Risk Factors Associated With Inferior Alveolar Nerve Injury After Extraction of Impacted Lower Mandibular Third Molars: A Prospective Cohort Study.

BACKGROUND: Inferior alveolar nerve (IAN) injury is one of the complications of impacted lower mandibular third molar (LM3) extraction. Given the unknown prognosis of IAN injuries and limited treatment options, it is critical to understand the risk factors of IAN injury before LM3 extraction. PURPOSE: The purpose of the study was to identify risk factors associated with IAN injury after LM3 extraction. STUDY DESIGN, SETTING, SAMPLE: This was a prospective cohort study including patients who underwent LM3 extraction from May to December 2021 at the authors' institution. Patients with systemic diseases, previous maxillofacial surgeries, or sensory abnormalities were excluded. PREDICTOR VARIABLE: The predictor variable is composed of several risk factors. The variables were grouped into four categories: demographic, radiographic, procedure-related, and surgeon experience. MAIN OUTCOME VARIABLE(S): The outcome variable was postoperative neurosensory disturbance coded as present or absent and was measured at 1-month (transient) and 1-year (permanent). COVARIATES: Not applicable. ANALYSES: The measurement data were represented by mean and standard deviation. The association of each variable with the presence of an IAN injury was tested by the χ2 test. Statistical significance was accepted at P < .05. RESULTS: The study sample consisted of 705 patients (37.0% male) with an average age of 28.51 ± 6.51 years. A total of 17/705 (2.4%) and 4/705 (0.57%) patients developed transient and permanent IAN injuries. The results demonstrated that the following factors were associated with higher rates of transient injury: use of chisels during surgeries (6.4%; 95% confidence interval (CI): 2.7 to 12.3; P = .02; relative risk (RR) = 11.4), LM3s located below the IAN canal (8.7%; 95% CI: 4.3 to 15.7; P < .01; RR = 7.3), compressed contact between LM3s and the IAN canal (36.4%; 95% CI: 12.3 to 78.2; P < .001; RR = 25.4), and not using corticosteroids after surgeries (3.8%; 95% CI: 1.9 to 6.5; P = .03; RR = 3.1). The only factor associated with permanent injury was compressed contact between LM3s and the IAN canal (18.2%; 95% CI: 2.2 to 62.3; P < .001; RR = 48.2). CONCLUSION AND RELEVANCE: Close proximity between LM3s and IAN canal and the use of chisels increase the risk of transient IAN injury. Corticosteroid treatment may promote nerve recovery. Compressed contact between LM3s and IAN canal is the only risk factor for permanent injury.

Soft tissue inflammation around upper third molar cause limited mouth opening: common but overlooked.

OBJECTIVES: The aim of this study was to explore inflammation of soft tissue around the upper third molar as a prevalent cause of limited mouth opening, identify the clinical and radiographic features, and summarize the therapeutic effectiveness of tooth extraction. MATERIALS AND METHODS: A retrospective analysis of data from 264 patients with limited mouth opening over the last five years was performed. RESULTS: Among the 264 patients, 24 (9.1%) had inflammation of the soft tissue around the upper third molar, which was the second most common cause of limited mouth opening. Twenty-one of the twenty-four affected patients, with an average mouth opening of 19.1 ± 7.6 mm, underwent upper third molar extraction. Gingival tenderness around the upper third molar or maxillary tuberosity mucosa was a characteristic clinical manifestation (p < 0.05). The characteristic features on maxillofacial CT included soft tissue swelling around the upper third molar and gap narrowing between the maxillary nodules and the mandibular ascending branch. Post extraction, the average mouth opening increased to 31.4 ± 4.9 mm (p < 0.05), and follow-up CT demonstrated regression of the inflammatory soft tissue around the upper third molar. CONCLUSIONS: Inflammation of soft tissue around the upper third molar is a common cause of limited mouth opening. Symptoms of pain associated with the upper third molar and distinctive findings on enhanced maxillofacial CT scans are crucial for diagnosis. Upper third molar extraction yields favorable therapeutic outcomes. CLINICAL RELEVANCE: Inflammation of the soft tissue around the maxillary third molar commonly causes limited mouth opening, but this phenomenon has long been overlooked. Clarifying this etiology can reduce the number of misdiagnosed patients with restricted mouth opening and enable more efficient treatment for patients.

