Effect of Head and Tongue Posture on the Pharyngeal Airway Dimensions and Morphology in Three-Dimensional Imaging: a Systematic Review

Abstract

ObjectivesNatural head position is recommended to be optimal at cone-beam computed tomography acquisition. For standardization purposes in control of treatment outcome, it is clinically relevant to discuss, if a change of posture from natural head position may have an effect on the pharyngeal airway dimensions and morphology, during computed tomography, cone-beam computed tomography or magnetic resonance imaging acquisition. This was the aim of the present literature review study for purposes of valid evidence, which was hypothesized, to be present.Material and MethodsThis systematic literature review has been registered in PROSPERO database with following number: CRD42015024567. A systematic literature search performed in PubMed, Embase and Cochrane was carried out in order to evaluate if the effect of human head or tongue posture has an effect on upper airway dimensions and morphology in CT, CBCT or MRI. Study quality assessment was performed. Predictor variable was head and tongue posture. Endpoints were numerical values of upper airway dimensions and morphology.ResultsOverall 1344 articles (Embase 1063, PubMed 269, and Cochrane 12) resulted in four included publications. Quality assessments revealed poor quality and low-level evidence by 46 - 67% of the maximum achievable score. Heterogeneous methodology made a meta-analysis impossible, consequently a narrative synthesis was performed.ConclusionsLimited, poor quality and low evidence level literature is available on the effect of head posture on upper airway dimensions and morphology in three-dimensional imaging. Valid evidence requires a standardized method of head and tongue posture during image acquisition in future studies.

Effects of maxillary expansion on the upper airways: Evidence from systematic reviews and meta‐analyses

“…The inconsistency of these results is probably due to the differences in the CBCT protocols used between studies where head posture, tongue position and segmentation procedures were not heterogeneous. Furthermore, the control of the position of the tongue and the soft palate are still factors that can influence the three‐dimensional evaluation of the pharyngeal airways …”

A new simple three-dimensional method to characterize upper airway in orthognathic surgery patient

“…craniofacial morphology and head posture) and focusing the attention on the effects of treatment interventions on the skeletal basis that may influence airway patency. 5,6,16,17 Nevertheless, some of the issues mentioned in these studies remain not completely answered due to the presence of technical drawbacks that hinder the reduction of the systematic errors. In the present study we presented a technical analysis able to overcome these limitations with the aim to characterize three-dimensionally the upper airway by using as references only stable, reproducible anatomical landmarks, which will not be affected by orthognathic surgical procedures.…”

“…Finally, head posture and tongue position during CBCT-acquisition has also been advocated to be an important factor for UA morphology, yet often underestimated as reported in a previous systematic review. 16 Regarding the second issue ("standard reference planes"), it has to be underlined that, the selection of reliable landmarks for upper airway analysis is of the outmost importance, even more when the changes are the result of orthognathic surgery. A variety of anatomic landmarks have been proposed, however, some refer to anatomical structures (e.g.…”

Influence of Denture Palatal Contouring on the Oropharyngeal Space in Complete Denture Wearers: A Cross-Over Radiographic Study

“…According to a systematic review conducted by Gurani et al (28) both airway volume and CSA showed an increase when evaluated in respect to head extension, head rotation, altered body position, and jaw protrusion. Therefore, the radiographic technique was standardized during CBCT scan in this study.…”