The influence of malocclusion on masticatory performance. A systematic review.
OBJECTIVE
To systematically review the relationship between malocclusions and masticatory performance. In addition, we will perform a qualitative analysis of the methodological soundness of the studies.


METHODS
A literature survey was done by applying the Medline database ( www.ncbi.nim.nih.gov ) in the period from January 1965 to June 2009, using the "Medical Subject Headings" term malocclusion crossed with various combinations of the following terms: masticatory performance, masticatory efficiency, and chewing efficiency. The articles were separated into two main topics: (1) the influence of malocclusion treatment (orthognathic surgery) and (2) the influence of malocclusion type and severity.


RESULTS
The search strategy used identified 78 articles. After selection according to the inclusion/exclusion criteria, 12 articles qualified for the final analysis. The research quality and methodological soundness were high in one study, medium in 10 studies, and low in one study. The most serious shortcomings comprised the clinical trials and controlled clinical trials designs with small sample sizes and inadequate description of selection criteria. Lack of method error analysis and the absence of blinding in measurements were other examples of shortcomings.


CONCLUSIONS
Malocclusions cause decreased masticatory performance, especially as it relates to reduced occlusal contacts area. The influence of malocclusion treatment (orthognathic surgery) on masticatory performance is only measurable 5 years after treatment.
Magalhães
Isabela Brandão
IB
Departament of Clinical Dentistry, Vale do Rio Verde University - UNINCOR, Três Coraçções-MG, Brazil.
Pereira
Luciano José
LJ
Marques
Leandro Silva
LS
Gameiro
Gustavo Hauber
GH
D002986:Clinical Trials as Topic; D018849:Controlled Clinical Trials as Topic; D006801:Humans; D008310:Malocclusion / Q000145:classification / Q000503:physiopathology* / Q000601:surgery; D008409:Mastication / Q000502:physiology*; D056948:Orthognathic Surgical Procedures