Maximal bite force, facial morphology and sucking habits in young children with functional posterior crossbite.
OBJECTIVE
The maintenance of normal conditions of the masticatory function is determinant for the correct growth and development of its structures. Thus, the aims of this study were to evaluate the influence of sucking habits on the presence of crossbite and its relationship with maximal bite force, facial morphology and body variables in 67 children of both genders (3.5-7 years) with primary or early mixed dentition.


METHODS
The children were divided in four groups: primary-normocclusion (PN, n=19), primary-crossbite (PC, n=19), mixed-normocclusion (MN, n=13), and mixed-crossbite (MC, n=16). Bite force was measured with a pressurized tube, and facial morphology was determined by standardized frontal photographs: AFH (anterior face height) and BFW (bizygomatic facial width).


RESULTS
It was observed that MC group showed lower bite force than MN, and AFH/BFW was significantly smaller in PN than PC (t-test). Weight and height were only significantly correlated with bite force in PC group (Pearson's correlation test). In the primary dentition, AFH/BFW and breast-feeding (at least six months) were positive and negatively associated with crossbite, respectively (multiple logistic regression). In the mixed dentition, breast-feeding and bite force showed negative associations with crossbite (univariate regression), while nonnutritive sucking (up to 3 years) associated significantly with crossbite in all groups (multiple logistic regression).


CONCLUSIONS
In the studied sample, sucking habits played an important role in the etiology of crossbite, which was associated with lower bite force and long-face tendency.
Castelo
Paula Midori
PM
Department of Biological Sciences, Federal University of São Paulo, Diadema, SP, Brazil. pcastelo@yahoo.com
Gavião
Maria Beatriz Duarte
MB
Pereira
Luciano José
LJ
Bonjardim
Leonardo Rigoldi
LR
D001732:Bite Force; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003799:Dental Stress Analysis; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D005386:Fingersucking / Q000009:adverse effects*; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008310:Malocclusion / Q000209:etiology*; D041361:Pacifiers / Q000009:adverse effects; D018709:Statistics, Nonparametric; D013391:Sucking Behavior