Protection of Inferior Alveolar Neurovascular Bundle in Alveolar Bone Operation.

PURPOSE: The aim of this study was to investigate the protection of the inferior alveolar neurovascular bundle in alveolar bone operation in conditions such as chronic osteomyelitis and cementoma. PATIENTS AND METHODS: The study enrolled 7 cases, 4 with chronic osteomyelitis and 3 with cementoma with pain. Computed tomography scan and 3-dimensional reconstruction were performed for the diseases. Data were processed by ProPlan CMF 1.3 software. The edge of lesion was defined and the inferior alveolar nerve was marked. Template was designed to guide the osteotomy line. Piezosurgery was used for osteotomy, with the avoidance of nerve canal. Current perception threshold (CPT) was performed to evaluate the nerve function after operation. RESULTS: The CPT difference of the affected side before and after operation showed no statistically significant differences compared with that of the unaffected side (P = 0.0556). CONCLUSIONS: Digital template protects the inferior alveolar neurovascular bundle with the aid of piezosurgery during alveolar bone resection, which obtained satisfying clinical results. As powerful assistive tools of functional surgery, digital template and piezosurgery achieve both the purposes of treatment and function.

Monofocal Chronic Nonbacterial Osteomyelitis in the Mandible Accompanied With Mucocutaneous Disease.

Chronic nonbacterial osteomyelitis (CNO) is a bone disease with nonbacteria osteitis of unknown etiology. Symptoms, including pain, swelling, fever, etc, always result in misdiagnosis and wrong therapy. This study aims to introduce the clinical features and the therapy of patients with CNO accompanied with mucocutaneous disease. The authors retrospectively reviewed the patients who presented to our hospital from 2000 to 2016, the final sample including 3 patients with CNO accompanied with mucocutaneous disease, who presented repeated severe pain of bone, swelling, tenderness, and fever during attack stage with no evidence of bacterial infections. One patient underwent surgery, and all of them took the therapy of nonsteroidal anti-inflammatory drugs and immunosuppressive agents. There was no significant effect after taken surgery, but good results with drugs. The study suggested us that medical therapy sometimes better than surgery in CNO accompanied with mucocutaneous disease.

Does Idiopathic Bone Cavity Involving Mandibular Condyle Need Surgical Intervention of Bone Cavity Filling?

Idiopathic bone cavity (IBC) is a rare, asymptomatic, unilateral, oval-shaped radiolucent defect in the mandible. It is extremely rare that IBC occurs in the mandibular branch and condylar process. This article presents a 16-year-old male with IBC occuring in the mandibular branch.

Three-Dimensional Reconstruction of the Distribution of Neurons Contributing to Ophthalmic, Maxillary, and Mandibular Nerves in the Trigeminal Ganglion of Experimental Model.

The authors introduce a new method to build a three-dimensional (3D) model of the 3 branches of the trigeminal nerve in the trigeminal ganglion of rabbit with 3 different kinds of fluorescence. Ten adult New Zealand rabbits of both sexes weighing between 2.0 and 3.0 kg were used in the experiment. Then through an operation under general anesthesia, the maxillary and mandibular nerves were exposed, and red and gold fluorescence were applied to investigate the neurons of the maxillary and mandibular nerves. Subsequently, DiI was used as a marker for the ophthalmic neuron for the other side of the same rabbit. After receiving images of the 3 branches under a fluorescence microscope, a 3D model of the 3 branches of the trigeminal nerve could be built. The authors obtained an image of the 3 branches of neurons in the trigeminal ganglion, and a 3D model of the 3 branches of the trigeminal nerve in the trigeminal ganglion was reconstructed. In the trigeminal ganglion, ophthalmic neurons were concentrated in the anteromedial section, the maxillary division in the middle, and the mandibular division posterolaterally. Overlap was observed between the ophthalmic and maxillary neurons, and also for the maxillary and mandible neurons.

Treatment of retinal detachment secondary to macular hole in highly myopic eyes: pars plana vitrectomy with internal limiting membrane peel and silicone oil tamponade.

