Endoscopic visualization of the inferior alveolar nerve associated with somatosensory changes after impacted
Jun-Qi Jiang1, Yan-Feng Kang2, Ke-Nan Chen1
1Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology and National Center of Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Research Center of Oral Biomaterials and Digital Medical Devices and Beijing Key Laboratory of Digital Stomatology and Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health and NMPA Key Laboratory for Dental Materials, No.22 Zhongguancun South Avenue, Haidian District, Beijing, 100081, People's Republic of China.
Abstract:
The aim of this study is to assess the relationship between somatosensory functional changes and inferior alveolar nerve (IAN) exposure after impacted mandibular third molars (M3M) removal. We recruited 35 patients who underwent impacted M3M extraction near the IAN. The M3Ms were extracted by combined endoscopy, piezosurgery, and contra-angle high-speed turbine handpiece. All IAN canal perforations and exposed regions were recorded and measured by endoscopy after extraction and on cone-beam computed tomography (CBCT) images before extraction. The patients were followed up 1, 7, and 35 days after surgery. A standardized quantitative sensory testing (QST) battery was performed on the lower lip skin. All of 35 cases had exposed IAN on CBCT images, 5 of which had no exposed IAN under endoscopy. For the other 30 cases, the endoscopy-measured IAN length and width were shorter than the CBCT measurements (P < 0.001). The warm and mechanical detection thresholds (MDT) on the operation side were significantly higher than the contralateral side after surgery (P < 0.05). Thermal sensory limen, MDT, and cold pain threshold were strongly correlated with the exposed IAN length and MDT also with the exposed IAN width one day after surgery. In conclusion, it was found that not all exposed IAN in CBCT images were real exposure after surgery. The intraoperative exposed IAN endoscopic measurements were smaller than by CBCT and strongly correlated with some QST parameters.
