The effect of orthognathic surgery on taste function on the palate and tongue

Abstract

Purpose: Perceived taste intensity and taste quality identification on localized regions of the palate and tongue were examined for 9 patients before orthognathic surgery and again at 1 to 2 and 6 to 9 months after surgery. Taste function would be at risk on the palate after maxillary Le Fort I osteotomy (LFI) and on the tongue after mandibular sagittal split osteotomy (SSO) because of potential damage to peripheral nerves conducting afferent chemosensory information from these regions.

Patients and methods: Three patients had LFI and SSO, 1 had LFI only, and 5 had SSO only. Patients rated taste intensity (using a 10-point fixed-interval scale) and identified taste quality of 4 solutions (NaCl, sucrose, citric acid, and quinine.HCl) brushed with a cotton-tipped applicator on each of 6 oral locations (left and right soft palate, left and right anterior and posterolateral tongue).

Results: Perceived taste intensity of NaCl, sucrose, and citric acid was reduced on average to 34% of presurgery values on the palate for patients who underwent LFI, but the taste intensity of quinine was not affected. LFI also affected the ability to correctly identify the quality of tastants applied to the palate: Patients made 38% correct quality identifications postsurgery compared with 91% presurgery. Perceived taste intensity of quinine.HCl placed on the tongue was reduced to 72% of its presurgery value after SSO, but the taste intensities of NaCl, sucrose, and citric acid were not affected. Correct quality identifications of sucrose, citric acid, and quinine.HCl were reduced to 75% at 2 months post-SSO compared with 96% presurgery and at 6 months postsurgery, but identification for NaCl was 96% before and after surgery.

Conclusion: In the patients studied, taste function on the palate was significantly decreased for 6 to 9 months after LFI, likely a result of impairment of function of the greater superficial petrosal branch of the facial nerve. Lingual taste function, reduced at 1 to 2 months after SSO, likely due to impaired chorda tympani nerve function, improved by 6 to 9 months. Palatal and lingual neurosensory testing can be used to identify reversible sequelae of oral maxillofacial surgery.