Maxillary Sinusitis as a Complication of Zygomatic Implants Placement: A Narrative Review

Aims: The aim of this review is to consider maxillary sinusitis as a complication of zygomatic implants placements. Maxillary sinusitis a common complication but in the literature there are no reviews that focus only on this condition and its possible treatment. This review was carried out with to highlight the main findings of the literature on this topic and to improve knowledge in this field. Methods: The search strategy resulted in 155 papers. After selection of the inclusion criteria only 11 papers were examined. From the papers these, 12.3% patients presented maxillary sinusitis but only four studies evaluated sinusitis (both clinical and radiological evaluation). The most common treatment used by the authors were antibiotics alone or combined with functional endoscopic sinus surgery (FESS). Results: The literature shows an absence of precise and shared guidelines diagnosis and post-operative follow-up, and of the treatment of maxillary sinusitis following zygomatic implantology. It has not been determined if the surgical placement of ZIs is better than the other techniques for treatment of the onset of maxillary sinusitis in the post-operative period. Conclusion: To date there are no shared protocols for maxillary sinusitis treatment. In our experience, and according to the literature in the presence of risk factors such as age, comorbidities, smoking, nasal septal deviation or other anatomical variants, we suggested that FESS is performed at the same time as placement of zygomatic implants.

Retrospective Analysis of Clinical and Radiologic Data Regarding Zygomatic Implant Rehabilitation with a Long-Term Follow-Up

Background: Zygomatic implants have been introduced to rehabilitate edentulous patients with severely atrophic maxillae. Their use has been reported by several studies, describing high overall survival rates at medium–long follow-up. The aim of this study was to retrospectively analyze if a few patient-related and implant-related features are correlated with implant success or the onset of complications. Materials and methods: Data of patients treated with zygomatic implants between May 2005 and November 2012 at three private clinics were collected and retrospectively analyzed. For each implant, the following data were collected: implant length, insertion path, ridge atrophy and sinus characteristics (width, pneumatization, thickness of mucosae, patency of sinus ostium). General patient characteristics and health status data were also recorded. The outcomes evaluated were implant failure, infective complications, early neurologic complications and overall complications. Results: A total of 33 patients (14 men, 17 women, mean age 59.1) that received 67 zygomatic implants were included in the study. The mean duration of the follow-up was of 141.6 months (min 109; max 198). In this period, a total of 16 (23.88%) implants in 8 (24.24%) patients were removed and 17 (51.51%) patients with 36 (53.73%) implants reported complications. Immediate loading resulted in a significantly lower risk of complications compared with the two-stage prosthetic rehabilitation (OR: 0.04, p = 0.002). A thickness of the sinus mucosa > 3 mm emerged to be correlated with a greater occurrence of infective complications (OR: 3.39, p = 0.019). Severe and extreme pneumatization of the sinus was significantly correlated with the incidence of overall complications (p = 0.037) and implant failure (p = 0.044). A large sinus width was predisposed to a higher risk of neurologic complications, infective complications and implant failure (p = 0.036, p = 0.032, p = 0.04, respectively). Conclusions: zygomatic implants are an alternative procedure for atrophic ridge rehabilitation when a conventional implant placement is not possible. Several clinical and anatomical factors can have a significant role in complication occurrence.

Rehabilitation of Maxillary Defect Using Zygomatic Implant Retained Obturator

Tumors involving the hard palate, maxillary sinus, or nasal cavity require maxillectomy based on the extent of the lesion. Lack of these boundaries affects the speech, esthetics, and masticatory function. Prosthetic rehabilitation of these defects can be done utilizing zygomatic implants. This present case describes the use of a zygomatic implant to retain a maxillary obturator in a 22-year-old male patient following partial maxillectomy (Brown’s Class 2b) due to odontogenic myxoma. A surgical obturator was secured in position subsequent to the implant placement. Following the healing period, an interim obturator using heat cure acrylic was fabricated. Mechanical retention for the definitive obturator was obtained through the ball attachment suspended from the multiunit abutment of the zygomatic implant. The case was followed up closely for a year to evaluate the function of the prosthesis. The prosthetic rehabilitation not only promoted esthetics and function but also improved the patient’s quality of life.

