Accuracy of digital planning in zygomatic implants

Background Zygomatic implants have been described as a therapeutic alternative for patients with severe maxillary atrophy in order to avoid bone augmentation procedures. Taking that into account, in these treatments, the key factor is the position of the implant, the virtual surgical planning (VSP) is widespread among most clinicians before surgery on the patient. However, there are no studies which evaluate the clinical relevance of these VSP. The aim of this study is to determine whether digital planning on zygomatic implants has any influence on the implant dimensions and position, even when performing conventional surgery afterwards. Results Fourteen zygomatic implants were placed in four patients. Pre-operative and post-operative helicoidal computed tomography were performed to each patient to allow the comparison between the digital planning and the final position of implants. Tridimensional deviation (TD), mesio-distal deviation (MDD), bucco-palatine deviation (BPD), and apico-coronal deviation (ACD) were evaluated as well as angular deviation (AD). Significative differences in apical TD were observed with a mean of 6.114 ± 4.28 mm (p < 0.05). Regarding implant position, only implants placed in the area of the first right molar reported significant differences (p < 0.05) for ACD. Also, implant length larger than 45 mm showed BPD significative differences (p < 0.05). Conclusions Zygomatic implant surgery is a complex surgical procedure, and although VSP is a useful tool which helps the clinician determine the number and the length of zygomatic implants as well as its proper position, surgical experience is still mandatory.

Dynamic Navigation for Zygomatic Implants: A Case Report about a Protocol with Intraoral Anchored Reference Tool and an Up-To-Date Review of the Available Protocols

Dynamic Navigation is a computer-aided technology that allows the surgeon to track the grip instruments while preparing the implant site in real time based on radiological anatomy and accurate pre-operative planning. The support of this technology to the zygoma implant placement aims to reduce the risks and the errors associated with this complex surgical and prosthetic treatment. Various navigation systems are available to clinicians currently, distinguished by handling, reliability, and the associated economic and biological benefits and disadvantages. The present paper reports on the different protocols of dynamic navigations following a standard workflow in correlation with zygomatic implant supported rehabilitations and describes a case of maxillary atrophy successfully resolved with this technology. An innovative and minimally invasive dynamic navigation system, with the use of an intraoral anchored trust marker plate and a patient reference tool, has been adopted to support the accurate insertion of four zygomatic implants, which rapidly resolved maxillary atrophy from a 75-year-old male system. This approach provided an optimal implant placement accuracy reducing surgical invasiveness.

Computer-Aided Rehabilitation Supported by Zygomatic Implants: A Cohort Study Comparing Atrophic with Oncologic Patients after Five Years of Follow-Up

The aim of this study was to evaluate the survival and clinical success rate, complications, and patients’ quality of life after computer-aided rehabilitation supported by zygomatic implants in cases of severe maxillary atrophy (ten patients) and in bone defects in oncologic patients (ten patients). All patients underwent computer-aided planning and surgery. Seventy-three zygomatic implants were placed. The mean follow-up period was 39.9 months. Implant survival and clinical success rate, the effectiveness of planning the implant length, biological and prosthetic complications, and the quality of life were evaluated. The five-year implant survival rate for patients with maxillary atrophy and oncologic patients was 97.4% and 96.7%, respectively. The prosthetic survival rate was 100%. Two implant failures occurred in the first year. One implant failure was observed in each group. Minor biological and prosthetic complications occurred in both groups without significant differences. All complications were managed without affecting the treatment. The quality of life increased by 71.3% in the atrophic group and by 82.9% in the oncologic group. Zygomatic implant rehabilitation seems to be a reliable technique for patients with maxillary atrophy and for oncologic patients. The three-dimensional computer-aided approach allows the surgeon to plan the surgery and increase its predictability. Early prosthesis loading certainly allows for better functional outcomes.

Immediate function with four zygomatic implants in patients with extreme maxillary atrophy - Case series

Purpose: Zygomatic implants have been in use since the 1990’s for the treatment of patients with severely resorbed maxillae. Eliminating grafting combined with immediate function increases patient acceptance. The purpose of this study was to evaluate a protocol for immediate function with fixed prostheses for patients with extreme maxillary atrophy, treated with four zygomatic implants (S.I.N.-Implant System, São Paulo, Brazil). Case report: This retrospective clinical study included 10 patients with 40 immediately loaded zygomatic implants with fixed provisional acrylic prosthesis attached 5 to 6 hours after surgery. The patients’ follow-up was from 12 to 60 months. Two zygomatic implants failed (implant survival rate 95%). There were no complications such as sinusitis, hygiene maintenance or speech impairment. The results support the hypothesis that immediate function with four zygomatic implants is a viable concept. The clinical success for these patients was enhanced by the shorter time span of the treatment process and the immediate rehabilitation in a comfortable manner as compared to grafting based procedures. Conclusion: The high survival rate, the increase of patients demand in immediate functional ability and the less morbidity following the surgical procedure renders this immediate function zygomatic procedure a viable treatment option of the resorbed fully edentulous maxillae.

Immediate function with four Zygomatic implants in patients with extreme maxillary atrophy – Case Series

Purpose: Zygomatic implants have been in use since the 1990’s for the treatment of patients with severely resorbed maxillae. Eliminating grafting combined with immediate function increases patient acceptance. The purpose of this study was to evaluate a protocol for immediate function with fixed prostheses for patients with extreme maxillary atrophy, treated with four zygomatic implants (S.I.N.-Implant System, São Paulo, Brazil). Case series:This retrospective clinical study included 10 patients with 40 immediately loaded zygomatic implants with fixed provisional acrylic prosthesis attached 5 to 6 hours after surgery.The patients’ follow-up was from 12 to 60 months. Two zygomatic implantsfailed (implant survival rate 95%). There were no complications such as sinusitis,hygiene maintenance or speech impairment.The results support the hypothesis that immediate function with four zygomatic implants is a viable concept. The clinical success for these patients was enhanced by the shorter time span of the treatment process and the immediate rehabilitation in a comfortable manner as compared to grafting based procedures. Conclusions: The high survival rate, the increase of patients’ demand in immediate functional ability and the less morbidity following the surgical procedure renders this immediate function zygomatic procedure a viable treatment option of the resorbed fully edentulous maxillae.

Virtual Implant Rehabilitation Of The Severely Atrophic Maxilla: A Radiological Study

Background: Advanced maxillary atrophy is often observed and implant placement could become difficult. Nevertheless, a volumetric evaluation using a proper diagnostic software could facilitate the implant planning. The purpose of the present study is to suggest the potential application of the maxillary retro-canine area as the designated place for virtual tilted implants also in severely atrophic maxillae. Methods: A sample of CBCT images from the Department of Dentistry (IRCCS San Raffaele, Milan) was evaluated. After a 3D anatomical evaluation of the maxilla tilted implants has been virtually positioned in the retro-canine regions. All the implants were inserted with the same procedure at 30° and 45° degrees of tilting. The length, the palatal angulation and the diameter of each implant were identified. Results: 220 tilted implants were placed. An average implant measurement of 13.508 mm of length and 3.42 mm of diameter were calculated. Also, an average buccal-palatal angulation of 6° was identified. After the statistical analysis implant length was found significantly higher at 45° degrees than at 30° degree (<0.0001).Conclusions: A considerable amount of patients show a significant degree of bone atrophy. The implant-supported treatment plan can rely on the three dimensional imaging of the residual bone as a guiding tool to establish the most effective implant position for each specific case. In this study it is founded that an implant could be longer if its mesio-distal angulation is more accentuated. In addition, it is possible to virtually insert tilted implants also in severely atrophic maxilla. This could help clinicians to consider the retro-canine area a viable place to insert longer tilted implant.

Virtual Implant Rehabilitation Of The Severely Atrophic Maxilla: A Radiological Study

Background : Advanced maxillary atrophy is often observed and implant placement could become difficult. Nevertheless, a volumetric evaluation using a proper diagnostic software could facilitate the implant planning. The purpose of the present study is to reveal the existence of a sufficient bone volume in the maxilla also in patients presenting a severely atrophic maxilla. Methods: A sample of CBCT images of 59 patients was evaluated. After a 3D anatomical evaluation, tilted implants has been virtually positioned in the retro-canine regions. All the implants were inserted with the same procedure at 30° and 45° degrees of tilting. The length, the palatal angulation and the diameter of the placed implant were identified. Results: 220 tilted implants were placed. An average implant measurement of 13,508 mm of length and 3,42 mm of diameter were calculated. Also, an average buccal-palatal angulation of 6° was identified. After the statistical analysis implant length was found significantly higher at 45° degrees than at 30° degree (<0.0001). Conclusions: A considerable amount of patients show a significant degree of bone atrophy. The implant-supported treatment plan can rely on the three dimensional imaging of the residual bone as a guiding tool to establish the most effective implant position for each specific case. In this study it is founded that in the majority of the maxillary atrophy the volumetric evaluation of the bone near the lateral wall of the nasal cavity could suggest the presence of an adequate basal bone volume for tilted implants placement.