Anatomy and Surfaces of the Maxillary Body
The body of the maxilla features four distinct surfaces:
- Orbital surface (Facies orbitalis) — forms the floor of the orbit. It features the infraorbital groove (Sulcus infraorbitalis), which continues anteriorly as the infraorbital canal (Canalis infraorbitalis). The canal terminates on the face at the infraorbital foramen (Foramen infraorbitale), located just below the margin within the canine fossa (Fossa canina).
- Anterior surface (Facies anterior) — bounded superiorly by the infraorbital margin (Margo infraorbitalis). Medially, it transitions into the nasal notch (Incisura nasalis), and inferiorly near the midline, it forms the anterior nasal spine (Spina nasalis anterior).
- Infratemporal surface (Facies infratemporalis) — largely occupied by the maxillary tuberosity (Tuber maxillae). This area features alveolar foramina (Foramina alveolaria), leading into alveolar canals (Canales alveolares) that transmit nerves and vessels to the roots of the maxillary molars and premolars.
- Nasal surface (Facies nasalis) — bounded anteriorly by the lacrimal sulcus (Sulcus lacrimalis). This surface features the large maxillary hiatus (Hiatus maxillaris), which opens into the maxillary sinus. Posteriorly, along the articulation with the palatine bone, runs the greater palatine groove (Sulcus palatinus major), which helps form the greater palatine canal.
Internal Structure: The Maxillary Sinus
The interior of the maxillary body houses the maxillary sinus (Sinus maxillaris), the largest of the paranasal sinuses. This air-filled cavity communicates with the nasal cavity via the maxillary hiatus on the nasal surface. In the intact skull, this opening is significantly narrowed by surrounding bones, including the ethmoid, inferior nasal concha, and palatine bones.
Topography and Articulations
The body of the maxilla extends into four processes: the frontal process (Processus frontalis), zygomatic process (Processus zygomaticus), alveolar process (Processus alveolaris), and palatine process (Processus palatinus). Inferiorly, the body helps form the boundaries of the ethmoidal labyrinth (Labyrinthus ethmoidalis).
Clinical Significance and Traumatology
The severity of facial bone trauma often correlates with the trajectory of the wounding projectile. Injuries involving the body of the maxilla and maxillary sinus account for approximately 30% of gunshot or high-impact fractures of the upper jaw.
Fracture tracts can be discontinuous. Traumas frequently produce significant facial asymmetry, with damage to the maxillary body on one side and contralateral injury to the hard palate, alveolar process, or oral floor. Secondary missiles—such as bone fragments and displaced teeth from the fractured alveolar process—often cause additional destruction to the body of the maxilla and sinus walls.
Surgical Management: When a fracture tract crosses the body of the maxilla, surgical exploration (revision) of the maxillary sinus, nasal meatuses, and ethmoidal labyrinth is mandatory.
- In severe wounds, blood clots, foreign bodies, and bone fragments are removed, and devitalized mucosa is debrided. Viable mucosa is preserved, repositioned over the bony framework, and supported with an iodoform gauze pack.
- A critical step is creating a permanent surgical antrostomy (artificial opening) into the inferior nasal meatus to drain the sinus and exteriorize the end of the gauze pack.
- For smaller entry wounds, exploration is typically performed via an intraoral approach, similar to the Caldwell-Luc radical antrostomy.