Natural frequencies and vibration modes of four kinds of teeth were calculated by using a mechanical model. The alveolar bone and the tooth were assumed as rigid bodies, while the periodontal ligament was assumed as an elastic spring. All the natural frequencies were within a range of 1 to 10 kHz. The first natural frequencies of four teeth were about 1.5 kHz, and decreased as the root length d...

Original scientific paper The relationships between the existence of gear teeth cracks as a cause and symptoms emerging as housing vibrations that can be detected with signals measured was investigated numerically and experimentally. Experimental measurements on one-stage gear drives have been carried out involving gears built in with different notch length in tooth root. Signals measured as ac...

Three root canals in the mesiobuccal root of maxillary first molar is unusual. The aim of this case report was to describe a maxillary first molar that presented three root canals in the mesiobuccal root. The distance among the three canal orifices was 1.5 mm. The working lengths of the three canals were within the normal range.

The aim of the present roentgenographic in vitro study was to determine the initial straight length from the cemento-enamel junction (CEJ) to the appearance of a root canal curvature in human mandibular premolars. A total number of 282 mandibular premolars were examined. Exclusion criteria comprised root caries, extensive restorations and endodontically treated teeth. The teeth were fixed and d...

abstract background: critical care patients are at higher risk for untreated pain. pain has persistent and untreated effects on most of the body systems and results in development of complications, chronic pain, and increased length of stay. the aim of this study was to determine the effects of the implementation of a pain management program on the length of stay in patients with decreased leve...

BACKGROUND The dimensions of the roots of the teeth are important in the assessment of orthodontic anchorage and to estimate the forces to be used during orthodontic tooth movement. AIMS To investigate the relations between the lengths, widths and projected areas of the roots of the permanent teeth. METHODS Intact, extracted human permanent teeth were photographed and the lengths, widths an...

Rapidly evolving implantation and alveolar ridge reconstruction techniques created a new area in modern dentistry where tooth loss is no longer a problem. Endless variations of implant's length, diameter, surface, and design along with autogenous, alogenous, aloplastic, or xenogenous bone substitutes made it possible to recreate physiological occlusion, esthetic and masticatory function. Howeve...

The aim of this study was to survey the association of congenitally missing anterior tooth and variations in craniofacial morphology in South Indian female patients. A total of 15 female patients with congenitally missing tooth in the maxillary anterior region were selected. 16 linear and 6 angular measurements were done on the lateral cephalograms of each subject with Legan and Burstone analys...

Second molar length and body weight are used to test the correlation between tooth size and body size in living Hominoidea. These variates are highly correlated (r= 0.942, p less than 0.001), indicating that tooth size can be used in dentally unspecialized fossil hominoids as one method of predicting the average body weight of species. Based on tooth size, the average body weight of Aegyptopith...

BACKGROUND It has previously been hypothesized that lower socio-economic status can accelerate biological ageing, and predispose to early onset of disease. This study investigated the association of socio-economic and lifestyle factors, as well as traditional and novel risk factors, with biological-ageing, as measured by telomere length, in a Glasgow based cohort that included individuals with ...