Morphology

Three phases of implant surgery are directly related to the morphology of the maxillary complex: the reflecting of tissues to expose the implant site and take impressions, the seating of the implant, and the effect of implant-restorative procedures on the nondental structures intimately connected with or near the operative site. In the maxillae, these are fairly complicated considerations, primarily because the upper jaw is not a distinct entity — as is the mandible.

The upper dental arch is formed by a prominence (1) or process of two paired bones, the maxillae. However, bearing the teeth is only one function of the maxillae. Each maxilla also contains an air-filled chamber, or sinus (2), that is connected by a continuous membrane with other sinuses in the upper face. The two maxillae are fused together, and where they are, they form the anterior lower walls and floor of the nasal cavity (3). The process almost directly opposite this fusion point joins the zygomatic (malar) bone (4), and these two bones — the maxillary and the zygomatic — form the floor of the orbit (5) and the anterior wall of the infratemporal fossa. Also, the lower portion of the maxilla giving rise to the dental arch (6) also joins a palatine bone (7). Both bilaterally paired bones — the maxillae and the palatine bones — are fused and form the hard palate. The maxillary complex — the maxillae, the zygomatic bones, and the palatine bones — thus help house the organs of sight, smell, and taste.

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