Maxillary Sinus Lift Surgery

What Is Sinus Augmentation?

The posterior maxillary crest is often resorbed due to sinus pneumatization after tooth extraction or trauma. That is why maxillary sinus floor augmentation with a lateral approach is the most widely used method to augment the alveolar bone height of the posterior part of the maxilla. The dental or the oral and maxillofacial surgeon’s anatomic knowledge and technique to access the maxillary sinus makes this procedure a relatively easier operative procedure. Also, to overcome the challenge of posterior maxilla pneumatization and bone height insufficiency in most cases, this technique is recommended by most surgeons to ensure dental implant success. Maxillary sinus floor elevation is described in the literature as a predictable surgical procedure to increase bone height and allow dental implant placement. A wide variety of graft materials had been used to augment the maxillary sinus. However, autogenous bone has been considered the gold standard for years, primarily due to its osteogenic potential.

Nevertheless, the use of autogenous bone grafts presents a risk of donor site morbidity and possible unpredicted graft resorption. Various graft materials have been used for sinus augmentation, including autografts, allografts, and synthetic bone grafts. Autogenous bone presented many limitations due to the larger amounts needed to graft a medium-size sinus accurately. Also, it is limited by donor site morbidity and uncontrolled resorption. Deproteinized bovine bone has been successfully used as a grafting material in the maxillary sinus. Due to different modalities for sinus grafting, lateral or crestal approach, hydraulic pressure, simultaneous implant placement or staged approach, and the variety of filing materials, the sinus elevation procedure remains an exciting area of research.

When Is Maxillary Sinus Lift Surgery Contraindicated?

• General contraindication to implant surgery.

• Immunosuppressed or immunocompromised.

• Previous history of irradiation of the head and neck area less than one year before surgery.

• Diabetes.

• Heavy smoker (more than 10 Cigarettes/day).

• Treated or under treatment with oral and intravenous amino-bisphosphonates.

• Substance abuse.

• Psychiatric disorder.

• Absence of sinus cyst and Active sinusitis.

• Lack of occluding dentition or prosthesis in the area intended for implant placement.

• Untreated periodontitis.

• Bruxism or clenching.

• Poor oral hygiene (full-mouth bleeding on probing and full-mouth plaque index greater than 25%).

• Refusal to sign the informed consent

What Is the Preoperative Prophylaxis and Preparation for Surgery (Lateral Window Approach)?

1. Patients usually undergo professional oral hygiene measures like deep dental cleaning or scaling and elimination of unwanted tooth defects like attrition, abrasion, erosion, replacement of other missing teeth, restorations, or fillings before the surgery (thus eliminating other sources of dental discomfiture).

2. A single dose of antibiotics (two grams of Amoxicillin and Clavulanic acid or Clindamycin 600 mg if allergic to penicillin) is administered prophylactically 1 hour before surgery.

3. Chlorhexidine rinses 0.2% is administered for 1 minute before the surgery.

4. Local Anaesthesia is induced using Articaine with Adrenaline (1:100,000).

5. A mucoperiosteal buccal flap is elevated, exposing the lateral bony wall of the sinus antrum.

6. A round diamond bur with a two millimeter diameter is usually preferred by surgeons, which is used to outline the lateral window.

7. The lateral window is removed, thus wholly exposing the underlying sinus membrane.

8. A tension-free reflection flap exposing the sinus wall needs to be achieved, and the membrane should be gently separated from the bone.

9. The membrane is then pushed away using a large flat curette.

10. 1 g of Amoxicillin or 300 mg of Clindamycin is administered every 12 hours for one week after surgery, and a dose of 80 mg of Ketoprofen two to three times daily is prescribed as needed. A 4 mg daily dose of Dexamethasone is also administered for two days to minimize edema.

11. Patients are instructed to take gastric protection and rinse with 0.2 % Chlorhexidine for two weeks and stay on a soft diet regimen for ten days.

12. Sutures are removed after two weeks.

13. CBCT scans are obtained seven months later to visualize graft material stability, the sinus membrane’s average thickness, and evaluate the regenerated tissue.

Preparation of Recipient Bed and Implantation:

1. A mucoperiosteal flap is elevated.

2. The implant drills are used to prepare the recipient bed according to the manufacturer’s instructions.

3. Patients are again instructed to rinse with 0.2 % Chlorhexidine for two weeks and stay on a soft diet for ten days.

4. Sutures are usually removed after two weeks (depending on the patient’s healing potential linked to the systemic conditions).

5. After three months of undisturbed healing, implants receive temporary screw-retained crowns.

6. Intra ideal radiographs of the study implants are taken at definitive loading after two and five years.

7. Patients are enrolled in an oral hygiene program with monitoring every three months for the first year of function and then every six months up to the fifth year.

When Is an Implant Considered a Failure?

An implant is considered a failure if there is:

• Any mobility, assessed by tapping or rocking the implant head with the metallic handles of two instruments.

• Any signs of radiolucency.

• Any biological or mechanical complication that renders the implant unusable, although still mechanically stable in the bone.

• A crown or a prosthetic abutment that needs to be replaced.

• Any prosthetic (e.g., provisional or definitive crown fracture, abutment mobility or fracture), biological (e.g., wound or implant infection, mucositis, abscesses or peri-implantitis), and surgical complications (e.g., Sinus membrane perforation, empyema, or sinus abscess) were recorded.

• Peri-implant mucosal response, probing pocket depth (PPD), and bleeding on probing (BOP) were measured using a periodontal probe at definitive loading and two and five years after definitive loading.

Post-operative review by the dental surgeons helps ensure the loaded implant’s continued success as a non-surgical treatment to counteract peri-implant mucositis or peri-implantitis.

Conclusion:

To conclude, in the posterior maxilla where the bone is less dense and softer compared to the mandibular region, the technique of maxillofacial surgery wherein the maxillary sinus augmentation or sinus lift surgery is done, usually through the lateral window approach (commonly used approach) for gaining adequate bone height for dental implantation with good success rates.