Tratamiento ortodóncico-quirúrgico en paciente clase III esquelético: presentación de un caso

A 24-year-old patient attended the Orthodontics Clinic of the Division of Postgraduate Studies and Research, Faculty of Dentistry, UNAM, with a previous orthodontic treatment and absence of lower 1st premolars. The chief complaint was an unattractive facial appearance due to a forward position of the mandible and anterior open bite. Upon facial examination, in the frontal view, a leptoprosopic face, collapsed paranasal areas and incompetent lips were observed. In the vertical facial proportions, the lower third was increased. The lateral and oblique view showed a greater projection of the chin, a concave profile and an increased mentocervical length. Intraorally, the molar relationship was class III; a 2 mm anterior open bite and complete anterior cross bite of 1 mm were also observed. The patient presented a mild discrepancy of the dental midline as well. Orthodontic treatment was carried out in three phases: pre-surgical, surgical and post-surgical. In the pre-surgical phase dental decompensation was performed and the patient was prepared for surgery. In the surgical phase a segmental maxillary surgery from lateralincisor to lateralincisor was performed in order to produce a movement of sagittal rotation thus projecting the nasogenian area and improving incisor inclination. A mandibular setback via bilateral sagittal osteotomy was also performed. In the post-surgical phase ideal occlusal relationships were achieved in terms of canine class, molar class, overjet, overbite, centered dental midlines as well as a more harmonious profile.