Evaluation of Open Reduction and Internal Fixation of Mandibular Condyle Fracture by Intraoperative Cone-Beam Computed Tomography in a Hybrid Operating Room.

Condylar fractures are the most common fractures of the mandible, and treatment of mandibular condylar fractures by maxillofacial surgeons is a very important procedure. However, the surgical approaches have anatomical limitations. Therefore, it is difficult to evaluate the reduction achieved in open reduction and internal fixation because of the uncertainty in securing a sufficient operative field. As a potential solution, the authors evaluated the benefits of intraoperative cone-beam computed tomography (CBCT) with high image quality performed in a hybrid operating room. Intraoperative CBCT is easy to perform in a hybrid operating room, and it is possible to quickly evaluate high-quality CT images, including 3D images. Because the state of reduction of mandibular condylar fractures also affects the prognosis of treatment, more precise reduction and fixation should improve prognoses. The use of CBCT in a hybrid operating room also avoids re-operation, and patients benefit from minimum invasive surgery. Intraoperative CBCT is a very useful strategy for evaluation of mandibular condylar fracture surgical treatment.

Risk Factors for Mandibular Fracture After Marginal Mandibular Resection.

PURPOSE: This study aimed to examine the relationship between post-operative mandibular fractures and its predictable risk factors in patients with marginal mandibular resection. Additionally, the timing of post-operative mandibular fractures was assessed. PATIENTS AND METHODS: Records of 37 patients with mandibular gingival carcinoma who underwent marginal mandibular resection at the Department of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, from April 2011 to March 2019 were retrospectively analyzed. The following variables were investigated: age, sex, location of carcinoma, tumor size, mandibular height on the surgical and healthy sides, surgical approach, number of residual teeth, post-operative radiotherapy, chemotherapy, and the presence or absence of diabetes and osteoporosis. Various risk factors for post-operative mandibular fractures were statistically investigated. RESULTS: Post-operative mandibular fracture was observed in 5 (13.5%) of the 37 mandibular marginal resection cases. The average residual mandibular height in patients with post-operative mandibular fracture was 8.5 mm. A significant difference in residual mandibular height (P = 0.013) was observed between patients with post-operative mandibular fracture and those with no fracture. The average time to post-operative fracture of the mandible was 305.4 days, and it was found to be correlated to the remaining height of the mandibular body. CONCLUSIONS: A decrease in mandibular height below 9 mm results in post-operative mandibular fracture. Furthermore, a correlation between the height of the mandibular bone and the period until the post-operative mandibular fracture was noted in this study. These findings contribute to the prediction and management of mandibular fractures after mandibular margin resection.

Maxillofacial Trauma Surgery Patients With Titanium Osteosynthesis Miniplates: Remove or Not?

The authors examined the timing and causes of titanium miniplate removal after maxillofacial trauma surgery. The authors performed a retrospective study of maxillofacial fracture patients in whom maxillofacial osteosynthesis miniplates were inserted or removed at the Kagawa Prefectural Central Hospital, between 2008 and 2017. Predictive variables were age, sex, fracture site distribution, and time to miniplate removal with or without complications in relation to primary outcome variables. Among 185 patients, 440 miniplates were inserted and 272 miniplates were removed. In total, 116 patients (73.4%) had 282 miniplates (64.1%) removed, of which 4.8% fracture sites and 5.7% miniplates were removed because of complications. The mean time to miniplate removal was 630.9 and 258.0 days in patients with and without complications, respectively. There was a statistically significant difference in miniplate removal and miniplate retention relative to age and sex. This difference was not related to the presence or absence of sex- or age-related complications. The miniplates as osteosynthesis material were safe and useful for a long period of time with relatively few complications. Because complications requiring miniplate removal occurred within 1 or after 5 years postoperatively, osteosynthesis miniplate treatments should be decided while considering the patient's age and sex. Long-term follow-up is recommended for miniplates that remain implanted for >1 year.

Morphological characteristics of radicular cysts using computed tomography.

