Evaluation of Neurosensory Disturbance Following Orthognathic Surgery: A Prospective Study

• Published in: Journal of maxillofacial and oral surgery Vol. 14; no. 1; pp. 24 - 31
• Main Authors: Degala, Saikrishna, Shetty, Sujeeth Kumar, Bhanumathi, M.
• Format: Journal Article
• Language: English
• Published: India Springer India 01-03-2015; Springer Nature B.V
• Subjects: Analgesics; Antibiotics; Dentistry; Edema; Medicine; Medicine & Public Health; Oral and Maxillofacial Surgery; Otorhinolaryngology; Pain; Plastic Surgery; Research Paper; Surgery; Bilateral sagittal split osteotomy (BSSO); Hypoesthesia; Neurosensory disturbance (NSD); Neuropraxia
• ISSN: 0972-8279; 0974-942X
• DOI: 10.1007/s12663-013-0577-5

Aim and Objectives
The prospective study was to evaluate the incidence, type of neurosensory disturbance (NSD), grade its severity and monitor its recovery occurring in the lower lip and chin due to damage to inferior alveolar nerve following orthognathic surgery involving mandible.
Materials and Methods
The study included 10 patients who have undergone sagittal split osteotomy, genioplasty, and anterior subapical osteotomy (ASO). All the patients examined preoperatively and post operatively 1 week, 1 and 6 months according to standardized test to clarify the subjective and objective neurosensory status of the injured nerve. Pin prick test, blunt test, two-point discrimator test, brush stoke direction, light touch test, warm and cold test were used bilaterally to lower lip and chin area.
Results
Seven patients underwent bilateral sagittal split osteotomy (BSSO) (70 %), one patient had BSSO with genioplasty (10 %), two patients had BSSO with ASO (20 %). During the operation none of the nerves were transectioned, in 60 % of patients nerve was not visible and in 40 % of patients nerve was seen in distal segment. 70 % of patients underwent setback, 30 % of patients underwent advancement. The subjective evaluation of the patients revealed the incidence of 90 % at 1 week, 30 % at 1 month, 20 % at 6 months and 10 % at 1 year post operatively. The altered sensation reported subjectively was hypoesthesia in 50 % of the patients, anaesthesia in 40 % of the patients. There was 100 % recovery in advancement cases and 93.5 % recovery in setback cases.
Conclusion
There is a high incidence of NSD of the lower lip and chin after BSSO related to advancement, setback, intraoperative nerve encounter and surgical skill. However, recovery of sensation occurs with increasing frequency during the follow-up period. The clinical neurosensory tests are effective guides to study the neurosensory deficit.