Unilateral posterior crossbite and mastication.
OBJECTIVE
This study was designed to characterize masticatory-cycle morphology, and distance of the contact glide in the closing masticatory stroke, in adult subjects with uncorrected unilateral posterior crossbite (UPXB), comparing the results obtained with those obtained in a parallel group of normal subjects.


METHODS
Mandibular movements (masticatory movements and laterality movements with dental contact) were registered using a gnathograph (MK-6I Diagnostic System) during unilateral chewing of a piece of gum. Traces were recorded on the crossbite and non-crossbite sides in the crossbite group, and likewise on both sides in the non-crossbite group.


RESULTS
Mean contact glide distance on the crossbite side in the UPXB group was significantly lower than in the control group (p<0.001), and mean contact glide distance on the non-crossbite side in the UPXB group was significantly lower than in the control group (p=0.042). Cycle morphology was abnormal during chewing on the crossbite side, with the frequency distribution of cycle types differing significantly from that for the noncrossbite side and that for the control group (p<0.001).


CONCLUSIONS
Patients with crossbite showed alterations in both contact glide distances and masticatory cycle morphology. These alterations are probably adaptive responses allowing maintenance of adequate masticatory function despite the crossbite.
Rilo
Benito
B
Prosthodontics Department, University of Santiago de Compostela, 15705 Santiago de Compostela, Spain. protesis@usc.es
da Silva
José Luis
JL
Mora
María Jesús
MJ
Cadarso-Suárez
Carmen
C
Santana
Urbano
U
D000222:Adaptation, Physiological / Q000502:physiology; D000293:Adolescent; D000328:Adult; D002638:Chewing Gum; D003724:Dental Arch / Q000503:physiopathology; D003766:Dental Occlusion; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000503:physiopathology*; D008334:Mandible / Q000503:physiopathology; D008409:Mastication / Q000502:physiology*; D009068:Movement; D014070:Tooth / Q000503:physiopathology
D002638:Chewing Gum