Anatomy of the alar lobule in the Asian nose.

摘要

OBJECTIVE: To provide details of the unique anatomical features on the alar lobule region in the Asian nose. METHODS: We hypothesized that the shape of the alar lobule is dependent on its anatomy. The alar lobules were classified into flared type and straight type depending on their gross prominence and roundness. A total of 20 fresh cadaver noses (10 of each type) were dissected. Anatomical differences between the flared and straight types were investigated by gross and histologic studies. RESULTS: The alar lobule consisted of three layers; external skin, muscle, and vestibular skin. The dilator naris anterior and dilator naris posterior muscles were well developed in the flared type alar lobules, whereas they were poorly developed in the straight type. The insertion of the dilator naris posterior muscle in the flared type was found to extend more anteriorly to the middle of alar lobule as well as to the alar base, whereas in the straight type the insertion was limited to the alar base only. External skin at the lateral end of the flared type was thicker than of the straight type. No significant differences were seen in other structures of the alar lobule region. CONCLUSIONS: The gross appearance of the alar lobule is mainly affected by the volume of the dilator naris anterior muscle, the insertion of the dilator naris posterior muscle, and the thickness of the external skin at the lateral end of the alar circumference.