title: Factors influencing secondary alveolar bone grafting in cleft lip and palate patients: prospective analysis using CT image analyzer.
abstract: OBJECTIVE
  To examine the effect of migration of the germ of the lateral incisor into the bone for eruption factors on bone bridge resorption.
  
  
  METHODS
  Twenty-five subjects who underwent secondary alveolar bone graft were enrolled. The volume of the alveolar bone grafts immediately after the operation (V1), bone bridge formation 6 months postoperatively (V2), and tooth (teeth) migration into the bone bridge (Vt) were measured using a computed tomography (CT) image analyzer. Based upon these measurements, the following points were examined: (1) the correlation between the tooth-occupied ratio (Rt = Vt/V2 x 100) and the ratio of bone bridge resorption (Rv = (V1 - V2)/ V1 x 100); and (2) comparison of the tooth-occupied ratio (Rt) and the ratio of bone bridge resorption (Rv) between the groups with and without the germ of the lateral incisor.
  
  
  RESULTS
  A significant negative correlation was found between Rv and Rt (p < .001). Comparison of Rv and Rt between the groups with and without a germ of the lateral incisor revealed that both indices were significantly higher in the former group than the latter one (p < .05).
  
  
  CONCLUSIONS
  In cleft lip and palate patients with a germ of the lateral incisor, it is beneficial to carry out secondary bone grafting to the alveolar cleft at the age of 5 to 7 years, preceding eruption of the canine, in order to form a good bone bridge that will facilitate eruption of the lateral incisor and subsequent normal dentition and occlusion.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan. ozawa@urahp.yokohama-cu.ac.jp
authors.forename: Tomomichi
authors.initials: T
authors.lastname: Ozawa
authors.forename: Susumu
authors.initials: S
authors.lastname: Omura
authors.forename: Eiji
authors.initials: E
authors.lastname: Fukuyama
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Matsui
authors.forename: Katuyuki
authors.initials: K
authors.lastname: Torikai
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fujita
mesh_terms: D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000601:surgery*; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D016025:Bone Transplantation / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D002971:Cleft Lip / Q000601:surgery*; D002972:Cleft Palate / Q000601:surgery*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods; D007180:Incisor; D008297:Male; D016348:Osseointegration / Q000502:physiology; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D014083:Tooth Germ / Q000000981:diagnostic imaging / Q000502:physiology*; D014097:Tooth, Unerupted / Q000000981:diagnostic imaging; D016896:Treatment Outcome