Combining local flap with depressor anguli oris transfer for lower lip reconstruction and orbicularis oris sphincter function restoration

Despite the versatility of flap designs for lower lip reconstruction, the notion of orbicularis oris (OO) ring integrity was barely stressed. Traditional flap transfer leads to fibrous orientation inconsistency with the remaining OO. Therefore, the aim of this study is to share the experience of combining local flaps with depressor anguli oris (DAO) transfer for lower lip reconstruction and OO sphincter function restoration.

48 patients were included in this study. Four types of local flaps were transferred for lower lip reconstruction. Each technique was modified by adding an additional DAO transfer for OO reconstruction. Functional outcomes were evaluated by grading scales based on clinical examination and observation. Aesthetic outcomes were evaluated by Patient and Observer Scar Assessment Scale.

The surgical outcomes were favorable in both functional and aesthetic aspects. No statistically significant differences were observed among different types of flaps. Patients at T1 stage showed statistically significant mouth opening compared with patients at T2 stage (P = 0.004). Patients whose commissure was preserved showed statistically significantly better competence compared with patients whose commissure was sacrificed (P = 0.006).

Combining local flap with DAO transfer is a reliable and effective approach for lower lip reconstruction and OO sphincter function restoration. Moreover, the modiolus seems to play a vital role in enhancing competence. Thus, it should be preserved during oncologic ablation if possible.

It is vital to match the orientation of the transferred muscle fiber with the orientation of the remaining OO. Therefore, DAO becomes an excellent candidate.