The use of zygomatic implants in severe maxillary atrophy: a systematic and meta-analysis review of randomised clinical trials / El uso de implantes zigomáticos para atrofia maxilar severa: una revisión sistemática y meta-análisis de ensayos clínicos aleatorizados

SUMMARY: Conventional implant treatment cannot always be used to rehabilitate edentulous patients with advanced maxillary atrophic. Zygomatic dental implants have been used over the past 20 years as an alternative treatment solution to bone grafting. The purpose of this meta-analysis is to evaluate the implant and prosthetic survival rate in non-oncologic patients with a severely atrophic maxilla. This review also aims to better understand the rate of peri-operative complications in this cohort of patients. A multi-database (PubMed, MEDLINE, EMBASE, and CINAHAL) focused systematic search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Any randomised control trials studies involving human participants treated with zygomatic osseous implants were included. After eliminating duplicates, a total of 4 studies met the inclusion criteria for this meta-analysis review. With all the studies included there was a total of 174 patients treated with zygomatic osseous implants. The overall implant success rate was 98.03 %. The prosthetic success rate was 96.4 %. The most frequent peri-operative complication was sinusitis. Based on the limited data available in literature, zygomatic dental implants represent a valid alternative to bone augmenting procedure. However, they are not without risks and longer follow-ups are required to confirm the validity of the treatment in long term.

Los tratamientos convencionales con implantes no siempre pueden ser usados para rehabilitar pacientes edentulos con atrofia maxilar avanzada. Los implantes dentales zigomáticos son usados por los pasados 20 años como alternativa de tratamiento a las reconstrucciones óseas. El objetivo de este meta-análisis es evaluar la sobrevida de implantes y prótesis en pacientes no oncológicos con maxila severamente atrófica. Esta revisión también pretende entender al promedio de complicaciones peri operatorias en esta cohorte de pacientes. Una búsqueda sistemática en bases de datos múltiples (PubMed, MEDLINE, EMBASE y CINAHAL) fue desarrollada de acuerdo a recomendaciones de Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Cualquier estudio clínico aleatorizado de participantes humanos donde se utilizaron los implantes zigomáticos fueron incluidos. Después de eliminar duplicados, un total de 4 estudios cumplieron los criterios de inclusión para esta meta análisis. Con todos los estudios incluidos se obtuvieron 174 pacientes tratados con implantes zigomáticos. El promedio de éxito fue de 98,03 %. El promedio de éxito de la rehabilitación fue de 96,4 %. La complicación mas frecuente fue la sinusitis. Basados en los datos limitados en la literatura, los implantes zigomáticos representan una alternativa valida a los procedimientos de aumento óseo. Sin embargo, estos no están libres de riesgos y seguimientos de mayores periodos son necesarios para confirmar la validez de los tratamientos en el largo plazo.

Prosthetic rehabilitation of a maxillary defect with a bone anchored prosthesis: A clinical report.

Mucormycosis is an opportunistic fungal infection that frequently infects sinuses, brain, or lungs and arises mostly in immunocompromised patients. Although its occurrence in the maxilla is rare, debridement and resection of the infected and necrotic area is often the best treatment but usually results in an extensive maxillary defect. Protocols for prosthetic obturation versus microvascular reconstruction have been established and used effectively in tertiary institutions for patients with such large defects. Aramany Class VI defects involving more than half of the palatal surface can be managed effectively by surgical reconstruction using microvascular free flaps as a platform for supporting bone-anchored prostheses. Providing fixed prostheses may offer advantages over a conventional obturator prosthesis in terms of hygiene, function, and esthetics. Nonetheless, fixed prostheses retained by endosseous implants in patients with reconstructive osteomyocutaneous flaps often require a sequential team approach by the surgeon and prosthodontist. This clinical report describes the reconstruction of a maxilla by using a scapular free flap with subsequent prosthetic rehabilitation in a patient with maxillary sinus infection secondary to mucormycosis.

