Inferior Alveolar Nerve Injury in Trauma-Induced Mandible Fractures.

PURPOSE: This prospective observational cohort study sought to determine the prevalence of inferior alveolar nerve (IAN) injury after mandibular fractures before and after treatment and to elucidate factors associated with the incidence of post-treatment IAN injury and time to normalization of sensation. MATERIALS AND METHODS: Consenting patients with mandibular fractures (excluding dentoalveolar, pathologic, previous fractures, or mandibular surgery) were prospectively evaluated for subjective neurosensory disturbance (NSD) and underwent neurosensory testing before treatment and then 1 week, 1.5, 3, 6, and 12 months after treatment. RESULTS: Eighty patients (men, 83.8%; mean age, 30.0 yr; standard deviation, 12.6 yr) with 123 mandibular sides (43 bilateral) were studied. Injury etiology included assault (33.8%), falls (31.3%), motor vehicle accidents (25.0%), and sports injuries (6.3%). Half the fractures (49.6%) involved the IAN-bearing posterior mandible; all condylar fractures (13.0%) had no NSD. Treatment included open reduction and internal fixation (ORIF; 74.8%), closed reduction and fixation (22.0%), or no treatment (3.3%). Overall prevalence of IAN injury was 33.7% (95% confidence interval [CI], 24.8-42.6) before treatment and 53.8% (95% CI, 46.0-61.6) after treatment. In the IAN-bearing mandible, the prevalence was 56.2% (95% CI, 43.2-69.2) before treatment and 72.9% (95% CI, 63.0-82.7) after treatment. In contrast, this prevalence in the non-IAN-bearing mandible was 12.6% (95% CI, 4.1-21.1) before treatment and 31.6% (95% CI, 20.0-43.3) after treatment. Factors associated with the development of post-treatment IAN injury included fracture site and gap distance (a 1-mm increase was associated with a 27% increase in odds of post-treatment sensory alteration). Time to normalization after treatment was associated with type of treatment (ORIF inhibited normalization) and fracture site (IAN-bearing sites took longer to normalize). CONCLUSION: IAN injury was 4 times more likely in IAN-bearing posterior mandibular fractures (56.2%) than in non-IAN-bearing anterior mandibular fractures (12.6%). After treatment, IAN injury prevalence (in 12 months) was higher (72.9% in posterior mandible, 31.6% in anterior mandible).

Gingival Necrosis Related to Sepsis-Induced Agranulocytosis Due to Pseudomonas aeruginosa Bacteraemia: A Case Report.

Background: There have been no reports of sepsis-induced agranulocytosis causing gingival necrosis in otherwise medically healthy patients to the authors' best knowledge. Even though there are several case reports of gingival necrosis secondary to medication-induced agranulocytosis, they have not systematically described the natural progression of agranulocytosis-related gingival necrosis. Methods: This paper presents a case report of a 29-year-old female Indian patient with generalised gingival necrosis and constitutive signs of intermittent fever, nausea, and vomiting. She also complained of abdominal pains. Blood counts showed agranulocytosis, and the patient was admitted for a workup of the underlying cause. Parenteral broad-spectrum antibiotics were administered, which brought about clinical resolution. Results: Her gingival necrosis was attributed to sepsis-induced agranulocytosis triggered by Pseudomonas aeruginosa bacteraemia, and upon clinical recovery, spontaneous exfoliation left behind exposed bone. Secondary healing over the exposed alveolar bone was noted after a year-long follow-up, albeit with some residual gingival recession. Conclusions: Oral manifestations of gingival necrosis, when present with concomitant constitutive symptoms, could indicate a serious underlying systemic condition that could be potentially life-threatening if left untreated. Dentists should be cognizant of this possibility so that timely intervention is not delayed.

Immediate repair of transected inferior alveolar nerves in sagittal split osteotomies.

