Supine Cephalometric Study on Sleep-Related Changes in Upper-Airway Structures in Normal Subjects

Hiyama, Shigetoshi; Ono, Takashi; Ishiwata, Yasuo; Kuroda, Takayuki

doi:10.1093/sleep/23.6.783

Cited by 23 publications

(17 citation statements)

References 42 publications

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“…All of the cephalometric analyses were performed by the same orthodontist before the follow-up polysomnographic study. The value of method errors for the cephalometric analyses (range 0.25-0.63 mm) was consistent with those in previous studies [10,11].…”

Section: Supine Cephalometrysupporting

confidence: 90%

“…The authors accept that this study with twodimensional cephalometry has known limitations to measure the transverse dimension [25], cross-sectional shape [27] and volume [28] of the UA. However, as long as data are collected following a standardised method [5,10], the superimposition of cephalometric tracings appears to be useful enough for the analysis of UA curvature in the sagittal dimension. Since the titration period (140 ¡ 87 days) of the OA in order to avoid known side-effects [4] is obviously longer than with nCPAP, where titration of nasal pressure is typically achieved in one night, it is acknowledged that this longer time period is a limitation of OA therapy especially when a rapid therapeutic response is required.…”

Section: Discussionmentioning

confidence: 99%

“…Baseline supine cephalometry was obtained before initial insertion of the OA and follow-up supine cephalometry was undertaken after titration with the OA in place by an established method [5,9,10]. Two reference lines ( fig.…”

Section: Supine Cephalometrymentioning

confidence: 99%

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Effects of mandibular advancement on airway curvature and obstructive sleep apnoea severity

Tsuiki¹,

Lowe²,

Almeida³

et al. 2004

Eur Respir J

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In a curved tube, the amount of airflow appears to be influenced by the amount of curvature. The purpose of this study was to investigate changes in obstructive sleep apnoea (OSA) severity and awake velopharyngeal curvature in response to an anteriorly titrated mandibular position in 20 male OSA patients.Baseline supine cephalometry was obtained before the initial insertion of a titratable oral appliance and follow-up supine cephalometry was undertaken after titration of the mandibular position with the appliance in place.The mean apnoea/hypopnea index (AHI) before treatment (31.6¡13.0 events?h -1 ) was significantly reduced (9.8¡7.4 events?h -1 ) after titration of the mandibular position in all 20 patients. There was a significant increase in the anteroposterior calibre and the radius of the curvature of the anterior wall of the velopharynx in 14 good responders who exhibited an AHI reduction to f15. Similar observations were not found in six poor responders.To conclude, an anteriorly titrated mandibular position reduced obstructive sleep apnoea severity, enlarged the velopharynx and diminished the curvature of the anterior velopharyngeal wall in good responders. It is proposed that this change in the upper airway curvature associated with mandibular advancement may effect obstructive sleep apnoea severity through its effect on airflow dynamics. The fluid flow through curved tubes in human organs such as the aortic arch and the coronal arteries are of interest physiologically in the study of cardiovascular systems, since an increase in the curvature induces pressure losses as well as higher resistance in the same region [1,2]. The upper airway (UA) has characteristics similar to those of the curved vessels in the cardiovascular system in that the airstream is curved from the nasal cavity to the hypopharynx at the level of the velopharynx. Nevertheless, an interaction between the curvature of the velopharynx and the pathogenesis of obstructive sleep apnoea (OSA) remains unknown.Recent developments in mandibular advancement oral appliances (OAs) have provided a better quality of life not only for patients with snoring and mild-to-moderate OSA, but also for severe OSA patients who could not tolerate nasal continuous positive airway pressure (nCPAP) [3,4]. An anterior titration of the mandibular position using OAs has been reported to increase the anteroposterior diameter [5] and cross-sectional area [6] of the velopharynx, resulting in a reduction of OSA severity. In addition to such anatomical changes, it was reported that advancement of the mandible decreased nasal resistance and facilitated nasal breathing [7,8]. These reports indicate a close relationship between morphological alteration and improvement of airflow dynamics in response to mandibular protrusion. If the anterior titration of the mandibular position decreased the curvature of the velopharynx, it may assist in improving airflow dynamics.It was hypothesised that an anteriorly titrated mandibular position would diminish the curvature of t...

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Section: Supine Cephalometrysupporting

confidence: 90%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of mandibular advancement on airway curvature and obstructive sleep apnoea severity

Tsuiki¹,

Lowe²,

Almeida³

et al. 2004

Eur Respir J

View full text Add to dashboard Cite

show abstract

“…This can be attributed to the fact that fat deposition increases tongue dimensions (length Eb-TT, height TgH, TgH Dorsum, and Eb-Tg Dorsum) but not necessarily its posterior projection into the retroglossal area. While the impact of larger tongues on the restriction of the retroglossal space is not evident in the upright position, it is likely to be more significant in the supine posture due to the sagging of the base of the tongue against the PPW, gravitational pull [64, 65], and the hypotonicity of the genioglossal muscle during sleep [66]. …”

Section: Discussionmentioning

confidence: 99%

Cephalometrics of Pharyngeal Airway Space in Lebanese Adults

Daraze

Delatte

Liistro

et al. 2017

International Journal of Dentistry

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Purpose. The upper airway space is significant in orthodontic diagnosis and treatment planning. The objectives of this study are to assess the dimensions of soft tissue elements of the upper pharyngeal space and evaluate potential correlations with modifying variables such as gender, skeletal class, and anthropometric parameters. Materials and Methods. Lateral cephalograms were obtained from 117 healthy young adult Lebanese subjects. Nineteen cephalometric linear/angular measurements of the nasopharynx, oropharynx, and hypopharynx were recorded. Anthropometric parameters including body mass index and neck circumference were measured. Results. Significant differences were demonstrated for 12 out of the 19 parameters considered between genders. Uvula and tongue dimensions and the distances between epiglottis-posterior pharyngeal wall and epiglottis-posterior nasal spine were significantly larger in males. The anteroposterior inclination of the uvula and the distances between the uvula and posterior pharyngeal wall were significantly greater in females. No significant differences were found between skeletal classes relative to most of the variables. Body mass index and neck circumference were positively correlated with the dimensions of tongue and uvula. Conclusions. Sexual dimorphism relative to some cephalometric variables and anthropometric parameters may account partly for larger oronasopharyngeal spaces in females. Anthropometric data need to be accounted for in population-related comparisons.

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“…A cephalometric study performed during stage 1-2 sleep revealed significant changes compared with the awake state: the mandible rotated clockwise, the hyoid bone moved downward toward the thorax, the anteroposterior UA dimension decreased, and the cervical bone was displaced anteriorly toward the chin [50]. The posture of the mandible periodically changes according to the sleep stage across [47].…”

Section: Activity During Sleepmentioning

confidence: 99%

Supine Cephalometric Study on Sleep-Related Changes in Upper-Airway Structures in Normal Subjects

Cited by 23 publications

References 42 publications

Effects of mandibular advancement on airway curvature and obstructive sleep apnoea severity

Effects of mandibular advancement on airway curvature and obstructive sleep apnoea severity

Cephalometrics of Pharyngeal Airway Space in Lebanese Adults

Tongue and upper airway function in subjects with and without obstructive sleep apnea

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