Three-Dimensional Printing: A Novel Approach to the Creation of Obturator Prostheses Following Palatal Resection for Malignant Palate Tumors.

BACKGROUND: A subgroup of patients who have an oronasal fistula live in areas that have limited access to oral prosthetics. For these individuals, a temporary prosthesis, such as a palatal obturator, may be necessary in order to speak, eat, and breath properly. The creation of an obturator, which requires a highly trained prosthodontist, can take time and can be expensive. Through the current proof-of-concept study, there is an attempt to create a patient-specific palatal obturator through use of free and publicly available software, and a low-cost desktop 3-dimensional printer. The ascribed study may provide a means to increase global access to oral prosthetics if suitable biomaterials are developed. METHODS: Computerized tomography data were acquired from a patient who had an oronasal fistula. Through use of free software, these data were converted into a 3-dimensional image. The image was manipulated in order to isolate the patient's maxilla and was subsequently printed. The palatal obturator models were designed, and reformed, in correspondence with the maxilla model design. A final suitable obturator was determined and printed with 2 differing materials in order to better simulate a patient obturator. RESULTS: Creating a suitable palatal obturator for the specified patient model was possible with a low-cost printer and free software. CONCLUSIONS: With further development in biomaterials, it may be possible to design and create an oral prosthesis through use of low-cost 3-dimensional printing technology and freeware. This can empower individuals to attain good healthcare, even if they live in rural, developing, or underserviced areas.

Influence of implant number, length, and tilting degree on stress distribution in atrophic maxilla: a finite element study.

This study aims to evaluate the stress values, created in peri-implant region as a consequence of loading on fixed hybrid dentures that was planned with different implant numbers, lengths, or tilting angulations. Thirteen three-dimensional (3D) finite element analysis models were generated with four, five, or seven implants (group A, B, and C). Except the distal implants, all implants were modeled at 4.1 mm (diameter) and 11.5 mm (length) in size. Distal implants were configured to be in five different lengths (6, 8, 11.5, 13, and 16 mm) and three different implant inclination degrees (0°, 30°, and 45°). A 150-N load was applied vertically on prosthesis. Released stresses were evaluated comparatively. The lowest von Mises stress values were found in group C, in the 11.5-mm implant model. Tilting the distal implants 30° caused higher stress values. In 45°-tilting implant models, lower stress values were recorded according to the 30°-tilting models. The ideal implant number is seven for an edentulous maxilla. Tilting the implants causes higher stress values. A 45° inclination of implant causes lower stress values according to the 30° models due to a shorter cantilever. The ideal implant length is 11.5 mm.

Zygomatic implant: late complications in a period of 12 years of experience

ABSTRACT: Purpose Zygomatic implants (ZI) constitute a suitable alternative for treating severe maxillary atrophy. However, a large number of complications associated with ZI have been reported in the literature. This paper presents the late complications associated with ZI during 12 years of experience in the same institution. Materials and methods All cases of ZI from 2000 to 2013 were retrospectively evaluated and the major complications relating to this type of rehabilitation were selected to report. Results The major complications found were: loss of implant, loss of osseointegration, bucco-sinusal communication, fenestration of alveolar mucosa, sinus pathology, and emergency palate fixations. Conclusion The clinical experience of the dental surgeon is critical in the success of zygomatic fixation. Furthermore, there should be careful planning of rehabilitation to reduce the rate of complications.

Quadruple zygomatic implants supported rehabilitation in failed maxillary bone reconstruction.

Extreme atrophy of the jaws constitutes a challenge for maxillofacial surgeons. The technique involving Le Fort I osteotomy, bone grafting, and endosseous implants remains the gold standard treatment for class V and class VI atrophy of the maxilla. As severe maxillary atrophy is associated to impaired microvascularization of overlying soft tissues, reconstruction using vascularized free fibula flaps together with endosseous implants is one of the possible treatment plans. When this approach fails, however, retreating these patients using traditional techniques often proves unsatisfactory. This study outlines our clinical experience with full-arch zygoma implant-supported prosthetic rehabilitation to treat severe atrophic maxilla following failure of strategies including multiple Le Fort I procedures or vascularized free fibular flaps.

