 |
|
Development of the Upper Lip
Craig W. Senders, MD;
Erik C. Peterson;
Andrew G. Hendrickx, PhD;
Mark A. Cukierski, PhD
Arch Facial Plast Surg. 2003;5:16-25.
Objectives To affirm and reanalyze George L. Streeter's "merging theory" of upper-lip development in primates by observing progressive embryologic stages in facial development using scanning electron microscopy (SEM) and to further understand upper-lip development.
Design The study was conducted at the California Regional Primate Research Center, Davis. Twenty primate embryos (Macaca fascicularis) and 2 fetuses were examined with SEM. The development of the frontonasal prominence, maxillary prominence, medial nasal prominence, and lateral nasal prominence were sequentially observed. The contribution of these prominences to the formation of the upper lip and nose were carefully analyzed.
Results The maxillary prominence and medial nasal prominence form the upper lip, whereas the lateral nasal, medial nasal, and maxillary prominences form the nose. There is fusion of the maxillary prominence with the medial nasal prominence. This fusion has not been previously described. This has resulted in a modification of the current theory of upper-lip development into one we refer to as the "dynamic fusion theory."
Conclusions The dynamic fusion theory explains the merging process of the mesenchymal and ecotodermal layers of the facial prominences that contribute to the upper-lip formation. The dynamic fusion theory of facial prominence movement details the interaction between epithelial layers: both epithelial layers must fuse properly to avoid cleft-lip deformities.
From the University of California, Davis. Dr Cukierski is now with Merck Research Laboratories, West Point, Pa.
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
Changing Perspectives in Cleft Lip and Palate: From Acrylic to Allele
Tollefson et al.
Arch Facial Plast Surg 2008;10:395-400.
ABSTRACT
| FULL TEXT
|