The purpose of this study was to evaluate computed tomography (CT) findings of radicular cysts with a focus on location, size, and condition of the surrounding bone. Subjects comprised 60 men and 86 women (mean age 47.2 years) with histopathologically confirmed radicular cysts who underwent CT examination between 2012 and 2014. Mesiodistal and buccolingual diameters were measured at the location where the lesion appeared to be largest on CT axial images. Of the 146 cases, 103 lesions were in the maxilla and 43 were in the mandible. Mesiodistal diameter of the maxillary lesions was significantly larger than that of the mandibular lesions. However, the ratio of mesiodistal diameter to buccolingual diameter in the mandible was significantly larger than that in the maxilla. Bone expansion was more significant in the maxilla than in the mandible. Mesiodistal and buccolingual diameters in only the maxilla and perilesional sclerotic radiolucency in images of both jaws were significantly associated with the severity of clinical symptoms. The findings suggest that radicular cysts in the maxilla are accompanied by bone expansion in the mesiodistal and buccolingual directions and those in the mandible progress in the mesiodistal direction without bone expansion. Clinical acute symptoms (pain and swelling) are correlated with lesion size in the maxilla; such a correlation is not clear for mandibular lesions, and discovery of mandibular lesions may, therefore, be delayed.

Feasible Advantage of Bioactive/Bioresorbable Devices Made of Forged Composites of Hydroxyapatite Particles and Poly-L-lactide in Alveolar Bone Augmentation: A Preliminary Study.

Purpose: We aimed to document the clinical usefulness of uncalcined and unsintered hydroxyapatite (u-HA) particles and poly-L-lactide (PLLA) composite materials and their advantageous properties. Methods: Between April 2016 and March 2018, five patients required anterior maxillary alveolar ridge augmentation using fixation with u-HA/PLLA screws for an onlay block bone graft harvested from the mandibular ramus at our institute. Bone biopsies were obtained from the dental implantation site following bone healing for histomorphometric and immunohistochemical (IHC) measurements. Results: Many stromal cells were positive for Osterix, RUNX2, and SOX9 but were negative for CD68. On cell counting, based on IHC staining for Osterix, RUNX2, SOX9 and CD68 from peripheral u-HA/PLLA screw or bone areas, both areas consistently showed no significant difference in terms of Osterix, RUNX2, and SOX9. Hematoxylin-eosin staining revealed direct bone connection to the biomaterials, and no inflammatory cells infiltrated the areas surrounding the bone or artificial material. Area between the bone and u-HA/PLLA screw was seamless with no boundary. Round small cells and immature fibroblasts were noted. The new bone showed the presence of bone lamellae, normal osteocytes, and osteoblasts. Conclusion: The u-HA/PLLA materials showed excellent biodegradability and bioactive osteoconductivity. In addition, this material induced no apparent inflammatory or foreign body reactions following implantation, and it directly bonded to the human bone. Therefore, this u-HA/PLLA material seems ideal and most suitable for use as a substitute for osteosynthesis.

Complications of a poly-L-lactic acid and polyglycolic acid osteosynthesis device for internal fixation in maxillofacial surgery.

The purpose of this study was to retrospectively evaluate and examine the incidence of complications using poly-L-lactic acid and polyglycolic acid (PLLA/PGA) copolymer plate system in maxillofacial osteosynthesis. The retrospective study included 87 patients (50 men, 37 women), who needed maxillofacial surgery. We examined the proportion of complications and their factors from clinical data. A comparison was also made for plate decomposition using the molecular weight of the plate without plate exposure and complications. Osteosynthesis sites healed in all patients. Ten cases (11.5%) showed plate exposure-related complications, with all occurring at intraoral surgical sites. There was no significant difference in molecular weight changes of plates in resorbable process. Statistical analysis of study variables between patients with and without exposed plates showed that the plate thickness was significantly associated with the risk of exposed plates (p < 0.05). The commercially available PLLA/PGA device could be a useful rapid resorbable material for maxillofacial osteosynthesis. When thick plates are used on the intraoral site, it may be necessary to pay attention to the complication of plate exposure. Even if exposure-related complications have occurred, resorption and degradation of this material proceeds, suggesting the ease of appropriate risk management.

Does a Retromandibular Transparotid Approach for the Open Treatment of Condylar Fractures Result in Facial Nerve Injury?

