Some species have conical teeth at the front of the jaws and cuspid teeth toward the rear, but the latter are not comparable to the molars of mammals in either form or function.
However, when raised on soft artificial food under laboratory conditions [ 52], in natural conditions in lakes not inhabited by snails [ 51], or in lakes inhabited by snails but also with a molluscivorous competitor present [ 53], they develop less stout pharyngeal jaws with cuspid teeth (papilliform).
Three maxillary teeth (cuspid and premolars) in the same quadrant were treated.
Clinical crown height was measured with digital calipers to the nearest one hundredth of a millimeter on the facial surface of each crown from the cusp tip or incisal edge to the deepest curvature of the gingival margin along the long axis of the tooth for bicuspid, cuspid, and incisor teeth and on the molar teeth at the mesiobuccal cusp (Fig. 1b).
Cuspidal structures are observed in virtually all fossil and extant groups: shark scales can be tricuspidate in some places of their body, placoderm "tubercles" on jaw-bones and body dermal bones are multi-cuspidate [ 58], teleost fishes display a variety of tooth shapes including multi-cuspidate ones [ 33], and mammals have variations in the number of cuspids on their teeth [ 60].
Artificial tooth setup was established with anterior and cuspid guidance in medio-laterotrusion and freedom in centric.
Finally, the occlusion was adjusted to anterior and cuspid guidance using 6 μm shim stock between the teeth.
Collecting the sensor signals on each tooth, we can see which of teeth dominantly interacts with foods and analyze different patterns of the interaction forces among the incisor, cuspid and molar teeth.
It is the smell of 3,000 human baby teeth and the crumbling 50-year-old envelopes that hold them, each one scribbled with a few bits of information: cuspid or molar, intact or rootless, milk-fed or breast.
From the FEA models, the distribution of Von Mises stresses in the M. paranensis tooth revealed hybrid patterns that reflect those observed in both the sharp triangular blades of the carnivorous red belly piranha, Pygocentrus nattereri, and the blunt cuspids of the durophagous pacu, Piaractus brachypomus (Fig. 4).
