A Cone-Beam Computed Tomography Assessment of the Relationship between Incisal and Condylar Guidance

Abstract

The success of complex prosthodontic treatment is believed to be conditioned by condylar path replication in the articulator, as there is a continuing debate in the scientific community regarding the anatomical relationship between joint and dental morphology. The purpose of this study was to investigate the potential correlation between incisal and condylar guidance. The study population consisted of 20-30-year-old full dentate individuals with Angle class 1 occlusion, whose cone-beam computed tomography (CBCT) scans were analyzed by two investigators. The anterior slope of the right and left glenoid fossa angle and the palatal slope of all maxillary frontal teeth were measured by software tools at three defined landmarks, and the mean values were calculated. Statistical analysis was performed using IBM SPSS Statistics software (version 19.0), and the Pearson r coefficient test was used to assess correlations. The results reveal a highly statistically significant correlation between median condylar slopes and between median incisal slopes of the anterior teeth, on the left and right side, in the three standard areas (p<0.01). However, no significant correlation was found between the condylar slopes and the incisal slopes of the anterior teeth (p>0.01) in class 1 Angle subjects. In conclusion, this study did not provide evidence to support the existence of a significant correlation between incisal and condylar guidance in the population under investigation.

FIGURE 1.

Adjusting the image in the three planes, respecting the parallelism between the axial plane and the Frankfort plane

FIGURE 2.

Example of the measurement of the inclination of articular slope angle at the level of the external pole on the left side on a sagittal section using the angle measurement tool in the Romexis Software

FIGURE 3.

Example of the measurement of the inclination of articular slope angle at the level of the central part of the left condyle on a sagittal section using the angle measurement tool in the Romexis Software

FIGURE 4.

Example of the measurement of the inclination of articular slope angle at the level of the internal pole of the left condyle on a sagittal section using the angle measurement tool in the Romexis Software

FIGURE 5.

Example of the measurement of the inclination angle of the palatal slope of tooth 11 in the sagittal plane at the mesial, central and distal point using the implant module of the Romexis Software. The axis aligned with the Frankfort plane is lowered to the cingulum, and the angle is measured between this line and the one joining the incisal edge to the cingulum.

TABLE 1.

Mean of both data sets for external pole (EP), medium pole (MP), and internal pole (IP) on the left and right sides

TABLE 2.

Mean angle values were measured for the palatal slope of the teeth on both data sets. For each tooth, the mean of the angle measurement was calculated and then the mean was obtained for both sets of data (t11mean = mean angle value for tooth 11, t12mean = mean angle value for tooth 12, t13mean = mean angle value for tooth 13, t21mean = mean angle value for tooth 21, t22mean = mean angle value for tooth 22, and t23mean = mean angle value for tooth 23)

TABLE 3.

Pearson correlation between the condylar angles and palatal dental angle values on the right side (EP=external pole, MP= medium pole, IP= internal pole)

TABLE 4.

Pearson correlation between the condylar and palatal dental angle values on the left side (EP=external pole, MP= medium pole, IP= internal pole)

TABLE 5.

Paired test for the correlation between the values of the condylar and dental palatal angles on the right and left side (EP=external pole, MP= medium pole, IP= internal pole)

TABLE 6.

The Pearson correlation between the mean values of the left-right condylar angles and the left-right dental palatal angles