Midline shift and lateral guidance angle in adults with unilateral posterior crossbite.
BACKGROUND
Unilateral posterior crossbite is a malocclusion that, if not corrected during infancy, typically causes permanent asymmetry. Our aims in this study were to evaluate various occlusal parameters in a group of adults with uncorrected unilateral posterior crossbite and to compare findings with those obtained in a group of normal subjects.


METHODS
Midline shift at maximum intercuspation, midline shift at maximum aperture, and lateral guidance angle in the frontal plane were assessed in 25 adults (ages, 17-26 years; mean, 19.6 years) with crossbites.


RESULTS
Midline shift at maximum intercuspation was zero (ie, centric midline) in 36% of the crossbite subjects; the remaining subjects had a shift toward the crossbite side. Midline shift at maximum aperture had no association with crossbite side. Lateral guidance angle was lower on the crossbite side than on the noncrossbite side. No parameter studied showed significant differences with respect to the normal subjects.


CONCLUSIONS
Adults with unilateral posterior crossbite have adaptations that compensate for the crossbite and maintain normal function.
Department of Prosthodontics, Faculty of Medicine and Odontology, Santiago de Compostela University, Santiago de Compostela, Spain. protesis@usc.es
Benito
B
Rilo
José Luis
JL
da Silva
María Jesús
MJ
Mora
Carmen
C
Cadarso-Suárez
Urbano
U
Santana
D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002508:Cephalometry; D003768:Dental Occlusion, Centric; D005146:Facial Asymmetry / Q000209:etiology; D005260:Female; D006801:Humans; D007574:Jaw Relation Record; D008297:Male; D008310:Malocclusion / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D008334:Mandible / Q000503:physiopathology; D018709:Statistics, Nonparametric