Satisfaction and quality of life with palatal positioned implants in severely atrophic maxillae versus conventional implants supporting fixed full-arch prostheses.

BACKGROUND: To evaluate satisfaction and quality of life in patients with palatal positioned implants supporting fixed full-arch prostheses to rehabilitate edentulous maxillae with horizontal atrophy and compare them with conventional well-centered implants placed in non-atrophic supporting fixed full-arch prostheses. MATERIAL AND METHOD: A clinical retrospective study was performed of patients that were rehabilitated with full-arch fixed implant-supported maxillary prostheses and had a minimum follow-up of 5 years after implant loading. Patients were divided into 2 groups: patients with class IV maxilla according to Cawood and Howell and treated with palatal positioned implants (test) and with class III maxilla and treated with implants well-centered in the alveolar ridge and completely surrounded by bone (control). Ten-cm visual analogue scales (VAS) (range 1-10) and the OHIP-14 (Oral Health Impact Profile) questionnaire were used respectively to estimate patient satisfaction and quality of life after implant therapy. Statistical analysis was performed applying Mann-Whitney Test using alpha set at 0.05. RESULTS: Mean global and specific satisfaction--except for self-esteem--were superior for the test group than the control group, although differences were not statistically significant. Regarding quality of life, the reported incidence of problems was lower in the test group for all the studied items except for 'problems at work'. However, differences were not statistically significant in any case. CONCLUSION: Despite the limitations of the study (retrospective and nonrandomized design) the results suggest that the prosthesis design needed to rehabilitate palatally positioned implants (more coverage of palate) does not lead to lower satisfaction and quality of life of patients, compared to patients treated with implants placed centered and conventional design prostheses that do not cover the palate.

Reliability of four zygomatic implant-supported prostheses for the rehabilitation of the atrophic maxilla: a systematic review.

PURPOSE: The reliability of oral rehabilitation by four zygomatic implants with no anterior support remains to be determined. The aim of this systematic review was to assess the predictability of this approach in regard to implant survival, technical and biologic complications, and quality of life. MATERIALS AND METHODS: An electronic literature search was conducted from September 2000 to November 2013. Human clinical trials in which oral rehabilitation was achieved by the use of four zygomatic implants with no additional placement of standard implants were included. The primary outcome was the survival rate of the zygomatic implants. In addition, random effects meta-analyses of the selected studies were applied to avoid potential bias caused by methodologic differences among studies. RESULTS: Zygomatic implant survival rate weighted mean (WM) was 96.7% (range, 95.8% to 99.9%), with a 95% confidence interval (CI) of 92.5% to 98.5%. Only a limited number of surgical complications were reported, with orbital perforation the most significant. Similar results were obtained for prosthetic complications (few occurrences). Additionally, patient satisfaction levels were shown to be high, approaching that of the general population. CONCLUSION: Data from the present systematic review suggest that maxillary rehabilitation by four zygomatic implants with no anterior support is a reliable approach.

Influence of maxillary obturator prostheses on facial morphology in patients with unilateral maxillary defects.

