The role of upper airway morphology in obstructive sleep apnea

On Monday, 22 January 2024, Xiaoxin Shi will defend her PhD thesis entitled 'The role of upper airway morphology in obstructive sleep apnea' at the University of Amsterdam. Her promotors are prof. dr. G. Aarab and prof. dr. F. Lobbezoo. Her co-promotors are prof. dr. J. de Lange and dr. W.E.R. Berkhout. Xiaoxin Shi receives a contribution from the NVGPT towards thesis printing. Below, a summary of her thesis is provided.

Obstructive sleep apnea (OSA) is a highly prevalent sleep-related breathing disorder, characterized by repetitive complete and/or partial obstructions of the upper airway during sleep.
It is suggested that impaired upper airway morphology is a fundamental pathophysiological trait of OSA. However, the exact role of the upper airway morphology in the pathogenesis and treatment of OSA is still not well known.
Therefore, the general aim of this thesis was to evaluate the role of upper airway morphology in the pathogenesis of different OSA phenotypes and in the effects of mandibular advancement device (MAD) therapy.
Upper airway morphology was investigated by cone beam computed tomography (CBCT). No significant differences in the upper airway morphology between positional and non-positional OSA (chapter 2), nor between Dutch and Chinese patients with mild to moderate OSA (chapter 3) were found.
Further, miniscrew-assisted orthodontic treatment with premolar extractions increased upper airway dimensions in young adults with Class II malocclusion (chapter 4). Finally, no significant differences in the changes in upper airway dimensions between two types of MADs in situ (chapter 5), nor between responders and non-responders (chapter 6) with mild to moderate OSA were found.
Therefore, it was concluded that the upper airway morphology does not play a significant role in the pathogenesis of different OSA phenotypes and in the treatment effects of MADs.
Future research involving both anatomical and non-anatomical factors is needed to better understand the pathogenesis and treatment outcomes of OSA.