Fusion: the union of two normally separated tooth buds with the resultant formation of a joined tooth with confluence of dentine [ 27 ].
In two cases (Table 1), we roughly separated tooth crowns from the roots and measured them as independent samples, but we made no attempt to separate cementum, dentine, and enamel because of the need to obtain at least 20 g of each material to reach the detection limit of the measurement.
Concrescence is the fusion of two separate teeth only in their cementum.
Ostraciidae have long been problematic because ostraciids exhibit mosaic morphologies (lacking pelvic fin elements and spinous dorsal fins, like tetraodontoids, but having separate teeth, like balistoids and triacanthoids).
Scleroderms were considered to be primitive tetraodontiforms, usually having a set of primitive characters such as pelvic fin elements, separate teeth, and spinous dorsal fins.
Members of the Triacanthidae have primitive morphological characters including paired pelvic fin spines, spinous dorsal fins, and separate teeth, and are often treated as basal members together with the Triacanthodidae [ 1, 4, 6, 18, 19, 34, 47, 48].
There are fewer than 30 tooth rows in either jaw; in the upper jaw, the first two large teeth are separated from the lateral teeth by a row of small intermediate teeth.
Separate your teeth slightly, and press the sides of your tongue against your upper back molars (the teeth in the back top of your mouth).
This sinus is closely related to the root apex of the premolar and molar teeth, and it is either separated from the teeth by a thin layer of bone or its mucous membrane is in direct contact with the teeth.
A diastema separates these teeth from the more posterior molariforms.