STATEMENT OF PROBLEM: Facial asymmetry is prominent with individuals with unilateral bone resorption and can lead to decreased quality of life. PURPOSE: The purpose of this study was to investigate the influence of maxillary obturator prostheses on facial morphology of individuals with unilateral maxillary defects by using 3-dimensional digital stereophotogrammetry. MATERIAL AND METHODS: The facial data of 8 participants with unilateral maxillary defects were acquired with a noncontact 3-dimensional digitizer, both with and without maxillary prostheses. The mid-facial plane was established by overlapping an original facial image with its mirror image. Displacement at 18 measurement points, including 7 bilateral pairs, was compared between the 2 sides, with and without the prostheses. Asymmetry indices of these 7 pairs also were calculated. Multivariate repeated-measures ANOVA was used to determine differences. RESULTS: Displacements of the lateral and inferior points at the ala of the nose were significantly greater on the defect side than on the normal side. The distances between the ideal and defect side points at the superior ala, the upper lip, and the angle of the mouth decreased significantly with the prosthesis. No significant differences were found in asymmetry indices, but the angle of the upper lip line to the mid-sagittal plane increased significantly with the prosthesis. CONCLUSIONS: The 3-dimensional analyzing method developed in this study can be useful in evaluating facial reconstruction with maxillary obturator prostheses with individuals with unilateral maxillary defects. The prostheses affect the region of the nasal ala, the upper lip, and the angles of the mouth.

Prosthetic rehabilitation of acquired maxillary defects secondary to mucormycosis: clinical cases.

Maxillary necrosis can occur due to bacterial infections such as osteomyelitis, viral infections, such as herpes zoster or fungal infections, such as mucormycosis, aspergillosis etc. Mucormycosis is an opportunistic fungal infection, which mainly infects immunocompromised patients. Once the maxilla is involved, surgical resection and debridement of the necrosed areas can result in extensive maxillary defects. The clinician is to face many a challenge in order to replace not only the missing teeth, but also the lost soft tissues and bone, including hard palate and alveolar ridges. The prosthesis (Obturator) lacks a bony base and the lost structures of the posterior palatal seal area compromise retention of the prosthesis. Furthermore, the post surgical soft tissues are scarred and tense, which exert strong dislodging forces. The present article describes the prosthetic rehabilitation of maxillary necrosis secondary to mucormycosis in two cases, one completely edentulous and the other partially edentulous.

Three-year follow-up of immediately loaded implants in the edentulous atrophic maxilla: a study in patients with poor bone quantity and quality.

PURPOSE: Immediate loading of implants in the edentulous maxilla has previously been successfully performed and reported. Severe resorption of the maxillary alveolar crest presents a more demanding situation for the restorative team. Thus, it would be valuable to assess outcomes for this immediate loading treatment protocol in subjects with marked maxillary alveolar crest atrophy. This study evaluated the 3-year results of dental implants that were immediately restored with provisional fixed prostheses in atrophic maxillae without previous augmentation. MATERIALS AND METHODS: Two centers enrolled subjects with resorbed edentulous maxillae (Lekholm and Zarb quality 3 or 4 and quantity C, D, or E). Six implants were placed in each subject and restored with screw-retained fixed provisionals within 24 hours. Impressions were taken for definitive restorations, which were placed 20 to 24 weeks later. Radiographs were used to analyze marginal bone level changes throughout the study. RESULTS: Fifty-one patients received 306 implants. Forty-five patients remained in the study at the 3-year follow-up visit and successfully used their definitive prostheses. Sixty-two percent of the implants were placed in bone quantity C and quality 3 or 4, and 38% were placed in quantity D and quality 3 or 4 bone. Thirteen implants in six subjects were lost, resulting in a cumulative survival rate of 96% after 3 years. The mean marginal bone loss during the first year was -0.4 ± 0.8 mm (255 implants); at 3 years it was -0.6 ± 1.1 mm (253 implants). CONCLUSION: Data from the first 3 years of this study revealed good clinical outcomes. Careful selection of patients and planning by the restorative team can enable successful treatment outcomes for patients presenting with marked resorption of the edentulous maxilla.

Rehabilitation of maxillary arch with attachment-retained mesh-reinforced single complete denture.

