Avaliação da estabilidade do espaço aéreo superior posterior em pacientes submetidos à cirurgia de avanço maxilo-mandibular em acompanhamento mínimo de 8 anos

Abstract

Orthognathic surgery is one of the main successful options for correcting dentoskeletal deformities. Studies conducted in recent decades have already demonstrated that bimaxillary advancements increase the PUA space both in two-dimensional and volumetric analyses. However, long-term evaluation using standardized exams and comparisons at different follow-up times is still scarce, requiring further investigation in these aspects. Thus, the objective of this research is to retrospectively evaluate the PUA by quantifying its minimum axial area in its entirety and total volume, separately in the nasopharyngeal, oropharyngeal, and hypopharyngeal regions in patients undergoing bimaxillary advancement with or without mentoplasty. Using a convenience sample from a private clinic in Fortaleza-CE, 20 patients were selected based on inclusion and exclusion criteria, with computed tomography scans to be analyzed at the immediate preoperative (T0), immediate postoperative at 15 to 30 days (T1), intermediate postoperative at 5 months to 1 year (T2), and late postoperative after at least 8 years of follow-up (T3) and the statistics analyses were performed. The results of the descriptive analysis showed a mean age of 27.4 years, with 55% of the sample being female. There was an equal distribution between Class II and Class III patients, and 60% of the surgeries involved the chin. In the volume analysis, an increase in size was observed at all time points compared to T0. In the nasopharyngeal region, there was a significant gain of 32.6%, from 4644±2355 mm3 to 6160±1516 mm3, when comparing T3 to T0 (p=0.014). For the oropharyngeal region, the statistically significant difference was observed at T1, with an increase of 44.8% (p=0.036). However, there was no significant difference in the hypopharyngeal analysis at any of the evaluated time points. Nevertheless, when analyzing the PUA, an increase was observed at both T1 and T3 compared to T0, with increases of 28.7% and 23.1%, respectively, and p-values of 0.013 at T1 and 0.017 at T3. When comparing the data regarding the most constricted area, a significant increase was observed only at T3, with mean values and standard deviations going from 146.3±93.5 mm3 to 208.4±112.9 mm3, representing a gain of 42.4% (p=0.035). Thus, it was observed that after an average of 10 years postoperatively, the gains in volume and the most constricted area in the PUA are real and can increase or decrease over time. However, there was no difference between Class II or Class III patients in this response, as both underwent advancements. Therefore, it is necessary to understand the factors that may influence this response.