Beyond Description: The Many Facets of Dental Biomechanics

Abstract

<jats:title>Abstract</jats:title> <jats:p>Teeth lie at the interface between an animal and its environment and, with some exceptions, act as a major component of resource procurement through food acquisition and processing. Therefore, the shape of a tooth is closely tied to the type of food being eaten. This tight relationship is of use to biologists describing the natural history of species and given the high instance of tooth preservation in the fossil record, is especially useful for paleontologists. However, correlating gross tooth morphology to diet is only part of the story, and much more can be learned through the study of dental biomechanics. We can explore the mechanics of how teeth work, how different shapes evolved, and the underlying forces that constrain tooth shape. This review aims to provide an overview of the research on dental biomechanics, in both mammalian and non-mammalian teeth, and to synthesize two main approaches to dental biomechanics to develop an integrative framework for classifying and evaluating dental functional morphology. This framework relates food material properties to the dynamics of food processing, in particular how teeth transfer energy to food items, and how these mechanical considerations may have shaped the evolution of tooth morphology. We also review advances in technology and new techniques that have allowed more in-depth studies of tooth form and function.</jats:p>

The moment of tooth: rate, fate and pattern of Pacific lingcod dentition revealed by pulse-chase

“…There are good functional reasons for this. The small, slender teeth that catch and grab soft tissue resist bending poorly and should fracture at a high rate [9,12]. A sharp dental battery must be replaced often-in our data small, sharp teeth are in place for just a few days.…”

“…A fundamental question in polyphyodont dentitions is whether replacement is driven by damage [9,10]-does a new tooth grow in response to a broken tooth, or does it appear because certain regions of the jaw experience greater mechanical stress [8,9,11]? This complexity is best showcased in the en bloc replacement of onequarter of the entire dental battery by piranhas [11].…”

“…However, we do not know whether it is a response to a single tooth being broken. An advantage of continuously replacing teeth is that they can occupy a risky region of the wear resistance ←→ performance continuum [9,12].…”

Dental form and function in the early feeding diversification of dinosaurs

“…5B ). The generalized carnivore tooth shape is sharp and pointed, suited to puncture and cut ductile and deformable tissues such as vertebrate flesh ( 22 , 35 ), while the mean herbivorous tooth is blunt and cusped to propagate fractures in tougher materials such as plant tissues ( 22 , 31 ). Also relevant for dietary inferences in dinosaurs is the overlap of herbivores, omnivores, and insectivores in both the biomechanical and morphological spaces ( Figs.…”

Armed to the teeth: the underestimated diversity in tooth shape in snakes and its relationship to feeding constraints

“…Work by Crofts and colleagues (2020), based on pioneering studies by Lucas (2004) [1] and Massare (1987) [3], showed how tooth morphology is associated with prey properties and dental biomechanics (e.g., toughness, bending abilities, mode of failure). Rounded teeth, for example, allow to crush hard prey items, they are tough, can barely bend and are susceptible to fragmentation [2]. Because of their tight and reliable relationship with diet and their abundance in the fossil record, teeth have been suggested to be good indicators of past climate and paleoenvironments (e.g., [4]), and are used to make inferences on the ecology of extinct species [3,[5][6][7].…”