Fabrication of conventional complete dentures was one of the most commonly advised treatment options to mange edentulous patients since many years. One of the commonly encountered challenging tasks in prosthodontics is a clinical situation in which patients have maxillary completely edentulous arches opposing mandibular natural dentition. This situation can be effectively managed by retaining some of the natural teeth as overdenture abutments. Tooth supported overdenture retained by attachments will improve retention, support and stability, and reduces rate of ridge resorption along with psychological benefits to the patients by providing tactile sensation. The present case report describes management of patients with edentulous maxillary arch opposing natural mandibular dentition-rehabilitated attachment-retained mesh-reinforced overdenture.

Prosthetic rehabilitation of a patient with a unilateral cleft palate: a clinical report.

Cleft palate is a congenital disorder characterized by maxillary growth defect and dental anomalies. Its correction requires an interdisciplinary approach, which includes surgical, orthodontic, and prosthetic treatments. This clinical report describes the prosthetic management of a 19-year-old woman with a unilateral cleft palate defect that had not been closed completely with surgical repair. The deficient maxillary residual anterior ridge was restored with a tooth-supported overdenture that improved her facial appearance, speech, and masticatory functions.

Evaluation of student perception of the lecture "oral functional medical rehabilitation: balneophysiotherapy".

UNLABELLED: Th aim of the study was to assess this course as perceived by the 6th year dentistry students. MATERIAL AND METHODS: Applying and validating the "Dundee Ready Education Environment Measure (DREEM)" for the first time in Romania. RESULTS AND DISCUSSION: The reliability of the test according to Cronbach alpha method, which measures the internal consistency of a test, was 0.87 (Cronbach alpha coefficient should be above 0.70). As to the reliability coefficients (internal consistency) for each test subscale and for the entire test, DREEM proved a very good overall reliability, with alpha = 0.89. The reliability of each DREEM subscale was also analyzed. The DREEM test results, with a global score of 149, indicate a "more positive than negative" perception (score between 101 and 150). CONCLUSIONS: The DREEM test showed that the assessment and treatment of pain in dental-maxillary pathology and TMJ dysfunctions through medical rehabilitation by means of balneophysiotherapy is of interest to final year dental medicine students. As a student-teacher partnership, modern education cannot ignore the practical needs of students and should add to their theoretical training with courses and practical training programs necessary in their future profession.

The positions of implant heads in relation to the fixed dental prosthesis: a comparison of multiple zygomatic implants with standard implants for the reconstruction of the atrophic maxilla.

PURPOSE: The aim of this study was to investigate the positions of dental implants at the crestal level and the occlusal level of a fixed dental prosthesis (FDP) in severely and moderately resorbed maxillae. Restorations supported by multiple zygomatic implants were compared with restorations supported by standard implants. MATERIAL AND METHODS: Between 2004 and 2007, measurements were performed on FDPs and working casts. Two groups were investigated: (1) patients with severe atrophy and extensive resorption into basal bone treated with multiple zygomatic implants (Zyg) and (2) patients with moderate atrophy with standard implants only (Stand). The areas bounded by the FDP at the implant level (A(impl)) and at the occlusal level (A(prost)) were calculated, and A(prost) -A(impl) represented the total horizontal overjet of the FDP. A(prost)/A(impl) was established as the degree of overlapping of these two areas. The transverse and sagittal dimensions at the implant level (T(impl) and S(impl)) and at the occlusal level (T(prost) and S(prost)) were also measured. T(impl)/S(impl) and T(prost)/S(prost) represented the shape of the superstructure at these respective levels. RESULTS: Seven consecutive patients in the Zyg group were matched by age and gender with seven individuals in the Stand group. In the Zyg group, 28 zygomatic and 5 standard implants were placed; in the Stand group, 41 standard implants were placed, of which 3 were lost. All patients received an FDP. T(impl) was shorter and S(impl) was longer in the Zyg group, yielding a smaller T(impl)/S(impl) in this group. The Zyg group also displayed less overjet and a smaller A(prost)/A(impl) compared to the Stand group. CONCLUSION: Multiple zygomatic implants emerged through the residual crest with a more even distribution in the sagittal plane compared to standard implants and with a better congruence with the occlusal location of the FDP.

