SPECIAL ARTICLE   

European Journal of Oral and Maxillofacial Surgery 2020 August;4(2):49-51

DOI: 10.23736/S2532-3466.19.00195-4

Copyright © 2019 EDIZIONI MINERVA MEDICA

lingua: Inglese

An embryological approach to philtral hair depletion in bilateral cleft lip deformities

Pierre WEILL ¹ ✉, Alexis VEYSSIERE ^{2, 3}, Jeanne ROSETTE ¹, Christian VACHER ⁴, Hervé BENATEAU ^{1, 3}

¹ Department of Maxillo-facial and Plastic Surgery, Caen University Hospital, Caen, France; ² BioConnect, University of Caen Normandie, Caen, France; ³ Faculty of Medicine, University of Caen Basse-Normandie, Caen, France; ⁴ Service of Maxillofacial Surgery, Beaujon Hospital, Clichy, France

In bilateral cleft lip deformities, surgeons have long been aware that the medial nasal prominence or prolabium is devoid of muscle. During cheiloplasty procedures, the orbicularis oris muscle is reconstructed by retrieving the muscle from the lateral lip edges. Surgeons are also aware that even once cleft lips have been repaired, hair growth is less developed on philtral skin, in other words skin from the medial frontonasal prominence, than on lateral labial skin. In individuals unable to benefit from reconstruction, biopsies have demonstrated that the histological structure of the prolabium is composed of relatively few hypoplastic muscle fibers. This finding is rather surprising since hair follicles develop from ectodermal cells and the ectoderm covering the prolabium appears to be normal. In bilateral lip clefts, normal fusion between the maxillary processes and the intermaxillary process fails to occur, and cranial neural crest cells (CNCCs) migration is perturbated. CNCCs from different places and with a different myoblast differentiation potential are stopped at each side of the cleft. Thus, poor concentration of myoblasts and myocytes in the medial process accounts for the absence of muscular layers in this area and subsequently impairs normal physiological development of the various philtral skin layers and more specifically of the skin appendages.

KEY WORDS: Abnormalities; Fetal development; Lip; Anatomy; Cleft lip