title: Effects of occlusal contact and its area on gravity fluctuation.
abstract: OBJECTIVE
  To examine changes in gravity fluctuation caused by experimentally altering the area of occlusal contact.
  
  
  METHODS
  Subjects consisted of 15 adult Japanese males with normal stomatognathic function, no missing teeth except for the third molars, and equivalent occlusal contact in the anterior and bilateral posterior regions. Silicon biteplates fabricated for each subject to evaluate gravity fluctuation in relation to changes in occlusal contact area were as follows: RP(-)-OC(+) (entire occlusal surface covered in centric occlusion); RP(+)-OC(+) (entire occlusal surface covered with bite slightly raised); Ant or Pos/RP(+)-OC(+) (anterior or posterior region selectively covered); and RP(+)-OC(-) (only retromolar pads covered, no occlusal coverage).
  
  
  RESULTS
  No significant differences in gravity fluctuation were noted between subjects wearing biteplates covering the entire occlusal surface. Subjects wearing biteplates with no occlusal contact showed greater gravity fluctuation than those with occlusal contact. In addition, gravity fluctuation for the Ant/RP(+)-OC(+) group (no occlusal contact in the posterior region) was greater than for RP(+)-OC(+) and Pos/RP(+)-OC(+). However, groups with unilateral occlusal contact in the posterior region exhibited large right and left sway amplitude.
  
  
  CONCLUSIONS
  These results suggest that occlusal contact, especially posterior occlusal contact, affects gravity fluctuation, and that appropriate occlusion attained by maintaining even occlusal contact in the posterior region is crucial for gravity fluctuation.
authors.affiliation: Department of Orofacial Development and Function, Tokyo Medical and Dental University, Japan. ohyeah.orts@tmd.ac.jp
authors.forename: Emi
authors.initials: E
authors.lastname: Oie
authors.forename: Mariko
authors.initials: M
authors.lastname: Horiuchi
authors.forename: Kunimichi
authors.initials: K
authors.lastname: Soma
mesh_terms: D000328:Adult; D001732:Bite Force; D003760:Dental Impression Materials / Q000737:chemistry; D003766:Dental Occlusion; D003768:Dental Occlusion, Centric; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000503:physiopathology; D017090:Occlusal Splints; D016382:Orthodontic Appliance Design; D011145:Polyvinyls / Q000737:chemistry; D004856:Postural Balance / Q000502:physiology*; D012833:Siloxanes / Q000737:chemistry; D014070:Tooth / Q000502:physiology*; D014716:Vertical Dimension
chemical_list: D003760:Dental Impression Materials; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane