A prospective electromyographic and computer-aided thermal sensitivity assessment of nerve lesions after sagittal split osteotomy and Le Fort I osteotomy.

PURPOSE: The purpose of this study was to determine the incidence of temporary and permanent sensory disturbance of the inferior alveolar nerve (IAN) after bilateral sagittal split osteotomy (BSSO) of the mandible and of the infraorbital nerve (ION) after Le Fort I osteotomy, as well as the rate of recovery of sensory function using subjective and objective measures. PATIENTS AND METHODS: Preoperatively and after 1 week, and 1, 3, 6, and 12 months postoperatively, sensibility in the distribution of 36 IONs after Le Fort I osteotomy and 24 IANs after BSSO in 19 patients were investigated by using sharp-blunt testing, 2-point discrimination, electromyographic recording, and thermal sensitivity (Pain and Thermal Sensitivity Test Device [PATH]) tests of the Adelta and C nerve fibers. RESULTS: With conventional clinical sharp-blunt and 2-point discrimination tests, the incidence of temporary impairment was 81% for the ION (29 of 36) and 83% for the IAN (20 of 24). The rate of permanent sensibility disturbance with conventional clinical testing was 6% for the ION and 15% for the IAN. Obvious recovery was found after 1 to 3 months for the ION, but it took 6 to 12 months for the IAN. In contrast, electromyography (EMG) testing showed lower rates of temporary sensory disturbance, namely, 54% (13 of 24) for the ION and 68% (15 of 22) for the IAN. Permanent sensory losses were not found. The results of the EMG test was confirmed by the PATH test. CONCLUSIONS: Objective tests for sensory disturbances show lower rates than the conventional tests. For quality control, preoperative and postoperative measurement and documentation of postoperative recovery of sensation is recommended.

Assessment of inferior alveolar and lingual nerve disturbances after dentoalveolar surgery, and of recovery of sensitivity.

In a follow-up of 1107 dentoalveolar operations in the postcanine region, 24 (2.2%) temporary sensitivity disturbances of the inferior alveolar nerve and 16 (1.4%) of the lingual nerve were found. Permanent disturbances were not present. Complete recovery had occurred by 6 months in all cases. The incidence of temporary sensitivity disturbances depended on the different surgical interventions performed. For evaluation and follow-up purposes, a computer-aided pain and thermal sensitivity (PATH) tester was used. By PATH testing, spontaneous recovery can already be ascertained at the third or fourth postoperative month.