The importance of the Hanau formula in construction of complete dentures

The casts of five patients whose kinematic mandibular axes had been previously located and tatooed on the face were mounted on six articulators (two of Denar D4-A, two of Whip-Mix, and two of Hanau model 130-28). The horizontal and lateral condylar guidances of all articulators were adjusted by using 15 interocclusal records (five protrusive and 10 right and left lateral) made in cold-curing acrylic resin. The adjustments for each articulator were repeated 20 times within five days. The lateral condylar guidances as adjusted by the interocclusal records were compared with those established by Hanau's formula. A significant difference in the means of the condylar readings occurred when the Hanau articulator was adjusted with a lateral interocclusal record and the Hanau formula. The range of means of lateral condylar guidances of Hanau articulators using the Hanau formula was small. This small possibility of variation in the lateral condylar guidance would suggest the use of lateral interocclusal records when precise restorative procedures are necessary. The Hanau formula is the only formula available at this time to determine the average lateral condylar guidance as related to the horizontal condylar guidance.