Mandibular open-close motion in children with anterior crossbite occlusion.
Anterior crossbite (ACB) malocclusions are frequent; however, its characteristic functional features have not been fully described. The purpose of this study was to determine the characteristics of habitual mandibular open-close motion in children with ACB of their primary dentition. Two groups of children were selected for study; 17 with ACB (eight boys and nine girls; four years one month to seven years one month) and 19 with normal occlusion (eight boys and 11 girls; four years six months to six years seven months). The motion was recorded using an optoelectronic analysis system with six degrees-of-freedom. Mandibular incisor and condylar motion were analyzed by measuring their three-dimensional ranges and trajectories. Also estimated incisor and condylar pathways of the two groups were compared. Patients with ACB opened wider with more anterior-posterior condylar translation and more mandibular rotation. Although between-subject (inter-individual) variance of all variables in children with ACB was larger, they had less within-subject variance at the condyles. These results indicate that open-close mandibular motion in children with ACB is completely different from that of children with normal occlusion. The different motions might be related to morphological differences between the two groups.
Section of Pediatric Dentistry, Division of Oral Health, Growth, and Development, Kagoshima University Graduate School of Medical and Dental Sciences, Japan.
Junko
J
Tokutomi
Haruaki
H
Hayasaki
Issei
I
Saitoh
Yoko
Y
Iwase
Atsushi
A
Fukami
Chaiki
C
Yamada
Yoshihiko
Y
Takemoto
Emi
E
Inada
Youichi
Y
Yamasaki
D002508:Cephalometry; D002648:Child; D002675:Child, Preschool; D003766:Dental Occlusion; D003768:Dental Occlusion, Centric; D004581:Electronics / Q000295:instrumentation; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007180:Incisor / Q000503:physiopathology; D008297:Male; D008310:Malocclusion / Q000473:pathology / Q000503:physiopathology*; D008334:Mandible / Q000473:pathology / Q000503:physiopathology*; D008335:Mandibular Condyle / Q000503:physiopathology; D008437:Maxilla / Q000473:pathology; D009068:Movement; D009295:Nasal Bone / Q000473:pathology; D055096:Optical Devices; D016059:Range of Motion, Articular / Q000502:physiology; D012399:Rotation; D014094:Tooth, Deciduous