ITI consensus report on zygomatic implants: indications, evaluation of surgical techniques and long-term treatment outcomes.

OBJECTIVES: The aim of the ITI Consensus Workshop on zygomatic implants was to provide Consensus Statements and Clinical Recommendations for the use of zygomatic implants. MATERIALS AND METHODS: Three systematic reviews and one narrative review were written to address focused questions on (1) the indications for the use of zygomatic implants; (2) the survival rates and complications associated with surgery in zygomatic implant placement; (3) long-term survival rates of zygomatic implants and (4) the biomechanical principles involved when zygoma implants are placed under functional loads. Based on the reviews, three working groups then developed Consensus Statements and Clinical Recommendations. These were discussed in a plenary and finalized in Delphi rounds. RESULTS: A total of 21 Consensus Statements were developed from the systematic reviews. Additionally, the group developed 17 Clinical Recommendations based on the Consensus Statements and the combined expertise of the participants. CONCLUSIONS: Zygomatic implants are mainly indicated in cases with maxillary bone atrophy or deficiency. Long-term mean zygomatic implant survival was 96.2% [95% CI 93.8; 97.7] over a mean follow-up of 75.4 months (6.3 years) with a follow-up range of 36-141.6 months (3-11.8 years). Immediate loading showed a statistically significant increase in survival over delayed loading. Sinusitis presented with a total prevalence of 14.2% [95% CI 8.8; 22.0] over a mean 65.4 months follow-up, representing the most common complication which may lead to zygomatic implant loss. The international experts suggested clinical recommendations regarding planning, surgery, restoration, outcomes, and the patient's perspective.

Long-term treatment outcomes with zygomatic implants: a systematic review and meta-analysis.

PURPOSE: The purpose of this study was to perform a systematic review with meta-analysis on the long-term survival rates of zygomatic implants (ZI). ZI success, prostheses survival and success, sinus pathology and patient reported outcomes were also investigated. METHODS: Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines were followed. Embase and OvidMedline databases were searched alongside the grey literature. The systematic review was recorded in PROSPERO (CRD42022358024). Studies reporting titanium/titanium alloy ZI survival data, ZI-supported prosthesis data, ZIs directly compared to any other implant therapy including grafted sites, a minimum follow-up time of 3 years and a minimum number of 10 patients were included. All study designs were considered if they met the inclusion criteria. Studies not involving ZIs, ZIs not made from titanium/titanium alloy, a follow-up time of < 3 years or < 10 patients, animal studies and in vitro studies were excluded. Long-term follow-up has not been defined in the literature. A minimum of 3 years follow-up was considered acceptable to capture survival after initial healing, alongside in-function prosthesis data via delayed or immediate load protocols. ZI success, was predominantly defined as ZI survival without biological or neurological complications. Meta-analyses were performed for ZI survival, ZI failure incidence, ZI success, loading protocol, prosthesis survival, and prevalence of sinusitis using random effects models. Descriptive analysis was used for ZI success, prosthesis success and patient reported outcome measures. RESULTS: Five hundred and seventy-four titles were identified, of which 18 met the inclusion criteria. Eligible studies included 1349 ZIs in 623 patients. Mean follow-up period was 75.4 months (range 36-141.6). The mean survival of ZIs was 96.2% [95% CI: 93.8; 97.7] at 6 years. Mean survival for delayed loading was 95% [95% CI: 91.7; 97.1] and 98.1% [95% CI: 96.2; 99.0] for immediate loading (p = 0.03). Annual incidence rate of ZI failure was 0.7% [95% CI 0.4; 1.0]. Mean ZI success was 95.7% [95% CI 87.8; 98.6]. Mean prosthesis survival was 94% [95% CI 88.6; 96.9]. Sinusitis prevalence was 14.2% [95% CI 8.8; 22.0] at 5 years. Patients' reported increased satisfaction with ZIs. CONCLUSIONS: ZIs have long-term survival comparable to conventional implants. Immediate loading showed a statistically significant increase in survival over delayed loading. Prosthesis survival was similar to that of prostheses supported by conventional implants, with similar complications. Sinusitis was the most frequently encountered biological complication. Patients reported improved outcome measures with ZI use.