Zygomatic Implants Placed in Immediate Function through Extra-Maxillary Surgical Technique and 45 to 60 Degrees Angulated Abutments for Full-Arch Rehabilitation of Extremely Atrophic Maxillae: Short-Term Outcome of a Retrospective Cohort

The use of new devices for the rehabilitation of the severely atrophic maxillae needs validation. We aimed to report the short-term outcome of severely atrophic jaws rehabilitated with zygomatic implants with no implant head angulation placed extramaxillary in conjunction with standard implants. Forty-four patients were consecutively included with 77 zygomatic implants (31 abutments of 45 degrees and 46 abutments of 60 degrees) and 115 standard implants. Outcome measures were prosthetic survival, implant/abutment success, complications, modified plaque index (mPLI), modified bleeding index (mBI), mucosal seal efficacy evaluation (MSEE) >4 mm, and Zygomatic implants classification level (ZICL). Two patients (4.5%) were lost to follow-up. No prosthesis was lost; one patient lost one zygomatic implant; two angulated abutments of 60 degrees needed to be replaced in one patient due to an aesthetic complaint; rendering a cumulative success rate at 2-years of 95.3% and 95.9% using patient and implant/abutment as unit of analysis, respectively. Mechanical and biological complications occurred in 13 and six patients, respectively; all resolved. The median mPLI and mBI was 1; MSEE > 4 mm occurred in 17% and 21% of patients at 1- and 2-years, respectively; ZICL1 was registered in 80% of patients. The current protocol enabled good short-term outcomes.

Biomechanical Stress in Obturator Prostheses: A Systematic Review of Finite Element Studies

Aim. This systematic review is aimed at investigating the biomechanical stress that develops in the maxillofacial prostheses (MFP) and supporting structures and methods to optimize it. Design and Methods. A literature survey was conducted for full-text English articles which used FEA to examine the stress developed in conventional and implant-assisted MFPs from January 2010 to December 2020. Results. 87 articles were screened to get an update on the desired information. 74 were excluded based on a complete screening, and finally, 13 articles were recruited for complete reviewing. Discussion. The MFP is subjected to stress, which is reflected in the form of compressive and tensile strengths. The stress is mainly concentrated the resection line and around the apices of roots of teeth next to the defect. Diversity of designs and techniques were introduced to optimize the stress distribution, such as modification of the clasp design, using materials with different mechanical properties for dentures base and retainer, use of dental (DI) and/or zygomatic implants (ZI), and free flap reconstruction before prosthetic rehabilitation. Conclusion. Using ZI in the defective side of the dentulous maxillary defect and defective and nondefective side of the edentulous maxillary defect was found more advantageous, in terms of compression and tensile stress and retention, when compared with DI and free flap reconstruction.

Dynamic navigation and technical improvements in zygomatic surgery

The rehabilitation of the severely atrophied edentulous maxilla poses a great challenge to surgeons and prosthodontics that work on this particular area. The classic approach implies bone augmentation techniques by means of bone grafting, bone distraction techniques, tilted and short implants. All of these require major surgery, sometimes associated with morbidity at donor and receptor sites and functional rehabilitation of the patient must occur in two surgical stages. Since the development of the zygomatic implants by Per-Ingvar Branemark, there’s an alternative to bone grafting techniques, using the body of the zygomatic bone as major point of anchorage to an intraoral osteointegrated implant. This procedure allows the patient to regain orofacial function in only one surgical stage, with high predictability, less morbidity, time spend and costs. In this scientific article the authors present a set of technical improvements in the zygomatic implant (S.I.N. - Implant System, São Paulo, Brazil) in combination with a new dynamic navigation system called StealthStation™ (Medtronic, Dublin, Irland) used for the first time in this type of surgery.

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.