The document summarizes various functions of the oro-facial region including mastication, swallowing, respiration, speech, facial expression and maintaining mandibular position. It describes the different phases of mastication and swallowing in infants and adults. Mastication involves 6 phases in adults: 1) preparatory phase, 2) food contact, 3) crushing phase, 4) tooth contact, 5) guiding phase, 6) centric occlusion. Swallowing occurs in 4 phases: 1) preparatory swallow, 2) oral phase, 3) pharyngeal phase, 4) esophageal phase. The document also briefly mentions respiration, speech, buccinator mechanism and trajectories of force in the maxilla