This population sample appears to exhibit the previously published tendency for bilateral, unilateral, or mixed-type congenital fistulae to be associated with cleft lip with or without cleft palate, while so-called microforms or conic elevations are almost exclusively associated with cleft palate.

Objective This study was conducted to evaluate the relationship between fistulae of the lower lip and cleft lip and/or palate in patients with Van der Woude syndrome. Methods The medical records of 11,000 patients with cleft lip and/or palate registered at the Cleft Lip-Palate Research and Rehabilitation Hospital, University of São Paulo, Bauru were reviewed. Of these patients, 133 (1.2%) presented with Van der Woude syndrome. Results Of the 133 patients, 88 (66.2%) exhibited full clefts, 22 (16.5%) only cleft lip, and 23 (17.3%) only cleft palate. The lower-lip fistulae observed in these 133 patients were bilateral symmetric in 66 (49.7%), bilateral asymmetric in 42 (31.6%), microform In 19 (14.3%), median in 5 (3.8%), and unilateral in 1 (0.7%). Conclusion This population sample appears to exhibit the previously published tendency for bilateral, unilateral, or mixed-type congenital fistulae to be associated with cleft lip with or without cleft palate, while so-called microforms or conic elevations are almost exclusively associated with cleft palate.

The walls of most of the fistulae consisted of stratified nonkeratinized squamous epithelium and a lamina propria of dense connective tissue with areas of lymphohistiocytic inflammatory infiltrates. Bundles of striated muscle fibers, blood vessels, nerves, adipose tissue, and mixed acinar glands were observed. These glands surrounded the entire wall of the lesion, and their excretory ducts opened into the lumen of the fistula, explaining the clinical observation of elimination of mucous secretion through the opening of the fistula. Two microform cases of fistula were analyzed that presented only a depression in the epithelium at the site corresponding to the opening of the fistula.

The objective of the present study was to evaluate the glands of wall of congenital fistulae of the lower lip with the transmission electron microscope in order to characterize their microstructural pattern. Thin section of Araldite resin embedded congenital fistulae of the lower lip of four patients with Van der Woude syndrome from the Hospital de Reabilitação de Anomalias Craniofaciais da Universidade de São Paulo, Bauru, SP, were analyzed with a transmission electron microscope. The results showed that the glands were mostly made by typical mucous acini exhibiting, with certain frequency, myoepithelial cells surrounding them. In some of lobules, a few acini smaller than the typical mucous, showed granules of moderate electron density or containing a dense core or exhibiting small dense spherule and predominance granular material. These granules resemble to described recently by others in various human minor salivary glands. We concluded that glands associated with congenital fistula of lower lip of patients with Van der Woude syndrome, in spite of being located in vermilion border of the lip, showed at the transmission electron microscope characteristics of labial minor salivary gland, i.e, are mostly mucous with a few seromucous units, while typical seromucous demilunes are not present.