Immediately loaded zygomatic implants: a 5-year prospective study.

PURPOSE: This prospective study was designed to assess the long-term outcome of immediately loaded zygomatic implants placed in atrophic maxillae. MATERIALS AND METHODS: Forty-two consecutively treated patients received 81 zygomatic implants and 140 conventional implants for oral rehabilitation and were followed for 5 years. Complete arch rehabilitation was accomplished in 37 patients and partial arch rehabilitation in 5 (one zygomatic implant in combination with two conventional implants). Outcome measures were prosthetic and implant failures, and complications. RESULTS: Twelve zygomatic and 22 conventional implants in 6 patients were not reviewed as patients were lost to follow-up. One zygomatic implant was removed at the 3-year follow-up visit because of lack of osseointegration and disturbances around the zygomatic region. The success rate of zygomatic implants was 98.5% (68/69). Six conventional implants were lost, with a success rate of 94.9% (112/118). One of the definitive prostheses was changed after 4 years of follow-up. Six complications occurred during the entire follow-up period. CONCLUSIONS: The 5-year prognosis was found to be good for immediately loaded zygomatic implants together with conventional implants in severely resorbed maxillae.

Immediate loading of zygomatic implants using the intraoral welding technique: a 12-month case series.

The aim of this prospective study was to evaluate the concept of intraoral welding as a suitable technique for fabricating a fixed restoration for the edentulous maxilla the day of surgery using standard and zygomatic implants. Ten consecutive patients (four men, six women; mean age, 62.3 ± 11.6 years) were involved in this study, each of whom had an edentulous atrophic maxilla and received two standard and two zygomatic implants. All implants were loaded immediately with a fixed prosthesis supported by an intraorally welded titanium framework. Definitive abutments were connected to the implants, and a titanium bar was welded to them using an intraoral welding unit. This framework was used to support the definitive prosthesis, which was fitted the day of implant placement. Patients were checked for swelling, pain, and framework stability at 1, 3, 6, and 12 months. A total of 20 immediately loaded standard and 20 zygomatic implants were used. The cases included in this study achieved a 100% prosthetic success rate at the 12-month follow-up. No fracture or radiographically detectable alteration of the welded frameworks was noticed. It is possible to successfully rehabilitate the edentulous atrophic maxilla with a permanently fixed prosthesis supported by an intraorally welded titanium framework attached to standard and zygomatic implants the day of surgery.

Early one-stage repair of complete unilateral cleft lip and palate.

BACKGROUND: The purpose of this prospective study was to evaluate craniofacial morphology in children with complete unilateral cleft lip and palate treated at the Brussels cleft center after a 1-stage complete closure at 3 months and compare the results with a series of children operated on at 3 and 6 months of age according to the Malek surgical protocol. METHODS: A series of 72 consecutive patients who were operated on for nonsyndromic complete unilateral cleft lip and palate were included in this study at approximately the age of 10 years. Thirty-four were treated according to the Malek surgical treatment protocol: the soft palate was closed at a mean (SD) age of 3.04 (0.20) months, followed by simultaneous repair of the lip and hard palate at 6.15 (0.67) months. Thirty-eight underwent 1-stage all-in-one (AIO) closure of the lip and hard and soft palates at 2.98 (0.16) months. Craniofacial morphology was evaluated by means of a digital cephalometric analysis. Cephalometric data were compared with a noncleft control group (n = 40) matched according to age. The same 2 series of children were followed up until 15 years of age, and the results were again compared. RESULTS: Statistical analysis (analysis of variance with post hoc Tukey test) showed in both groups who were operated on a decreased anteroposterior growth compared with the children without cleft at 10 years but the AIO group only was not different from the group without cleft. The maxillary (MxPI/SN) plane was significantly (P = 0.002) increased in the Malek cleft group compared with the AIO group with cleft. At 15 years of age, a difference was not observed anymore between the 2 groups for the anteroposterior growth or for the maxillary plane inclination. CONCLUSIONS: One-stage AIO closure based on the Malek surgical principles provided good anteroposterior midfacial morphology and resulted in less opening of the maxillary plane to the anterior cranial base.

Sinus reactions to immediately loaded zygoma implants: a clinical and radiological study.

