title: Only severe malocclusion correlates with mastication deficiency.
abstract: OBJECTIVE
  The relation between level of dentofacial deformity and extent of masticatory deficiency was studied.
  
  
  METHODS
  Three groups of human young adults were formed: (i) subjects needing orthodontics plus orthognathic surgery (SevDFD, n=18), (ii) subjects needing orthodontic treatment only (ModDFD, n=12), and (iii) subjects needing no treatment (NoDFD, n=12). For mastication tests, carrot boluses were collected at the deglutition time. Bolus particle size range was expressed as d50 value, which was compared with the Masticatory Normative Indicator (MNI). Index of treatment need (IOTN), global oral health assessment index (GOHAI) and chewing kinematic characteristics were also recorded. We used a general linear model univariate procedure followed by a Student-Newman-Keuls test.
  
  
  RESULTS
  All the SevDFD subjects showed impaired mastication with MNI above the normal limit (d50 mean=7.23mm). All the ModDFD subjects but one were below this limit (d50 mean=2.54mm), and so could adapt to a low level of masticatory impairment as also indicated by kinematics. IOTN indicated a treatment need for ModDFD (3.7±0.5) and SevDFD (4.3±0.6) groups, while GOHAI values were unsatisfactory only for SevDFD (42.6±9.2 vs. 55.3±1.9).
  
  
  CONCLUSIONS
  Our findings emphasize the need for an objective evaluation of masticatory function to discern truly deficient mastication from mild impairment allowing satisfactory adaptation of the function. However, malocclusions are known to worsen with time justifying thus their corrections as early as possible.
authors.affiliation: Centre Hospitalo-Universitaire, Service d'Odontologie, Clermont-Ferrand, France; UFR Odontologie, Université d'Auvergne, Clermont-Ferrand, France. Electronic address: pierre.bourdiol@u-clermont1.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bourdiol
authors.affiliation: Centre Hospitalo-Universitaire, Service d'Odontologie, Clermont-Ferrand, France; UFR Odontologie, Université d'Auvergne, Clermont-Ferrand, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Soulier-Peigue
authors.affiliation: Centre Hospitalo-Universitaire, Service d'Odontologie, Clermont-Ferrand, France; UFR Odontologie, Université d'Auvergne, Clermont-Ferrand, France.
authors.forename: Pauline
authors.initials: P
authors.lastname: Lachaze
authors.affiliation: Centre Hospitalo-Universitaire, Service d'Odontologie, Clermont-Ferrand, France; UFR Odontologie, Université d'Auvergne, Clermont-Ferrand, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Nicolas
authors.affiliation: Centre Hospitalo-Universitaire, Service d'Odontologie, Clermont-Ferrand, France; UFR Odontologie, Université d'Auvergne, Clermont-Ferrand, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Woda
authors.affiliation: Centre Hospitalo-Universitaire, Service d'Odontologie, Clermont-Ferrand, France; UFR Odontologie, Université d'Auvergne, Clermont-Ferrand, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Hennequin
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D003679:Deglutition / Q000502:physiology; D063169:Dentofacial Deformities / Q000150:complications* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000150:complications* / Q000503:physiopathology*; D008409:Mastication / Q000502:physiology*; D009909:Oral Health; D009970:Orthodontics; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Dentofacial deformity; Global oral health assessment index; Index of treatment need; Malocclusion; Masticatory deficiency; Masticatory normative indicator