Evolution of a new crown shape index for the mandibular incisors

ABSTRACT

In this study the role played by the mandibular incisors crown size and shape in influencing their alignment has been tested. A new crown shape index [gingival MD width] was deviced and evaluated on a incisal MD width sample of 137 subjects divided into 3 groups having normal, crowded and spaced mandibular incisors. Statisttically, the gingival MD width of the mandibular incisors was able to differentiate between the 3 groups. The crown shape indices of both the mandibular central and lateral incisors demonstrated a highly statistically significant difference between the three groups. From the results of this study, it is clear that the crown shape index be considered in the routine diagnosis as an important cause of mandibular incisors crowding and that the orthodontic clinicians should evaluate it and normalize it