Alterações condilares e de vias aéreas superiores em pacientes submetidos a cirurgia ortognática : revisão sistemática e estudo clínico controlado

Abstract

Facial skeletal deformities cause changes in the positioning of the facial bones. With this controlled clinical study, the effects on area and volume of the nasal cavity, maxillary sinuses and nasopharynx were evaluated in patients undergoing bimaxillary OC. Data from 156 CBCT sets were divided into two groups (Class II and Class III) at times T0 (preoperative) and T1 (12 months postoperative) and analyzed using Dolphin Imaging® 3D software v.12. The results show that for maxillary impaction movements of 3mm, the inferior turbinate must be removed to preserve or increase nasal area and volume in class II and class III patients. In maxillary advancements from 3 to 6 mm, there is a gain of 500 mm3 for every 1 mm of movement in Class II patients. In Class III patients, in advances greater than 5mm, area and volume are lost. Regarding the maxillary sinuses, there is a gain of 200mm2 and 2000mm3 for every 1 mm of maxillary desimpaction. Evaluating the nasopharynx, in advances of 2mm of the maxilla, 200mm2 and 2500mm3 are gained and when the maxilla is disimpacted, 200mm2 and 2500mm3 are gained for every 2mm of movement. The “A”, “ANS”, and “PNS” points of the maxilla form a reproducible and accurate pattern for analyzing the area and volume of the nasal cavity, maxillary sinus and nasopharynx. When these structures are at risk of decrease, it is suggested to oral and maxillofacial surgeons to plan the removal of the nasal septum, vomer and lower nasal turbinates.