Letter to editor on “Efficiency of bimaxillary advancement surgery in increasing the volume of the upper airways: a systematic review of observational studies and meta-analysis”

Excerpt

We read with great interest, the recent article published by Rosario HD describing the efficiency of bimaxillary advancement surgery in increasing the volume of the upper airways: a systematic review of observational studies and meta-analysis [1]. We congratulate the authors for conducting a systematic review and meta-analysis of such a meaningful and much warranted topic using cone beam computed tomography. In this study, authors located 1860 relevant studies on the subject. They found only six studies suitable according to PRISMA guidelines for quantitative meta-analysis. It is pertinent to mention here that upper airway and its definition include both pharynx and the nasal cavity [2]. The short listed and included studies in this review provided data on pharyngeal volume only, and none of the studies included nasal cavity volume, an integral part of upper airway. It is well known that high nasal resistance is one of the major contributing factors of obstructive sleep apnoea (OSA), and it comprises nearly two-thirds of the airway resistance during normal breathing [3]. Therefore, the interpretation of data on pharyngeal volume alone is likely to provide imprecise information on this aspect of the study. …