PURPOSE: To evaluate efficacy of vitrectomy with internal limiting membrane peel and silicone oil tamponade in highly myopic eyes with retinal detachment secondary to macular hole (MH). METHODS: Twenty-one consecutive cases of MH-retinal detachment in highly myopic eyes were retrospectively reviewed. Eyes underwent pars plana vitrectomy, internal limiting membrane peeling, and silicone oil tamponade. A face-down or side-lying position was maintained postoperatively. Silicone oil was removed 3 months to 12 months later. Outcomes included MH closure and retinal reattachment rates, best-corrected visual acuity, and complication rates. RESULTS: Mean patient age was 59.3 ± 6.5 years and mean spherical equivalent was -15.2 ± 4.3 diopters. After silicone oil removal, 18 eyes (86%) had MH closure with retinal reattachment and 2 eyes needed reattachment with endolaser photocoagulation and fluid/gas exchange, and 1 patient refused further treatment. At the last follow-up, median best-corrected visual acuity was +1.48 ± 0.12, up from preoperative +2.11 ± 0.17 (P = 0.03). Transient intraocular pressure elevation was observed in 11 eyes (52%). Iatrogenic retinal break occurred in one case. CONCLUSION: Combining pars plana vitrectomy with internal limiting membrane peel and silicone oil tamponade was safe and effective in treating MH-retinal detachment in highly myopic eyes. Silicone oil tamponade may improve initial anatomical success rates because of longer tamponade duration.

Dental Pulp Stem Cell-Derived Exosomes Promote Sciatic Nerve Regeneration via Optimizing Schwann Cell Function.

Repair strategies for injured peripheral nerve have achieved great progresses in recent years. However, the clinical outcomes remain unsatisfactory. Recent studies have found that exosomes secreted by dental pulp stem cells (DPSC-exos) have great potential for applications in nerve repair. In this study, we evaluated the effects of human DPSC-exos on improving peripheral nerve regeneration. Initially, we established a coculture system between DPSCs and Schwann cells (SCs) in vitro to assess the effect of DPSC-exos on the activity of embryonic dorsal root ganglion neurons (DRGs) growth in SCs. We extracted and labeled human DPSC-exos, which were subsequently utilized in uptake experiments in DRGs and SCs. Subsequently, we established a rat sciatic nerve injury model to evaluate the therapeutic potential of DPSC-exos in repairing sciatic nerve damage. Our findings revealed that DPSC-exos significantly promoted neurite elongation by enhancing the proliferation, migration, and secretion of neurotrophic factors by SCs. In vivo, DPSC-exos administration significantly improved the walking behavior, axon regeneration, and myelination in rats with sciatic nerve injuries. Our study underscores the vast potential of DPSC-exos as a therapeutic tool for tissue-engineered nerve construction.

Study on the Role and Mechanism of Exosomes Derived from Dental Pulp Stem Cells in Promoting Regeneration of Myelin Sheath in Rats with Sciatic Nerve Injury.

The prognosis of peripheral nerve injury (PNI) is usually poor, and currently, there is no effective treatment for PNI. Studies have shown that exosomes derived from mesenchymal stem cells could promote nerve regeneration by optimizing the function of endogenous Schwann cells (SCs), while the mechanism is unclear. Autophagy, a highly conserved intracellular catabolic process responsible for maintaining cellular homeostasis, has been proved to be involved in the regulation of nerve repair after injury. We explored the effect of exosomes derived from dental pulp stem cells (DPSC-Exos) on the regeneration of myelin sheath in rats with sciatic nerve injury (SNI). In vitro and in vivo experiments were performed to clarify whether the effect of DPSC-Exos is associated with autophagy of SCs and to reveal the mechanism at the molecular level. Our results showed that the SCs of SNI rats exhibited the obvious autophagic characteristics, and the increase of P53 expression was an internal factor of autophagy. Our mechanism research indicated that DPSC-Exos could deliver miR-122-5p from DPSCs into SCs and suppressed the rapamycin (RAPA)-induced autophagy in SCs by inhibiting P53 expression. Rescue experiments showed that both the use of GW4869 and overexpression of exogenous P53 in SCs could reverse the inhibitory effect of DPSCs on the autophagy in SCs from co-culture system. In short, our study indicated that DPSC-Exos could promote the regeneration of the myelin sheath through suppressing the autophagy in SCs caused by PNI via miR-122-5p/P53 pathway; this provides researchers with another option for precise repair of PNI.

