Developing Class III Malocclusion & Pre Eruptive Dental Compensation

Objectives: It is always advantageous to be able to predict a developing skeletal disharmony. This is particularly true for developing Class III, because these malocclusions tend to become increasingly more severe as an individual matures. We are presenting a simple method, where a common diagnostic record, the panoramic radiograph, routinely obtained in evaluating children's dental development, can also be used to predict this unfavorable occlusal pattern. Bilateral distal inclination of lower second bicuspid tooth buds serves as a predictor of subsequent Class III malocclusion as growth progresses. When alerted early, the clinician can optimize his chances of interceptively treating such a condition.

Experimental Methods: Criteria for inclusion: examination of panoramic radiographs of early mixed dentition (~8-10 years old), bilateral distal inclination of unerupted second premolar tooth buds and evaluation of cephalometric radiographs using Witt's Analysis. Distal inclination is defined as at least 10 degree decrease of the angle between long axis of developing tooth and inferior border of mandible.

Results: Over 2500 cases were screened, of which 21 cases matched the inclusion criteria. An average degree of second premolar distal inclination was 66.5 (range 50-77) 10 out of 21 exhibited cephalometric Class III skeletal growth patterns. Initial findings suggest that distal inclination is a reliable predictor of developing Class III malocclusion. 10 out of 21 subjects have been confirmed to exhibit characteristics of developing Class III malocclusion.

Conclusion: In addition to its use as a diagnostic tool for dental development, in certain instances panoramic radiographs can be used as a diagnostic predictor of skeletal growth. Further studies should determine whether the degree of pre-eruptive compensation correlates with the severity of Class III malocclusion.