objective : tooth eruption has been a subject of extensive scientific studies; and literature is replete with different mechanisms of migration of a tooth from its bony crypt into the oral cavity. however, there is no common ground on the nature and source of the propelling force among the proponents of these theories. the purpose of this study was to explore the possibility of unifying the cur...

this report presents a case of 10 years old girl who was referred to the pediatric dentistry clinic sustaining a severe trauma led to crown fracture and intrusive luxation of immature maxillary incisors. antibiotic therapies were initiated at first visit, and after surgical exposure both intruded and extruded teeth were endodontically treated by calcium hydroxide. orthodontic repositioning was ...

Several different theories have been advanced to explain the mechanism of tooth eruption. This has been defined by Massler and Schour' as the process whereby a developing tooth migrates from an intraosseous location in the jaw to its functional position within the oral cavity. They also evaluated each of these theories with regard to clinical and experimental observations. Substantial factual e...

The aim of this study was to determine whether a force applied in an antero-posterior direction would adequately reduce incisor eruption. This is needed to achieve a constant direction of force which is one of the demands for a good model for studying orthodontic tooth movement. Twenty male Wistar rats aged 11-12 weeks were divided into two equal groups: in the appliance group, a superelastic c...

Intermittent tongue, lip and cheek forces influence precise tooth position, so we here examine the possibility that tissue remodelling driven by functional bite-force-induced jaw-strain accounts for tooth eruption. Notably, although a separate true 'eruptive force' is widely assumed, there is little direct evidence for such a force. We constructed a three dimensional finite element model from a...

Seismograms observed at Longmire, Washington, for four eruptions of Mt. St. Helens (May 18, June 13, August 7, and August 8, 1980), can be interpreted as Lamb pulses excited by a nearly vertical single force that represents the counter force of the eruption. These data provide reliable estimates of the impulse of the force K (time integral of the force) from which the total momentum and the kin...

Aims. We report observation of a large-amplitude filament oscillation followed by an eruption. This is used to probe the pre-eruption condition and the trigger mechanism of solar eruptions. Methods. We used the EUV images from the Extreme-Ultraviolet Imaging Telescope on board SOHO satellite and the Hα images from the Flare Monitoring Telescope at Hida Observatory. The observed event is a polar...

The volcanic eruption of Mount Pinatubo in June 1991 is the largest terrestrial eruption since the beginning of the satellite era. Here, the monthly evolution of atmospheric temperature, zonal winds, and precipitation following the eruption in 14 CMIP5 models is analyzed and strong and robust stratospheric and tropospheric circulation responses are demonstrated in both hemispheres, with troposp...

Fast rotating cool stars are characterised by high magnetic activity levels and frequently show dark spots up to polar latitudes. Their distinctive surface distributions of magnetic flux are investigated in the context of the solar-stellar connection by applying the solar flux eruption and surface flux transport models to stars with different rotation rates, mass, and evolutionary stage. The ri...