concept in BSSO procedures to prevent antegonial notching, which is currently underestimated and underreported. However, further extensive quantitative assessment is mandatory and will be presented in part 2., Competing Interests: Declaration of Competing Interest G.R.J. Swennen is a clinical developer in collaboration with KLS Martin SE & Co. KG, Tuttlingen, Germany. All other authors report no conflict of interest., (Copyright © 2025. Published by Elsevier Inc.)

Introduction: Osteoradionecrosis (ORN) of the mandible is an unfortunate potential sequela of radiotherapy for head and neck cancer. In advanced cases of ORN, mandibulectomy, and free fibula flap reconstruction are required. We hypothesized that patients undergoing fibula free flap reconstruction and mandibulectomy for ORN pose unique challenges and experience more complications than patients undergoing fibula free flaps after oncologic mandibulectomy., Methods: After IRB approval, we created a database of all free fibula flaps for mandible reconstruction from April 2005 through February 2019. Medical records were retrospectively reviewed for patient and surgical characteristics and postoperative outcomes., Results: Four-hundred seventy-nine patients met the inclusion criteria (168 ORN vs. 311 non-ORN patients). Propensity-matching was performed based on age, BMI, smoking status, preoperative chemotherapy, and virtual surgery planning use, which yielded 159 patients in each group. ORN patients received more double-skin-island fibula flaps than non-OR patients (20.8% vs. 5.7%, p < 0.001). Recipient artery other than the facial artery was utilized more commonly in ORN patients (42.1% vs. 17.0%, p < 0.001). In the unmatched cohort, ORN patients had higher rates of delayed wound healing (26.2% vs. 16.8%, p = 0.01) and surgical site infections (21.4% vs. 13.2%, p = 0.02). Rates of flap loss, return to the operating room, hematoma, operative time, and length of stay were similar between the groups. On logistic regression analysis, osteoradionecrosis was an independent risk factor for delayed wound healing., Conclusion: Based on these data, mandibular reconstruction with fibula flaps for osteoradionecrosis appears more complicated than mandible reconstruction following de novo cancer resection. Surgeons should anticipate employing two skin islands for intraoral and extraoral resurfacing, utilizing unconventional recipient vessels, and managing the delayed wound healing that ensues more commonly than non-ORN patients., (© 2024 Wiley Periodicals LLC.)

The aim of this study was to assess the occurrence of neurosensory disturbance of the inferior alveolar nerve (IAN) following modified mandibular bilateral sagittal split osteotomy (BSSO) that preserves the mandibular inferior border. All patients undergoing BSSO, associated or not with a Le Fort I osteotomy (performed by the same senior operator) between January 2018 and December 2019, were eligible. The modified BSSO consists of a modification of the technique described by Epker: the bony section of the buccal cortex stops 3-4 mm above the basal mandibular edge. While respecting the basilar border, sectioning is then performed up to the gonial angle where bicortical section is finally performed. Sensibility of the labial and chin area was evaluated immediately postoperatively, and at six months and two years of follow up. A total of 140 eligible patients underwent the modified BSSO between January 2018 and December 2019, and 72 were included. Hypoaesthesia was found in 81.9% of the patients (59/72 patients) at initial evaluation. It decreased to 45.8% (33/72 patients) at the six-month examination and to 12.5% (9/72 patients) at the last examination. Four bad splits were recorded. The modified BSSO preserves the inferior border of the mandible and maintains the IAN in the lingual fragment. There is no need to release the IAN, hence its manipulation is reduced and the incidence of IAN postoperative hypoaesthesia is also reduced. [ABSTRACT FROM AUTHOR]

