Protracted delay in taste sensation recovery after surgical lingual nerve repair: a case report

INTRODUCTION: Lingual nerve injury is sometimes caused by dental treatment. Many kinds of treatment have been reported, but many have exhibited poor recovery. Here the authors report changes in somatosensory and chemosensory impairments during a long-term observation after lingual nerve repair. CASE PRESENTATION: A 30-year-old Japanese woman claimed dysesthesia and difficulty eating. Quantitative sensory test results indicated complete loss of sensation in the right side of her tongue. She underwent a repair surgery involving complete resection of her lingual nerve using a polyglycolic acid tube containing collagen 9 months after the injury. A year after the operation, her mechanical touch threshold recovered, but no other sensations recovered. Long-term observation of her somatosensory and chemosensory function after the nerve repair suggested that recovery of taste sensation was greatly delayed compared with that of somatosensory function. CONCLUSION: This case shows characteristic changes in somatosensory and chemosensory recoveries during 7 postoperative years and suggests that taste and thermal sensations require a very long time to recover after repair surgery.