Three-dimensional analysis of the effect of maxillary movements on nasolabial soft tissue changes after orthognathic surgery

The aim of this study is to analyze the linear and angular anthropometric changes in the nasolabial region in three dimensions in patients who have undergone double jaw surgery with Le Fort I maxillary osteotomy, to associate these changes with the three most commonly used maxillary surgical movements and to resolve the disagreements in the literature. The patients included in the study consisted of a total of 39 people, 19 of whom were women (48.7%) and 20 were men (51.3%). The tomographies obtained from these patients were in DICOM format, and MIMICS version 20.0 software, a software that allows three-dimensional hard and soft tissue analysis with DICOM format, was used. By using hard tissue measurements, the amount and direction of three-dimensional movement of the maxilla were determined as a result of the operation, and the patients were divided into three groups, 13 patients in each group, according to these movements. The 1st group consisted of patients in which the maxilla was brought forward, the 2nd group consisted of patients with both the maxilla forward and impaction, and the 3rd group consisted of patients with both the maxilla forward and down position. In our study, 11 linear and 3 angular measurements were made on soft tissue anatomical points, and both the preoperative and postoperative changes of these measurements and the changes in 3 different groups were examined. Alar width, alar base width, mouth width, right and left nostril width and alar base angle increased in all groups, while right and left nostril length and upper lip angle decreased. There was no significant difference in the measurements of intercantal distance, nasal length and nasal tip protrusion. While the upper lip is lengthened in advancing and advancing-down positioning movements of the maxilla, the upper lip is shortened in advancing- impacting movements. While the nasolabial angle decreases in advancing and advancing-impacting movements of the maxilla, the nasolabial angle increases in advancing-down positioning movements. In orthognathic surgery, Le Fort I osteotomy causes significant changes especially in the upper lip and lower 1/3 of the nose.