Optimisation de la prothèse complète supra-radiculaire mandibulaire par l'usage de l'attachement barre: rapport de cas / Optimization of the mandibular supra-radicular complete prosthesis by the use of the bar attachment: a case report

Introduction : L'équilibre d'une prothèse complète amovible mandibulaire est délicat vu la surface d'appui restreinte. L'objectif du travail était de décrire l'intérêt de la prothèse amovible supra-radiculaire retenue par l'attachement barre dans la gestion d'un édentement subtotal mandibulaire. Observation : Un patient consultait pour bénéficier d'une prothèse esthético-fonctionnelle. L'examen clinique montrait la présence d'un édentement total maxillaire et subtotal mandibulaire avec persistence des canines séparées d'une crête rectiligne. L'examen radiologique révélait un rapport couronne sur racine radiologique égal à 1. L'examen des moulages sur articulateur visualisait une hauteur occlusale utilisable suffisante. La décision prothétique était une prothèse complète maxillaire et une prothèse complète supra-radiculaire (PCSR) mandibulaire retenue par une barre. Le traitement prothétique commençait par une préparation Richmond des plateaux radiculaires. Après sculpture des chapes et fixation de la barre calcinable, la coulée était faite. Une empreinte anatomo-fonctionnelle de situation était réalisée pour confectionner l'infrastructure métallique. Suite à l'enregistrement de l'occlusion, le montage des dents était fait et validé. Le jour de la mise en bouche des conseils d'utilisation et de maintenance étaient prodigués au patient. Commentaires : La PCSR est avantageuse par le maintien du système proprioceptif desmodontal et d'un profil de crête favorable à l'appui. Les racines à conserver doivent valider certains critères pour être exploitables. La barre offre une rétention importante, mais son indication dépend du parallélisme radiculaire, de l'espace prothétique utilisable et de la forme de la crête édentée. Conclusion : Le recours aux attachements en PCSR est intéressant à condition d'établir un plan de traitement rigoureux et d'assurer la maintenance post-prothétique.

Introduction: The balance of a complete removable mandibular prosthesis is delicate given the limited support area. The objective of this work was to describe the benefit of the supra-radicular removable prosthesis retained by the bar attachment in the management of subtotal mandibular edentulism. Observation: A patient consulted to benefit from an aesthetical and functional prosthesis. The clinical examination showed the presence of total maxillary and subtotal mandibular edentulism with persistence of the canines separated by a straight ridge. The radiological examination revealed a crown by radiological root ratio equal to 1. Examination of the casts on the articulator visualized sufficient usable occlusal height. The prosthetic decision was a maxillary complete prosthesis and a mandibular complete supra-radicular prosthesis (CSRP) retained by a bar attachment. The prosthetic treatment began with a Richmond preparation of the root plates. After sculpting the copings and fixing the castable bar, the casting was done. An anatomo-functional impression was made to perform the metal infrastructure. Following the occlusion recording, the assembly of the teeth was done and validated. On the day of denture insertion, instructions about the use and the maintenance was provided to the patient. Comments: PCSR is advantageous by maintaining the periodontal proprioceptive system and a favorable ridge profile for prosthetic bearin. The roots to be kept must validate certain criteria to be usable. The bar offers significant retention, but its indication depends on the root parallelism, the usable prosthetic space and the shape of the edentulous ridge. Conclusion: The use of attachments in CSRP is interesting provided that a rigorous treatment plan is established and post-prosthetic maintenance is ensured.

Histologic Assessment of Peri-implant Tissues Around Endosseous Dental Implants Placed Along with Intentionally Retained Root Fragment in Animal Models: A Systematic Review.