Human migration in the eastern Tianshan Mountains between the 7th and 12th centuries.

OBJECTIVE: Mid- to late-Holocene large-scale population migration profoundly impacted the interaction of ethnic groups and cultures across Eurasia, notably in Central Asia. However, due to a lack of thorough historical documents, distinctive burial items, and human remains, the process of population migration during this historical era in the area is still unclear. Using an interdisciplinary approach at the Lafuqueke (LFQK) cemetery, this study investigates the spatiotemporal processes and explores the factors that influenced human migration in the eastern Tianshan Mountains between the 7th and 12th centuries. MATERIALS AND METHODS: In this study, tooth enamel from 56 human remains found in the LFQK cemetery in Hami Basin, eastern Tianshan Mountains, is examined for strontium and lead isotopes. RESULTS: The early, middle, and late phases of migration might potentially be represented by a three-phase migration model, according to the isotopic study. The highest proportion of the early phase (ca. 7th-mid 7th century) comprised non-locals (54.55%), although this percentage decreased in the middle phase (mid 7th-mid 8th centuries, 30.77%). After the 10th century, the proportion of non-locals again fell (16.13%). CONCLUSION: In this study, the interdisciplinary approach was employed to propose a new model for the diachronic changes that accompanied human migration and cultural interaction in the eastern Tianshan Mountains and identified geopolitics as a significant factor influencing the migratory behavior of LFQK population in this region between the 7th and 12th centuries.

On Fatigue Detection for Air Traffic Controllers Based on Fuzzy Fusion of Multiple Features.

Fatigue detection for air traffic controllers is an important yet challenging problem in aviation safety research. Most of the existing methods for this problem are based on facial features. In this paper, we propose an ensemble learning model that combines both facial features and voice features and design a fatigue detection method through multifeature fusion, referred to as Facial and Voice Stacking (FV-Stacking). Specifically, for facial features, we first use OpenCV and Dlib libraries to extract mouth and eye areas and then employ a combination of M-Convolutional Neural Network (M-CNN) and E-Convolutional Neural Network (E-CNN) to determine the state of mouth and eye closure based on five features, i.e., blinking times, average blinking time, average blinking interval, Percentage of Eyelid Closure over the Pupil over Time (PERCLOS), and Frequency of Open Mouth (FOM). For voice features, we extract the Mel-Frequency Cepstral Coefficients (MFCC) features of speech. Such facial features and voice features are fused through a carefully designed stacking model for fatigue detection. Real-life experiments are conducted on 14 air traffic controllers in Southwest Air Traffic Management Bureau of Civil Aviation of China. The results show that the proposed FV-Stacking method achieves a detection accuracy of 97%, while the best accuracy achieved by a single model is 92% and the best accuracy achieved by the state-of-the-art detection methods is 88%.

Personalized tooth-supported digital guide plate used in the treatment of trigeminal neuralgia with balloon compression.

