In-house protocol for fully guided zygomatic implant surgery and prosthesis repositioning. A technical note

AIM: The present study aims to describe an in-house protocol for fully guided zygomatic implant surgery and prosthesis repositioning. MATERIALS AND METHODS: Four extramaxillary zygomatic dental implants (ZIs) were placed in one patient. The preoperative phase included digital planning, through which a surgical guide was designed and created. The analysis of the accuracy of guided surgery and the guided prosthesis repositioning was carried out by superimposing the digital planning with the final postsurgical implant positioning through CBCT. The radiologic evaluation included implant angular deviation, entrance and exit deviation, platform deviation, and apex apicocoronal and mesiodistal deviation. The prosthetic evaluation was performed in three directions: buccopalatal, apicocoronal, and mesiodistal. RESULTS: All the ZIs successfully osseointegrated after 3 months of healing, with no complications. The mean axial angular implant deviation was 0.52 ± 0.36 degrees, and the mean implant depth deviation was 0.47 ± 0.28 mm. The entrance and exit deviation of the implants was 0.74 ± 0.42 mm and 0.7 ± 0.43 mm, respectively. The virtual prosthesis was superimposed and compared with the standard tessellation language file of the provisional polymethyl methacrylate prosthesis at the level of the first molars and central incisors; the mean buccopalatal deviation was 0.6 ± 0.035 mm, the mean apicocoronal deviation was 0.65 ± 0.11 mm, and the mean mesiodistal deviation was 0.3 ± 0.07 mm. CONCLUSIONS: According to the results obtained in this first case of the present case series, careful and meticulous digital planning based on the correct prosthetic parameters can safely guide the performance of surgery.

Vascular Delay Soft Tissue Technique in Oral/Maxillary Bone Reconstructive Surgery: A Technical Note.

PURPOSE: The present study describes a new presurgical soft tissue technique in oral/maxillary bone reconstructive surgery for reducing the risk of soft tissue dehiscence and its related complications. MATERIALS AND METHODS: Ten consecutive patients with Cawood and Howell type V atrophy were scheduled for CAD/CAM titanium mesh bone reconstructive surgery after applying the vascular delay technique 21 days before regenerative surgery. The surgical and healing complications were clinically assessed at nine time points, ranging from the time of bone regenerative surgery to 9 months after surgery. Surgical complications included flap damage and neurologic and vascular complications. Healing complications were subdivided into four classes. These classes comprised Class I: small membrane exposure (≤ 3 mm) without purulent exudate; Class II: large membrane exposure (> 3 mm) without purulent exudate; Class III: membrane exposure with purulent exudate; and Class IV: abscess formation without membrane. RESULTS: The study sample included seven men and three women (mean age: 48.2 ± 3.5 years) with seven mandibular cases and three maxillary cases. The defect length ranged from three to six teeth, with a mean mesiodistal distance of 29.9 ± 8.5 mm and a mean volume augmentation of 2.03 ± 0.9 cm3. There were no surgical complications. One patient presented a Class I healing complication that did not affect the regeneration outcome. CONCLUSIONS: The vascular delay technique appears to reduce the risk of soft tissue dehiscence and exposure in bone regenerative surgery, though randomized studies involving larger samples and longer follow-up periods are needed in order to draw firm conclusions.

Three-Dimensional Evaluation of the Accuracy of Zygomatic Implant Placement Through an In-House Fully Guided Approach.

Purpose: To validate guided surgery for zygomatic implants (ZIs) by analyzing the final position of the implants relative to the preoperatively planned position. Material and Methods: Five patients with fully edentulous atrophic maxillae treated with four ZIs through a fully guided implant surgical approach were evaluated. The preoperative phase included digital planning, through which the surgical guide was designed and created. Analysis of the guided surgery accuracy was carried out by superimposing the digital planning over the final position of the implants using preoperative and postoperative CBCT. The radiologic evaluation included implant angular deviation, entrance deviation, exit deviation, platform deviation, and apex apicocoronal and mesiodistal deviation. Results: All five patients (two men and three women; mean age: 61.8 ± 3 years) were each treated with four ZIs using a fully guided approach with an extrasinusal path, obtaining ideal emergence of the implants. Superimposition comparison found a mean axial angular implant deviation of 0.79 ± 0.41 degrees and a mean implant entrance deviation of 0.95 ± 0.26 degrees. The platform deviation was 0.62 ± 0.19 mm buccopalatally and 0.76 ± 0.14 mm mesiodistally, while the apical deviation was 0.42 ± 0.13 mm buccopalatally and 1.06 ± 0.37 mm mesiodistally. Conclusions: Guided surgery in zygomatic implants appears to be sufficiently accurate to make it a safe and predictable technique.

Extramaxillary Zygomatic Implant Coverage with a Pedicled Buccal Fat Pad Flap Through a Tunnel Approach: A Prospective Case Series.

PURPOSE: To describe the benefits of covering the extrasinusal length of extramaxillary zygomatic implants with a pedicled buccal fat pad flap through a tunnel approach. MATERIALS AND METHODS: Four extramaxillary zygomatic implants were placed in 10 patients and loaded immediately with an acrylic provisional fixed prosthesis. The extrasinusal length of every implant was covered with a pedicled buccal fat pad flap. Study variables were implant survival rate, peri-implant soft tissue recession (PISTR), peri-implant soft tissue condition (PISTC), modified Bleeding Index (mBI), and suppuration. The statistical analysis comprised the Brunner-Langer model of longitudinal data for each variable and the analysis of variance to assess main effects and interactions. RESULTS: All the zygomatic implants showed osseointegration, resulting in a survival rate of 100%. The PISTR was evaluated after surgery (T0) and after 12 months (T1), statistically significant differences being observed (P = .014). Recession also depended on specific implant positioning; zygomatic implants in the anterior were found to have a higher risk of recession vs implants in the posterior (P = .065). The PISTC was assessed at T0 and T1, and no statistically significant changes were observed (P = .718). Bleeding on probing was present in 10% of the implants at T0 and in 15% at T1, the difference being nonsignificant (P = .317). CONCLUSION: The use of a pedicled buccal fat pad flap to cover the extrasinusal length of extramaxillary zygomatic implants appears to reduce the risk of soft tissue recession and exposure of the implant surface to the oral cavity.