PURPOSE: To evaluate whether the placement of endosseous dental implants along with intentionally retained root fragments enhances peri-implant histologic characteristics and outcomes in healthy animal models. MATERIALS AND METHODS: Two review authors independently performed electronic literature searches across the PubMed/MEDLINE, LILACS, EBSCOhost, and Science Direct databases by using different keywords and Medical Subject Headings terms to identify relevant articles. Only preclinical animal trials evaluating the histology of peri-implant tissues around endosseous dental implants placed along with intentionally retained root fragments were included in the review. The risk of bias assessment was investigated using the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) tool, and the reporting quality of each trial was evaluated using the Animal Research: Reporting in Vivo Experiments guidelines. RESULTS: Seven preclinical trials including a total of 33 animals and 155 endosseous dental implants were eligible for the analysis. One trial reported the histologic assessment of peri-implant tissues around endosseous dental implants with ankylotic root fragments, whereas the other six studies used nonankylotic root fragments. The effects of the length of retained root fragments on peri-implant tissues were reported in two trials that showed contrasting results. The effects of the width of retained root fragments were assessed in two trials reporting that a remaining thickness < 2 mm and buccal bone thickness > 3 mm favors alveolar bone preservation over a period of 12 weeks. Although the mean quality assessment score for all preclinical trials was moderately high, the summary for the risk of bias presented a high risk. CONCLUSION: Limited data and short-term preclinical evidence showed optimal peri-implant histologic findings of endosseous dental implants placed along with intentionally retained root fragments. However, further preclinical histologic evaluation with homogenous populations and long-term controlled clinical studies are needed to substantiate its applicability in clinical situations.

Alloplastic temporomandibular joint replacement: present status and future perspectives of the elements of embodiment.

Medical device embodiment involves the following elements: materials, design, and manufacturing. Failure of any one of these elements can result in failure of the device, despite the others being satisfactory. The abundance of clinical and basic science literature published since 1986, demonstrates the safety and efficacy of alloplastic temporomandibular joint replacement (TMJR). Currently, there are 19 countries producing 41 TMJR devices. More than 75% are custom designed, and 27% are additively manufactured. In light of the increasing number of TMJR devices being designed and manufactured around the world, this paper will discuss TMJR embodiment so that clinicians understand their present status as well as the prospects for the future of new and/or improved TMJR devices, to ensure that these devices continue to be safe and effective long-term surgical options for the management of end-stage TMJ pathologies.

Clinical T4b Squamous Cell Carcinoma Resection With Hemimandibulectomy and Temporomandibular Joint Reconstruction With Bridging Plate and Modified Dautrey Procedure.

ABSTRACT: Clinical T4b oral squamous cell carcinoma is traditionally considered nonoperable. We present a case of right mandibular squamous cell carcinoma (PT4bN0M0, stage IVB). The tumor had extended to the right mandibular condylar head and masticatory space. The patient received right modified radical neck dissection and radical operation with hemimandibulectomy to remove the right mandibular condyle. Then, we reconstructed the resected portion with an anterior lateral thigh free flap and bridging plate, which was bent to form an artificial condyle and fixed using the modified Dautrey procedure. The patient had stable postoperative occlusion and normal hinge movement of the temporomandibular joint. After postoperative concurrent chemotherapy and radiotherapy, the patient is under regular out patient department follow-up with satisfactory jaw function and oral intake.

The Use of Customized Three-Dimensionally Printed Mandible Prostheses with a Pressure-Reducing Device: A Finite Element Analysis in Different Chewing Positions, Biomechanical Testing, and In Vivo Animal Study Using Lanyu Pigs.

Segmental bony defects of the mandible constitute a complete loss of the regional part of the mandible. Although several types of customized three-dimension-printed mandible prostheses (CMPs) have been developed, this technique has yet to be widely used. We used CMP with a pressure-reducing device (PRD) to investigate its clinical applicability. First, we used the finite element analysis (FEA). We designed four models of CMP (P1 to P4), and the result showed that CMP with posterior PRD deployment (P4 group) had the maximum total deformation in the protrusion and right excursion positions, and in clenching and left excursion positions, posterior screws had the minimum von Mises stress. Second, the P4 CMP-PRD was produced using LaserCUSING from titanium alloy (Ti-6Al-4V). The fracture test result revealed that the maximum static pressure that could be withstood was 189 N, and a fatigue test was conducted for 5,000,000 cycles. Third, animal study was conducted on five male 4-month-old Lanyu pigs. Four animals completed the experiment. Two animals had CMP exposure in the oral cavity, but there was no significant inflammation, and one animal had a rear wing fracture. According to a CT scan, the lingual cortex of the mandible crawled along the CMP surface, and a bony front-to-back connection was noted in one animal. A histological examination indicated that CMP was significantly less reactive than control materials (p = 0.0170). Adequate PRD deployment in CMP may solve a challenge associated with CMP, thus promoting its use in clinical practice.

