Dental wear facets on the occlusal surface of premolars and molars are traces of their main function, themastication and therefore reflect masticatory movements and also paramasticatory (i.e. non-dietary useof teeth) behavior. Here we present the Modular Wear Facet Nomenclature applicable to most mammaliandentitions. Topographic positions of wear facets in relation to the major cusps and crests of the teeth areused to designate the areas of the occlusal surface the facets occupy (e.g. their mesial, distal, lingual, orbuccal position). Previous published systems for labeling wear facets have been inconsistent with eachother. Therefore, we provide a synoptic review of the most widely-used terminologies, and introducethe alternative Modular Wear Facet Nomenclature. This nomenclature aims to overcome the difficultiescaused by the existing inconsistent wear facet terminologies. Our new approach is applicable to dentitionswhere the occlusal morphology does not change significantly for most of the lifetime of the animal. Inthose dentitions, the primary occlusal surfaces are not significantly modified as wear facets become moreextensive with wearing. This appears to be a common pattern in pre-tribosphenic, tribosphenic molars,and the teeth derived from tribosphenic precursors (e.g. bunodont molar morphologies). In teeth wherethe secondary occlusal surface is functionally intensely modified (i.e. high-crowned and evergrowingteeth with large areas of dentine exposed) any facet labeling system appears to be challenging, since theidentification of individual facets is blurred and their spatial position may be indeterminable.