title: A longitudinal study of changes in masticatory performance of patients undergoing orthognathic surgery.
abstract: OBJECTIVE
  Individuals with developmental deformities of the jaws may be less efficient at chewing food. Previous studies have reported masticatory deficiency in patients with such deformities. This study was designed to detect any changes in masticatory performance that accompany orthognathic surgery.
  
  
  METHODS
  Masticatory performance was tested in 18 patients with various jaw deformities before application of orthodontic appliances and 2 to 3 years after surgical correction of their malocclusion. A control group was tested at three 6-month intervals. The subjects chewed carrots and masticatory performance was measured using a standard sieve technique. The Rosin-Rammler equation was used to calculate the median particle size and broadness index of each set of carrots. The number of chewing cycles required for each subject to swallow one piece of carrot was also recorded.
  
  
  RESULTS
  A statistically significant difference in median particle size between patients and controls was found both preoperatively and postoperatively (P < .05), but no difference in median particle size or broadness index was seen between trials for controls or patients (P > .05).
  
  
  CONCLUSIONS
  It was concluded that before surgery patients have a lower level of performance than controls and surgical correction of the malocclusion does not significantly enhance performance.
authors.affiliation: Division of Oral and Maxillofacial Surgery, University of Texas Southwestern Medical Center, Dallas 75235-9109, USA.
authors.forename: H M
authors.initials: HM
authors.lastname: Zarrinkelk
authors.forename: G S
authors.initials: GS
authors.lastname: Throckmorton
authors.forename: E
authors.initials: E
authors.lastname: Ellis
authors.forename: D P
authors.initials: DP
authors.lastname: Sinn
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007569:Jaw Abnormalities / Q000503:physiopathology* / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008310:Malocclusion / Q000503:physiopathology* / Q000601:surgery*; D008409:Mastication; D008875:Middle Aged; D010316:Particle Size; D018709:Statistics, Nonparametric; D016896:Treatment Outcome