• (n.) A division along the mesial plane; also, one of the parts so divided.
Surgical separation of a multi-rooted tooth.
A surgical procedure whereby the roots of a tooth are separated and treated as individual teeth.
(hem″e-sek´shәn) division into two equal parts. surgical removal of one root of a large mandibular molar along with the corresponding crown area.
Hem`i·sec'tion noun (Anat.) A division along the mesial plane; also, one of the parts so divided. 
Type: Term Pronunciation: hem′ē-sek′shŭn Definitions: 1. Surgical removal of a root and its related coronal portion of a multirooted tooth.