OBJECTIVE The purpose of this study was to determine the root canal anatomy of mandibular first premolar teeth in an Emirati subpopulation using a decalcification and clearing method. MATERIALS AND METHODS One hundred permanent mandibular first premolar teeth extracted for orthodontic purposes from an Emirati subpopulation from the United Arab Emirates were used for this study. They were subj...

Deciduous teeth (dentes lactales, dentes decidua, dentes caduci) differ from permanent teeth by morphological and histological characteristics. Of the morphological characteristics, the most pronounced differences are in number, shape, size and color of teeth. A special fea­ ture is the existence of enamel­dentin ridge located on the vestibular surface of molars, which protects gingiva from foo...

By accompanying human travels since prehistorical times, the house mouse dispersed widely throughout the world, and colonized many islands. The origin of the travellers determined the phylogenetic source of the insular mice, which encountered diverse ecological and environmental conditions on the various islands. Insular mice are thus an exceptional model to disentangle the relative role of phy...

As the most important working area of gear, teeth play the role of transmitting load and power. Tooth line and tooth profile are the two main characteristics of the tooth surface, which affect the shape of the tooth surface, tooth meshing characteristics and contact characteristics. Taking the elliptical cylinder gear pair in the reversing device of a new type of drum pumping unit as the resear...

The shape of shark teeth varies among species, but traditional testing protocols have revealed no predictive relationship between shark tooth morphology and performance. We developed a dynamic testing device to quantify cutting performance of teeth. We mimicked head-shaking behaviour in feeding large sharks by attaching teeth to the blade of a reciprocating power saw fixed in a custom-built fra...

An unerupted supernumerary tooth was attached to the root surface of an unerupted permanent lateral incisor. It was necessary to remove both the supernumerary and the permanent lateral incisor as a single unit. The permanent lateral incisor was separated from the supernumerary and placed back into the original developmental crypt. The replanted lateral incisor erupted normally one year later. W...

Landmark-based high-dimensional diffeomorphic maps of the hippocampus (although accurate) is highly-dependent on rater's anatomic knowledge of the hippocampus in the magnetic resonance images. It is therefore vulnerable to rater drift and errors if substantial amount of effort is not spent on quality assurance, training, and re-training. A fully-automated, FreeSurfer-initialized large-deformati...

Introduction: the Restoration of endodontically treated teeth is critical, and the Awareness of stresses developed by oblique and vertical forces in restorative methods take a great role in treatment plans. Due to the anatomical shape and inherent form of the stress distribution premolars, could be lost by fractures. Some fractures such as vertical fracture which is probable in...

Previous research has demonstrated that species and subspecies of extant chimpanzees and bonobos can be distinguished on the basis of the shape of their molar crowns. Thus, there is potential for fossil taxa, particularly fossil hominins, to be distinguished at similar taxonomic levels using molar crown morphology. Unfortunately, due to occlusal attrition, the original crown morphology is often...