title: [Quantitative analysis of the palatal features affected by digit-sucking habit using a laser scanning system].
abstract: OBJECTIVE
  To investigate the influence of digit-sucking habit on palatal features in pre-school children by using a laser scanning system.
  
  
  METHODS
  Forty pre-school children were chosen according to the results of questionnaires, among which 20 with digit-sucking habit(digit-sucking group) and 20 without any oral habits(control group). Impression of the upper jaw was taken from each child. After laser scanning the plaster casts, and three-dimensional reconstruction by the computer, parameters of anterior and posterior palatal length, width and height were measured, ratios of height/width, length/width and width ratio of anterior and posterior palatal were analyzed. The differences of palatal features between two groups were analyzed by t test.
  
  
  RESULTS
  There was statistical significance between digit-sucking group and control group in posterior palatal width, anterior palatal length and anterior palatal height. The ratios of height/width and length/width in both posterior and anterior areas were statistically significant (P < 0.05). Compared to the control group, the results indicated that palatal features were relatively deeper, narrower and more protrusive in digit-sucking group.
  
  
  CONCLUSIONS
  The digit-sucking habit may have some deleterious impacts on the palatal features in pre-school children with primary dentition. And it is practical to measure the spacial palatal features by using laser scanning system to some extent.
authors.affiliation: The Second Dental Center, Peking University School and Hospital of Stomatology, Beijing 100101, China.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Ji
authors.forename: Lihong
authors.initials: L
authors.lastname: Ge
authors.forename: Jiangxia
authors.initials: J
authors.lastname: Miao
mesh_terms: D002648:Child; D002675:Child, Preschool; D005386:Fingersucking; D006184:Habits; D006801:Humans; D007834:Lasers; D008310:Malocclusion; D008437:Maxilla; D014094:Tooth, Deciduous