AIM: There are no published studies regarding sinus reactions to immediately loaded zygomatic implants. The aim of this study was to evaluate the maxillary sinus in a cohort of patients by means of clinical criteria and computerised tomography performed before surgery and after zygomatic implant placement (immediate function protocol). MATERIALS AND METHODS: A total of 36 patients with 71 immediately loaded zygomatic implants were evaluated to find clinical criteria of maxillary sinus disturbance 13 to 42 months (average 21.9 months) after zygoma implant placement. A total of 44 implants had a machined surface and 27 had a porous titanium oxide surface. Twenty-six patients with 52 immediately loaded zygomatic implants were evaluated by means of a CT scan of the paranasal sinuses, 3 to 20 months (average 10.5 months) after zygomatic implant placement. All patients had no sinus symptoms before surgery and had a preoperative CT scan. RESULTS: No clinical signs or symptoms of sinusitis were found. Radiological opacity of the antrum was found in two sinuses (out of 52), and minimal thickening of the Schneiderian membrane was found in 12 patients (out of 26). In eight of them, this was present in the preoperative CT scan. CONCLUSIONS: Sinuses penetrated by zygomatic implants seem to maintain a normal physiology. However, in approximately 15 to 20% of patients, early radiological findings without clinical symptoms were observed.

Clinical outcome of 42 patients treated with 81 immediately loaded zygomatic implants: a 12- to 42-month retrospective study.

AIM: Rehabilitation of the edentulous atrophic maxilla by implants to allow placement of a fixed dental prosthesis remains a challenge, especially if immediate function is provided. The aim of this retrospective study was to evaluate the success rate of immediately loaded zygomatic implants placed in atrophic maxillae. MATERIALS AND METHODS: Forty-two consecutively treated patients (19 men and 23 women), with a mean age of 57 years (range: 34 to 79 years) were followed for at least one year (range: 12 to 42 months, mean: 20.5 months). Thirty-seven patients were totally edentulous and five were partially edentulous. In total, 81 zygomatic and 140 conventional implants were inserted. The success criteria for the zygomatic implants were: (1) confirmed individual implant anchorage to the zygomatic bone by means of anteroposterior cranial radiograph; (2) the implant acting as an anchor for the functional prostheses; (3) no suppuration, pain, or ongoing pathological process at maxillary and zygomatic level; (4) confirmed individual implant stability. All patients had a fixed prosthesis screwed onto implants within 48 hours of implant placement. Descriptive statistics were used to analyse the data. RESULTS: After one year, there was no patient drop-out. None of the zygomatic implants were lost over the observation period (100% success rate). Four conventional implants were lost, resulting in a success rate of 97%. All the prostheses were stable. Oroantral fistula and sinusitis was found in one patient, which was solved with antibiotics and meatotomy, with no further complications. Soft tissue swelling and pain at the zygomatic area were found in another patient after 10 days of surgery. This was solved with antibiotics, with no further complications. CONCLUSIONS: Zygomatic implants together with conventional implants in severely resorbed maxillae appear to be a reliable technique for providing immediate function to patients. The time of treatment can be substantially decreased in a predictable way if zygomatic implants are loaded immediately after placement.

Clinical evaluation of the zygoma implant: 3-year follow-up at 16 clinics.

PURPOSE: The purpose of this clinical investigation was to evaluate the treatment outcome with zygoma implants with regard to implant survival, patient satisfaction, and function of prosthesis replacement after 3 years. PATIENTS AND METHODS: The treatment outcome of 76 patients treated with 145 zygoma fixtures at 16 centers was evaluated with regard to implant survival. Status of peri-implant mucosa and amount of plaque were registered annually. Patients' and dentists' evaluations of the functional and esthetic outcome of the treatment were assessed at delivery of prosthesis and thereafter at each follow-up visit. RESULTS: Sixty of 76 patients were followed for 3 years after prosthetic delivery. Five of 145 placed zygoma implants failed during the course of the study resulting in an overall implant survival rate of 96.3%. At the 3-year follow-up, 75% of the implants sites were registered with normal peri-implant mucosa and 68% with no visible plaque. The patients were fully satisfied with the esthetic and functional outcome of the treatment in 86% and 71%, respectively, at the 3-year follow-up visit. All reported data from dentists scored from acceptable to excellent. CONCLUSION: The multicenter study showed a high predictability of the zygoma implant-supported rehabilitation.