Immediately loaded implants simultaneously placed in fresh extraction and healed sites supporting four-implant-supported fixed mandibular prostheses using the all-on-4 concept: A 5-year prospective study.

OBJECTIVES: To evaluate the peri-implant marginal bone level for immediately loaded implants placed simultaneously in both fresh extraction sites (FES) and healed sites (HS) supporting a 4-implant supported mandibular fixed prosthesis (4-ISFMP) using the all-on-4 concept. MATERIAL AND METHODS: A 5-year prospective study was conducted in 24 patients (96 implants) treated with 4-ISFMP including 55 implants inserted in FES and 41 implants in HS. At implant placement (baseline) and at the 1st -, 3rd - and 5th -year follow-up examinations, peri-implant marginal bone level was evaluated radiographically and compared between placement in FES and HS. Marginal bone loss was calculated as the difference in the marginal bone level evaluated at the follow-up periods. Additionally, implant and prosthesis survival rates as well as the presence of peri-implant mucositis (bleeding on probing+[BOP]) and peri-implantitis (BOP+ >2 mm MBL) were evaluated. RESULTS: 22/24 patients with 88/96 implants (dropout rate: 8.3%) were continually followed for 5 years (survival rate: 100%). Radiographically measured marginal bone level differed significantly between FES and HS at implant placement (1.46 ± 0.80 mm vs. 0.60 ± 0.70 mm; p < .001), at the 1-year (-0.04 ± 0.14 mm vs. -0.18 ± 0.20 mm; p = .002) and 3-year (-0.26 ± 0.49 mm vs. -0.58 ± 0.48 mm, p = .049), but not at the 5-year evaluation (-0.90 ± 0.66 mm vs. -1.00 ± 0.59 mm, p = .361). The marginal bone loss differed significantly (p < .001) between FES and HS between implant placement and the 1-year evaluation but not for the 1- to 3-year (p > .99) and the 3- to 5-year period (p = .082). At the 5-year follow-up evaluation, no implant/prosthesis failed (100% survival) and peri-implant mucositis and peri-implantitis were noted in 41.2% and 11.7% at patient level and in 17.6% and 4.5% at implant level respectively. CONCLUSION: Implants placed in FES showed a prolonged peri-implant remodelling process but provided for similar peri-implant marginal bone levels as implants placed in HS at the 5-year evaluation for immediately loaded 4-ISFMP.

Synovial entrapment in alloplastic temporomandibular joint replacement.

Complications of alloplastic temporomandibular joint (TMJ) prostheses can lead to stress and anxiety for the patient and the surgical team, and prosthesis substitution is sometimes required. The aim of this case report is to describe the surgical finding of synovial entrapment with interposed fibrosis in a postoperative alloplastic TMJ revision, managed effectively with adequate surgical debridement. The authors believe that synovial entrapment needs to be considered as a possible postoperative complication of total joint replacement when no clear symptoms of infection, metal hypersensitivity, osteolysis, or heterotopic bone formation are present. The implications of synovial entrapment in TMJ alloplastic replacement remains relatively unpredictable and poorly understood.

Mandibular guidance prosthesis: Conventional and innovative approach: A case series.

