ABSTRACT
A dentist referred a 32-year-old man with the Prader-Willi syndrome to a center for special dental care because of the poor cooperation of the patient, progressive toothwear and advanced palatal trauma. The dental problems were, among others, caused by the disto-relation (Class II-2), a poor oral hygiene, the frequency of sugar intake, oesophageal reflux and a strongly reduced salivary pH of 5.5. Treatment of the dentition was established by minimal invasive and adhesive dentistry.
Subject(s)
Dental Care for Disabled/methods , Prader-Willi Syndrome/complications , Tooth Erosion/etiology , Adult , Dietary Sucrose/administration & dosage , Gastroesophageal Reflux/complications , Gastroesophageal Reflux/etiology , Humans , Hydrogen-Ion Concentration , Male , Oral Hygiene , Palate/injuries , Saliva/chemistryABSTRACT
Jaw-closing muscles have architectural features suited to force production; supra- and infrahyoid muscles are better adapted to produce velocity and displacement. It was hypothesized that this difference in function would be reflected in myosin heavy-chain (MyHC) composition (equivalent to contraction velocity) and fibre-type cross-sectional area (equivalent to force). MyHC composition was determined in muscles obtained from eight human cadavers, using monoclonal antibodies against MyHC isoforms. Jaw closers contained 4.2 times fewer type IIA fibres and 5.2 times more hybrid fibres than suprahyoid muscles, and 3.9 times fewer type IIA fibres and 3.2 times more hybrid fibres than the infrahyoid muscles. In the jaw closers, MyHC-I was expressed in approx. 70% of all fibres (pure+hybrid), in the suprahyoid muscles in approx. 40%, and in the infrahyoid muscles in approx. 46%. In the jaw closers, type I fibres were 40% larger in diameter than in the supra- and infrahyoid muscles. It can be concluded that the jaw closers have characteristics of slow muscles, and that the supra-/infrahyoid muscles have characteristics of fast muscles.
