The Effect of Molar Bite Raising on Anterior Overbite

To evaluate the effect of first and second molar bite raising on anterior incisal overbite using steel bearing balls of predefined dimensions.

The study involved 23 young adults (mean age 25 years, range 22 to 34 years) and was composed of two parts-preclinical and clinical. (a) Preclinical: Initial evaluations were conducted on dental casts of the participants mounted on a semiadjustable articulator. Stainless-steel bearing balls (2-mm and 3-mm diameter, respectively) were temporarily positioned in the occlusal central groove of the mandibular first or second molars. Photographs assessed changes in anterior overbite. (b) Clinical: Subsequent evaluations used intraoral scans on the same participants, excluding those with molar restorations, before and after applying 2-mm-diameter stainless-steel bearing balls on the mandibular first molars. Overbite measurements were performed digitally. Reliability was defined through repeated measurements using intraclass correlation coefficients (ICC).

Preclinical measurements showed a decrease in overbite of 2.8 ± 0.5 mm with 2-mm-diameter bearing balls on the mandibular first molars and 3.6 ± 0.5 mm on the mandibular second molars. For 3-mm-diameter bearing balls, the decrease was 3.7 ± 0.5 mm on the first molars and 4.5 ± 0.5 mm on the second molars. ICC showed excellent reliability. Clinical intraoral scans revealed a mean overbite decrease of 2.7 ± 0.4 mm with 2-mm-diameter bearing balls on the mandibular first molars. No significant difference was found between clinical and preclinical results for the same participants.

Larger bite raisers and more posterior placement result in greater overbite reduction. The ratio of bite raising to anterior overbite decrease was 1.6 for 2-mm-diameter and 1.4 for 3-mm-diameter raisers. Considerable interindividual variability was noted.