Prevalence and features of palato-radicular grooves: an in-vitro study.

The presence of a morphological defect called a palato-radicular groove (PRG) is considered to be an important contributing factor to the development of localized chronic periodontitis, for it favors the accumulation and proliferation of bacterial plaque deep into the periodontium. This anomaly affects maxillary incisors, especially lateral incisors. The prevalence and different morphologic conditions of the PRG were evaluated in 376 maxillary lateral and central incisors. The teeth were evaluated by a single examiner, considering their presence, localization, origin of formation, extension and depth in millimeters, using a magnifying glass, a precision pachymeter and a millimeter-scaled periodontal probe. Results showed a higher prevalence in lateral incisors (11.1%), with higher prevalence in proximal localization (62.8%), origination from central fossa (57.1%) and predominance in oblique trajectory (62.8%). Of all these teeth, only 8.6% of PRGs reached the root apex, while 97.1% were considered as flat (< 1 mm). Thus, in the presence of a PRG, periodontal pathologic conditions could be more severe in proximal faces, reaching in a few cases the tooth apex and the pulp canal.