Zygomatic implant-guided rehabilitation based on inverted support technique: a pilot study

OBJECTIVE: Zygomatic implant insertion surgery is a challenging operation. The primary aim of this pilot study was to assess the accuracy of EZgoma® “Inverted Support Technique” for the zygomatic implant-guided surgery. Secondly, any factors which may affect the surgical protocol results, such as implant-prosthetic virtual plan, surgical model matching, intra or post-operative complications, time rate between surgical procedure and prosthetic loading, zygomatic implant survival rate and implant success rate were analyzed. PATIENTS AND METHODS: A total of 20 zygomatic implants were placed in atrophic maxillae of 5 patients. The final position of zygomatic implants after surgery was compared with the pre-operative digitally planned position. The analyzed parameters were zygomatic implants apex and base mean linear distance and zygomatic implants axis mean angular deviation. RESULTS: The comparison was provided by a tridimensional imaging elaboration platform, provided by Geomagic, which allows the overlay of virtual plan STL data with post-operative control CT scan DICOM data. As a result, all the mean values regarding the 20 placed zygomatic implants respected the universally agreed values in guided zygomatic implant surgery: the mean linear distance of the implant platform and of the implant apex were 1.59 mm and 1.62 mm respectively, while the mean angular deviation of the implant axis was equal to 1.74°. One of the patients had mucositis as a post-operative complication. In one patient the anterior wall of the maxillary sinus fractured, and in one zygomatic implant primary stabilization was not achieved. No other complications occurred. CONCLUSIONS: As a conclusion, data obtained from this study suggested that guided zygomatic implant rehabilitation may represent a reliable, efficient, rapid, ergonomic, and safe surgical protocol, however further investigations are needed.