Table 1: Classification of four-rooted maxillary second molar [5].

TypeCharacteristics

ITwo widely divergent palatal roots that are often long and tortuous. Buccal roots of tooth are often cow horned and less divergent. Four separate root apices are seen on radiograph.
IIFour separate roots seen, but are often shorter, run parallel have buccal and lingual root morphology, and have blunt apices. Radiograph with buccolingual superimposition may make this appear as having only a mesial and distal root.
IIIConstricted in root morphology with MB, MP, and DP canal encaged in a web of root dentin. The DB root in these cases appears to stand alone and may even diverge.