Clinical evaluation of three different anterior reference points on protrusive condylar guidance angle using a semi adjustable articulator and lateral cephalogram

Abstract

Background: Studies had shown that different anterior reference points can mount the maxillary cast in variable position in the articulator which may affect the protrusive condylar guidance angle on setting the semi adjustable articulator. So there is a need for search of reliable anterior reference point in orienting the maxillary cast on the articulation for accurate prosthesis fabrication. 

Aim: The aim of this study was to determine the effect of 3 different anterior reference points Orbitale, Orbitale minus 7mm, 36mm from the incisal edge of maxillary central or lateral incisor on the protrusive condylar guidance values registered on Hanau wide vue  articulator and compare it to the protrusive condylar guidance angle obtained from lateral Cephalometric tracings.

Materials and methods: A total of 30 healthy human subjects were randomly selected for this study from volunteer dental students. Orbitale, Orbitale minus 7mm, 36mm from the maxillary incisal edge of the subjects were the three anterior reference points used for facebow transfer using Hanau springbow. With the help of protrusive  records, articulation was done in Hanau wide vue articulator using this record and condylar inclination values were noted on right side and left side.Three sets of lateral cephalometric radiographs were taken in maximum intercuspation and protrusive position, traced manually and values tabulated for all 30 subjects.

Results: Mean value of orbitale is highest and mean value of 36mm from the maxillary incisal edge is lowest. 

Conclusion: Orbitale can be used as a reliable anterior reference point in facebow transfer using hanau wide  vue articulator.