title: Histological investigation of the palatine bone in prenatal trisomy 21.
abstract: OBJECTIVE
  The purpose of the present study was to investigate the horizontal part of the palatine bone in palates from human fetuses with trisomy 21 to improve the phenotypic classification of the genotypic anomaly.
  
  
  METHODS
  Material from 23 human trisomy 21 fetuses was included in the study. The crown rump lengths of the fetuses ranged from 80 mm to 190 mm, corresponding to about 12 to 21 weeks of gestational age. The material was examined histologically.
  
  
  CONCLUSIONS
  Histological examination demonstrated four different palatal phenotypes on the basis of the development of the horizontal part of the palatine bone: type I, palatine bone complete; type II, the mesial region of the horizontal part of the palatine bone is lacking; type III, complete absence of the horizontal part of the palatine bone; and type IV, auxiliary bones in the region of the transpalatine suture. This finding shows that different types of malformations may occur in the horizontal part of the palatine bone in human trisomy 21 fetuses.
authors.affiliation: Department of Pathology, Hvidovre University Hospital, Copenhagen, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Lauridsen
authors.forename: B
authors.initials: B
authors.lastname: Fischer Hansen
authors.forename: I
authors.initials: I
authors.lastname: Reintoft
authors.forename: J W
authors.initials: JW
authors.lastname: Keeling
authors.forename: I
authors.initials: I
authors.lastname: Kjaer
mesh_terms: D002356:Cartilage / Q000196:embryology; D003393:Cranial Sutures / Q000196:embryology; D018568:Crown-Rump Length; D004314:Down Syndrome / Q000145:classification / Q000196:embryology* / Q000235:genetics; D005333:Fetus; D005838:Genotype; D005865:Gestational Age; D006801:Humans; D021362:Palate, Hard / Q000196:embryology*; D010641:Phenotype