Molar inclination in panoramic x-rays as an indicator for extraction decisions.

Objective: Recommendations concerning the necessity of extraction therapy are often based upon clinical findings and panoramic x-rays. Since the success of this approach greatly depends on the individual examiner's clinical expertise, we believed it to be of interest to evaluate whether panoramic x-ray findings alone suffice for making the decision to extract. The aim of this study was to evaluate whether the need for extraction therapy can be verified by measuring the angulations between the first and second lower molars.

Material And Methods: Orthopantomograms of 30 patients who underwent extraction of four premolars were examined prior to and after treatment. Initial study casts were also evaluated for any correlations between molar inclination and other examination parameters. Orthopantomograms of 30 patients who had experienced comprehensive orthodontic treatment without extraction served as age- and gender-matched controls.

Results: Contrary to expectation, the lower second molars showed a stronger mesial inclination before rather than after treatment, and the changes were highly significant. The controls also showed highly significant changes on the left side. The extraction and non-extraction groups did not differ significantly in terms of molar inclination at the beginning of treatment. Gender differences occurred in both groups, but only on one side. No other findings indicated gender differences in terms of molar inclination.

Conclusion: Our data failed to prove a correlation between distally- inclined lower second molars in the panoramic x-ray and the indication of extraction therapy.