Maxillary molar with four distinct roots is a rarity!
The overall incidence of four-rooted maxillary molars has been reported to be less than 0.4%. Nevertheless, dentists should be aware of such variation.
When examining the pre-operative periapical radiographs of maxillary molars, if the outlines of the roots are unclear, the root canals show sharp density changes, or the apices cannot be well defined, then extra roots can be suspected! Horizontally angulated radiographs can also be helpful to distinguish the multiple root morphology of maxillary molars. Most definitive means however is visualizing the “road map” on the pulp chamber floor.
The following two cases had pulp chambers shaped like a quadrangle with one orifice in each corner.
Case 1: Tooth #14 (palatal roots length: 23mm on both)
Pre-op
Post-op
Case 2: Tooth #15 (palatal roots length: 25mm MP and 24mm DP )
Pre-op
Post-op
In both cases canals were instrumented with a combination of hand files and Protaper rotary instruments and sealed with Resilon cones and sealer using warm vertical condensation.