A Comparative Evaluation of Lateral Condylar Guidance by Clinical and Radiographic Methods – Hanau's Formula Revisited

Abstract

Background: Various clinical methods for recording the condylar guidance (CG) are the intraoral check bite method, graphic tracings, and functional recordings. Accuracy of graphic tracings is affected by patient-related factors such as neuromuscular control of the individual, stability of record bases as well as stability of recording media. The current recommended average settings using Hanau's formula questionable, and thus reassessment is needed. Purpose: The purpose of this study is to use radiographic technique to determine the lateral CG and compare these values with those obtained using Hanau's formula and to evaluate whether there are differences between the right and left paths of the condyles. Materials and Methods: Twenty completely edentulous patients were selected. Articulator was modified with sectioned protractor for obtaining per degree interval calibration. With the protrusive records, the horizontal CG (H) was adjusted and the Bennett's angle (LCG-C) was calculated using the formula. With the tracing device in the mouth, sub-mento vertex projection radiographs were obtained. Each radiograph was traced and superimposed for Bennett angle determination (LCG-M). Results: The median (interquartile range [IQR]) of right and left LCG-C were 15.45 (0.8) and 15.50 (0.7), respectively. The median (IQR) of right and left LCG-M were 37.00 (6.0) and 36.50 (6.8), respectively. A statistically significant difference exists between LCG-C and LCG-M. Both LCG-C and-M values exhibited no variations on both sides. Conclusions: Radiographic technique yielded an amplified LCG when compared to the value obtained by Hanau's formula.

Comparative Evaluation of Condylar Guidance Angles Measured Using Arcon and Non-Arcon Articulators and Panoramic Radiographs—A Systematic Review and Meta-Analysis

“…Individuals ranging in age from 18 to 75 were included in the research. Only three studies [ 22 , 29 , 31 ] considered CGV values acquired using a non-arcon articulator, while all studies [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ] used an arcon articulator for CGV analysis. In the majority of studies [ 21 , 24 , 25 , 30 , 31 , 32 ], radiographs evaluated significantly higher values compared to the articulator, with panoramic X-rays evaluating higher CGVs compared to their mechanical measurement counterparts.…”

“…Only three studies [ 22 , 29 , 31 ] considered CGV values acquired using a non-arcon articulator, while all studies [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ] used an arcon articulator for CGV analysis. In the majority of studies [ 21 , 24 , 25 , 30 , 31 , 32 ], radiographs evaluated significantly higher values compared to the articulator, with panoramic X-rays evaluating higher CGVs compared to their mechanical measurement counterparts. Although in one study [ 31 ], males scored higher total mean values than females using both articulators for both HCGV and LCGV, with the arcon articulator obtaining higher overall mean values than the non-arcon articulator, gender correlation was not frequently sought.…”

“… Bias assessment of individual studies using RoB-2 tool across five different domains [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. …”

“… Forest plot representing the risk difference of the efficacy of an articulator compared to a panoramic X-ray for measuring CGVs in the 13 studies that were evaluated in this review [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. …”

Comparison between cone beam CT and TMJ digital tracing to record the Bennett angle and their effect on the occlusion of complete denture

“…Research on the condylar mechanism and endeavors to record mandibular movement can be traced back to the latter part of the 18th century. The objective of conducting a movement recording is to replicate the occlusion and mandibular pattern of movement of the patient with utmost precision in the articulator (1) .…”