A two-piece sectional interim obturator. A clinical report.

Prosthetic rehabilitation of acquired maxillary defects can be achieved satisfactorily if all facets of treatment planning and design considerations are taken into account before the rehabilitation process. Complications associated with maxillary defects limit treatment protocols to a great extent. The prosthodontist has to identify these problem areas and suitably devise feasible options and incorporate them in the design. In this report, an acquired maxillary defect with unfavorable undercuts in the defect was successfully treated by making a two-piece sectional obturator. The two pieces were connected by the use of double-die pin system. The methodology greatly reduced chairside time and number of visits, and effective obturation was satisfactorily achieved.

Impact of dental and zygomatic implants on stress distribution in maxillary defects: a 3-dimensional finite element analysis study.

The aim of this study was to evaluate the stress distribution in the bone around dental and zygomatic implants for 4 different implant-supported obturator prostheses designs in a unilaterally maxillary defect using a 3-dimensional finite element stress analysis. A 3-dimensional finite element model of the human unilateral maxillary defect was constructed. Four different implant-supported obturator prostheses were modeled; model 1 with 2 zygomatic implants and 1 dental implant, model 2 with 2 zygomatic implants and 2 dental implants, model 3 with 2 zygomatic implants and 3 dental implants, and model 4 with 1 zygomatic implant and 3 dental implants. Bar attachments were used as superstructure. A 150-N vertical load was applied in 3 different ways, and von Mises stresses in the cortical bone around implants were evaluated. When the models (model 1-3) were compared in terms of number of implants, all of the models showed similar highest stress values under the first loading condition, and these values were less than under model 4 conditions. The highest stress values of models 1-4 under the first loading condition were 8.56, 8.59, 8.32, and 11.55 Mpa, respectively. The same trend was also observed under the other loading conditions. It may be concluded that the use of a zygomatic implant on the nondefective side decreased the highest stress values, and increasing the number of dental implants between the most distal and most mesial implants on the nondefective side did not decrease the highest stress values.

Rehabilitation of the atrophic posterior maxilla with pterygoid implants: a review.

The purpose of this article is to review the literature published and to assess the success of treatment of patients with atrophic posterior maxilla with pterygoid implants. Studies from 1992 to 2009 on patients with atrophic posterior maxilla rehabilitated with pterygoid implants were reviewed. Those reporting clinical series of at least 5 patients with atrophic posterior maxilla (Class IV and V of Cawood and Howell), rehabilitated with pterygoid implants and fixed prosthesis, and with 12 months minimum follow-up were included. In each study the following were assessed: number of patients, number of implants, surgical technique, prosthetic rehabilitation, success rate, bone loss, complications and patient satisfaction. Thirteen articles were included, reporting a total of 1053 pterygoid implants in 676 patients. The weighted average success of pterygoid implants was 90.7%; bone loss evaluated radiographically ranged between 0 and 4.5 mm. No additional complications compared with conventional implants were found, and patient satisfaction level with the prosthesis was high. Pterygoid implants have high success rates, similar bone loss levels to those of conventional implants, minimal complications and good acceptance by patients, being therefore an alternative to treat patients with atrophic posterior maxilla. Two anatomical locations in which implants are placed in the retromolar area can be distinguished: the pterygoid process and the pterygomaxillary region. Implant lengths and angulations vary between these two techniques.

Rehabilitation of a maxillary defect secondary to recurrent giant cell granuloma.

This is a presentation of the treatment history of a young woman with a benign lesion resulting in a large maxillary defect. This patient's complex treatment resulted in a full spectrum of rehabilitation modalities. Her story shows alternative treatment options with the ultimate goal of restoring form, function, and quality of life to a patient with an extensive maxillary defect.