Effects of Twin-Block with an expanding device on the upper airway in growing children with skeletal class II malocclusion-a retrospective study based on the consistency of three-dimensional and two-dimensional data

The dentofacial and upper airway morphology of adults with obstructive sleep apnea: A systematic review and meta-analysis

The purpose of this systematic review is to summarize evidence regarding the dentofacial and upper airway features of obstructive sleep apnea (OSA) with adults. This systematic review included 32 cross-sectional studies that compared characteristics ascertained from lateral cephalograms or cone beam computed tomography (CBCT) in adults with and without OSA. Comprehensive searches were conducted in PubMed, Embase, and Web of Science from inception to December 2024. Meta-analyses revealed that the inter-first premolar distance (MD = -2.01, P < 0.00001), sella nasion plane length (SN, MD = -2.08, P < 0.00001), posterior airway space (PAS, MD = -1.95, P = 0.03) were notably smaller in the OSA group compared to controls. Conversely, anterior total facial height (ATFH, MD = 2.66, P < 0.0001), the soft palate length (UL, MD = 5.41, P < 0.00001) and the angle constituted by subspinale, nasion and supramentale (ANB, MD = 0.64, P = 0.01) were significantly larger in the OSA group. In comparison to healthy individuals, it is evident that OSA patients may present with a constricted maxillary arch, underdeveloped and clockwise-rotated mandible, augmented vertical facial growth, an inferiorly positioned hyoid bone, and a diminished pharyngeal airway space.

Impact of palatopharyngeal sizes changing on pharyngeal airflow fluctuation and airway vibration in a pediatric airway

Snoring is common in children and is associated with many adverse consequences. One must study the relationships between pharyngeal morphology and snoring physics to understand snoring progression. Although some model studies have provided fluid-structure interaction dynamic descriptions for the correlation between airway size and snoring physics, the descriptions still need to be further investigated in patient-specific airway models. Fluid-structure interaction studies using patient-specific airway structures complement the above model studies. Based on reported cephalometric measurement methods, this study quantified and preset the size of the palatopharynx airway in a patient-specific airway and investigated how the palatopharynx size affects the pharyngeal airflow fluctuation, soft palate vibration, and glossopharynx vibration with the help of a verified FSI method. The results showed that the stenosis anterior airway of the soft palate increased airway resistance and airway resistance fluctuations, which can lead to increased sleep effort and frequent snoring. Widening of the anterior airway can reduce airflow resistance and avoid obstructing the anterior airway by the soft palate vibration. The pharyngeal airflow resistance, mouth inflow proportion, and soft palate apex displacement have components at the same frequencies in all airway models, and the glossopharynx vibration and instantaneous inflow rate have components at the same frequencies, too. The mechanism of this same frequency fluctuation phenomenon can be explained by the fluid-structure interaction dynamics of an ideal coupled model consisting of a flexible plate model and a collapsible tube model. The results of this study demonstrate the potential of FSI in studying snoring physics and clarify to some degree the mechanism of airway morphology affecting airway vibration physics.