Maxillary sinusitis is inflammation of the maxillary sinuses. The human mouth contains upper (maxillary) and lower (mandibular) molars. The glandular system contains four glands&colon; the mandibular, maxillary, labial, and postpharyngeal glands. In addition to proclination of the maxillary incisors, mandibular incisors retrusion will also happen. This can be done by observing the maxillary and mandibular incisors during the slide. The oblique ridge is found on the occlusal surfaces of maxillary molars. Microdontia of a single tooth is more likely to occur in a maxillary lateral incisor. The maxillary sinus is supplied by superior alveolar nerves from the maxillary and infraorbital nerves. Lateral to the turbinates is the medial wall of the maxillary sinus. It often appears between the roots of the maxillary central incisors. Canines and most premolars, except for maxillary first premolars, usually have one root. The four paired paranasal sinuses are the frontal, ethmoidal, maxillary, and sphenoidal sinuses. OAC refers to an abnormal connection between the oral cavity and antrum (or maxillary sinus). Expansion of the cyst causes erosion of the floor of the maxillary sinus. Valsalva is also used by dentists following extraction of a maxillary molar tooth.