A clinico-radiographic analysis of sagittal condylar guidance determined by protrusive interocclusal registration and panoramic radiographic images in humans

Abstract

Purpose:To evaluate the correlation between sagittal condylar guidance obtained by protrusive interocclusal records and panoramic radiograph tracing methods in human dentulous subjects.Materials and Methods:The sagittal condylar guidance was determined in 75 dentulous subjects by protrusive interocclusal records using Aluwax through a face bow transfer (HANAU™ Spring Bow, Whip Mix Corporation, USA) to a semi-adjustable articulator (HANAU™ Wide-Vue Articulator, Whip Mix Corporation, USA). In the same subjects, the sagittal outline of the articular eminence and glenoid fossa was traced in panoramic radiographs. The sagittal condylar path inclination was constructed by joining the heights of curvature in the glenoid fossa and the corresponding articular eminence. This was then related to the constructed Frankfurt's horizontal plane to determine the radiographic angle of sagittal condylar guidance.Results:A strong positive correlation existed between right and left condylar guidance by the protrusive interocclusal method (P 0.000) and similarly by the radiographic method (P 0.013). The mean difference between the condylar guidance obtained using both methods were 1.97° for the right side and 3.18° for the left side. This difference between the values by the two methods was found to be highly significant for the right (P 0.003) and left side (P 0.000), respectively. The sagittal condylar guidance obtained from both methods showed a significant positive correlation on right (P 0.000) and left side (P 0.015), respectively.Conclusion:Panoramic radiographic tracings of the sagittal condylar path guidance may be made relative to the Frankfurt's horizontal reference plane and the resulting condylar guidance angles used to set the condylar guide settings of semi-adjustable articulators.

A Comparative study to measure the horizontal condylar guidance obtained by protrusive interocclusal records and panoramic radiographic images in completely edentulous patients

“…This difference might be attributed to the chewing patterns that most of the individuals favor the right side for chewing which could be related to more wear of the right articular eminence as compared to the left. Previous studies 18,19 which were conducted in dentate individuals reported that the mean HCG angles were higher than that of the present study which was conducted in completely edentulous patients. Csado et al 23 reported the mean HCG angles obtained by panoramic radiograph in dentulous individuals were higher than that of the completely edentulous individuals and concluded the correlation of flattening of articular eminence could be related to ageing.…”

“…Literature suggests that the right and left eminences rarely have the same slants and contours. 24 The smaller mean differences between the right and left HCG angles are in accordance with the studies done by Csado et al, 23 Shrestha et al, 25 Prasad et al 19 These values are statistically not significant but clinically and radiographically, the value of HCG angles was higher in the right side as compared to the left side. This difference might be attributed to the chewing patterns that most of the individuals favor the right side for chewing which could be related to more wear of the right articular eminence as compared to the left.…”

“…Previous study 10 also found the positive correlation between the radiographic image of the horizontal condylar inclination and its actual anatomic outline in dry skulls. The study by Prasad et al 19 reported the positive correlation between HCG angle values obtained by protrusive interocclusal record and panoramic radiograph in dentulous individuals. Due to the inaccuracies of the interocclusal record technique with inherent errors of up to 30 degrees, 6 the radiographic articular eminence may have clinical significance10.…”

“…As an alternative to this conventional method of registration of protrusive interocclusal record to obtain HCG angle, orthopantomograph has been used in later periods by different researchers in the dentate individuals. 18,19 In this study, the conventional method of protrusive interocclusal records and the panoramic radiographs were used to obtain the values for horizontal condylar guidance (HCG) angle in the completely edentulous individuals. In this study, the variations of HCG angle ranged between 10 degrees to 30 degrees and 5 degrees to 28 degrees for the right and left side respectively from the protrusive interocclusal record.…”

Correlation between sagittal condylar guidance angles obtained using radiographic and protrusive occlusal record methods

“… 2 4 The SCGA on an articulator is determined using either the protrusive or lateral interocclusal records of the patient. 4 5 6 Christensen's method was introduced in 1905 as a way to obtain the SCGA using wax directly on the articulator. 7…”