title: [Analysis of the difference in the tissue surfaces between the old and new upper complete dentures].
abstract: OBJECTIVE
  To investigate the reduction in residual ridges of maxillary edentulous models duplicated from old and new complete dentures using the 3-D data analysis.
  
  
  METHODS
  Twenty-six pairs of maxillary edentulous models copied from the fitting surfaces of new and old upper complete dentures were selected for this study. The 3-D data were collected with a laser scanning system. The data were matched using Geomagic Studio 8 and Rapidform2006 software and then the fitting surfaces of new complete dentures were analyzed in comparison with old ones.
  
  
  RESULTS
  The total amount of morphologic change of fitting surface [(39.8+/-14.2)%] was greater than the change of width [(28.2+/-16.0)%]; the area reduction of the residual ridge in anterior region [(43.0+/-15.2)%] was larger than that in posterior region [(36.1+/-14.1)%]; and the area reduction of residual ridge in buccal aspect [(42.9+/-13.8)%] was larger than that in lingual aspect [(35.5+/-15.2)%]. All the differences were statistically significant (P<0.05).
  
  
  CONCLUSIONS
  The results of this study reveal that 3-D analysis of the whole change of the residual ridge is significant and verify that the residual ridge resorption of edentulous maxilla in three dimensions is greater in buccal aspect than in lingual aspect and greater in anterior region than in posterior region.
authors: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Cheng-cai
authors: CC
authors: Huang
authors: Hai-lan
authors: HL
authors: Feng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000209:etiology*; D000539:Alveolar Process / Q000473:pathology*; D003827:Denture, Complete, Upper; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged