(1) Hypoxaemia during the rapid eye movement phase of sleep is common in older healthy normal subjects over 55 years of age; the sleep apnoea syndromes--such as obstructive sleep apnoea, where oro-nasal airflow ceases for more than 10 seconds on many separate occasions throughout the night, due to failure of contraction of the genio-glossus muscle; "blue and bloated" patients with chronic bronchitis and emphysema, where profound nocturnal hypoxaemia is common in REM sleep, and is associated with further elevation of pulmonary arterial pressure; the overlap syndrome--where "blue and bloated" chronic bronchitis is associated with an obstructive sleep apnoea syndrome; and bronchial asthma, where hypoxaemia is associated with irregular breathing and possibly nocturnal bronchoconstriction.
(2) 1) According to our observation, the Genio-hyo-glossus consists of two large bundles; and upper bundle and a lower bundle.
(3) The surgical groups studied were Le Fort I osteotomy (LEFORT; n = 13), sagittal split ramus osteotomy (SSRO; n = 6), intraoral vertical ramus osteotomy (IVRO; n = 9), and isolated genioplasty (GENIO; n = 5).
(4) It give a skeletal appearance and fills the canine fossa which become a heavy fold and increases the apparent depth of the naso genio labial sulcus.
(5) These results suggest that Genio-hyo-glossus acts as a power generating force in contrast to the Hyo-glossus and Stlo-glossus which are fatigue-resisting.
(6) The percentage distribution of red muscle fibres in the Hyo-glossus and Stlo-glossus is more than Genio-hyo-glossus.
(7) 3) The cross-sectional area (mm2) and the total number of the muscle fibres is highest in the Genio-hyo-glossus.
(8) The Cross-sectional area and the total number of muscle fibre is greatest in the Genio-hyo-glossus.
(9) The SSRO group had the highest percentage of sites with immediate postsurgical NSD to both SLT (72%) and MTD (67%), followed by the LEFORT (SLT = 50%, MDT = 58%), GENIO (SLT = 27%, MTD = 6%), and IVRO groups (SLT = 11%, MTD = 18%), respectively.
(10) Each group also varied in the severity of the initial postoperative deficit as measured by SLT, with the SSRO group showing the greatest deficit followed by the LEFORT, GENIO, and IVRO groups.