Immediate function in the atrophic maxilla using zygoma implants: a preliminary study.

STATEMENT OF PROBLEM: Oral rehabilitation of the edentulous atrophic maxilla to allow placement of a fixed dental prosthesis remains a challenge, especially if immediate function is provided. PURPOSE: The aim of this retrospective, preliminary study was to evaluate, after a period of a 6 to 29 months' follow-up of prosthetic loading, the survival rate of 36 immediately loaded zygomatic implants placed in 18 atrophied maxillae. MATERIAL AND METHODS: Eighteen consecutive patients (6 men and 12 women), with an average age of 58 years (range of 44-74 years), were followed up to 29 months (average of 14 months). The clinical criteria included stability of the implants and the prosthesis, resonance frequency analysis (RFA), and evaluation of swelling, pain, or discomfort. Radiographic analysis was completed for conventional implants, but not for zygoma implants. All patients had a fixed prosthesis screwed onto implants within 48 hours after implant placement. Descriptive statistics were used to analyze the data. RESULTS: No zygomatic implants were lost over the observation period. Survival rate was 100% over an average 14-month observation period. Three conventional implants were lost, resulting in a survival rate of 95.6%. All the provisional prostheses were stable, and no relevant complications were noted. CONCLUSIONS: The use of zygoma implants, together with conventional implants, in severely resorbed maxilla, appears to be a reliable technique for providing immediate function to patients.

Dentocraniofacial morphology of 21 patients with unilateral cleft lip and palate: a cephalometric study.

OBJECTIVE: To assess the skeletal and dental craniofacial proportions of unilateral cleft lip and palate patients who were operated upon using the Malek technique, and compare them with a normal group to highlight the effect of surgical correction on craniofacial development during growth. DESIGN: Retrospective. METHODS: The cleft palate was closed using the Malek technique in a single operation at 3 months for 11 patients (complete closure of lip and palate) and in a two-stage operation for 10 patients (soft palate at 3 months, lip and hard palate at 6 months). Comparisons were made with a normal control group. Angular and linear measurements of anterior and posterior dimensions of the upper and lower compartments of the face were measured in the 7th and 12th years. RESULTS AND CONCLUSION: No significant differences were observed between the two groups of palate technique repair, although significant differences were observed between craniofacial dimensions of normal versus cleft lip and palate patients. At a skeletal level, the maxilla and mandible were retrusive relative to the cranial base in the cleft lip and palate group. In fact, there was a backward rotation of the palatal plane with repercussions on the maxillo-mandibular complex position. Furthermore, the maxilla was shorter than in normal patients, whereas the mandible was normally shaped. The upper incisors were retroclined and they locked the lower incisors in linguoversion. There was a posterior skeletal deficit of the respiratory compartment, compensated by more marked posterior maxillary alveolar growth. Facial growth in cleft lip and palate patients followed the same pattern, but was delayed compared with normal patients.

Multidisciplinary approach in the treatment of a patient with cleft lip and palate: a case report.

Treatment of the patient with cleft lip and palate represents a real problem from both functional and esthetic points of view. Today a functional result is not enough. An esthetic result is both necessary and possible to improve the quality of life. The direct placement of an implant in the grafted alveolar cleft is not the ideal choice. Using a rational, multidisciplinary approach, it is possible to obtain esthetic results in these patients. In our case study, a 17-year-old patient previously treated for a unilateral cleft lip and palate and agenesis of the right lateral incisor was given an osseointegrated implant. Computer-assisted dental design (Procera CAD/CAM software, Nobel Biocare AB, Gothenburg, Sweden) was used for the prosthetic rehabilitation, and the end of growth was determined prior to placing the implant. No sign of failure or mobility after loading has been detected at the time of this writing, 8 months after the procedure's completion, and the esthetic result is considered satisfactory by the patient and practitioners.

Rehabilitation of a patient with cleft lip and palate with an extremely edentulous atrophied posterior maxilla using zygomatic implants: case report.

