Tongue-mandible coupling movements during saliva swallowing

International audienc

Substantiation of an artificial saliva formulated for use in a masticatory apparatus.

The aim of this work was to substantiate artificial saliva prepared for use in a masticator apparatus. Mastication's goal is to produce a viscous and plastic food bolus where these properties authorize a safe swallow. Apart from its biochemical contribution, saliva is mainly used in this kind of apparatus to provide a viscous component to the bolus. Artificial saliva was prepared with water and minerals, and completed with mucin and amylase. Different physico-chemical conditions were applied and the resultant viscosity was compared to that of human saliva. Mechanically- or chemically-stimulated salivas of ten healthy subjects were collected. Viscosity was measured with a capillary viscometer in response to changes in measurement's temperature, air exposure or pH. The effects of circadian saliva collection and the stimulation type on viscosity of human saliva were also studied. Viscosity of artificial and human salivas was comparable. An increase in the measurement's temperature or a 30 min-exposure of saliva to air led to a significant decrease in viscosity of both types of saliva. Amylase in artificial saliva did not change viscosity. The viscosity of human saliva displayed important subject variability as well as a dependence on the stimulation type of saliva production. This work allowed a useful evaluation of the formulated artificial saliva. It exhibited similar viscosity as the natural saliva in response to different methodological conditions. Therefore the proposed artificial saliva satisfies the major requirement of viscosity for a use in the masticator apparatus designed to prepare a food bolus

Douleur dentaire chez l’enfant : les parents sont-ils de bons evaluateurs? Etude preliminaire.

International audienc

The Masticatory Normative Indicator

ANR (SensInMouth, ANR 07-PNRA-O14), IFN "Prix Bernard Beaufrere 2006", and Conseil Regional d'Auvergne supported this study. Drs. P. I. N'Gom and R. Ryan helped in manuscript writing and language editingThere is no established quantitative, objective method to differentiate individuals with good masticatory function from those lacking this attribute. The aim of this study was to specify a normal range of median particle size values for masticated raw carrots collected just before being swallowed. The masticatory normative indicator (MNI) value thus obtained was based on seven studies carried out by different investigators using different methods for measuring particle size in carrot boluses. A simple mathematical transformation of variables and the choice of an interval of +/- 1.96 times the standard deviation gave 4.0 mm as the upper limit of normal median particle size for carrots in a population of young persons with good oral health. This value identifies boluses that may be considered as resulting from impaired mastication, as illustrated in healthy individuals with experimentally hampered mastication, denture wearers, and individuals presenting with obesity or Down syndrome

Development and validation of a mastication simulator

More and more research are being done on food bolus formation during mastication. However, the process of bolus formation in the mouth is difficult to observe. A mastication simulator, the Artificial Masticatory Advanced Machine (AM2) was developed to overcome this difficulty and is described here. Different variables can be set such as the number of masticatory cycles, the amplitude of the mechanical movements simulating the vertical and lateral movements of the human lower jaw, the masticatory force, the temperature of the mastication chamber and the injection and the composition of saliva. The median sizes of the particles collected from the food boluses made by the AM2 were compared with those of human boluses obtained with peanuts and carrots as test foods. Our results showed that AM2 mimicked human masticatory behavior, producing a food bolus with similar granulometric characteristics

La chirurgie bariatrique affecte les besoins en protéines liés à l'obésité

FONCTION INTESTINALE ET OBÉSITÉIntroduction et but de l’étude: Après chirurgie bariatrique, un déficit en protéines est fréquemment rapporté chez les patients souffrant d'obésité morbide alors que les besoins en protéines n’ont pas été précisément déterminés dans cette population. L'objectif de cette étude est d'évaluer le besoin protéique moyen (BPM) chez les sujets obèses, avant, 3 mois et 12 mois après la chirurgie bariatrique en utilisant la méthode de bilan azoté.Matériel et méthodes: Une étude longitudinale prospective, incluant 21 patients en obésité morbide (IMC 43,9±1,4 kg/m²) a été mise en place pour évaluer le bilan azoté calculé à partir des mesures des apports alimentaires et des pertes d'azote dans les urines et les selles collectées durant 3 jours avant (M0), 3 mois (M3) et 12 mois (M12) après sleeve gastrectomie ou by-pass gastrique. Une régression linéaire entre les apports en protéines et le bilan azoté a été utilisée pour déterminer la valeur du BPM. Une étude transversale plus large a été réalisée pour valider le BPM chez des patients obèses appariés non opérés (n = 106). Les valeurs de BPM sont exprimées en moyenne [Intervalle de confiance (IC) à 95%] et les autres valeurs en moyenne ± écart-type à la moyenne.Résultats et Analyse statistique : Avant la chirurgie, le BPM des patients obèses était de 0,76 [IC à 95%, 0,66-0,92] g/kg de poids corporel/j dans le groupe expérimental et de 0,74 [0,70-0,80] g/kg/j dans le groupe de validation. Il était de 0,62 [0,51-0,75] g/kg/j à M3 et de 0,87 [0,75-0,98] g/kg/j à M12, sans différence entre les procédures chirurgicales. Les apports spontanés en protéines étaient respectivement de 0,80±0,05; 0,43±0,03; 0,71±0,04 g/kg/j respectivement à M0, M3 et M12.Conclusion: Cette étude indique un changement temporel des besoins en protéines après chirurgie bariatrique quel que soit le type de chirurgie. Les apports spontanés après chirurgie bariatrique ne couvrent pas les besoins en protéines de la plupart des patients, ce qui suggère que des recommandations spécifiques sur les protéines alimentaires doivent être adaptées chez les patients obèses candidats à une chirurgie bariatrique