Surgical resection of the lower jaw due to the presence of a benign or malignant tumor is the most frequent cause of mandibular deviation. Location and extent of the tumor decide the surgical modality of mandibulectomy to be performed. The clinician must wait for an adequate span of time for completion of the healing and acceptance of the osseous graft before considering a definitive prosthesis. During the inceptive healing period, prosthodontic intervention is of utmost priority for preventing the mandibular deviation. A corrective appliance termed "guide flange prosthesis (GFP)" is indicated to limit this clinical manifestation. The basic intention of rehabilitation is to train the mandibular muscles and to re-establish an acceptable occlusal relationship so that the patient can adequately control the opening and closing movements. This case series describes early prosthodontic management of three patients who had undergone hemimandibulectomy, with different techniques of fabrication of a GFP. The three techniques described consist of two conventional methods of fabrication while the third technique is a new innovative approach.

[Three-dimensional finite element analysis of different framework materials in implant-supported fixed mandibular prosthesis].

Objective: To evaluate the biomechanical behaviors of different framework materials in implant-supported fixed mandibular prosthesis using three-dimensional finite element analysis. Methods: A model of implant-supported fixed mandibular prosthesis was established. The simulations were divided into six groups according to the framework materials: pure titanium, cobalt-chromium alloy, gold alloy, zirconia, polyether ether ketone (PEEK) and carbon fiber-reinforced PEEK. An oblique load of 300 N with a 75° angle to the occlusal plane was applied from the lingual side on the buccal cusps of the two premolars and the first molar teeth. The stresses on implants, surrounding bones and frameworks were analyzed and compared among the framework materials both quantitatively and qualitatively. Results: In implant-supported fixed mandibular prosthesis model, the highest stresses were located around the neck of the implants and cortical bone during oblique loading among six designs. In addition, the stresses were concentrated on the buccal and distal cortical bone around the implants of the posterior region. Stress values of implants and cortical bones from low to high were as follows: zirconia, cobalt-chromium alloy, pure titanium, gold alloy, carbon fiber-reinforced PEEK, PEEK. The von Mises stress values of implant and cortical bone in the first molar site of PEEK framework material were 44.96 and 29.13 MPa, while the von Mises stress values of implant and cortical bone in the first molar site of zirconia framework material were 21.29 and 17.79 MPa. The zirconia and medal framework materials were more advantageous in stress distribution around implants than PEEK framework material. Conclusions: In implant-supported fixed mandibular prostheses, biomechanical analysis showed that the zirconia and medal framework materials were more advantageous in stress distribution around implants than PEEK framework materials.

The use of cutting/positioning devices for custom-fitted temporomandibular joint alloplastic reconstruction: current knowledge and development of a new system.

Alloplastic replacement of the temporomandibular joint (TMJ) is the treatment of choice in cases of TMJ end-stage disease. Improvements in computer-aided design/computer-aided manufacturing (CAD/CAM) translated into the possibility ongf designi very precise TMJ prostheses based on the anatomy of each single patient. Custom-made TMJ prostheses are described in the most recent literature and provide facilitations in terms of ease of placement and accuracy. Although before the era of custom-made surgical guides, they did not play a prominent role in the field of TMJ surgery, their use has become mandatory when custom-made prostheses are used. Surgical guides, generally known also as cutting guides, allow the subcondylar bone cut to be performed according to the exact shape and size of the planned prostheses. Additionally, they allow the predrilling of fixation holes in the mandible to minimize errors in prostheses positioning. However, the design of surgical guides did not evolve over time as much as prostheses did. In this paper the authors critically analysed literature on this topic and described the improvements of surgical guides over time. Moreover, based on the findings of literature research, a new cutting guide system was developed and is proposed in this article.

A completely digital approach to replicating functional and esthetic parameters in mandibular implant-supported complete-arch prostheses.

Making an intraoral digital scan for fixed mandibular implant-supported complete-arch prostheses is a clinical challenge. The absence of references in the mandibular arch for precise scan alignment may complicate the correct digital design of the prosthesis framework. This article presents a straightforward method that allows a completely digital approach to digital scanning for fixed mandibular implant-supported prostheses.

The effect of the design of a mandibular implant-supported zirconia prosthesis on stress distribution.

