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.

[Analysis of potential pathogenic factors of trigeminal neuralgia in rats].

PURPOSES: Transcriptomics-based analysis of key transcriptional molecules in the pathogenesis of trigeminal neuropathic pain was conducted to screen key molecules in the pathogenesis of trigeminal neuralgia. METHODS: Rat trigeminal nerve pathological pain model, namely chronic constriction injury of distal infraorbital nerve (IoN-CCI), was constructed and animal behaviors postsurgery were observed and analyzed. Trigeminal ganglia were collected for RNA-seq transcriptomics analysis. StringTie was used to annotate and quantify genome expression. DESeq2 was applied to compare between groups with P value less than 0.05 and fold change greater than 2 times and less than 0.5 times to screen differential genes, and display them with volcano graphs and cluster graphs. ClusterProfiler software was used to perform GO function enrichment analysis of differential genes. RESULTS: On the fifth postoperative day (POD5), the rat's face-grooming behavior increased to a peak; on the seventh postoperative day (POD7), the von-frey value dropped to the lowest value, indicating that the mechanical pain threshold of rats was significantly decreased. RNA-seq analysis of IoN-CCI rat ganglia found that the significantly up-regulated signaling pathways included B cell receptor signaling pathway, cell adhesion, complement and coagulation cascade pathways; significantly down-regulated pathways were related to systemic lupus erythematosus. Multiple genes among Cacna1s, Cox8b, My1, Ckm, Mylpf, Myoz1, Tnnc2 were involved in mediating the occurrence of trigeminal neuralgia. CONCLUSIONS: B cell receptor signaling pathway, cell adhesion, complement and coagulation cascade pathways, neuroimmune pathways are closely related to the occurrence of trigeminal neuralgia. The interaction of multiple genes among Cacna1s, Cox8b, My11, Ckm, Mylpf, Myoz1, Tnnc2 leads to the occurrence of trigeminal neuralgia.

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.

Tooth-supported personalized template-assisted foramen ovale puncture system for trigeminal neuralgia treatment.

PURPOSE: To introduce a tooth-supported personalized template-assisted foramen ovale (FO) puncture system for trigeminal neuralgia (TN) treatment, analyze its advantages, and review other previously reported methods. METHODS: Sixty-seven patients were included. According to the preoperative digital design, the personalized puncture path was determined. Then, a tooth-supported personalized template was designed and manufactured. Finally, surgery (radiofrequency thermocoagulation or balloon compression) was carried out with the assistance of the template. The puncture effect and puncture-associated complications were evaluated, and the related literature was reviewed. RESULTS: The FO was successfully punctured in one attempt in all patients. The procedure was completed in 15 s in 35 (52.24%) patients and in 15-30 s in 28 (41.79%) patients. The required position was accurately reached in all patients, and the center point error range was within 1 mm. No complications associated with puncture occurred. CONCLUSION: The tooth-supported personalized template-assisted FO puncture system reported in this paper is an exceedingly simple, highly effective and safe FO puncture method that is worth popularizing.

Skull Base Erosion Resulting From Primary Tumors of the Temporomandibular Joint and Skull Base Region: Our Classification and Reconstruction Experience.

PURPOSE: We sought to introduce our classification and reconstruction protocol for skull base erosions in the temporomandibular joint and skull base region. PATIENTS AND METHODS: Patients with neoplasms in the temporomandibular joint and skull base region treated from January 2006 to March 2017 were reviewed. Skull base erosion was classified into 3 types according to the size of the defect. RESULTS: We included 33 patients, of whom 5 (15.2%) had type I defects (including 3 in whom free fat grafts were placed and 2 in whom deep temporal fascial fat flaps were placed). There were 8 patients (24.2%) with type II defects, all of whom received deep temporal fascial fat flaps. A total of 20 patients (60.6%) had type III defects, including 17 in whom autogenous bone grafts were placed, 1 in whom titanium mesh was placed, and 2 who received total alloplastic joints. The mean follow-up period was 50 months. All of the patients exhibited stable occlusion and good facial symmetry. No recurrence was noted. CONCLUSIONS: Our classification and reconstruction principles allowed reliable morpho-functional skull base reconstruction.

Modified Decompression of the Infraorbital Canal to Treat Trigeminal Neuralgia Affecting the Maxillary Branch.

PURPOSE: To modify the method of treating trigeminal neuralgia (TN) affecting the maxillary branch and to provide clinical evidence of an etiologic hypothesis of narrowing bone canal compression. MATERIALS AND METHODS: Forty patients who met the inclusion and exclusion criteria were included, and those with bony compression of the affected infraorbital canal (IOC) were selected by preoperative computer measurement. Modified decompression of the IOC was performed through the maxillary sinus with the assistance of a piezoelectric device and an endoscope. The results of the operation were evaluated. RESULTS: Fourteen patients (35.00%) had bony compression of the affected IOC. During a mean follow-up period of 29.4 months, 11 patients (78.57%) had complete pain relief (excellent); 1 (7.14%) had moderate relief with carbamazepine administration. The success rate was 85.71% (12 of 14). The postoperative numbness rate was 35.71% (5 of 14). CONCLUSION: Narrowing of the IOC might be a reason some patients with TN have no intracranial neurovascular compression and have pain localized to the distribution of the maxillary branch. Modified decompression of the IOC through the maxillary sinus is a safe, highly effective, and minimally invasive method to treat these patients.