PURPOSE: The retromandibular transparotid approach (RMA) to condylar fractures of the mandible provides excellent access, but can increase the risk of complications. The aim of this study was to estimate the frequency of facial nerve paralysis (FNP) and associated postoperative complications after open reduction and rigid internal fixation (ORIF) of subcondylar fractures through the RMA. MATERIALS AND METHODS: This was a retrospective cohort study of patients with condylar fractures requiring ORIF through the RMA. The inclusion criteria were 1) a medical record of surgical treatment of a subcondylar fracture by RMA; 2) preoperative and postoperative radiographs; 3) mental status permitting an adequate neuromotor examination; 4) absence of a post-injury or pretreatment functional facial nerve deficit; and 5) regular postoperative follow-up longer than 6 months with documentation of complications, functional results, and fixation stability. The predictive variables were age, gender, fracture site, fracture pattern, concomitant fractures, etiology, and plate types. The outcome variable was FNP. Univariate, bivariate, and multiple logistic regression statistics were computed. RESULTS: Fifty patients with 55 displaced mandibular subcondylar fractures (35 men, 15 women; mean age, 44.5 yr; range, 17 to 87 yr) met the inclusion criteria. The condylar fracture involved the neck in 35 patients (63.6%) and the base in 20 patients (36.4%). The fracture pattern was deviation in 11 patients (20.0%), displacement in 23 (41.8%), and dislocation in 21 (38.2%). Precise ORIF with double-buttress fixation resulted in immediate functional recovery in all patients. Seven fractures (12.7%) were associated with FNP that resolved completely within 6 months. Further statistical analysis showed that dislocated and displaced condylar neck fractures were significant risk factors for postoperative FNP (P < .05). Other postoperative complications were minimal. CONCLUSION: The RMA for subcondylar fractures is feasible and safe. Dislocated condylar neck fractures are associated with a highly increased risk of temporary postoperative FNP as a surgical complication.

Clinical Evaluation of an Unsintered Hydroxyapatite/Poly-L-Lactide Osteoconductive Composite Device for the Internal Fixation of Maxillofacial Fractures.

INTRODUCTION: OSTEOTRANS MX (Takiron Co, Ltd, Osaka, Japan) is a resorbable osteosynthetic material composed of an unsintered hydroxyapatite/poly-L-lactide composite, and its osteoconductive capacity has been documented. The authors here report their clinical experience using OSTEOTRANS MX. METHODS: The authors treated 35 patients (19 men, 16 women; age, 14-88 years; mean ±â€Šstandard deviation, 38.4 ±â€Š19.9 years) with maxillofacial fractures. The authors used standard surgery to stabilize fractures in all patients, fitting resorbable plates (thickness, 1.0 or 1.4 mm) and screws (diameter, 2 mm) according to Arbeitsgemeinschaft für Osteosynthesefragen/Association (AO) for the Study of Internal Fixation guidelines. RESULTS: All patients eventually achieved satisfactory healing with favorable restoration of form and function without foreign body reaction. Complications occurred in 3 patients-plate exposure in 2 and discomfort in 1. However, fracture sites healed in all patients. Scanning electron microscopy revealed that the devices bonded directly to the bone without interposition of nonmineralized tissue. CONCLUSION: OSTEOTRANS MX is a useful material with few complications. Its osteoconductive bioactivity is advantageous for the early functional improvement of maxillofacial fractures.

Identification of osteoporosis using ensemble deep learning model with panoramic radiographs and clinical covariates.

Osteoporosis is becoming a global health issue due to increased life expectancy. However, it is difficult to detect in its early stages owing to a lack of discernible symptoms. Hence, screening for osteoporosis with widely used dental panoramic radiographs would be very cost-effective and useful. In this study, we investigate the use of deep learning to classify osteoporosis from dental panoramic radiographs. In addition, the effect of adding clinical covariate data to the radiographic images on the identification performance was assessed. For objective labeling, a dataset containing 778 images was collected from patients who underwent both skeletal-bone-mineral density measurement and dental panoramic radiography at a single general hospital between 2014 and 2020. Osteoporosis was assessed from the dental panoramic radiographs using convolutional neural network (CNN) models, including EfficientNet-b0, -b3, and -b7 and ResNet-18, -50, and -152. An ensemble model was also constructed with clinical covariates added to each CNN. The ensemble model exhibited improved performance on all metrics for all CNNs, especially accuracy and AUC. The results show that deep learning using CNN can accurately classify osteoporosis from dental panoramic radiographs. Furthermore, it was shown that the accuracy can be improved using an ensemble model with patient covariates.

Is attention branch network effective in classifying dental implants from panoramic radiograph images by deep learning?

