Archives of oral biology
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Archives of oral biology · Aug 1999
Mandibular posture during sleep in patients with obstructive sleep apnoea.
Vertical mandibular posture is thought to be related to narrowing of the upper airway, because mouth opening is associated with an inferior-posterior movement of the mandible and the tongue which influences pharyngeal airway patency. To test whether the mandibular posture is related to the occurrence and/or termination of obstructive sleep apnoea (OSA), the vertical mandibular position was recorded intraorally using a magnet sensor during a standard sleep study in seven patients with OSA. Measurements were recorded during sleep both in the supine and lateral recumbent positions. ⋯ In non-rapid eye-movement sleep, mandibular opening increased progressively during apnoeic episodes and decreased at the termination of apnoeic episodes. In contrast, no significant change in mandibular posture occurred in apnoeic episodes during rapid eye-movement sleep. It was concluded that the vertical mandibular posture is more open during sleep in patients with OSA than in healthy adults and that mandibular opening increases progressively during apnoeic episodes and decreases at the termination of those episodes.
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Archives of oral biology · Aug 1999
Haemodynamic changes in human masseter and temporalis muscles induced by different levels of isometric contraction.
This study evaluated the influence of low contraction forces on intramuscular haemodynamics in human masseter and temporalis using near-infrared tissue spectroscopy. This method allowed the intramuscular haemoglobin (Hb) to be assessed dynamically before, during and after a 5, 15, 25 and 100% maximum voluntary contraction (MVC). Twenty volunteers, 10 males and 10 females, without pain or dysfunction in the masticatory system were included in this study. ⋯ Specifically, the Hb during the contractions in the masseter appeared more stable than in the temporalis, which showed a strong return to baseline. Obviously the contracting masseter had a stronger and more sustained venous occlusion than the contracting temporalis. It is speculated that variation in architecture between the two muscles contributes to these differences in blood flow.