STATEMENT OF PROBLEM: Prosthetic complications have been frequently reported in implant-supported complete-arch prosthesis. Prosthetic restorations designed with an all-on-four treatment concept and fabricated from zirconia ceramic may be used to overcome these problems. PURPOSE: The purpose of this biomechanical study was to evaluate the effects of cantilever length and inclination of implant on the stress distribution in bone tissue, implant, and a monolithic zirconia ceramic-lithium disilicate glass-ceramic superstructure for all-on-four prosthesis. MATERIAL AND METHODS: All-on-four mandibular prosthesis fabricated from a zirconia and lithium disilicate glass-ceramic (LDGC) superstructure was designed with cantilever lengths of either 5 mm or 9 mm and posterior implants with a distal tilt of either 15 or 30 degrees. Stresses were evaluated with a simulated application of a static load of 600 N. RESULTS: Increasing implant inclination from 15 to 30 degrees led to a decrease in maximum principal stress (MaxPS) values of approximately 4 to 7 MPa in cortical bone around all implants except the right anterior implant in the designs with short cantilevers and an increase in MaxPS values (approximately 3 to 19 MPa) in the same places in the designs with the long cantilevers. Increasing cantilever length from 5 to 9 mm resulted in an increase in minimum principal stress (MinPS) values of approximately 3 to 13 MPa in the cortical bone surrounding all posterior implants. In the designs with the long cantilever, MaxPS values increased approximately 3 to 4 MPa in spongy bone adjacent to the right posterior implant. An increase in cantilever length also led to higher vMS values at the first and second implant grooves in the right posterior implant in the design with the 15-degree implant tilt. An increase in implant inclination in the design with the short cantilever resulted in lower vMS values at the apex and all grooves of the left posterior implant, whereas in the design with the long cantilever, an increase in implant inclination resulted in lower stress values in the first and second grooves of the same implant. An increase in implant inclination led to in an increase in vMS values in the core structure. CONCLUSIONS: In zirconia ceramic restorations by using an all-on-four design with an LDGC superstructure, short cantilevers may be preferable because they result in a more favorable distribution of stress than long cantilevers. An increase in implant angulation from 15 to 30 degrees decreased MaxPS values in cortical bone.

Is the Fixed Mandibular 3-Implant Retained Prosthesis Safe and Predicable for Full-Arch Mandibular Prostheses? A Systematic Review.

PURPOSE: To evaluate implant and prosthetic survival rates of full-arch rehabilitations retained by three implants in patients with edentulous mandibles. MATERIALS AND METHODS: This systematic review was developed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The focused question was: Are fixed mandibular 3-implant retained prostheses safe and predicable for full-arch mandibular prostheses? The Medline/PubMed and Cochrane Library databases were used to conduct the systematic search for clinical trials on fixed mandibular 3-implant retained prostheses published between 1999 and 2020. Only English-language studies that presented information on implant and prosthetic survival were included. RESULTS: A total of 302 studies were identified, of which 13 addressed the inclusion criteria. Additionally, 574 participants were included in these studies. As reported, 73 (4.57%) of 1596 implants failed, with a survival rate of 95.43%. In addition, the mean survival rate of the presented prostheses was 89.66%. The mean marginal bone loss was 1.09 mm. CONCLUSION: Within the limitations of the present review, implant and prosthetic survival rates of fixed mandibular 3-implant retained prostheses were similar to those of full-arch mandibular prostheses retained by four or more implants. Further research exploring the topic is necessary.

The role of non-contact digitizer in geometrical evaluation of mandibular prostheses effect on facial asymmetry of mandibulectomy patients.

