The treatment of impacted third molars that have neither symptoms nor disease is controversial. One school of thought is that these teeth should be extracted before they do become symptomatic and/or diseased. A second school of thought advocates retaining these teeth until such time when they show evidence of developing symptoms or disease. The purpose of this review is to present the reasoning behind the two opposing schools of thought. Studies involving both the risks and the benefits of extracting and retaining asymptomatic, disease-free third molars were examined. There are studies to support the proponents of each school of thought. Proponents of removal are of the belief that many asymptomatic and disease-free impacted third molars eventually do become symptomatic and/or diseased, and do so when the patient is older. The morbidity and incidence of complications common to the procedure increase with age, and therefore proponents of removal prefer that surgery be performed at a younger age when the complications are less likely to be as severe or permanent. Those in support of retaining and monitoring these teeth are of the opinion that the status of these asymptomatic and disease-free impacted third molars may never change and therefore never require surgical intervention. They believe the increased complication rate and morbidity experience by some of the older surgical patients do not justify the routine removal of all asymptomatic, disease-free impacted third molars at an early age. Both groups recognize that when surgical intervention is employed, complications such as pain, swelling, alveolar osteitis, periodontal problems, temporomandibular joint disorders, nerve involvement, sinus communication, and financial stress are not uncommon. Ultimately, the clinician must consider the information presented in this review, and combine it with his/her academic knowledge and personal clinical experience to inform the patient of the risks and benefits of both treatment options. That way, the clinician and the patient together can decide the strategy for management of an asymptomatic, disease-free third molar.

L'objectif du travail est de mettre en place des méthodes d'évaluation des risques microbiologiques et des bénéfices nutritionnels lors de la transformation des légumes, en vue d'une analyse risque-bénéfice. Le risque (industriel) considéré est l'altération des conserves de haricots verts due à la bactérie thermophile Geobacillus stearothermophilus, et le bénéfice nutritionnel est la teneur en vitamine C des haricots verts appertisés. Des paramètres de référence ont d'abord été acquis, par une méta-analyse par approche bayésienne pour la partie risque. Les paramètres de résistance thermique D à 121.1°C et pH 7, zT et zpH de G.stearothermophilus ont ainsi été estimés respectivement à 3.3 min, 9.1°C et 4.3 unités pH en moyenne en milieu aqueux. Les modèles risque et bénéfice ont ensuite été analysés par la méthode de simulation de Monte Carlo à deux dimensions, permettant une propagation séparée de la variabilité et de l'incertitude. Les pertes en vitamine C prédites par le modèle entre la matière première et les légumes appertisés sont de 86% en moyenne, et le taux de non-stabilité à 55°C prédit est de 0.5% en moyenne, globalement en accord avec la réalité. Une analyse risque-bénéfice a ensuite visé à optimiser le bénéfice tout en gardant le risque à un niveau acceptable, par exploration de scénarios d'interventions possibles basés sur les résultats d'analyses de sensibilité. Enfin, un modèle d'évaluation des risques dus à la bactérie pathogène Bacillus cereus dans une purée de courgettes a été confronté à des données de contamination dans des produits incubés, par le biais d'une inférence bayésienne. / The aim of this work is to set up microbiological risk and nutritional benefit assessment methods in the transformation of vegetables, in view of a risk-benefit analysis. The considered (industrial) risk is the alteration of green bean cans due to thermophilic bacteria Geobacillus stearothermophilus, and the nutritional benefit is the vitamin C content in appertized green beans. Reference parameters have first been acquired, by a meta-analysis using Bayesian inference for the risk part. Thermal resistance parameters D at 121.1°C and pH 7, zT and zpH of G.stearothermophilus have been respectively estimated at 3.3 min, 9.1°C and 4.3 pH units on average in aqueous media. The risk and benefit models have then been analyzed by a two-dimensional Monte Carlo simulation method, allowing a separated propagation of uncertainty and variability. The vitamin C losses between fresh and appertized green beans predicted by the model are of 86% on average, and the predicted non-stability at 55°C rate is of 0.5% on average, in good accordance with reality. A risk-benefit analysis has then been carried out to optimize benefit while keeping risk at an acceptable level, by exploring possible intervention scenarios based on some sensibility analysis results. Finally, a risk analysis model involving pathogenic bacteria Bacillus cereus in a courgette puree has been confronted to incubated product contamination data, by means of a Bayesian inference.