Biomechanics Needed in Maxillary Incisor Retraction in Blacks Versus Whites

Objectives: To analyze the cant of maxillary incisors in Black Males and White Males and determine the appropriate biomechanics necessary to retract the incisors to an acceptable position morphologically, functionally and esthetically in both ethnic groups, but with special attention to incisors in Black Males.
Methods: The cephalograms of 40 Black Males from Nashville were used. They were evaluated for the degree of protrusion of the dentoalveolar and dental structures based on the sella-nasion-point A and sella-nasion upper-incisor angles. Means and standard deviations were calculated. Similar data on White Males from Ann Arbor were available. The two groups were compared with special emphasis on the cant of the incisors. Estimates were made on the distance and force needed to retract the incisors Based on the estimations, several persons were treated in Nashville (both Black and White). ANOVA, t-tests and graphs were usedv to aid in analysis of the data.
Results: The SNA and SNUpper Incisor were more protrusive in Black Males but there was an overlap of of close to 50% where the difference was not significant either statistically nor clinically.

More anti-tip force was needed to get bodily movement and prevent :Rabbiting" of the teeth in a large number of Blacks and a few Whites.
Conclusions: The biomechanics used in treating Blacks and Whites are about the same. Some modifications are needed to prevent rabbiting of the alveolar area and incisors in persons with excessive protrusion. There were more protrusion in Black Males. The good clinician owes it to the patient to be cognizant of the subtle adjustments needed to give the patient the best outcome.

Further study is needed to maximize scientists efforts to better our quality of life.