Analysis of head and mandibular tapping movements in patients with mandibular protrusion.
The present study was conducted to investigate whether there was a functional coupling between the head and mandibular movements in ten patients with mandibular protrusion (MP) and ten control subjects with normal occlusion (Normal), using a six degrees-of-freedom measuring device. Single-peak waveforms were predominantly seen in both MP (98.2%) and Normal (99.3%). However, vertical displacements of the upper and lower incisor points (VD(UIP) and VD(LIP)) were all significantly larger in MP than those in Normal. The ratio VD(UIP)/VD(LIP) also increased more sharply with an increase in VD(LIP) in MP, compared to that in Normal. Mandibular rotation in MP was also significantly larger than that in Normal. The results showed that, in MP, the head moves more vertically in rhythmical coordination with mandibular movement during tapping. Finally, it may be that this larger vertical head movement is related to the greater condylar rotation in MP subjects.
Division of Orthodontics, Department of Oral Biological Science, Section for Oral Life Science, Graduate School of Medical and Dental Sciences, Niigata University.
Hiroshi
H
Nibe
Kazuhiro
K
Yamada
Tadao
T
Fukui
Shoji
S
Kohno
Kooji
K
Hanada
D000293:Adolescent; D000328:Adult; D000703:Analog-Digital Conversion; D002508:Cephalometry; D003725:Dental Articulators; D003766:Dental Occlusion; D005260:Female; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007180:Incisor / Q000503:physiopathology; D007574:Jaw Relation Record; D008334:Mandible / Q000503:physiopathology*; D008335:Mandibular Condyle / Q000503:physiopathology; D009068:Movement; D010474:Percussion; D011378:Prognathism / Q000503:physiopathology*; D012399:Rotation