title: Three-dimensional biometric study of palatine rugae in children with a mixed-model analysis: a 9-year longitudinal study.
abstract: BACKGROUND
  The palatine rugae have been suggested as stable reference points for superimposing 3-dimensional virtual models before and after orthodontic treatment. We investigated 3-dimensional changes in the palatine rugae of children over 9 years.
  
  
  METHODS
  Complete dental stone casts were biennially prepared for 56 subjects (42 girls, 14 boys) aged from 6 to 14 years. Using 3-dimensional laser scanning and reconstruction software, virtual casts were constructed. Medial and lateral points of the first anterior 3 rugae were defined as the 3-dimensional landmarks. The length of each ruga and the distance between the end points of the rugae were measured in virtual 3-dimensional space. The measurement changes over time were analyzed by using the mixed-effect method for longitudinal data.
  
  
  RESULTS
  There were slight increases in the linear measurements in the rugae areas: the lengths of the rugae and the distances between them during the observation period. However, the amounts of the increments were relatively small when compared with the initial values and individual random variability. Although age affected the linear dimensions significantly, it was not clinically significant; the rugae were relatively stable.
  
  
  CONCLUSIONS
  The use of the palatine rugae as reference points for superimposing and evaluating changes during orthodontic treatment was thought to be possible with special cautions.
authors.affiliation: Department of Oral Anatomy and Dental Research Institute, School of Dentistry, Seoul National University, Korea.
authors.forename: Hong-Kyun
authors.initials: HK
authors.lastname: Kim
authors.forename: Sung-Chul
authors.initials: SC
authors.lastname: Moon
authors.forename: Shin-Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Young-Seok
authors.initials: YS
authors.lastname: Park
mesh_terms: D000293:Adolescent; D059925:Anatomic Landmarks; D056667:Biometric Identification; D002508:Cephalometry / Q000592:standards; D002648:Child; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008137:Longitudinal Studies; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D003765:Models, Dental; D008962:Models, Theoretical; D009061:Mouth Mucosa / Q000033:anatomy & histology* / Q000254:growth & development; D009970:Orthodontics / Q000379:methods*; D017063:Outcome Assessment, Health Care / Q000379:methods; D010159:Palate / Q000033:anatomy & histology* / Q000254:growth & development; D012016:Reference Values; D015203:Reproducibility of Results