Furcation groove of buccal root of maxillary first premolars - A morphometric study

Furcation grooves on the palatal aspect of the buccal roots of 35 maxillary first premolars, randomly selected, were assessed and found to exist in 97 % of the sample. The buccal roots were sectioned into slices, 1 mm thick, a nd morphometric horizontal and vertical measurements were taken by a Toolma ker Microscope. The slice with the deepest invaginations served as the refe rence plane. The deepest invaginations were found to be at a mean distance of 1.18 mm from the bifurcation, with a mean depth of 0.4 mm, The canal had a kidney-shaped appearance in cross-section, and the mean distance from th e invagination to the canal wall was 0.81 mm. It is thus hazardous to use r otary instruments for flaring these roots and any circular-shaped post spac e preparation at this level is contraindicated, The outcome of such procedu res might be root thinning, perforation, or vertical root fracture, thus ca using a poor prognosis.