Introduction

Insufficient bone height for dental implant placement is often encountered in the posterior maxilla. Its main causes are postextraction alveolar ridge resorption and increased maxillary sinus size due to the prolonged absence of teeth.1,2 

Different procedures to increase the bone volume available for implant placement have been described. Among them, sinus elevation using a lateral window is well documented and predictable.35  Despite the procedure's generally high success rate, intraoperative complications may occur. A frequently encountered problem is tearing of the Schneiderian membrane, which can often be resolved, enabling successful treatment completion, with the placement of an internal resorbable membrane.69  When this is not possible, surgical closure and later re-attempting of the procedure may be advisable. Surgical flap closure without a membrane may result in insufficient bony repair of the lateral wall. The use of barrier membranes for guided bone regeneration may achieve bony repair of the defect.10 

This report describes a case in which d-polytetrafluoroethylene (dPTFE) membrane use resulted in complete repair of the buccal wall and Schneiderian membrane.

Case

A 61-year-old nonsmoking woman in good general health with no medication use presented in April 2014 with the main complaint of insufficient retention of her complete maxillary denture. Her maxilla had been edentulous for approximately 20 years. Evaluation revealed a severely atrophied maxillary ridge (Figure 1) and severe periodontitis in the mandible (probing pocket depth, 5–6 mm). After discussion of treatment options, the patient opted for a complete implant-supported maxillary denture. An orthopantomograph (Orthophos 5, Sirona Dental Systems GmbH, Bensheim, Germany) revealed insufficient bone height (∼10 mm) for implant placement near the bilateral maxillary sinuses, necessitating sinus elevation. After discussion of the risks and benefits of this treatment and acquisition of consent, the patient was scheduled for treatment. The mandibular teeth were treated with scaling and root planing.

Figures 1–7

Figure 1. Orthopantomograph section. Sinus before surgery. Figure 2. Opened lateral window. Figure 3. Axial cone-beam computerized tomography section of the sinus after membrane tear. Figure 4. Volumetric 3D representation of hard tissue after membrane tear. Figure 5. Lateral window coverage with a d-polytetrafluoroethylene membrane. Figure 6. Volumetric 3D representation of hard tissue at re-entry. Figure 7. Transverse con-beam computerized tomography view of the sinus at re-entry.

Figures 1–7

Figure 1. Orthopantomograph section. Sinus before surgery. Figure 2. Opened lateral window. Figure 3. Axial cone-beam computerized tomography section of the sinus after membrane tear. Figure 4. Volumetric 3D representation of hard tissue after membrane tear. Figure 5. Lateral window coverage with a d-polytetrafluoroethylene membrane. Figure 6. Volumetric 3D representation of hard tissue at re-entry. Figure 7. Transverse con-beam computerized tomography view of the sinus at re-entry.

Starting 1 day preoperatively, the patient took an analgesic 100 mg once daily for 4 days (diclofenac, GlaxoSmithKline, Munich, Germany) and a systemic antibiotic 600 mg once daily for 6 days (clindamycin, Ratiopharm, Ulm/Donautal, Germany) and was instructed to rinse twice daily with 0.1% chlorhexidine digluconate solution (Chlorhexamed, GlaxoSmithKline, Buehl, Germany). Local anesthesia was achieved with a 4% articaine HCl injection containing 1:100 000 epinephrine, two carpules (Ultracain D-S forte, Sanofi-Aventis, Frankfurt am Main, Germany).

A midcrestal incision and 14-mm–long medial and distal fascial releasing incisions were made in the edentulous area of teeth #3–5. A full-thickness flap was elevated and the lateral window was created using a diamond bur (no. 801, Hager & Meisinger, Neuss, Germany) on a straight handpiece (S11, 1:1, W&H, Buermoos, Austria; Figure 2). A large, nonrepairable membrane tear occurred during elevation, and approximately 70% of the planned Schneiderian membrane procedure was performed. We did not attempt to repair or cover this large defect with a resorbable collagen membrane. Cone-beam computerized tomography (CBCT, Pax Duo 3D; VATECH Global, Gyeonggi-do, Korea) was used to evaluate the bone damage (Figures 3 and 4). The patient was informed of the situation and gave consent to abort the procedure and re-attempt the planned treatment later. The lateral window was covered with a dPTFE membrane (Cytoplast TXT-200, Osteogenics, Lubbock, Tex), without the use of fixation pins (Figure 5). Tension-free flap closure was achieved and interrupted sutures (4-0 Ethibond Excel, Johnson & Johnson Int, Neuss, Germany) were placed.

Ten months postoperatively, CBCT demonstrated complete bony closure of the lateral window (Figures 6 and 7). Using the same surgical approach, the dPTFE membrane was removed (Figure 8). The clinical situation confirmed the CBCT findings (Figure 9). A new lateral window was created and a new formed Schneiderian membrane was found and elevated successfully (Figure 10). The sinus was grafted using a bovine xenograph (BioOss spongiosa, 0.25–1 mm, Geistlich Biomaterials, Wolhusen, Switzerland; Figure 11) and the lateral window was covered with a resorbable membrane (Bio-Gide, Geistlich Biomaterials; Figure 12). After releasing the flap, tension-free closure was obtained and sutures were placed (4-0 Ethibond Excel, Johnson & Johnson Int). Implants were placed 6 months later (Figure 13).

Figures 8–13

Figure 8. Re-entry, removal of the d-polytetrafluoroethylene membrane. Figure 9. Re-entry, clinical situation. Figure 10. Lateral window creation, new Schneiderian membrane. Figure 11. Sinus augmentation using a xenograph. Figure 12. Window closure with a collagen membrane. Figure 13. Orthopantomograph section. Implant placement 6 months after sinus augmentation.

Figures 8–13

Figure 8. Re-entry, removal of the d-polytetrafluoroethylene membrane. Figure 9. Re-entry, clinical situation. Figure 10. Lateral window creation, new Schneiderian membrane. Figure 11. Sinus augmentation using a xenograph. Figure 12. Window closure with a collagen membrane. Figure 13. Orthopantomograph section. Implant placement 6 months after sinus augmentation.

Discussion

Tearing of the Schneiderian membrane, a common complication of sinus elevation, is addressed mainly with the use of resorbable membranes. This approach eliminates the need for a second procedure to remove the membrane11,12  but is not necessary when a re-attempt of sinus elevation is planned, as the membrane can be removed during this procedure.

In the presented case, dPTFE membrane use achieved complete repair of the bone defect and Schneiderian membrane, enabling successful treatment completion upon re-entry. In general, the use of nonresorbable materials for socket preservation has been linked to a higher incidence of membrane exposure. Healing was uneventful in the present case, likely due to the achievement of sufficient tension-free flap closure. This case letter is meant to describe a technique to repair a defect of the lateral sinus wall after a failed attempt of sinus augmentation. Therefore, no follow up on the long-term success of the sinus augmentation procedure itself is given.

Further studies are needed to confirm the ability of this approach to achieve bone defect and Schneiderian membrane repair, in comparison with the use of resorbable membranes.

Abbreviations

    Abbreviations
     
  • CBCT

    cone-beam computerized tomography

  •  
  • dPTFE

    d-polytetrafluoroethylene

Note

The authors report no conflicts of interest.

References

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