Splitted off lower ist molar cusp deeply

Yes hemsection can be done , only the defected root will be cut and removed other roots will be treated by root canal therapy  and finally cap will be placed .may be smaller in size. I will nit cause death surely

Death by not chewing is not common but you shouldn't delay treatment. Your habit of chewing from one side can cause disbalance of forces and can lead to other complications. If the tooth is sound hemisectioning can be done. If the tooth is decayed completely extraction is the option. Symptoms like pain, abscess will play major role in deciding the treatment plan.

don't delay further. get the treatment done

Namaskaram, The term split tooth is complete fracture initiated from the crown and extending deep to root, It is evolution of a cracked tooth, though a split can occur suddenly or it results more commonly from long-term growth of an incomplete cracked tooth. Split tooth can be saved intact, but the prognosis and treatment depends on the position and the apical extent of the crack. Long term chewing on one side may effect jaw-joint issues later. Untreated, dental disease can quickly progress into a serious situation this can cause problems for your oral health as well as general health because what happens in your mouth doesn't stay in your mouth. Team Shambhala.