Head posture in obstructive sleep apnoea

Abstract

In growing subjects, obstruction of the upper airway may lead to excessive vertical facial development. According to the soft-tissue stretching hypothesis (Solow and Kreiborg, 1977) this could be due to an increased cranio-cervical angulation triggered by the airway obstruction. The present study aimed to examine the effect of airway obstruction on cranio-cervical posture in a sample of adult patients with severe obstructive sleep apnoea (OSA). Lateral cephalometric radiographs taken in the natural head position (mirror position) were obtained from 50 male patients aged 28-70 with polysomnographic diagnosis of obstructive sleep apnoea. The Apnoea Index ranged from 21 to 98 episodes per hour with a mean of 54.6. Control samples were available from previous cephalometric studies of head posture in five samples of healthy subjects and one sample of congenitally blind subjects. The average cranio-cervical angle, NSL/OPT, was found to be extremely large (mean 104.1, SD 9.1) exceeding the average values in the control samples by 1-2 standard deviations (P < 0.001). It is suggested that the large cranio-cervical angle in OSA patients is a physiological adaptation aiming to maintain airway adequacy while the head, and thus the visual axis, is kept in its natural relationship to the true vertical. The findings thus provide evidence for the hypothesis that upper airway obstruction may trigger an increase in the cranio-cervical angulation.

Obstructive Sleep Apnoea Hypopnoea Syndrome and the Cranio Facio-hyoid Morphology in Adults: Linear and Angular Measurements

“…This further shows forward positioning of the head. Similar study found the OPT/CVT to be lesser in the OSAHS group mean 4.5° and SD 2.91 [41]. Similar research found OPT/CVT to be also reduced in the obese OSAHS group (mean 1.1°, SD 2.6), than the control (mean 1.5°, SD 3.1) [42], A comprehensive cephalometric analysis of cranio-cervico-faciohyoid skeletal morphology in 100 male patients with obstructive sleep apnoea (OSA) and 36 male controls was performed, with aberrations in the OSA group features are; shorter dimension of cranial base with slight counter-clockwise rotation and depression of clivus; shorter maxillary length with normal height; maxillomandibular retrognathia related to nasion perpendicular plane (N⊥FH) despite normal angles of prognathism; 47% of the OSA group had mandibular retrognathia; increased anterior lower facial height and mandibular plane angle; reduced size of bony pharynx; inferiorly positioned hyoid bone at C4-C6 level; deviated head posture with larger cranio-cervical angle, and came with the conclusion that cephalometric analysis is highly recommended in OSA patients as one of the most important tools in diagnosis and treatment planning [43].…”

Sleep apnea and cervical spine pathology

“…As the notochord determines the development of cervical vertebrae and the basilar part of the occipital bone, it also induces the formation of the para-axial mesoderm forming the vertebral arches and the remaining aspect of the occipital bone [4]. Other authors argue that patients with OSA have a more extended head posture as a physiological adaptation to maintain airway patency [8]. However, Svanholt et al [6] revealed that OSA patients with endogenous cervical fusions demonstrated no significant difference in cranial base angle or posture of the head from that of controls.…”

Development of craniofacial and dental arch morphology in relation to sleep disordered breathing from 4 to 12 years. Effects of adenotonsillar surgery

“…Solow demonstrated that individuals snoring regularly and OSA patients have a deviant posture of their head and neck compared to non-snoring controls [3]. He also pointed out the pressure on the growing facial skeleton by -soft tissue stretching‖ [4].…”