Introduction: Skeletal unit growth may be due to epigenetic influence exerted by the functional matrix on the skeleton. Penn analysis is a method used to evaluate tomographically the transverse alterations of the maxilla. Objective: To analyze the association between transverse collapse of the maxilla and facial biotype in patients of the Polyclinic of the Orthodontics Postgraduate Program of the Autonomous University of Baja California, Mexicali campus. Materials and methods: An observational, analytical and cross-sectional study was carried out. The sample consisted of 75 patients who met the inclusion criteria. Initial tomographic studies were used to determine the presence of transverse collapse by means of Penn analysis. Lateral skull teleradiographs were plotted to determine the facial biotype by means of the Vert coefficient of Ricketts' lateral cephalometric analysis. The chi-square test was performed for statistical analysis of the association between the presence of transverse collapse of the maxilla and facial biotypes. Results: No significant results were found between the chi-square values and the p-value for patients with transverse collapse of the maxilla in association with facial biotypes. However, a statistical chi-square value of 4.8422 and a p-value of 0.2777 were obtained for the sample of female patients with transverse collapse of the maxilla. Conclusions: No association was found between the presence of maxillary transverse deficiencies and facial biotypes.