[Pathogenic occlusion and functional occlusion: definition of completion].

The masticatory system is widely adaptable and tolerant especially in young people ; this characteristic can be helpful but it can also incur risks because there are limits to everything. Guided solely by the insubstantial support provided by data derived from evidence-based medicine, a researcher would have to be both excessively clever and unusually cunning to define the borderline between physiological and pathological occlusion. Accordingly, the optimization of masticatory function through the intermediary of efficient occlusal interaction of upper and lower teeth remains a fundamental common sense objective of all dental treatment.

Cytotoxicity of orthodontic bands, brackets and archwires in vitro.

Objectives: In orthodontic therapy, different materials are used and subjected to a damp oral environment, which can modify their properties. In order to evaluate the biocompatibility of metallic and non-metallic orthodontic appliances their in vitro cytotoxicity has been measured.

Methods: Twenty-eight new and nine clinically used materials, including brackets, molar bands and archwires were used.

[Schuchardt's procedure and surgery of open bite].

Posterolateral segmentary maxillary impaction osteotomy has a role to play in the treatment of gaps between the upper and lower jaws. It has several advantages, especially an uncomplicated postoperative period and the single-maxillary contention it provides. The indication must be established after an articulator assessment in order to take into account the mandibular protrusion caused by autorotation and to prevent a sagittal shift.

[Do magnetic forces potentiate the histophysiology of orthodontic movement?].

A comparative clinical research has been made to prove if magnet forces can be superior to mechanical forces for tooth movement. Six dogs went through a distalazing movement of their lower premolars on one side with a magnet system and on the other side with a mechanical system producing similar forces. A histological analysis of the moved premolars has showed a more important rate of osteoclasts and a reduction of the hyalinisation area with the magnet system.

[Impact of early extraction of the 1st molars on vertical dimension].

Early extractions of first permanent molars, done on twenty cases without any orthodontic treatment, have not shown, following the Student's analysis, any statistical difference relative to a pilot group as far as the angles. SN- ANS- PNS, SN-OP, SN-GoGn, FMA, Y-axis are concerned. On the other hand, it has been revealed a closure of the angle ANS- Xi- MP associated with an opening of the mandibular arch.