OBJECTIVE: This case report describes the clinical and surgical management of a patient with a unilateral alveolar cleft and associated extremely atrophied totally edentulous maxilla. METHOD: Two zygomatic implants and four endosseous oral implants were placed under general anesthesia in a compromised maxilla to rehabilitate a 33-year-old patient with cleft lip and palate. The two specially designed zygomatic implants were utilized to avoid the need for bone grafting in the patient. The final prosthetic rehabilitation was an esthetic and functional maxillary overdenture prosthesis supported by implants. RESULTS: Preliminary results have shown how dental prostheses supported by endosseous implants in grafted alveolar cleft are a reliable possibility in the dental rehabilitation of this malformation. CONCLUSION: The use of zygomatic implants may be considered a reliable alternative to more resource-demanding techniques such as bone grafting in patients with cleft palate.

A clinical evaluation of the Zygoma fixture: one year of follow-up at 16 clinics.

PURPOSE: To evaluate treatment outcome with Zygoma fixtures (Nobel Biocare, Göteborg, Sweden) with regard to fixture survival, patient satisfaction, and function of prosthesis replacement. MATERIALS AND METHODS: The treatment outcome of 76 patients treated with 145 Zygoma fixtures at 16 centers was evaluated. Patient's and dentist's evaluations of the functional and aesthetic outcome of the treatment were assessed at delivery of prosthesis and at the 1-year follow-up visit. At the 1-year follow-up visit, the status of the peri-implant mucosa around the abutments and the amount of plaque were registered. RESULTS: Sixty-six of the 76 patients, with 124 Zygoma fixtures supporting the prosthetic restorations, were evaluated at the 1-year follow-up. The overall survival rate for the Zygoma fixtures was 97.9% after 1-year of follow-up. Eighty percent of the patients were fully satisfied with both aesthetic and functional outcome at the time of prosthetic insertion and at the 1-year follow-up. All reported data from the dentists, with the exception of one restoration with several abutment screw loosenings, scored from acceptable to excellent for the aesthetic and functional outcome of the treatment. The status of peri-implant mucosa was recorded as normal in approximately 60% of the sites. Plaque, when present, was more often detected on the palatal surfaces compared with the buccal surfaces. CONCLUSION: This 1-year follow-up of Zygoma fixtures has shown good results with an acceptable number of minor complications and a majority of satisfied patients.

Mandibular morphology in complete unilateral cleft lip and palate.

OBJECTIVE: The purpose of this study was to evaluate and compare mandibular morphology and spatial position in children with complete unilateral cleft lip and palate (UCLP) treated at two different cleft centers (Hannover and Brussels) following different surgical treatment protocols. PATIENTS: A total of 62 Caucasian children (40 boys, 22 girls) with nonsyndromic complete unilateral cleft lip and palate (UCLP) were evaluated by means of conventional cephalometric analysis at approximately the age of 10 years. Data of both cleft groups were compared with a control, noncleft group (n = 40) matched according to age and sex. INTERVENTIONS: The Hannover children with cleft (n = 36) underwent lip repair at a mean age of 5.83 +/- 1.16 months. The hard and soft palates were closed at a mean age of 29.08 +/- 4.68 and 32.25 +/- 4.29 months, respectively. The Brussels children with cleft (n = 26) were treated according to the Malek surgical protocol with soft palate repair at a mean age of 3.04 +/- 0.20 months and simultaneous lip and hard palate repair at a mean age of 6.15 +/- 0.68 months. RESULTS: Statistical analysis (analysis of variance with post hoc Tukey's test) showed a significant (p =.001) smaller mandibular ramus length (Co-Go) in the Brussels cleft group, compared with the control group. The Hannover-Brussels comparison data revealed that the S-N-B angle was significantly (p =.047) less in the Brussels cleft group. CONCLUSIONS: The influence of surgical procedures in patients with UCLP might not be restricted to the maxilla but could influence mandibular spatial position to the cranial base. Because of these positional changes of the mandible, both cleft groups showed facial balance.

Clinical outcome of 103 consecutive zygomatic implants: a 6-48 months follow-up study.

