The X-ray maxilla is used to assess for facial fractures, as well as acute sinusitis. The maxillae (or maxillary bones) are a pair of symmetrical bones joined at the midline, which form the middle third of the face. Each maxilla forms the floor of the nasal cavity and parts of its lateral wall and roof, the roof of the oral cavity contains the maxillary sinus, and contributes most of the inferior rim and floor of the orbit. It bears the upper tooth-bearing alveolar process.