During mastication, the foods are cut by the incisors and ground by the molars. The mandible can close very strongly on the maxilla to perform the grinding and, furthermore, during mastication, can make lateral movements. The lips and cheeks on one side and the tongue on the other, continually move the food to place it on the occlusal surfaces of the molars, thus forming the food bolus. Throughout this process, saliva secreted by the salivary glands moistens the food, permitting the formation of the bolus. Swallowing is divided into three phases: oral, pharyngeal and esophageal (3)(6).