Avaliação tridimensional da via aérea superior na apneia obstrutiva do sono: revisão sistemática da literatura e estudos tomográficos em pacientes tratados com aparelho de avanço mandibular e cirurgia ortognática bimaxilar

Abstract

The aim of this study was to search the literature for methodological parameters involving cone beam computed tomography (CBCT) for the analysis of the upper airway (UA), to evaluate its craniofacial aspects in patients with obstructive sleep apnea (OSA), as well as to compare the influence of mandibular advancement device (MAD) and bimaxillary orthognathic surgery (BOS) on the UA dimensions. Three studies were designed: systematic review (chapter 1), prospective cohort study (chapter 2) and comparative retrospective cohort study (chapter 3). In study 1, 29 articles were included, most of which reported position during CBCT (vertical or supine) and hard tissues as references for assessing UA. The authors differed in the delineation and terminology of the UA. Risk of bias moderate and high were found. The meta-analysis evaluated two subgroups (vertical and supine). No statistical difference was identified between the control group and the OSA group (p = 0.18) considering the area of the upper airway. The volume in the OSA group was statistically lower than the control (p <0.003 and Cohen's d = -0.81) in the vertical position, but not in the supine position. OSA patients demonstrated smaller anteroposterior dimensions (p = 0.02; Cohen's d = -0.52) than the control group without differences between subgroups. The lateral measurements were lower in the AOS group in the supine position, but not in the vertical position (p = 0.002; Cohen's d = -0.6).In study 2, the transverse width measured in the frontomaxillary suture (p <0.01) and the angle between the mandibular ramus and the Frankfurt horizontal (p = 0.03) were inversely correlated with the apnea and hypopnea index (AHI) , while the goniac angle (p = 0.04) was directly correlated with therapeutic protrusion. The total volumes of the UA (p = 0.01), upper oropharynx (p = 0.04) and lower (p = 0.09) were also directly correlated with the mandibular therapeutic protrusion. The total surface area of the upper airways showed an inverse statistical correlation with the improvement in AHI (p = 0.01). Study 3 compared an OSA group with MAD, which generated a statistical increase in volume (p = 0.003) and upper surface area (p = 0.003) of the oropharynx, with a COB group without OSA, which showed significant improvement in all UA regions after surgery. The increase in the upper oropharynx was significantly greater (p = 0.001) in the surgical group than in the group with braces. The mandibular rotational movements differed significantly (p <0.001), the groups with MAD and BOS had respectively clockwise and counterclockwise mandibular rotation. As a conclusion, it was possible to verify that the methodological parameters to evaluate the UA were not standardized. The meta-analysis demonstrated that differences in methods can interfere with the results, decreasing the quality of the evidence from the studies. In addition, it was found that the craniofacial anatomy influences the volume of the upper airway, as well as the determination of an adequate mandibular advancement for successful treatment. In the study involving MAD and BOS, both methods of treatment were effective, being the most efficient device in the upper oropharynx region, and surgery in all regions of the upper airways through mandibular rotations, retrospectively in the clockwise and counterclockwise directions.