BACKGROUND: Injury to the inferior alveolar nerve (IAN) in orthognathic surgery is a well-documented complication with the incidence of IAN transection in sagittal split osteotomies (SSOs) ranging from 1.3% to 7.0%. PATIENTS AND METHODS: We describe our clinical experience with 3 cases of immediate microneural repair of IANs transected during SSO. RESULTS: Three cases of IAN transection (2 Sunderland degree V injuries, and 1 degree VI injury) that occurred during SSO were microsurgically repaired immediately by a trained microsurgeon. The other orthognathic surgery sites were positioned and fixed before the nerve repair commenced, and fixation of the nerve injury site was completed by the microsurgeon after nerve repair. All 3 patients were followed for at least 1 year with neurosensory testing, and showed recovery to mild or no sensory impairment. None had functional problems such as drooling, lip-biting, or speech difficulties at 1 year after surgery. CONCLUSION: Immediate nerve repair for transected IANs during SSO may be a feasible option, but requires the availability of a microsurgeon, instrumentation, and operating-room time.

Canine and Premolar Root Dimensions in Chinese. A Reference for Osteoodontokeratoprosthesis Surgery.

PURPOSE: Osteoodontokeratoprosthesis (OOKP) surgery is used to restore vision in end-stage corneal disorders, where an autogenous tooth supporting an optical cylinder is implanted through the cornea under a buccal mucosal graft. The ideal tooth for OOKP is a healthy single-rooted permanent tooth with sufficient buccolingual/palatal root diameter to accommodate an optical cylinder. The aim of this study was to determine the buccolingual/palatal diameters of canine and premolar roots in Chinese, for selection of teeth for OOKP surgery. DESIGN: This was an anatomical study on root dimensions of extracted intact teeth. METHODS: Extracted canine and premolar teeth (excluding maxillary first premolars) were collected and the buccolingual/palatal and mesiodistal diameters of the root at the cervical line and at 2-mm intervals below the cervical line were measured with Vernier calipers. Other measurements included total tooth length, crown buccolingual/palatal diameter, and root length. Mean and minimum buccolingual/palatal root diameters were compiled for each 2-mm interval. RESULTS: A total of 415 extracted teeth (198 male, 217 female) were collected and measured. Recorded dimensions of keratoprostheses in 55 previous OOKP surgeries were used to establish acceptable lamina dimensions to ascertain root size adequacy. Premolars in Chinese female patients were undersized in a small minority. Minimal dimensions of teeth were insufficient if at 6 mm root level, the buccolingual/palatal width was less than 5 mm, or the mesiodistal width was less than 3 mm. This was noted in female mandibular first premolars (5.6%), maxillary second premolars (4.5%), and mandibular second premolars (1.5%). CONCLUSIONS: Canines have adequate dimensions for OOKP surgery. However, premolars in Chinese females may be undersized in a small minority.

Effect of exposed inferior alveolar neurovascular bundle during surgical removal of impacted lower third molars.

PURPOSE: In this prospective study, we sought to determine the incidence of inferior alveolar nerve (IAN) paresthesia in patients with an exposed IAN bundle seen intraoperatively. PATIENTS AND METHODS: We included consecutive patients undergoing third molar surgery in whom an exposed IAN bundle was seen in the third molar socket intraoperatively. Data recorded from patients included radiographic findings, variations in surgical method, intraoperative findings, complications, and postoperative sequelae. Patients were reviewed 1 week after surgery and evaluated subjectively and objectively to determine the incidence of paresthesia when the IAN bundle was exposed. Patients with paresthesia were followed for 2 years or until it resolved. RESULTS: An exposed IAN bundle was seen in 192 operation sites in 170 patients over a 5-year period, of which 166 patients with 187 operation sites were included in this study. Thirty-eight operation sites (20.3%) showed paresthesia at 1 week after surgery (95% confidence interval, 14.5% to 26.1%); 20 sites (15.0%) showed abnormal objective assessment results. By 3 months from surgery, 57.9% of nerves had recovered to normal sensation, 65.8% of nerves recovered by 6 months, and 71.1% of nerves recovered by 1 year. Eight patients were lost to follow-up. Logistic regression showed that the operator, male gender, older age, and root curvature were significant risk factors for paresthesia. CONCLUSIONS: Sighting an exposed intact IAN bundle during third molar surgery indicates its intimate relationship with the third molar and carries a 20% risk of paresthesia, with a 70% chance of recovery by 1 year from surgery.