title: Analysis of paranasal sinus development and anatomical variations: a CT genetic study in twins.
abstract: OBJECTIVE
  To determine if anatomical variations in the paranasal sinuses of twins are the result of genetic or environmental influences.
  
  
  METHODS
  A prospective, observational study.
  
  
  METHODS
  An academic hospital in Brussels, Belgium.
  
  
  METHODS
  Twenty-five volunteer twins (17 identical twins and eight non-identical twins). Of the identical twins, six were both female and 11 both male. The mean age was 40.6 years (18-49). Of the non-identical twins, one pair was female and seven were male. The mean age was 39.6 years (25-48).
  
  
  METHODS
  The CT-scan similarity in anatomical structures (frontal cells, agger nasi cells, concha bullosa, infraorbital cells and changes in the shape of the lamina orbitalis), and the intranasal and paranasal sinus morphology was compared between the twins.
  
  
  RESULTS
  Among the studied variables, there was no statistically significant difference between the two twin groups (Fisher's exact test, P > 0.05). Regarding combine-studied parameters, there were no identical CT scans in the twins. However, a tendency of non-genetic influence existed in the development of frontal cell type III and IV, and infraorbital cells, as well as a liability of genetic influence in the presence of concha bullosa.
  
  
  CONCLUSIONS
  In this study, the differences in anatomical structure of the paranasal sinuses between identical and non-identical twin pairs were not statistically significant. This indicates that environmental factors are more significant than genetic ones in the development of anatomical variations in paranasal sinus anatomy.
authors.affiliation: Department of Otolaryngology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. schaiyasate@yahoo.com
authors.forename: S
authors.initials: S
authors.lastname: Chaiyasate
authors.forename: I
authors.initials: I
authors.lastname: Baron
authors.forename: P
authors.initials: P
authors.lastname: Clement
mesh_terms: D000293:Adolescent; D000328:Adult; D001530:Belgium; D004200:Diseases in Twins / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009300:Nasal Septum / Q000002:abnormalities / Q000000981:diagnostic imaging; D010256:Paranasal Sinuses / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012931:Social Environment; D014057:Tomography, X-Ray Computed; D014420:Turbinates / Q000002:abnormalities / Q000000981:diagnostic imaging; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics