Zygomatic implant penetration to the central portion of orbit: a case report

Semi-autonomous two-stage dental robotic technique for zygomatic implants: An in vitro study

OBJECTIVE

To assess the feasibility and accuracy of a semi-autonomous two-stage dental robotic technique for zygomatic implants.

METHODS

Twenty-six zygomatic implants were designed and randomly divided into two groups using 10 three-dimensionally printed resin models with severe maxillary atrophy. In one group, the conventional drilling technique was used, in the other group, the drilling process for the alveolar ridge section (first stage) was completed, after which drilling for the zygoma section (second stage) was done. Based on preoperative planning combined with postoperative cone-beam computed tomography (CBCT), coronal, apical, depth, and angle deviations were measured. Zygomatic implant placement technique-related deviations (sinus slot, intrasinus, and extrasinus) were also recorded and analyzed.

RESULTS

The two-stage technical group's coronal, apical, depth, and angle deviations were 0.57 ± 0.19 mm, 1.07 ± 0.48 mm, 0.30 ± 0.38 mm, and 0.91 ± 0.51°, respectively. The accuracy of the two-stage technique was significantly higher than that of the conventional one-stage technique (p < 0.05). The apical deviation in the intrasinus group was 1.12 ± 0.56 mm, which was significantly better than that in the other two groups (p < 0.05). The angle deviation in the sinus slot group was 1.96 ± 0.83°, which was significantly worse than that in the other two groups (p < 0.05).

CONCLUSION

Using the semi-autonomous two-stage dental robotic technique for zygomatic implants is feasible and is more accurate than using the conventional one-stage technique.

CLINICAL SIGNIFICANCE

The two-stage technique enabled the semi-autonomous robot to overcome the mouth-opening restriction for zygomatic implants and improved accuracy.

Autonomous dental robotic surgery for zygomatic implants: A two-stage technique

Zygomatic implants (ZIs) can be a treatment option for patients with severe atrophy in the maxilla, but deviation during ZI placement could lead to serious complications. Surgical guides and dynamic navigation have been used to improve the accuracy of ZI placement, but both techniques are subject to human error. A 2-stage technique is described that enabled an autonomous dental robot to overcome mouth-opening restrictions for ZI placement. The technique enables the complete digitalization of ZI placement, further improving the accuracy of the drilling process.

Maxillary Sinus Osteoma as a Support for Dental Implant Associated to Sinus Augmentation Procedure: A Case Report and Literature Review

Background: Maxillary sinus augmentation is a method extensively used to restore sufficient bone volume in the posterior maxilla to allow for the placement of fixtures. The purpose of the present case report was to describe a rare case of sinus osteoma used for implant support and to review the relevant literature. Materials and Methods: A 58-year-old man with a radiopaque intrasinusal lesion was referred for rehabilitation of the maxilla. The lesion was probably an osteoma and involved the nasal wall of the maxillary sinus. After discussing the options with the patient, he agreed to maintain the lesion and a sinus augmentation with a bone graft. A part of the osteoma was partially removed for histological analysis while avoiding perforation or tearing of the schneiderian membrane. After six months, 6 implants (Bone System Implant, Milano, Italy) were placed in the maxilla, two of which were inserted in the osteoma. Results: The two implants placed in the osteoma were perfectly osseointegrated. The graft material appeared well-integrated with no local signs of inflammation. No postoperative events or symptoms were reported after the surgery stages and at a 6-month follow-up. Regarding the two implants placed in the osteoma: article selection identified 9 case reports, 2 case series, and 1 retrospective study for a total of 58 subjects, 35 males and 25 females. The patients’ ages were heterogeneous and ranged between 12 and 79 years old. Conclusions: In the present case, we decided to leave the osteoma because it was asymptomatic and used as dental implant support. The effectiveness of the present investigation can provide useful guidance for surgeons and dentists in the management of similar clinical situations.

Mechanical Behaviour and Primary Stability of a Self-Condensing Implant: A Laboratory Critical Simulation of a Severe Maxillary Atrophy on Polyurethane Lamina

Background: Posterior maxillary atrophies could emerge after the loss of teeth, trauma, infections, or lesions that often require regenerative approaches. In these critical conditions, the achievement of implant primary stability represents a clinical challenge in the operative practice. Therefore, a two-stage approach is often preferred with a delay of the rehabilitation time and a consistent increasing of the biological and the operative costs. The aim of this study was to evaluate the mechanical behaviour of a self-condenser implant compared to a standard implant in a critical simulation on different thicknesses and densities of polyurethane lamina. Materials and methods: A total of two implant models were tested: a self-condensing device (test) and a standard implant (control). The study evaluated the insertion torque and the pull-out strength values of the test and control implants inserted in different sizes (1, 2, and 3 mm) and density polyurethane lamina (10, 20, and 30 pcf) for a total of 320 experimental sites. Results: In total, 320 experimental sites were produced in the polyurethane samples. A statistically significant difference of insertion and pull-out torque values between the test and control Implants was found in the different bone densities (p < 0.05). The insertion and pull-out torque values were always higher for the test implants in all experimental conditions. In all bone densities, the insertion torque values were higher than the pull-out torque values. The self-condenser dental implant design evaluated in this in vitro study showed a high level of stability in all experimental conditions. Conclusions: The test implant could represent a useful tool for a one-stage surgical approach in the presence of limited residual native bone as an alternative to a delayed technique.