Cheilognatopalatoschisi: Analisi morfologica ed istoenzimatica del muscolo orbicolare della bocca

Palate and lip muscle alterations with cleft are poorly known. Few data about patients orbicularis oris muscle with cleft are reported and often in contrast each other. We decided to analyze histologic and histoenzimatic features of the orbicularis oris muscles obtained from 26 biopsyes taken from the both sides of the schisis in 13 patients affected by unilateral or bilateral cleft lip and palate divided in two groups: 7 patients gone to primary cheiloplasty and 6 to secondary cheiloplasty. Muscles section were stained with hematoxylin-eosin, modified Gomori trichrome and NADH-TR. The analyzed parameters were: organization and type of muscle fibers, presence of ragged red fibers, characteristics of nuclei, degree of fibrosis, presence of adipose tissue and inflammatory infiltrate. Our results showed the presence in the first group and the persistence in the second one, although surgical repair of the schisis, of dystrophic-like alterations of the orbicularis oris muscle such as variability of fiber size, fibers disorganization and increase of connective tissue. We found no neurogenic atrophy, ragged red fiber or inflammatory infiltrate. The marked alterations of lip muscle in children with cleft, that perstist in adults even after surgery, suggest that muscle damage could represent a significant pathogenetic factor in this type of malformation. Muscular biopsy of orbicularis oris muscle during cheiloplasty could offer useful damage evaluation and functional prognostic information in patients with cleft lip and palate.