A mathematical method for calculating the compensating anterior stop pin setting of a semiadjustable arcon articulator

The geometry of a semiadjustable arcon articulator and development of mathematical formulae to calculate the setting of the anterior stop pin that compensates for the thickness of the interocclusal centric relation record are discussed. Measurements of the facebow mounted maxillary cast and interocclusal centric relation record are used in these formulae. Testing on 30 diagnostic mountings indicated that the formulae can reliably predict the amount of anterior stop pin opening necessary to allow near parallelism of the maxillary and mandibular bows of the articulator when the interocclusal centric relation record is removed and the mounted casts are brought into occlusion. The vertical component of dental malocclusion is identified as a source of variability in the setting of the anterior stop pin and therefore in the geometry of the articulator; it is defined as a need for further study.