Measurements of mandibular length: a comparison of articulare vs condylion.

This study examines the validity of articulare for mandibular length measurements by exposing 3 lateral cephalograms on each of 60 consecutive patients. The radiographs were exposed with the patient in a closed-mouth position in habitual occlusion, a closed-mouth position with the patient in centric relation, and in an open-mouth position. The linear distances (mm) of articulare (Ar) to pogonion (Pog), Ar to gonion (Go), and Go to Pog were measured on the 2 closed-mouth cephalograms and compared with each other as well as the linear distances of condyle (Co) to Pog, Co to Go, and Go to Pog measured from the open-mouth cephalogram on each individual. Product-moment correlation coefficients were used to measure the linear associations among the mandibular measurements from the 3 techniques. Repeated measures analyses of variance were also fit to estimate the correlations between the 3 measurements adjusted for age and sex. The results of this study show that measurements taken from both closed-mouthed techniques agreed extremely well (intraclass correlation coefficient = 0.99). In addition, measurements from both closed-mouth techniques highly agreed with the corresponding measurements taken with the open-mouth technique (intraclass correlation coefficient = 0.94). This data suggests that measurements taken from Ar correlate very well with measurements taken from Co and that this correlation is not dependent on whether the patient is positioned in habitual occlusion or centric relation.