title: Maximal bite force, facial morphology and sucking habits in young children with functional posterior crossbite.
abstract: 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.
authors.affiliation: Department of Biological Sciences, Federal University of São Paulo, Diadema, SP, Brazil. pcastelo@yahoo.com
authors.forename: Paula Midori
authors.initials: PM
authors.lastname: Castelo
authors.forename: Maria Beatriz Duarte
authors.initials: MB
authors.lastname: Gavião
authors.forename: Luciano José
authors.initials: LJ
authors.lastname: Pereira
authors.forename: Leonardo Rigoldi
authors.initials: LR
authors.lastname: Bonjardim
mesh_terms: 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