Attention mechanism, which is a means of determining which part of the forced data is emphasized, has attracted attention in various fields of deep learning in recent years. The purpose of this study was to evaluate the performance of the attention branch network (ABN) for implant classification using convolutional neural networks (CNNs). The data consisted of 10191 dental implant images from 13 implant brands that cropped the site, including dental implants as pretreatment, from digital panoramic radiographs of patients who underwent surgery at Kagawa Prefectural Central Hospital between 2005 and 2021. ResNet 18, 50, and 152 were evaluated as CNN models that were compared with and without the ABN. We used accuracy, precision, recall, specificity, F1 score, and area under the receiver operating characteristics curve as performance metrics. We also performed statistical and effect size evaluations of the 30-time performance metrics of the simple CNNs and the ABN model. ResNet18 with ABN significantly improved the dental implant classification performance for all the performance metrics. Effect sizes were equivalent to "Huge" for all performance metrics. In contrast, the classification performance of ResNet50 and 152 deteriorated by adding the attention mechanism. ResNet18 showed considerably high compatibility with the ABN model in dental implant classification (AUC = 0.9993) despite the small number of parameters. The limitation of this study is that only ResNet was verified as a CNN; further studies are required for other CNN models.

Subcutaneous Emphysema Related to Dental Treatment: A Case Series.

Cervicofacial subcutaneous emphysema (SE) is primarily caused by dental treatment introducing gas into the subcutaneous tissue. Air rapidly dissects into the subcutaneous tissue with face and neck swelling, leading to respiratory distress, patient discomfort, and chest pain. Computed tomography (CT) can detect spreading SE patterns. However, the true volume of SE and the degree of air changes in the body over time remain unknown. We evaluated the healing process of SE and the temporal changes in the volume of emphysema in three cases detected using our hospital's electronic health record systems based on inclusion and exclusion criteria over the past 10 years, with CT and three-dimensional (3D) images. The first case was a 46-year-old woman who presented with complaints of swelling from her right eyelid to the neck and clavicles, pain on swallowing, respiratory distress, and hoarseness. The second case was a 35-year-old man who presented with complaints of swelling over the face. The third case was a 36-year-old man who presented with complaints of swelling from the left cheek to the neck. CT revealed SE and pneumomediastinum in all cases. All the patients were administered an antibacterial drug. The CT and 3D images showed an improvement in emphysema 3 days after the onset, with more than half of the volume reduction in emphysema. This made it possible to evaluate the changes in the air content of SE. Observation with CT until the healing process of SE is completed is crucial, and 3D images also help evaluate changes over time.

Evaluation of multi-task learning in deep learning-based positioning classification of mandibular third molars.

Pell and Gregory, and Winter's classifications are frequently implemented to classify the mandibular third molars and are crucial for safe tooth extraction. This study aimed to evaluate the classification accuracy of convolutional neural network (CNN) deep learning models using cropped panoramic radiographs based on these classifications. We compared the diagnostic accuracy of single-task and multi-task learning after labeling 1330 images of mandibular third molars from digital radiographs taken at the Department of Oral and Maxillofacial Surgery at a general hospital (2014-2021). The mandibular third molar classifications were analyzed using a VGG 16 model of a CNN. We statistically evaluated performance metrics [accuracy, precision, recall, F1 score, and area under the curve (AUC)] for each prediction. We found that single-task learning was superior to multi-task learning (all p < 0.05) for all metrics, with large effect sizes and low p-values. Recall and F1 scores for position classification showed medium effect sizes in single and multi-task learning. To our knowledge, this is the first deep learning study to examine single-task and multi-task learning for the classification of mandibular third molars. Our results demonstrated the efficacy of implementing Pell and Gregory, and Winter's classifications for specific respective tasks.

Deep learning model for analyzing the relationship between mandibular third molar and inferior alveolar nerve in panoramic radiography.

In this study, the accuracy of the positional relationship of the contact between the inferior alveolar canal and mandibular third molar was evaluated using deep learning. In contact analysis, we investigated the diagnostic performance of the presence or absence of contact between the mandibular third molar and inferior alveolar canal. We also evaluated the diagnostic performance of bone continuity diagnosed based on computed tomography as a continuity analysis. A dataset of 1279 images of mandibular third molars from digital radiographs taken at the Department of Oral and Maxillofacial Surgery at a general hospital (2014-2021) was used for the validation. The deep learning models were ResNet50 and ResNet50v2, with stochastic gradient descent and sharpness-aware minimization (SAM) as optimizers. The performance metrics were accuracy, precision, recall, specificity, F1 score, and area under the receiver operating characteristic curve (AUC). The results indicated that ResNet50v2 using SAM performed excellently in the contact and continuity analyses. The accuracy and AUC were 0.860 and 0.890 for the contact analyses and 0.766 and 0.843 for the continuity analyses. In the contact analysis, SAM and the deep learning model performed effectively. However, in the continuity analysis, none of the deep learning models demonstrated significant classification performance.

