The role of the external auditory canal in the development of the malleal manubrium in humans.

OBJECTIVE

To determine if the external auditory canal (EAC) plays a role in the induction and proper positioning of the malleal manubrium in humans.

STUDY DESIGN

Retrospective study between 1994 and 2002.

SETTING

Academic, tertiary care referral medical center. Patients Fifty-five ears of 50 patients with congenital atresia (n = 47) or stenosis (n = 8) of the EAC, for which meatoplasty was performed at the University hospital between 1994 and 2002.

MAIN OUTCOME MEASURES

The presence of the manubrium was examined during surgery, and the corre-lation between the presence of the manubrium and the grade of the microtia was evaluated.

RESULTS

The manubrium was identified in all ears with EAC stenosis, whereas it was absent in all ears with EAC atresia. No correlation was observed between manubrium formation and auricular deformity.

CONCLUSIONS

Our results demonstrated a close relationship between the formation of the EAC and that of the malleal manubrium in humans. This is consistent with the recent findings in knockout mice. This information is useful for surgical intervention in cases of congenital EAC anomalies.