Background: Balloon compression (BC) is a simple and effective operation to treat trigeminal neuralgia (TN). The most difficult procedure in BC is related to fast and accurate foramen ovale (FO) insertion. In this study, we introduced a new method incorporating a personalized tooth-supported digital guide plate to reduce patient trauma, improve the accuracy and the success rate of insertion, and reduce surgeons' radiation exposure. Methods: In total, 15 TN patients aged 55-70 years were recruited between January 2019 and November 2020 and retrospectively analyzed. Before the operation, based on Mimics 3D reconstruction and the modeling of patients' maxillary teeth, personalized tooth-supported digital guide plates were designed and 3D printed. All operational procedures were simulated. Then, all patients underwent BC with a personalized tooth-supported digital guide plate. Results: In the study, guide plate insertion was completed within 60 seconds for all patients. Puncturing time was limited to 5 seconds. Successful insertion into the FO was achieved in 1 attempt for all 15 participants. No patients required more than 3 postinsertion adjustments to obtain a pear-shaped balloon. There were no postoperative complications, such as cerebrospinal fluid leakage, intracranial infection, or visual acuity change. The trigger points, attack frequency per day, attack duration, and Barrow Neurological Institute (BNI) pain intensity scores of all 15 participants were significantly improved postoperation. The visual analog scale (VAS) score significantly decreased postoperation compared with that obtained preoperation (all P<0.001) and gradually decreased with the extension of follow-up time. Conclusions: By applying a personalized tooth-supported digital guide plate, we can significantly avoid the use of an incision outside the mouth, decrease the difficulty of FO insertion, and reduce patient trauma. The operation is more suitable for novice surgeons and protects surgeons from the harm of radiation. This new technology may improve the success rate and accuracy of FO insertion, although a multicenter, large sample, randomized controlled trial is needed.

Sculpting Enzyme-Generated Giant Polymer Brushes.

We present a simple yet versatile method for sculpting ultra-thick, enzyme-generated hyaluronan polymer brushes with light. The patterning mechanism is indirect, driven by reactive oxygen species created by photochemical interactions with the underlying substrate. The reactive oxygen species disrupt the enzyme hyaluronan synthase, which acts as the growth engine and anchor of the end-grafted polymers. Spatial control over the grafting density is achieved through inactivation of the enzyme in an energy density dose-dependent manner, before or after polymerization of the brush. Quantitative variation of the brush height is possible using visible wavelengths and illustrated by the creation of a brush gradient ranging from 0 to 6 µm in height over a length of 56 µm (approximately a 90 nm height increase per micron). Building upon the fundamental insights presented in this study, this work lays the foundation for the flexible and quantitative sculpting of complex three-dimensional landscapes in enzyme-generated hyaluronan brushes.

Digital evaluation of orbital development after self-inflating hydrogel expansion in Chinese children with congenital microphthalmia.

BACKGROUND: Assessment of the growth of bony orbit in children with blind microphthalmia is essential to its management. In this study, variables were measured to evaluate the development of the bony microphthalmic orbits after treatment with self-inflating hydrogel expanders. METHODS: This is a retrospective study with an interventional case series. Thirteen pediatric patients with congenital unilateral blind microphthalmia who had undergone tissue expansion with hydrogel expanders and computed tomography (CT) scanning before and after operation were included in the study. The orbital volume, depth, width, and height and retardation of the orbital rims before and after treatment were measured and analyzed using the iPlan Cranial Software. RESULTS: The mean age at the time of first implantation was 44 months (range, 3-113 months). Of the 13 patients, eleven received orbital expansion, while two received socket expansion. In the orbital expansion group, the mean microphthalmic/contralateral ratio (MCR) of orbital volume was 79.3% before surgery, which increased to 89.8% 3 years post operation (P < 0.001). The mean MCR of orbital width also increased from 88.8% to 91.8% (P = 0.003). The development of inferior and lateral rims showed the greatest retardation before treatment; the retardation of these two rims decreased significantly at the final measurement (P = 0.004). It is also noted that the development of the microphthalmic orbits was limited in the two patients who only underwent socket expansion. CONCLUSIONS: The affected orbit enlarged in children with congenital blind microphthalmia following treatment with hydrogel expanders; this suggested that microphthalmia-associated orbital asymmetry can be treated with self-inflating hydrogel expanders.

Decompression of the inferior alveolar nerve to treat the pain of the mandible caused by fibrous dysplasia-case report.

Fibrous dysplasia is a kind of benign bone lesion characterized by the manifestation of the replacement of the normal substance of bone by fibro-osseous connective tissue. A patient diagnosed fibrous dysplasia had unbearable pain in the left mandibular region only. To treat the patient, an navigation template was designed to guide the decompression of inferior alveolar nerve, and piezosurgery was performed to do the osteotomy. After the surgery, the pain disappeared. The sensation of the lower lip recovered.

Tumors and pseudotumors at the temporomandibular joint region in pediatric patients.

