title: Comparison of condylar displacement between three biotypological facial groups by using mounted models and a mandibular position indicator.
abstract: OBJECTIVE
  Facial-type-associated variations in diagnostic features have several implications in orthodontics. For example, in hyperdivergent craniofacial types, growth imbalances are compensated by displacement of the condyle. When diagnosis and treatment planning involves centric relation (CR), detailed knowledge of the condylar position is desirable. The present study aimed to measure condylar displacement (CD) between CR and maximum intercuspation in three facial types of an asymptomatic orthodontic population.
  
  
  METHODS
  The study was conducted in 108 patients classified into three groups of 36 individuals each (27 women and 9 men; mean age, 20.5 years), based on the following facial patterns: hyperdivergent, hypodivergent, and intermediate. To quantify CD along the horizontal and vertical axes, the condylar position was analyzed using mounted casts on a semi-adjustable articulator and a mandibular position indicator. The Student t-test was used to compare CD between the groups.
  
  
  RESULTS
  Vertical displacement was found to be significantly different between the hyperdivergent and hypodivergent groups (p < 0.0002) and between the hyperdivergent and intermediate groups (p < 0.0006). The differences in horizontal displacement were not significant between the groups. In each group, vertical CD was more evident than horizontal displacement was.
  
  
  CONCLUSIONS
  All facial types, especially the hyperdivergent type, carried a significantly high risk of CD. Therefore, the possibility of CD should be carefully evaluated and considered in the assessment of all orthodontic cases in order to accurately assess jaw relationships and avoid possible misdiagnosis.
authors.affiliation: Department of Orthodontics, Faculty of Dental Medicine of University of Porto, Porto, Portugal.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Ponces
authors.affiliation: Department of Civil Engineering, Faculty of Engineering of University of Porto, Porto, Portugal.
authors.forename: José Pedro
authors.initials: JP
authors.lastname: Tavares
authors.affiliation: Department of Orthodontics, Faculty of Dental Medicine of University of Porto, Porto, Portugal.
authors.forename: Jorge Dias
authors.initials: JD
authors.lastname: Lopes
authors.affiliation: Department of Orthodontics, Faculty of Dental Medicine of University of Porto, Porto, Portugal.
authors.forename: Afonso Pinhão
authors.initials: AP
authors.lastname: Ferreira
keywords: Centric relation; Cephalometrics; Condylar displacement; Growth evaluation; Maximum intercuspation