Resection of oral and maxillofacial tumors is often accompanied by the inferior alveolar nerve neurectomy, resulting in abnormal sensation in lower lip. It is generally believed that spontaneous sensory recovery in this nerve injury is difficult. However, during our follow-up, patients with inferior alveolar nerve sacrifice showed different degrees of lower lip sensory recovery. In this study, a prospective cohort study was conducted to demonstrate this phenomenon and analyze the factors influencing sensory recovery. A mental nerve transection model of Thy1-YFP mice and tissue clearing technique were used to explore possible mechanisms in this process. Gene silencing and overexpression experiments were then conducted to detect the changes in cell morphology and molecular markers. In our follow-up, 75% of patients with unilateral inferior alveolar nerve neurectomy had complete sensory recovery of the lower lip 12 months postoperatively. Patients with younger age, malignant tumors, and preservation of ipsilateral buccal and lingual nerves had a shorter recovery time. The buccal nerve collateral sprouting compensation was observed in the lower lip tissue of Thy1-YFP mice. ApoD was demonstrated to be involved in axon growth and peripheral nerve sensory recovery in the animal model. TGF-β inhibited the expression of STAT3 and the transcription of ApoD in Schwann cells through Zfp423. Overall, after sacrificing the inferior alveolar nerve, the collateral compensation of the ipsilateral buccal nerve could innervate the sensation. And this process was regulated by TGF-β-Zfp423-ApoD pathway.
Mice ; Animals ; Lip/innervation* ; Prospective Studies ; Mandibular Nerve/pathology* ; Sensation/physiology* ; Trigeminal Nerve Injuries/pathology*

OBJECTIVETo investigate the functional reconstruction technique for partial lower lip defects.

METHODS7 patients with lower lip cancer (3 cases of basal cell carcinoma, 2 cases squamous cell carcinoma and 2 cases papillary carcinoma) underwent excision. The full-thickness lower lip defects were one-third to two-third of the total lower lip length. All the defects were reconstructed with V-Y island advancement flaps based on the mental neurovascular bundle.

RESULTSThere was no flap loss. No recurrence was observed during the follow-up period of 3 months to one year. Both the aesthetic appearance, muscle function and sensation of the reconstructed lower lip were satisfactory.

CONCLUSIONSMental neurovascular V-Y island advancement flap is an ideal method for functional repair of partial lower lip defect.

Aged ; Carcinoma, Basal Cell ; surgery ; Chin ; innervation ; Female ; Humans ; Lip ; injuries ; Lip Neoplasms ; surgery ; Male ; Middle Aged ; Reconstructive Surgical Procedures ; methods ; Surgical Flaps ; blood supply