OBJECTIVE: To describe the clinical manifestations and types of, and our surgical experience with, neoplasms in the region of the temporomandibular joint (TMJ) in pediatric patients. MATERIALS AND METHODS: From September 1997 to December 2013, a total of 18 patients with neoplasms in the region of the TMJ were treated at our department. They all underwent open surgeries. The clinical manifestations and radiological aspects of all the patients were reviewed. The average follow-up period was 61.8 months with a range of 12-221 months. We reviewed the history, physical examination, images, and related radiological examinations. RESULTS: Of the 18 patients, 14 had benign tumors or pseudotumors, and four had malignant tumors. The ratio of pseudotumor to benign tumor to malignant tumor was 2.5:1:1. Limitations of mouth opening were more likely to occur with malignant tumors, and facial deformity had a higher incidence in benign tumors. Local resection was the first choice for patients with benign tumors or pseudotumors. All patients with malignant tumors underwent whole-tumor resection along the boundary, including the joint capsule, disc, and part of the temporal bone and mandible. During the follow-up period, no tumor reformation or new deformity was detected. CONCLUSIONS: In the diagnosis of masses in the TMJ region, CT and MRI play an important role. Surgical removal of the mass with/without joint attachment was sufficient to treat benign and malignant tumors.

Preservation of the inferior alveolar neurovascular bundle in the osteotomy of benign lesions of the mandible using a digital template.

Our aim was to evaluate the effect of a digital template in the preservation of the inferior alveolar neurovascular bundle during osteotomy for benign lesions of the mandible in 6 patients who were treated with mandibular osteotomies during 2013. Computed tomographic (CT) data were imported into ProPlan CMF 1.4 software. The borders of the lesion and the inferior alveolar canal were marked, and a digital template designed to mark the borders, outline the canal, and guide the osteotomy. A mirror image of the unaffected mandible was used to make a stereolithographic model by a rapid prototyping technique to prefabricate the reconstruction plate for the bone graft. The accuracy of the designs and the templates was evaluated during operation and postoperatively by CT. The sensation of the skin was tested using a Neurometer® CPT (current perception threshold) sensory detector (Neurotron Inc, Baltimore USA) to evaluate the function of the preserved inferior alveolar neurovascular bundle during follow up. With the digital template it was possible to guide removal of the bony lesion while accurately protecting the neurovascular bundle. Follow up for a mean of 8 months (range 5 -12) showed good facial symmetry, a stable occlusion, and recovery of sensation in the lower lip on the affected side. We conclude that a digital template can successfully help the resection of benign lesions of the mandible while preserving the function of the inferior alveolar neurovascular bundle.

A new rat model of glaucoma induced by intracameral injection of silicone oil and electrocoagulation of limbal vessels.

BACKGROUND: A satisfied glaucoma model is absent now. The aim of this study was to evaluate the effect of a combination of intracameral injection of silicone oil and electrocoagulation of corneal limbal vessels and episcleral veins in the rats to establish glaucoma model. METHODS: Operation was performed in each of the left eyes of 90 adult male rats. Right eyes were used as controls. Measurement of intraocular pressure (IOP) was performed with an applanation tonometer (Tono-Pen). Retinal ganglion cells (RGCs) were retrogradely labeled by applying FluoroGold onto the bilateral superior colliculus. RESULTS: During the follow-up (24 weeks), the IOP of the study eyes was significantly higher (P < 0.05) than the control eyes (at final examination, IOP of control eyes was (13.4 ± 1.0) mmHg and IOP of study eyes was (16.1 ± 1.8) mmHg). Correspondingly, at 24 weeks after operation, the RGCs density of the study eyes (2286.11 ± 290.45/mm(2)) was significantly lower than the control eyes (2626.46 ± 164.85/mm(2), P < 0.01). In the operated eyes, histological examination showed excavation of optic disc and increased neuroglial cells in the optic nerve, reduced thickness of retina and diminution of retinal ganglion cells, and atrophy of ciliary body and iris. Notably, the anterior chamber angle of the operated eye remained open. CONCLUSIONS: A combination of intracameral injection of silicone oil and electrocoagulation of corneal limbal vessels and episcleral veins may establish a reliable glaucoma model for further research.