Prognostic Factors in Endodontic Surgery Using an Endoscope: A 1 Year Retrospective Cohort Study.

This retrospective study clarified the success rate of endoscopic endodontic surgeries and identified predictors accounting for successful surgeries. In this retrospective study, 242 patients (90 males, 152 females) who underwent endoscopic endodontic surgery at a single general hospital and were diagnosed through follow-up one year later were included. Risk factors were categorized into attributes, general health, anatomy, and surgery. Then, the correlation coefficient was calculated for the success or failure of endodontic surgery for each variable, the odds ratio was calculated for the upper variable, and factors related to the surgical prognosis factor were identified. The success rate of endodontic surgery was 95.3%, showing that it was a highly predictable treatment. The top three correlation coefficients were post, age, and perilesional sclerotic signs. Among them, the presence of posts was the highest, compared with the odds ratio, which was 9.592. This retrospective study revealed the success rate and risk factors accounting for endoscopic endodontic surgeries. Among the selected clinical variables, the presence of posts was the most decisive risk factor determining the success of endodontic surgeries.

Incidence and Risk of Anti-Resorptive Agent-Related Osteonecrosis of the Jaw after Tooth Extraction: A Retrospective Study.

Bone-modifying agents (BMA) such as bisphosphonates and denosumab are frequently used for the treatment of bone metastases, osteoporosis, and multiple myeloma. BMA may lead to anti-resorptive agent-related osteonecrosis of the jaw (ARONJ). This study aimed to clarify the risk factors for and probabilities of developing ARONJ after tooth extraction in patients undergoing BMA therapy. In this study, the records of 505 target sites of 302 patients undergoing BMA who presented with mandibular fractures at the Department of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, from March 2014 to January 2022, were retrospectively analyzed for the onset of ARONJ after tooth extraction. The following variables were investigated as attributes: anatomy, health status, and dental treatment. The correlation coefficient was calculated for the success or failure of endodontic surgery for each variable, the odds ratio was calculated for the upper variable, and the factors related to the onset of ARONJ were identified. The incidence rate of ARONJ was found to be 3.2%. Hypoparathyroidism was an important factor associated with ARONJ development. Thus, systemic factors are more strongly related to the onset of ARONJ after tooth extraction than local factors.

Transoral open reduction with rigid internal fixation for subcondylar fractures of the mandible using a small angulated screwdriver system: is endoscopic assistance necessary?

PURPOSE: Although endoscopically assisted transoral open reduction and internal fixation of condylar mandible fractures is currently a popular technique, the need for it and its benefits remains unclear. This prospective study evaluated the efficacy and safety of open reduction and rigid internal fixation of subcondylar fractures of the mandible using a new small angulated screwdriver system without endoscopic assistance. PATIENTS AND METHODS: Fifteen patients with 15 linear subcondylar fractures were treated using this intraoral approach from June 2007 through March 2010 at the Division of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, Kagawa, Japan. The anatomic reduction of the displaced condylar segments and rigid fixation with 2 2.0-mm locking miniplates were performed using a small angulated screwdriver system, with an average follow-up of 13 months (range, 6 to 30 months). RESULTS: Correct anatomic reduction of the condylar segments at centric occlusion followed by immediate functional recovery was achieved in all patients. Mean operating time was 50 minutes (range, 35 to 70 minutes) when performed by the consultant surgeon and the residents. In addition, all patients had good temporomandibular joint articular function, with no harmful clinical symptoms or deviation. CONCLUSIONS: The surgical treatment of linear subcondylar fractures of the mandible can be achieved with an intraoral approach alone, using a small angulated screwdriver system, without endoscopic assistance, offering reliable clinical results and safe and minimally invasive surgery.

Feasibility of Navigation-Assisted Bone Lid Surgery for Deeply Impacted Maxillary Tooth - A Case Report.

RATIONALE: Bone lid surgery (BLS) is minimally invasive surgery that removes the cortical bone and returns it to original position after removing lesions. However, jawbone lesions are completely covered with cortical bone, and it can be difficult to accurately determine the lesion position from the outside. PATIENT CONCERNS: A 24-year-old Japanese woman, identified as having an impacted maxillary canine, was referred to our department. Periapical radiolucent lesion, with lateral incisor root absorption by canine compression, was confirmed. DIAGNOSIS: The diagnosis was incisor root absorption due to an impacted canine. TREATMENT: As a potential solution, we performed navigation-assisted BLS. OUTCOMES: Using navigation, we could confirm the state of impacted tooth under the covered bone. We could establish reliable bone cutting and the removed cortical bone was successfully returned to the presurgical position. TAKE-AWAY LESSONS: Navigation-assisted BLS for the removal of impacted teeth may increase surgical accuracy and minimize invasion.

