Influence of Class II Elastics on Centric Relation and Centric Occlusion Discrepancy after Orthodontic Treatment

The objective of this study was to verify the influence of the use of Class II intermaxillary elastics on centric relation (CR) to centric occlusion (CO) occlusal discrepancy. A total of 30 patients had been at the contention stage for at least three months were divided in two groups: G1 15 had been submitted to intramaxillary orthodontic mechanics only, and G2 15 had used Class II intermaxillary elastics. Distances of horizontal and vertical overlap and the distance or coincidence of the mandibular dental midline in relation to the maxillary midline were measured in CR and CO positions. Intergroup comparisons were performed using the Mann–Whitney test. No statistically significant differences (P>0.05) were found between G1 and G2. Both in the horizontal and vertical directions, these discrepancies were smaller than or equal to 1mm in 96.66 % of the patients. In the transverse plane, there was no discrepancy in 63.33 % of the patients, and in 33.33 % these discrepancies were equal to 0.5 mm. The use of Class II elastic didn’t be capable of increasing the occlusal discrepancies between CR and CO.

[1]  C. Cabrera.  Elastic in Orthodontics: Behavior and Clinical Application Elásticos em Ortodontia: Comportamento e Aplicação Clínica , 2003 .

[2]  S. Kandasamy,et al.  Centric relation: A historical and contemporary orthodontic perspective. , 2006, Journal of the American Dental Association.

[3]  J. Türp,et al.  Dental occlusion: a critical reflection on past, present and future concepts. , 2008, Journal of oral rehabilitation.

[4]  L. Andrews.  The six keys to normal occlusion. , 1972, American journal of orthodontics.

[5]  James B. Morris.  Functional Occlusion: From TMJ to Smile Design , 2008 .

[6]  R. Kulbersh,et al.  Condylar distraction effects of standard edgewise therapy versus gnathologically based edgewise therapy , 2003 .

[7]  R. Behrents,et al.  The effect of orthodontic treatment on centric discrepancy. , 1996, Cranio : the journal of craniomandibular practice.

[8]  F. Cordray.  Three-dimensional analysis of models articulated in the seated condylar position from a deprogrammed asymptomatic population: a prospective study. Part 1. , 2006, American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics.

[9]  B. Lindqvist,et al.  Occlusal interferences in orthodontic patients before and after treatment, and in subjects with minor orthodontic treatment need. , 2002, European journal of orthodontics.

[10]  Roth Rh.  Occlusion and condylar position. , 1995 .

[11]  R. Kulbersh,et al.  Maximum intercuspation-centric relationdisharmony in 200 consecutively finished cases in a gnathologically oriented practice , 2003 .

[12]  A. Milosevic,et al.  Functional occlusion after fixed appliance orthodontic treatment: a UK three-centre study. , 1998, European journal of orthodontics.

[13]  R. Evans,et al.  Functional occlusal relationships in a group of post-orthodontic patients: preliminary findings. , 1998, European journal of orthodontics.

[14]  W. S. Hunter,et al.  The CR-CO discrepancy and its effect on cephalometric measurements. , 1994, The Angle orthodontist.

[15]  K. Takada,et al.  The difference in condylar position between centric relation and centric occlusion in pretreatment Japanese orthodontic patients. , 2009, The Angle orthodontist.

[16]  Roth Rh.  Functional occlusion for the orthodontist. , 1981 .