Experimental study of epithelialization of the muscle-only flap in the oral cavity.

PURPOSE

The purpose of this study was to observe the epithelialization process of the muscle-only flap used for reconstruction of the oral mucosal defects.

MATERIALS AND METHODS

Forty-three male adult Japanese rabbits were used. A superiorly based cleidomastoid muscle flap was designed after vascular assessment. The flap was transferred into the oral cavity to cover a mucoperiosteal defect made in the mandibular alveolus. Epithelialization of the flap was histologically evaluated at designated intervals.

RESULTS

The flaps survived without ischemic necrosis. By 8 days postoperation, the flap was infiltrated by acute inflammatory cells and being replaced by granulation tissue originating from the adjacent tissues. The oral epithelial cells advanced onto this granulating muscle flap, with eventual coverage by 21 days. The granulation tissue matured to fibrous tissue with significant contraction by 2 months. At 6 months postoperation, abnormally hyperkeratinized epithelium was seen on the flap. This differed from the surrounding parakeratinized oral epithelium.

CONCLUSIONS

The muscle-only flap in the oral cavity epithelializes after the granulation process.