Biological Effects of Bioresorbable Materials in Alveolar Ridge Augmentation: Comparison of Early and Slow Resorbing Osteosynthesis Materials.

The purpose of this study was to investigate the bone healing properties and histological environment of a u-HA/PLLA/PGA (u-HA-uncalcined and unsintered hydroxyapatite, PLLA-Poly L-lactic acid, PGA-polyglycolic acid) composite device in humans, and to understand the histological dynamics of using this device for maxillofacial treatments. Twenty-one subjects underwent pre-implant maxillary alveolar ridge augmentation with mandibular cortical bone blocks using u-HA/PLLA or u-HA/PLLA/PGA screws for fixation. Six months later, specimens of these screws and their adjacent tissue were retrieved. A histological and immunohistochemical evaluation of these samples was performed using collagen 1a, ALP (alkaline phosphatase), and osteocalcin. We observed that alveolar bone augmentation was successful for all of the subjects. Upon histological evaluation, the u-HA/PLLA screws had merged with the bone components, and the bone was directly connected to the biomaterial. In contrast, direct bone connection was not observed for the u-HA/PLLA/PGA screw. Immunohistological findings showed that in the u-HA/PLLA group, collagen 1a was positive for fibers that penetrated vertically into the bone. Alkaline phosphatase was positive only in the u-HA/PLLA stroma, and the stroma was negative for osteocalcin. In this study, u-HA/PLLA showed a greater bioactive bone conductivity than u-HA/PLLA/PGA and a higher biocompatibility for direct bone attachment. Furthermore, u-HA/PLLA was shown to have the potential for bone formation in the stroma.

Multi-Task Deep Learning Model for Classification of Dental Implant Brand and Treatment Stage Using Dental Panoramic Radiograph Images.

It is necessary to accurately identify dental implant brands and the stage of treatment to ensure efficient care. Thus, the purpose of this study was to use multi-task deep learning to investigate a classifier that categorizes implant brands and treatment stages from dental panoramic radiographic images. For objective labeling, 9767 dental implant images of 12 implant brands and treatment stages were obtained from the digital panoramic radiographs of patients who underwent procedures at Kagawa Prefectural Central Hospital, Japan, between 2005 and 2020. Five deep convolutional neural network (CNN) models (ResNet18, 34, 50, 101 and 152) were evaluated. The accuracy, precision, recall, specificity, F1 score, and area under the curve score were calculated for each CNN. We also compared the multi-task and single-task accuracies of brand classification and implant treatment stage classification. Our analysis revealed that the larger the number of parameters and the deeper the network, the better the performance for both classifications. Multi-tasking significantly improved brand classification on all performance indicators, except recall, and significantly improved all metrics in treatment phase classification. Using CNNs conferred high validity in the classification of dental implant brands and treatment stages. Furthermore, multi-task learning facilitated analysis accuracy.

Submandibular approach through the submandibular gland fascia for treating mandibular fractures without identifying the facial nerve.

BACKGROUND: : The submandibular, or Risdon, approach is the classic, reliable extraoral approach for treating mandibular fractures. Although the intraoral approach has been used recently for open reduction and internal fixation, in some cases, such as comminuted fractures or fractures in an atrophic mandible, the submandibular approach is still prerequisite. Damage to the marginal mandibular branch of the facial nerve is the only concern other than skin scarring. METHODS: : To minimize the risk of neuropraxia, we prospectively assessed an approach for treating mandibular fractures at 24 surgical sites in 22 patients (17 men, 5 women; mean age, 54.3 years) using direct submandibular gland capsule fascial layer elevation that did not require identifying the facial nerve. RESULTS: : As complications, one patient (4.2%) had temporary facial weakness in the mandibular branch, but this resolved completely within 3 months. The postoperative clinical course was uneventful in the other patients with one minor fistula and minimal scarring. CONCLUSIONS: : In conclusion, submandibular gland capsular layer elevation without facial nerve identification is a safe and less time-consuming technique applying the submandibular approach for the treatment of mandibular fractures.