The assessment of the stability of orthognathic surgery is often time-consuming, relies on manual re-identification of anatomical landmarks, and has been based on short-term follow-up. The purpose of this study was to propose and validate a semi-automated approach for three-dimensional (3D) assessment of the long-term stability of segmental bimaxillary surgery. The approach was developed and validated using cone beam computed tomography scans obtained at 2 weeks and 2 years postoperative. The stability of the surgical outcome was calculated as 3D translational and rotational differences between the short- and long-term postoperative positions of the individual bone segments. To evaluate reliability, intra-class correlation coefficients were calculated at a 95% confidence interval on measurements of two observers. Ten class II and III patients (six male, four female; mean age 24.4 years), who underwent a combined three-piece Le Fort I osteotomy, bilateral sagittal split osteotomy, and genioplasty, were included in the study. Intra- and inter-observer reliability were excellent (range 0.82–0.99). The range of the mean absolute difference of the intra- and inter-observer translational and rotational measurements were 0.14 mm (0.13)–0.44 mm (0.50) and 0.20° (0.16)–0.92° (0.78). The approach has excellent reliability for 3D assessment of long-term stability of segmental bimaxillary surgery. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare two techniques for temporary intraoperative maxillomandibular fixation (TIO-MMF) during orthognathic surgery: steel-wire ligatures versus power chains. Patients undergoing orthognathic surgery between October 2019 and March 2020 were included in a prospective cross-sectional study conducted in three participating hospitals. Data were collected using a standardized measurement form. A total of 44 patients were included, in whom TIO-MMF was applied 79 times. A statistically significant difference in intraoperative loss of stability of the segment relationship was found between steel-wire ligatures (11.4%) and power chains (0%). The mean application time of TIO-MMF differed significantly between steel-wire ligatures (99 seconds) and power chains (157 seconds) (P < 0.001). There was no statistical difference in occurrence of adverse events between the two techniques. This study found that the application of TIO-MMF with power chains is more stable compared to steel-wire ligatures. Steel-wire ligatures were significantly faster to apply, although the absolute difference (less than 1 minute) was small. Other possible advantages of the proposed technique are discussed. The results of this study suggest that power chains for the application of TIO-MMF in orthognathic surgery are a valuable alternative to steel-wire ligatures. [ABSTRACT FROM AUTHOR]

Juvenile idiopathic arthritis (JIA) involving the temporomandibular joint (TMJ) can result in significant dentofacial deformities that may require orthognathic surgical correction. The aim of this study was to assess the functional and aesthetic results relative to stability after bimaxillary surgery with counterclockwise rotation of the occlusal plane in patients with JIA. A retrospective chart review was conducted of all patients affected by JIA who underwent orthognathic surgery between January 2000 and December 2019 at the Face Surgery Centre (Parma, Italy). Patient records were evaluated for surgical indications, complications, and outcomes. The final study sample included 13 patients (12 female, one male). The mean age of the patients was 18.6 years (range 17–26 years) at the time of surgery; 12 patients had bilateral TMJ disease. At the 1-year follow-up, all patients except one had a stable occlusion with a natural, well-balanced morphology of the face and adequate dynamic excursion of the mandible. The 1-year postoperative cone beam computed tomography (CBCT) scan revealed complete ossification at all osteotomy sites. Bilateral sagittal split osteotomy with mandibular advancement is an effective procedure with a low rate of complications for patients with JIA with stable disease confirmed by preoperative CBCT or magnetic resonance imaging. [ABSTRACT FROM AUTHOR]

Aim: To present a chin wing osteotomy in two patients who had undergone a virtual surgical planning workflow for surgical procedures and were followed up for 4 years. Case reports: Two retrognathic patients with normal occlusion were evaluated by means of dental and facial photographs, cone beam computed tomographs and digitization of dental arches. Virtual surgical planning was performed by using the Dolphin Imaging software to simulate the chin wing osteotomy. Next, three-dimensional models were imported into computer-aided design system (Rhino 6) for designing two hybrid (dental-bone supported) cutting and repositioning guides. Chin wing osteotomies were carried out by using the cutting guides and the osteotomized segments were placed by using L-shaped plates and screws assisted by the repositioning guides. Bone grafts were interposed in the mandibular angle region bilaterally. In both cases, the patients reported aesthetically and functionally favorable outcomes. Conclusion: Chin wing osteotomy is an appropriate treatment for retrognathic mandible in patients with normal occlusion and no additional discrepancies as the technique provided chin advancement and improvement in facial contour. The post-operative outcomes showed reliable workflow of virtual planning and surgical procedures, which could be adopted as an alternative in similar cases. [ABSTRACT FROM AUTHOR]