To report the incidence and classification of dentofacial deformities from the Maxillofacial Department at the Specialty Hospital at the 21st Century National Medical Center of the Mexican Institute of Social Security in Mexico City. A descriptive, retrospective and transversal study was carried out.Clinical files from 120 patients were reviewed from May 1997 to May 1998 with the purpose of classifying and determining the types of maxillofacial deformities and also to report whether these deformities were corrected by orthognatic surgery.One hundred twenty clinical files were reviewed and dentofacial deformities were found in 47 (39%). All patients were treated with orthognatic surgery. Surgical treatment was often combined (orthodontia and surgery).Regardless of the type of dentofacial deformities, an individualized treatment protocol must be designed for each patient. It is important to list the priorities and needs of the patients in order to find appropriate solutions, in regard to their importance.