Hypsodontia in Castor canadensis: an anatomical and histological study.

OBJECTIVES: The aim of this original study is to describe the dental morphology and anatomy of Castor canadensis and to compare results with existing data in the literature relating to this mammal. This will give us a better knowledge of its very distinctive dental system, representative of rodent typology. MATERIAL AND METHODS: The authors used an osteological sample that is rarely found in Europe. A series of horizontal histological sections of the labial and jugal dental organs were prepared at different coronal and radicular levels for study under the optic microscope. Coloration was applied for tissue differentiation. RESULTS: Observation of the histological sections reveals an enlargement of the space reserved for the pulp tissue which increases from the crown towards the widely open apex of the incisors. These characteristics are not found in the jugal teeth which, although they also have an open apex, present a different configuration. CONCLUSION: The dental organs of Rodents in general and Castorides in particular are subject to a constant eruptive force throughout their lifetime. This permanent dental growth occurs as the dental system undergoes intense abrasion, especially the incisors.

[Digital volume tomography using the NewTom system: advantages of this new technique in children]. / La tomographie volumétrique numérisée par le système NewTom: intérêt de ce nouvel examen d'imagerie médicale chez l'enfant.

In some cases, after preliminary clinical examination, medical imaging can provide indispensable complementary information for the care of young patients. Volume imaging using two- and three-dimensional reconstructions provides the most complete information possible. Problems involving the superposition of anatomical structures, which can occur with conventional X-rays, are a thing of the past, and this technique represents the future in this field. In high-density tissue such as bone or teeth, tomodensitometry is the preferred examination as it can give a three-dimensional approach to the study. However, because of the high radiation dose required, scanner is still a second intention examination. Development of digital volume tomography using NewTom system, designed for maxillofacial exploration, produces the same type of image for a very much reduced X-ray dose, and at low cost. Although the use of this new examining technique is developing rapidly in Europe and throughout the world since its recent introduction, France is lagging behind as to date there are only seven machines in the entire country. The main uses in children, illustrated by original clinical cases, relate to preoperative surgery planning, post-trauma diagnostic workups, orthodontic checkups, postoperative follow-up and TMJ examinations. The purpose of this article is to inform dental surgeons, paediatricians and doctors about this new medical imaging examination, which will most definitely have a place in the battery of diagnostic tools available to us. After weighing the advantages/risks involved, it should be possible to reduce the number of tomodensitometry exams in favour of this new examination technique in children according to the clinical examination data and diagnostic information required.

[The polyols in pediatric dentistry: advantages of xylitol]. / Les polyols en odontologie pédiatrique : intérêt du xylitol.

Sugars ingested outside of meals play an important role in the etiology of caries. In this respect, sugar substitutes present a very interesting alternative. In addition to the recommendations and usual care to their patients, dental surgeons also have to inform them on a dietetic level. Chewing sugar-free chewing gum after any light meal when it is not followed by a brushing presents a real interest. The authors describe the different polyols and their respective uses. Polyols are widely found in foodstuffs (sweets, chewing-gum, biscuits, cooked meals for diabetic), pharmaceutical products (syrups, pastilles to be sucked, various medicines), non-pharmaceutical chemists (toothpastes, mouth-washes...). By the light of the most recent published works, the particular properties of xylitol are described. Polyols are more particularly indicated for sugar-eater or sick children (syrups), and for those carrying a hight risk of developing caries (progressive polycaries, hyposialie...). Therefore polyols are not only a means of stabilizing some pathologies (diabetes, obesity) but also a weapon in the prevention of dental caries.

[Contribution of day care general anaesthesia for dental care in children and handicapped patients]. / Apport de l'anesthésie générale ambulatoire pour les soins buccodentaires des enfants et des patients handicapés.

Dental surgeons, pediatrists and doctors daily note the precocity and the importance of caries in children. This evolution makes essential the general anaesthesia in paediatric dentistry among the therapeutic arsenal of pedodontists. Fortunately, with the greatest knowledge of the child physiology, the better control of the anaesthetic operative protocols, general anaesthesia is very efficient. Furthermore, the development of the day care treatment now allows the access of these treatments to an increasingly large public. For pedodontists and anaesthetist, generals anaesthesia is essentially indicated for children with many decays, presenting behaviour disorders, a physical or cerebral handicap, a turmoil engraves general state. This operating mode aims to restore: This particular aspect of the dental practice remains still too little developed and cannot answer the demands. The necessity made it a rule to set up a theoretical and practical training. This specialized dentistry waits for recognition on behalf of supervisory organisms and a similar message spread by all nursing persons.