1610s, "teething, the cutting of teeth," from Latin dentitionem (nominative dentitio) "teething," noun of action from past participle stem of dentire "to cut the teeth," from dentem (nominative dens) "tooth" (see tooth). Meaning "arrangement of teeth" is from 1849.
dentition den·ti·tion (děn-tĭsh'ən)
The natural teeth, considered collectively, in the dental arch.
The type, number, and arrangement of a set of teeth.
The process of growing new teeth; teething.