Characteristics and prediction of the alveolar bone loss: essay of modeling.

The alveolar bone loss is a phenomenon which intervenes throughout the life and which can be aggravated by the action of individual and behavioural factors. From this observation we shall try to characterize it and to propose formulas of prediction of the alveolar bone loss according to the age of the patient. We shall expose an analysis of factors bound to the alveolar bone loss and propose a modeling of the alveolar bone loss according to the age in an essentially predictive purpose. The methodology is based on the medical exploitation of CT-dentascanners and medical questionnaire as well as administrative questionnaire used in odontology. Measures of the distance ECJ and the summit of crest are made on the radiology and the individual factors and behavioural factors are scored. The descriptive analysis of the data allowed us to characterize the phenomenon of alveolar bone loss in a therapeutic purpose. The statistical treatment of these data will establish various models according to gender. The described method is simple and its applications seem numerous in the several domains: prevention, improvement of prosthetic and periodontal therapeutics.

Assessment of oral status and oro-pharyngeal candidosis in elderly in short-term hospital care.

OBJECTIVES: To evaluate prevalence of oral candidosis and predisposing conditions in hospitalized elderly patients. DESIGN: We examined 104 elder patients recently hospitalized in two geriatric hospitals for shortterm hospital care. METHODS: Information was collected on patients' sex, age, mental and physical disabilities, smoking habits, medical prescriptions, oral pathologies, denture wearing, oral hygiene habits and oral hygiene level. Quality of existing dentures was evaluated. Oral mucosae were examined for clinical signs suggesting oral candidosis. Semiquantitative cultures of Candida were carried out to confirm the clinical diagnosis. RESULTS: The diagnosis of oral candidosis was confirmed in 18/54 patients showing clinical signs of oral candidosis. Confirmed oral candidosis was associated with the presence of other infections, proteo-caloric denutrition, ongoing antibiotic therapy, and denture wearing. Dentures in patients with confirmed oral candidosis at poorer technical quality of the acrylic surface in contact with the underlying mucosa. CONCLUSION: The wearing of removable dentures is a major predisposing factor for oro-pharyngeal candidosis of elderly patients in short-term hospital care. Appropriate oral and denture hygiene measures as well as denture wearing habits should be introduced or maintained to prevent this infection.

Oral functional characteristics and gastrointestinal pathology: an epidemiological approach.

One of the main problems for aged people is that of having a balanced diet, improved by correct conditioning of the alimentary bolus. Does the masticatory status influence the appearance of gastrointestinal disorders? Such a question justifies the present study. The present work concerned all the patients (211) of eight geriatric institutions, and was completed by a retrospective approach (case-control study). The main result brought by the case-control study, showed that poor oral functional characteristics represent a risk for gastrointestinal pathology (age being neutralized; odds ratio (OR): 2.62). This result indicates that the loss of teeth must be compensated by functionally effective dentures. Not only will the patients' physical and psychic health improve but also medical and public health problems will be solved.

Polymetallism and osseointegration in oral implantology: pilot study on primate.

In oral implantology, successful results in osseointegration are obtained in the medium term (6-12 months) with commercially pure titanium implants. However, current superstructures can be of a different nature (precious metal or titanium) and of different manufacture (cast or machine-produced). Polymetallism between the implant and the superstructure may lead to conditions of galvanic corrosion, and influence osseointegration. The study described establishes, on the one hand, the procedures of animal experimentation in primates and on the other, the techniques of analysis of histological sections. The first technique of analysis is based on histomorphometry and leads to the definition of an osseointegration index. The second technique of analysis consists of X spectrometry by dispersion of energy which enables a spectral analysis of selected points below the crestal neck of the implant (vulnerable area in the case of corrosive attack) to be obtained. It is noted that after 6months, two of which were of activation, osseointegration did not vary according to the nature of the superstructure (precious alloy or titanium). After 2 months, the presence of a precious alloy superstructure lead to titanium migration towards the area around the cervical region of the implant (10-50 microm). This phenomenon did not occur with a titanium implant. It can therefore be presumed that polymetallism leads to detectable corrosion after 2 months but without apparent modification of osseointegration.

Activation of T cells via CD55: recruitment of early components of the CD3-TCR pathway is required for IL-2 secretion.

It was previously reported that the glycosylphosphatidylinositol (GPI)-anchored CD55 molecule provides a co-stimulatory signal for T lymphocytes and is constitutively associated with the Src-related kinase p56lck. The present studies were undertaken to clarify the mechanism of action of CD55 in T cells. We describe the failure of cross-linking of CD55 alone to induce both the elevation of the intracellular calcium concentration and the tyrosine phosphorylation of PLC-gamma in CD3+ Jurkat cells. By contrast, it is sufficient to induce the phosphorylation of tyrosine residues on p56lck, the TCR-zeta chain as well as ZAP-70. Surprisingly, the observed TCR-zeta and ZAP-70 tyrosine phosphorylations appear delayed compared to stimulation via CD3. Calcium ionophore A23187 in combination with cross-linked CD55 mAb initially caused an acceleration in the kinetic of these two phosphorylation events, followed by IL-2 secretion. Furthermore, transfection of the cytoplasmic domain of TCR-zeta in CD3- Jurkat cells, using a CD16-zeta chimera, demonstrates that CD55-mediated T-cell activation depends on the expression of this chain of the CD3-TCR complex.

[Optimal conditions of gamma type irradiation for inactivating HIV in bone fragments. Consequences in biomechanical resistance of the bone tissue]. / Conditions optimales d'irradiation de type gamma en vue de L'inactivation du VIH présent dans les fragamants osseux. Conséquences sur la résistance biomécanique du tissue osseux.

In order to determine bone-dependent penetration differences, we conducted a dosimetric study of gamma radiation using 2.5 mega rads on cancellous bone fragments at 4 degrees C and below 0 degrees with or without a surrounding solution. Variations in dose received inside and outside the femoral head were independent of radiation temperature but varied with the presence or absence of a surrounding solution. We then verified the gamma radiation effect on femoral heads infected with HIV: as free virus and in chronically infected cells. we evaluated infectious capacity after radiation by visualizing syncitia formation and by reverse transcriptase assay. The results for the controls were negative for free virus and positive for chronically infected cells. The virus was still after radiation. At the same time, we studied the effect of gamma radiation at different doses (0, 2.5, 5 mega rads) on biomechanical characteristics of bone, particularly crush resistance. Statistical analysis of the compression curves showed that resistance declined after high radiation at 5 mega rads, but the mean values obtained were within the range of values commonly accepted for human bone crush resistance.

[A neuromusculoarticular reeducation technic from pieziography]. / A propos d'une technique de rééducation neuro-musculo-articulaire issue de la piézographie.

Once defined the neutral equilibrium space in edentulous patients, we examined the importance of phonation for the determination of this space. This allows us to highlight the interest of recording mandibular pressures as a procedure of neuro-muscular rehabilitation. On the basis of recording pressures, we developed an original method of neuro-muscular rehabilitation for complete edentulous patients.