Christopher Choi1 and Dale J. Misek2
1Private Practice, Inland Empire Oral and Maxillofacial Surgeons, Rancho Cucamonga, California, USA
2Private Practice, Carolinas Center for Oral and Facial Surgery, Charlotte, North Carolina, USA; and Department of Oral and Maxillofacial Surgery, Louisiana State University Health Science Center, New Orleans, Louisiana, USA
A procedure designed to augment the vertical height of the maxillary sinus to facilitate implant placement in patients with pneumatized sinuses.
- Pneumatized maxillary sinus with a lack of vertical osseous support (<10 mm) for dental implant(s) placement within the posterior maxilla
- Chronic and acute maxillary sinusitis
- Odontogenic infection
- Maxillary sinus pathology (cysts, tumors, or polyps)
- Medical comorbidities:
- Coagulopathy or patients on anticoagulants
- Uncontrolled systemic disease
- Heavy smoking
Pneumatization of the maxillary sinus refers to the enlargement of the sinus cavity that occurs with advancing age and tooth loss. The maxillary alveolus resorbs, and the sinus walls thin with loss of masticatory forces and function. The Schneiderian membrane lines the sinus cavity and contains ciliated epithelium, which propel sinus contents against gravity through an ostium located along the medial wall of the maxillary sinus, which drains into the middle meatus of the nose. Membrane thickness varies from 0.13 to 0.5 mm. Bony septae are variable in size and can be found emanating from the sinus floor, dividing the sinus cavity into multiple compartments. The blood supply to the maxillary sinus originates from three arteries—the infraorbital artery, the posterior superior alveolar artery, and the posterior lateral nasal artery—all of which are branches of the maxillary artery. Intraosseous, and sometimes extraosseous, anastomoses between the infraorbital and posterior superior alveolar arteries give off networks of fine branches toward the alveolus.
- Antibiotic prophylaxis is recommended prior to any invasive sinus procedure. Intravenous sedation is typically utilized for prolonged cases, sinuses requiring extensive grafting, or anxious patients. For smaller grafting procedures and for procedures lasting less than 45 minutes, local anesthesia alone is frequently sufficient.
- Local anesthetic is infiltrated within the maxillary vestibule and the alveolar mucosa. Infraorbital and posterior superior alveolar blocks are recommended. Injection into the greater palatine canal provides profound anesthesia to the sinus cavity.
- The patient’s face is prepped with betadine, and sterile towels are placed to isolate the oral cavity. The teeth and gingiva are brushed with betadine or chlorhexidine to disinfect the oral cavity.
Adjacent to the edentulous region, a full-thickness semilunar incision is made at the mucogingival junction with extension into the vestibule. A subperiosteal dissection is performed to expose the maxillary antral wall at the proposed site of entry into the maxillary sinus (see Figure 6.2 in Case Report 6.1).
A round diamond bur with copious irrigation is used to create an oval window (Figure 6.3, Case Report 6.1) within the area of the proposed bone graft. Care is taken to not perforate the Schneiderian membrane during removal of the antral bone window. An island of bone (Figure 6.4, Case Report 6.1) may be left in the center of the sinus window, which will be elevated with the Schneiderian membrane. Piezosurgical manipulation can be used as well, but with a thick lateral sinus wall, bone removal can be tedious.
Various instruments are used to carefully lift the Schneiderian membrane from the walls of the maxillary sinus (Figure 6.5, Case Report 6.1). Once initially freed, the membrane is elevated from the floor and medial wall of the maxillary sinus. The anterior boundary of the sinus cavity should be determined with instrument palpation. The membrane should be freed in all directions to allow for the placement of sufficient grafting material. The sinus window can be enlarged with the use of a Kerrison rongeur (Figure 6.6, Case Report 6.1), if needed.
The bone graft of choice is placed and compacted within the sinus cavity without perforating the Schneiderian membrane (Figure 6.7, Case Report 6.1). To minimize voids, the graft should be packed anteriorly and medially first (Figure 6.8, Case Report 6.1). With simultaneous implant placement (Figure 6.9, Case Report 6.1), the implants are placed after initial medial and anterior packing, and then additional grafting material is packed lateral (Figure 6.10, Case Report 6.1) to the implants.
- A membrane may be placed lateral to the graft, but it is not mandatory. The mucosa/>