Summary  and ConclusionSome masticatory function tests have been carried out on 6 selected patients for the purpose of obtaining clues concerning chewing ability of different posterior occlusal patterns. To make it more valid, the subjective analysis as well as the study of tissue displacements were also tested.In such a study, it appears that in order to reach scientific conclusions, there mus be two rules to abide by:I— A common base for all the posterior teeth to be tested.II — A proper full balance of the dentures.The findings of this investigation may be summarized as follows :1. Peanuts are more finely ground with flat-plane teeth.2. High cusped teeth seem more effective for carrois and beef meats.3. Centrimatic teeth are less effective in all the occlusal patterns in relation to chewing efficiency.4. The differences in chewing efficiency are not significant among the posterior patterns to test. This also explains the uncertainty of patient's preference.5. Mucosal irritation is not shown in neither of the occlusal patterns. This must be related with balanced articulation of dentures.6. Having accustomed to dentures is directly proportional with the duration of wearing them.7. The chewing efficiency is also directly proportional with the number of chewing strokes.8. High cusped teeth is responsible in tissue displacement. However, this is quite difficult to differentiate it from the improper balanced articulation. Centrimatic teeth seem the best in this matter.9. The homogenity of food seems important in the field of chewing efficiency.