Maxilla

The maxilla is the upper jawbone, and unlike the mandible, it is a fixed bone that does not move. It forms the upper dental arch, the floor of the nasal cavity, the floor of each eye socket (orbit), and a significant portion of the mid-face structure. The two maxillary bones (left and right) are fused together at the midline of the palate.

One of the most clinically significant features of the maxilla is the maxillary sinus, a large air-filled cavity located within the bone above the upper premolars and molars. When upper back teeth are lost, the sinus tends to expand downward into the space where the tooth roots used to be, a process called sinus pneumatization. This reduces the available bone height for implant placement and often necessitates a sinus lift (sinus augmentation) procedure, where the sinus membrane is gently elevated and bone graft material is placed underneath to create enough volume for an implant. The maxilla also plays a role in orthodontics. In growing children, the palatal suture (the joint where the two maxillary bones meet at the roof of the mouth) can be expanded using a palatal expander to widen a narrow upper arch and correct crossbites. This is only possible while the suture is still flexible, which is why timing matters in orthodontic treatment planning.

For your practice, understanding the maxilla is important for explaining upper jaw procedures to patients. Sinus lifts, upper denture fit issues, and palatal expansion are all directly related to maxillary anatomy. When a patient asks why an upper implant costs more than a lower one, the answer often involves the additional sinus lift procedure required by the anatomy of the maxilla.