introduction:temporomandibular disorders (tmds) are referred to signs and symptoms involving masti catory muscles, temporomandibular joint and rele vant structures. having been prevalent noticeably, we decided to evaluate the frequency of tmd, among patients referred to the dental clinic of guilan university of medical sciences. materials and methods: in this cross-sectional study, a sample of ...

background and aims. bruxism is defined as a habitual nonfunctional forceful contact between occlusal tooth surfaces. in younger children bruxism may be a consequence of the masticatory neuromuscular system immaturity. the aim of this study was to assess the prevalence of bruxism and investigate the relationship between occlusal factors and bruxism among preschool children. materials and method...

In recent years, many dental professionals have changed their philosophy regarding the use of trays with at-home bleaching regimens. However, facts do not change--and successful vital tooth bleaching still occurs only when tooth surfaces are in direct contact with the appropriate concentration of active whitening agent for a specific amount of time. Because the science of tooth whitening is sti...

OBJECTIVES this study investigated the effects of growth and tooth loading on the structural adaptation of the developing alveolar bone adjacent to the tooth root as the tooth erupted into function. Growth and occlusal function were expected to lead to increased alveolar bone density. Meanwhile, the supporting alveolar bone was expected to develop a dominant trabecular orientation (anisotropy) ...

The purpose of this study was to validate the elastomeric impression after temporary tooth separation as a method of cavitation detection in proximal caries lesions in primary molars with outer half dentin radiolucency. Fifty-one children (4-10 years old), presenting radiolucency in the outer half of the dentin at the proximal surfaces of primary molars and proximal anatomic contact with the ad...

In order to enhance the load capacity of gears, researchers take notice in the asymmetric tooth gears. Asymmetric gear which has higher pressure angle of back tooth aiming to improve banding strength has been analyzed (Deng, et al., 2003). Brown et al. (Brown, et al., 2010) investigate the asymmetric tooth from both point of view of bending and scuffing. Kruger et al. (Kruger et al., 2013) anal...

OBJECTIVES This study aimed to clinically quantify the apicoincisal height of the upper interproximal areas directly in patients' mouths compared to measurements on stone models. SUBJECTS AND METHODS One hundred and fifty participants (75 females and 75 males, age range 20-45 years) were recruited for this study. A digital caliper was used to measure the anterior maxillary interproximal conta...

objectives : this finite element method study aimed to compare the amount of stress on an isolated mandibular second premolar in two conventional reciprocal parallel interface designs of removable partial dentures (rpds) and the same rpd abutment tooth (not isolated). materials and methods: a kennedy class 1, modification 1 rpd framework was simulated on a 3d model of mandible with three differ...

Gear transmission systems are widely used in various fields. The occurrence of gear cracks, tooth pitting, and other faults will lead to the dynamic characteristics deterioration system. In order calculate meshing stiffness faulty pairs more effectively precisely, this article improves loaded contact analysis (LTCA) method by analyzing influence different fault types on deformation, including b...

The concentric face gear split-torque transmission system (CFGSTTS) is a new form of drive that primarily used in helicopter systems. Its load-sharing performance among different branches and tooth contact characteristics have great impact on the service life transmissions. It contains ten meshing pairs, load distribution complicated, areas are difficult to determine. Therefore, based multi-poi...