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T M Xu

Publications and source records attributed to T M Xu.

7 recordsLinked to original sources
PubMed1994

Bite-opening mechanics as applied in the Begg Technique.

In the Begg Technique, factors controlling the anterior intrusive force provided by the archwire have yet to be fully clarified. The rationale for bite opening with very light forces, the effect of Class II elastics on intrusive force magnitude and the intrinsic quality of 'Australian' wire in bite opening are examined in this paper. A formula is presented which allows the intrusive force that archwires exert in different individuals to be predicted. The values derived from the formula were compared with case model measurements. It was found that the intrusive force of the archwire was affected by the length of the individual dental arch. The magnitude of this intrusive force was seen to increase gradually during the period of bite opening and appeared to be related to the use of Class II elastics. The study revealed factors which affected the magnitude of the intrusive force.

Dental Arch↗
PubMed1993

[A theoretical study of bite opening with Begg technique].

The authors made a thorough and careful study on the Begg Stage I appliance and established a model of mechanics in accordance with the actual situation of arch wire being activated and derived a mathematical formula based on the elastic small deflection theory. This study provides not only the basis of choosing intrusive-force value for individual arches, but also the possibility of analysing dynamically the changes of intrusive- force value in the process of bite opening.

Biomechanical Phenomena↗
PubMed1992

Effect of the vertical force component of Class II elastics on the anterior intrusive force of maxillary archwire.

Class II elastics are usually employed in the treatment of excessive overbite and overjet with the Begg technique. The effect of Class II elastics on bite opening and the extent of such an effect is uncertain. This article, based on measurements of 30 cases, illustrates that the effect of the vertical component of force from Class II elastics in reducing the intrusive force generated by the anchor bands in the upper archwire is less than previously believed. The position of the circles in the archwire for intermaxillary elastics has the greatest influence on the anterior intrusive force of the upper archwire. The direction of the Class II elastics and the length of the dental arch (a negative correlation) came second, while the force actually exerted by the elastics had the smallest influence. It is, therefore, suggested that the position of the intermaxillary elastic circles should be located according to the differing clinical objectives.

Dental Stress Analysis↗
PubMedDate not supplied

China: moral puzzles.

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Bioethical Issues↗