The purpose of this study was to evaluate retrospectively, after a period of 6-48 months follow-up of prosthetic loading, the survival rate of 103 zygomatic implants inserted in 55 totally edentulous severely resorbed upper jaws. Fifty-five consecutive patients, 41 females and 14 males, with severe maxillary bone resorption were rehabilitated by means of a fixed prosthesis supported by either 1 or 2 zygomatic implants, and 2-6 maxillary implants. This retrospective study calculated the success and survival rates at both the prosthetic and implant levels. Out of 55 prostheses, 52 were screwed on top of the implants, while 3 were modified due to loss of standard additional implants and transformed in semimovable prosthesis. Although osseointegration in the zygomatic region is difficult to evaluate, no zygomatic implant was considered fibrously encapsulated and they are still in function. This study confirms that zygoma bone can offer a predictable anchorage and support function for a fixed prosthesis in severely resorbed maxillae.

A surgical stent for the Brånemark Novum bone reduction procedure.

BACKGROUND: The Brånemark Novum concept (Nobel Biocare AB, Göteborg, Sweden) was introduced to load implants immediately with a definitive fixed prosthesis in the edentulous mandible. This concept is based on the use of prefabricated templates to allow precise placement of three implants and a prefabricated bar structure for the prosthetic procedure. To obtain three-dimensional stability in these prefabricated templates, surgical bone reduction may be necessary to obtain a stable adaptation between the templates and the recipient bone site. PURPOSE: The aim of this work was to design a surgical stent for predictable reduction of the residual alveolar crest prior to the implant placement procedures. MATERIALS AND METHODS: A predetermined alveolar crest platform based essentially on a lateral cephalometric radiographic evaluation was simulated on a cast in order to design a transparent resin surgical guide. The predictability potential of the procedure was then evaluated in 10 patients. The prosthetic outcomes were compared with those of a similar group of 10 patients treated without the presented stent by evaluating two factors, namely, the anterior dimensions of the prostheses and the required posterior adjustments of the upper bar. RESULTS: Correlation analysis of our series suggested a good predictability potential for this procedure (r = 0.9215). The mean anterior prosthetic dimension was 32% lower and was more predictable (narrow range of 8-12 mm vs broad range of 8-21 mm) when the stent was used. Furthermore, since half as many posterior adjustments of the upper bar were required, the laboratory procedure was facilitated. CONCLUSION: This individualized guide allows appropriate bone reduction for obtaining a predictable surgery and prosthetic stage.

Accuracy of drilling guides for transfer from three-dimensional CT-based planning to placement of zygoma implants in human cadavers.

The accuracy of surgical drilling guides was assessed for placement of zygoma implants. Six zygoma fixtures of length 45 mm (Nobel Biocare, Göteborg, Sweden) were placed in three formalin-fixed human cadavers using surgical drilling guides. The fabrication of these custom-made drilling guides was based on three-dimensional computerized tomography (3D-CT) data for the maxillary-zygomatic complex. The installation of the implants was simulated preoperatively using an adopted 3D-CT planning system. In addition, anatomical measurements of the zygomatic bone were performed on the 3D images. The preoperative CT images were then matched with postoperative ones in order to assess the deviation between the planned and installed implants. The angle between the planned and actually placed implants was < 3 degrees in four out of six cases. The largest deviation found at the exit point of one of the six implants was 2.7 mm. The present study showed that the use of surgical drilling guides should be encouraged for zygoma implant placement because of the lengths of the implants involved and the anatomical intricacies of the region.

Use of an onplant as orthodontic anchorage.

Considerable limitations in the clinical application of orthodontic treatment can result from the lack of teeth suitable for anchorage. If prosthetic rehabilitation is necessary, endosseous implants can be first used as orthodontic anchorage and then loaded by a prosthetic superstructure. However, in a plan of exclusive orthodontic treatment, alveolar bone is not always available, and an orthodontic osseointegrated anchorage system might be necessary. We report the use of an onplant for palatal anchorage to extrude the unerupted horizontal maxillary first molars in a 12-year-old white girl with tooth aplasia and secondary cleft palate. After a healing period of 5 months, the onplant remained stable under indirect elastic tension of approximately 160 g applied for 17 weeks, and the maxillary first molars were successfully extruded.