Mandibular advancement and obstructive sleep apnoea: a method for determining effective mandibular protrusion.

The objectives of the study were to test the hypotheses that it is possible, during routine polysomnography (PSG), to prospectively identify favourable candidates for mandibular repositioning appliance (MRA) therapy in the treatment of obstructive sleep apnoea (OSA) and to accurately estimate an optimal protrusive distance at which to fabricate the MRA. A series of subjects underwent a remotely controlled mandibular positioner (RCMP) test during PSG monitoring. The ability of the RCMP test to eliminate OSA and the target protrusion at which that occurred was compared with the success of a custom oral MRA in the 33 subjects who completed the protocol. The RCMP test was a success in 15 subjects and a failure in 18 subjects. Appliance therapy was initiated in 38 subjects and completed in 33. MRA therapy was successful at target protrusion in 80% of subjects who had a successful RCMP test and failed in 78% of those who failed the RCMP test. In conclusion the remotely controlled mandibular positioner test outcome demonstrated a statistically significant association with mandibular repositioning appliance outcome. The target protrusion determined during the remotely controlled mandibular positioner test was the effective therapeutic protrusion in subjects with a successful remotely controlled mandibular positioner test.

Dysplastic enamel in odontomas.

A series of odontomas was studied by light microscopy, with special emphasis on abnormal enamel in these lesions. The findings were compared to those in amelogenesis imperfecta and in other conditions in which abnormal enamel is found. It was concluded that dysplastic enamel exhibits a number of appearances which are described in this article. A strongly basophilic laminated material was also found, often covering prismatic enamel, but it did not itself appear to be a form of enamel; its identity is not clear. Odontomas, being readily available, offer a good opportunity to study dysplastic enamel.