Changes in airway and hyoid position in response to mandibular protrusion in subjects with obstructive sleep apnoea (OSA)

Abstract

This prospective clinical study examined the alterations in airway and hyoid position in response to mandibular advancement in subjects with mild and moderate obstructive sleep apnoea (OSA). Pairs of supine lateral skull radiographs were obtained for 13 female and 45 male, dentate Caucasians. In the first film, the teeth were in maximal intercuspation, while in the second the mandible was postured forwards into a position of maximum comfortable protrusion. Radiographs were traced and digitized, and the alterations in the pharyngeal airway and position of the hyoid were examined. Males and females were analysed separately. In males only, correlations were sought between the changes in hyoid and airway parameters, and the initial and differential radiographic measurements. In males, mean mandibular protrusion at the tip of the lower incisor was 5.3 mm, increasing its distance from the posterior pharyngeal wall by 6.9 mm (or 9 per cent). Movement of the hyoid showed extreme inter-subject variability, both in the amount and direction. In relation to the protruded lower jaw, the hyoid became closer to the gonion by 6.9 mm and to the mandibular plane by 4.3 mm. With respect to the upper face, a 1.3-mm upward and 1.1-mm forward repositioning was seen. The percentage alterations in airway dimensions matched or bettered the mandibular advancement. The minimum distances behind the soft palate and tongue improved by 1.0 and 0.8 mm, respectively. Despite their smaller faces, females frequently showed greater responses to mandibular protrusion than males. No cephalometric features could be identified which might indicate a favourable response of the airway to mandibular protrusion. Larger increments of hyoid movement were associated with an improved airway response, but the strength of the correlations was generally low.

Effects of Functional Appliance Therapy on the Depth of the Pharyngeal Airways: Activator vs. Forsus

“…Our result agrees with those of previous studies [29,30] that also reported that a wider lower pharyngeal airway resultant from anterior positioning of the mandible in his their subjects.…”

“…Yamaoka et al [28] found that the tongue root was situated more posteriorly in Class II females subjects compared with Class III ones. Also, the change in hyoid bone position and lower pharyngeal airway space caused by anteroposterior position of the mandible is well documented [29].In our study the depth of the inferior pharyngeal airway was increased, and had a significant correlation with the changes in SNB angle, ANB angle, and the distance from Pog to N perp. These results suggest that as the mandible was anteriorly positioned in our subjects, the tongue root was positioned more anteriorly away from the posterior pharyngeal wall, the hyoid bone as well was positioned more anteriorly, and as a consequence, the lower pharyngeal airway was widened.…”

“…Yamaoka et al [28] found that the tongue root was situated more posteriorly in Class II females subjects compared with Class III ones. Also, the change in hyoid bone position and lower pharyngeal airway space caused by anteroposterior position of the mandible is well documented [29].…”

“…Also, the change in hyoid bone position and lower pharyngeal airway space caused by anteroposterior position of the mandible is well documented [29].…”

Efetividade do aparelho ortopédico Bionator de Balters no tratamento do ronco e apnéia do sono

“…Os outros 7 pacientes não deram continuidade ao tratamento, pois alegaram desconforto durante a utilização. O índice de aceitação pode ser considerado baixo, quando comparado ao do estudo clínico de Battagel et al 3 , que verificou um índice de cooperação de 76%. O desconforto alegado pelos pacientes ao utilizarem o aparelho refere-se a dificuldades de adaptação devidas aos efeitos colaterais produzidos pelo uso do Bionator de Balters.…”