Unilateral hypoglossal nerve palsy following orthognathic surgery: A case report and literature review.

INTRODUCTION: Hypoglossal nerve palsy (HNP) can be caused by nerve damage from the central nerve to a peripheral nerve, and individuals with multiple factors could be predisposed to HNP. We report a case of isolated unilateral HNP after orthognathic surgery. CASE PRESENTATION: A 56-year-old Japanese woman complained of jaw distortion and malocclusion. She had undergone a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) under general anesthesia in August 2021. On postoperative day 3, she experienced tongue motility, and when the tongue protruded forward, the tongue tip shifted to the right, and swelling of the right lateral pharyngeal wall was observed. An additional blood test revealed increased antibody titer levels (40×), cytomegalovirus IgG EIA titer (16.9 U/mL), HSV-IgG EIA titer (40 U/mL), and EBV-viral capsid antigen (VCA) IgG EIA titer (1.4 U/mL). We administered valacyclovir hydrochloride 1000 mg/day for 7 days, prednisolone (PSL) 60 mg/day, mecobalamin 1500 µg/day, and adenosine triphosphate (ATP) disodium hydrate 300 mg/day. A neurological examination revealed no central lesions, and we continued the patient's tongue-function training and oral hygiene guidance. The tongue apex deviation was resolved approx. 3 months postoperatively. DISCUSSION: There are no major reports on the etiology of HNP after orthognathic surgery. The possibility of HNP triggered by endotracheal intubation or through packing gauze under general anesthesia and viral infection cannot be ruled out. CONCLUSION: Clinicians should be aware of the possibility of unilateral HNP following orthognathic surgery.

Association between impaired healing after orthognathic surgery and irritable bowel syndrome: A case report and literature review.

INTRODUCTION: In the disease irritable bowel syndrome (IBS), gastrointestinal function is worsened even though no organic abnormalities are observed in the gastrointestinal mucosa. We report the case of an orthognathic surgery patient with suspected irritable bowel syndrome. CASE: In September 2017, a 15-year-old Japanese female was referred to us with dental crowding, malocclusion, and mandibular protrusion. In June 2019, a disagreement with classmates led to abdominal pain, diarrhea, and hemorrhage; in August 2019, a preoperative blood test showed sudden anemia, and her surgery was thus postponed. Subsequent upper and lower gastrointestinal endoscopy revealed no organic abnormality, and no definitive diagnosis was made. In March 2020, after an improvement in anemia was observed, a segmental Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) were performed under general anesthesia. On the third post-operative day, due to the mucosal dehiscence adjacent to the suture part, the titanium plate was exposed, and irrigation of the wound with normal saline solution and oral hygiene instruction was continued daily for 2 weeks. Two years and eight months have passed since the surgery, and the healing of the oral mucosa and bone has been uneventful. DISCUSSION: The relationship between IBS and post-operative impaired healing associated with the fragility of the oral mucosa is unknown. However, psychological stress has been reported as a cause of IBS and to be related to oral microorganisms. CONCLUSION: Reducing risk factors for IBS and maintaining proper perioperative oral hygiene is essential in managing similar cases.

Two middle-aged cases of deep overbite without molar support treated by orthognathic surgery.

INTRODUCTION: Patients with severe overbite in middle age often undergo prosthetic treatment without a diagnosis of dentofacial deformity, but soft tissue trauma can occur in such patients due to the lack of inter-occlusal space. Comprehensive surgical orthodontic treatment and prosthetic treatment are indicated to correct the overbite and soft tissue injury for such patients. PRESENTATION OF CASE: We report the cases of two middle-aged patients with dentofacial deformity and severe overbite without molar support. In both cases, prosthetic treatment had been performed for many years without any improvement of the occlusion. Case 1: A 47-year-old Japanese man had a maxillary incisor protrusion and reduced lower anterior facial height profile with the left mandibular molars lost due to periodontal disease. After preoperative orthodontic treatment and occlusal elevation in the molar teeth using an implant prosthesis, a sagittal split ramus osteotomy (SSRO) was performed. Case 2: A 57-year-old Japanese woman had mandibular retrognathia with maxilla and mandibular-arch length discrepancy. The left mandibular molars needed to be extracted due to periodontal disease. After preoperative orthodontic treatment and reconstruction of the molar occlusion using an implant prosthesis, three-segment Le Fort I osteotomy and SSRO were performed. DISCUSSION: Malocclusion with dentofacial deformity is a risk factor for severe deep overbite or other occlusion collapse. CONCLUSION: In middle-aged patients with deep overbite with missing molar teeth, we should consider both prosthodontic treatment and comprehensive dental therapy, including orthognathic surgery.

Evaluation of the mandibular ramus fracture line after sagittal split ramus osteotomy using 3-dimensional computed tomography.

PURPOSE: The true fracture line on the mandibular ramus after sagittal split ramus osteotomy cannot be observed using conventional x-ray techniques such as an orthopantomography. The aim of this study was to observe the fracture lines on the mandibular ramus after sagittal split ramus osteotomy by 3-dimensional computed tomography. PATIENTS AND METHODS: The subjects of this study were 30 patients with mandibular prognathism (7 men and 23 women). Their ages ranged from 17 to 45 years (mean age, 24 years). Osteotomy was performed by 3 techniques--the short medial cut, the lateral cut at the mandibular angle, and the connected cut. Sixty mandibular splits were evaluated by 3-dimensional computed tomography 1 to 2 weeks postoperatively. RESULTS: The mandibular ramus was fractured at 3 sites--the lingual surface, the posterior border, and the buccal surface. No fracture lines through the mandibular canal were observed. In relation to the 3 types of lateral bone cut end (A, lingual surface; B, inferior border; C, buccal surface) and the 3 fracture sites, 36 of the 37 lingual surface fractures were type A, 12 of the 14 posterior border fractures were type B, and 9 of the 9 buccal surface fractures were type C. CONCLUSION: A desirable splitting pattern occurred when a short lingual cut just above the lingula and a lateral bone cut of the mandibular angle were made, extending to the inside through the inferior border of the mandible. These observations also proved that the split patterns of the mandibular ramus could be controlled by the position of the lateral bone cut end.

The stability of an alar cinch suture after Le Fort I and mandibular osteotomies in Japanese patients with Class III malocclusions.

We previously reported a modified technique for the placement of symmetrical cinch sutures after switching from a nasal to an oral endotracheal tube. We undertook a study to assess the effectiveness of our technique and the stability of changes in the nasolabial morphology after bimaxillary surgery. The study group comprised 30 patients aged 17-36 years who had skeletal Class III malocclusion. All patients had bimaxillary surgery with an alar base cinch suture and V-Y closure. The nasal region was measured directly or on cephalograms before, and 1 week and 1 year after operation. The suture did not alter the width of the alar base, but the nasolabial angle and projection of the tip increased significantly. The length of the upper lip did not change significantly.