The use of a deprogramming appliance to obtain centric relation records

The purpose of this study was to investigate the effect of an anterior Rat plane deprogramming appliance (Jig) in 40 subjects for whom centric relatio n (CR) records were obtained before and af ter the use of the appliance. In cisal overbite and overjet dimensions and three-dimensional instrument cond ylar representation using the Panadent condylar path indicator (CPI) were r ecorded from maximum intercuspation and centric relation. Subjects were ass essed subjectively to determine the degree of difficulty manipulating the m andible to obtain the centric relation record. The mean overbite difference from maximum intercuspation (MI) to centric relation without (CR) and with (CRJ) the appliance were statistically significant and decreased 1.58 mm a nd 2.23 mm, respectively. The mean overjet values from MI to CR and CRT wer e statistically significant and increased .44 mm and .57 mm, respectively. Significant differences were determined on the Panadent articulator for the absolute vertical (Z) and absolute horizontal (X) values for centric relat ion with and without the appliance. The number of subjects who exceeded the threshold values of 2 mm for CPI recordings in either the horizontal or ve rtical direction was 7 (18%) from MI to CR and 16 (40%) from MI to CRJ. The Lucia-type jig deprogramming appliance provides a centric relation record with greater displacement from MI than a centric relation record alone. Thi s appliance may be a useful adjunct in a patient where mandibular manipulat ion in taking a centric relation bite registration is deemed not easy.