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.


METHODS
Retrospective study between 1994 and 2002.


METHODS
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.


METHODS
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.
Department of Otolaryngology, Faculty of Medicine, University of Tokyo, Tokyo, Japan. shinchan-tky@umin.ac.jp
Shin-Ichi
S
Ishimoto
Ken
K
Ito
Kenji
K
Kondo
Tatsuya
T
Yamasoba
Kimitaka
K
Kaga
D000293:Adolescent; D000328:Adult; D002648:Child; D004424:Ear Canal / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery*; D004427:Ear Diseases / Q000151:congenital / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008371:Manubrium / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery*; D013506:Otologic Surgical Procedures; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome