Clark GT, Kobayashi H, Freymiller E,

Mandibular Advancement and Sleep Disordered Breathing.

CDA journal,1996 April:49-61

Abstract: The term "sleep disordered breathing" encompasses several conditions. This article gives definitions for and discusses the types of sleep disordered breathing. It also looks at the use of prosthetic devices and surgery to treat those problems and provides a suggested treatment algorithm.

Method to Determine an Ideal Maxillomandibular Relationship from Tapping Movements Using as Reference the Most Stable Position of Condyle

Keisuke Ikeda，Shoji Kohno，Yukihiro Tsuchida，Takeshi Matsuyama　and　Hiroy uki Ohtake

J Jpn Prosthodont Soc, 40: 000〜000, 1996

Abstract: 　The purpose of this study was to determine an optimum condition for tappin g movements for bite registration. The closing path of incisal and condylar tracking points were measured with a system for recording jaw movements in 6 degrees of freedom during tapping movements in five normal subjects under various conditions such as different head positions (Camper plane, Frankfort plane; parallel to the floor)，tapping frequency（2Hz, 3Hz）and in terincisal distance (20mm, 30mm). 　The most stable position of condyle was found by plotting both tracking po ints,on which almost pure mandibular rotation was observed. Each tapping condition was evaluated by comparing the incisal path's range of rotation of the vertical component, which was termed the rotation value of the mandible. 　Results: When the head was positioned on the Camper plane, with a 3Hz tap ping frequency at a interincisal distance of 30mm, the highest rotation value was found; the most posterior closing path of the mandible recorded at the most condylar stable position did not cause posterior displacement of the condyle. It is concluded that a reliable bite registration can be obtained by using the most posterior closing path of the mandible as reference when the above mentioned tapping conditions are met.

Mizuto Muramatsu.

Spontaneous discharge evoked after endurance clenching in masticatory and sternocleidomastoid muscles.

J Jpn Prosthodont Soc 1996; 40: 564-73.

Abstract: The masticatory and neck muscles of some TMD patients may show spontaneous discharges on the electromyogram. The objective of this study was to clarify whether or not endurance clenching test (TEST) could evoke spontaneous discharges on the mucles of 18 subjects without TMD symptoms. Surface electromyography was taken to seek the spontaneous discharge just after the TEST and the TMD symptoms were examined. The results were as follows: 1. The spontaneous discharge was evoked in 17 out of 18 subjects. 2. The average duration of the spontaneous discharge was : Masseter (M), 3.8 seconds (s) ; Anterior Temporal (Ta), 4.4s ; and Sternocleidomastoid muscle (SCM), 5.2 s. 3. The mean amplitude of the spontaneous discharge was : M, 227.1μV ; Ta, 215.2μV ; and SCM, 98.0μV. 4. The incidence of the spontaneous discharge in the muscles studied was : M, 63.9% ; Ta, 69.4% ; SCM, 55.6%. 5. Some TMD symptoms such as discomfort and/ or spontaneous pain in the muscles were elicited by the TEST. All the symptoms dissappeared within 48 hours after the experiment. 6. In almost all the muscles on which the spontaneous discharge was evoked, discomfort and/ or spontaneous pain were felt and the onset of these symptoms occured within 12 hours after the experiment. Naoki Sakurai A study on effect of occlusal interference concerning distance between upper and lower molars during lateral excursion of patients with internal derangement of TMJ J Jpn Prosthodont Soc, 1995;39:453〜463. Abstract 　 The objective of this study is to investigate the quantitative occlusal condition of patients with internal derangement of the TMJ. To achieve this objective, the shape of the occlusal table of the upper and lower molars was scanned, reference points obtained and compared against the 3-dimensional movement of the mandible in a lateral occlusal position when a fixed incisal point is 2 mm distant from the intercuspal position. Eighteen subjects with internal derangement of the TMJ and eighteen asymptomatic subjects as control group were selected for this investigation. The following results were obtained: 1) the angle of the condylar path of the non-working side and the path of the lower molars on the non-working side was larger in the patients group than in the control group;　2)the incl ination of the cusp slope of the upper molars of the non-working side in the patients group tended to be larger than that of the control group, especially in the second molar, where this difference was statistically　sig nificant; 3)the interocclusal distance between upper and lower second molars in the non-working side of the patients group tended to be smaller than that of the control group,but it is statistically insignificant. paper The Distance between Upper and Lower Molars in a Lateral Occlusal Position on Patients with Internal Derangement of TMJ Naoki Sakurai,Shoji Kohno,Shuichi Nomura,Masahiro Suzuki. J.Jpn.Soc.TMJ 1995;7(1):222〜223. Abstract The purpose of this study is to investigate the quantitative occlusal condition on patients with internal derangement of TMJ. The distance between each occlusal surface of upper and lower molars(also canines) at a lateral occlusal position was measured. The results were as follows: 1)The occlusal distance between upper and lower second molars in non-working side on the patients' group tended to be smaller than those of control group. 2)The occlusal distance of canines in working side on the patients' group tended to be larger than those of control group. Two Different Functions in the Masticatory Muscles during Voluntary Clenching Performances