PURPOSE: This study sought to geometrically evaluate the effect of a mandibular prosthesis on facial asymmetry in patients with one of two different types of mandibulectomy defect. METHODS: Facial data from 20 participants (9 men and 11 women; mean age 68 years) with either a reconstructed segmental defect (segmental group,n = 10) or a marginal mandibulectomy defect (marginal group, n =10) were acquired with a non-contact three-dimensional (3D) digitizer. Facial asymmetry was evaluated by superimposing a facial scan onto its mirror scan using 3D evaluation software. Facial scans with and without the mandibular prosthesis in place were also superimposed to evaluate the effect of the mandibular prosthesis. RESULTS: Facial asymmetry differed significantly between subjects with and without the prosthesis in the segmental group (P = 0.005) but not in the marginal group (P = 0.16). There was no significant difference in the effect of the prosthesis on facial appearance between the two groups (P = 0.052). The ratio of 3D deviation of facial asymmetry without the prosthesis and in the mirror scan with the prosthesis differed significantly between the two groups (P = 0.01). CONCLUSIONS: Placement of a mandibular prosthesis has a notable effect on facial asymmetry in patients with segmental mandibulectomy defects.

Accuracy of fit analysis of the patient-specific Groningen temporomandibular joint prosthesis.

Total joint replacement (TJR) with a prosthesis can be indicated for patients with severe temporomandibular joint (TMJ) dysfunction. Surgical accuracy is necessary for correct translation of the preoperatively predicted functional outcome, wear, and biomechanical behaviour of the patient-specific TMJ-TJR prosthesis. This study describes the first clinical applications of the patient-specific TMJ-TJR prosthesis according to the Groningen principles (G-TMJ-TJR), which was developed and validated in a prior human cadaver test study. The aim of this study was to validate the accuracy of placement of the patient-specific G-TMJ-TJR in the clinical setting. It was hypothesized that a virtual surgical plan (VSP) combined with guided placement of the patient-specific G-TMJ-TJR would be performed as predictably and accurately as in the prior cadaver series. All patients who received a VSP-based patient-specific G-TMJ-TJR between December 2017 and March 2020 were included in this study. The accuracy analysis was based on postoperative cone beam computed tomography (CBCT) data. All 11 prostheses could be inserted using routine pre-auricular and retromandibular surgical approaches. Analysis of the VSPs and postoperative CBCTs showed an average three-dimensional deviation of 1.07mm (standard deviation 0.46mm, range 0.33-1.91mm) for all of the fossa and mandibular components. The patient-specific G-TMJ-TJR can be applied predictably and accurately in a clinical setting.

Biomechanical analysis of costochondral graft fracture in temporomandibular joint replacement.

This study is the first attempt to explore the reason of costochondral graft fracture after lengthy mandible advancement and bilateral coronoidectomy by combining finite element analysis and mechanical test. Eleven groups of models were established to simulate costochondral graft reconstruction in different degrees of mandible advancement, ranging from 0 to 20 mm, in 2 mm increment. Force and stress distribution in the rib-cartilage area were analyzed by finite element analysis. Mechanical test was used to evaluate the resistance of the rib-cartilage complex. Results showed a sharp increase in horizontal force between 8 and 10 mm mandible advancement, from 26.7 to 196.7 N in the left side, and continue increased after 10 mm, which was beyond bone-cartilage junction resistance according to mechanical test. Therefore, we concluded that bilateral reconstruction with coronoidectomy for lengthy mandible advancement (≥ 10 mm) may lead to prominent increase in shear force and result in a costal-cartilage junction fracture, in this situation, alloplastic prosthesis could be a better choice. We also suggested that coronoidectomy should be carefully considered unless necessary.

[Oral appliances for obstructive sleep apnoea: What can we expect?] / Orthèses d'avancée mandibulaire et syndrome d'apnées-hypopnées obstructives du sommeil : qu'en attendre ? Revue de la littérature, comparaison par design.

INTRODUCTION: Mandibular appliances are a treatment option for obstructive sleep apnea. There are many designs, but in the literature they tend to be grouped into a single entity without considering that efficiency, tolerance, compliance, or side effects are inherent in the design of each of them. A more detailed literature review is therefore warranted for the reader who wants to understand the relative effectiveness of each appliance. STATE OF KNOWLEDGE: We conducted a literature search using the "oral appliance" and "obstructive sleep apnea" criteria on Pubmed, Embase and Cochrane. This allowed us to compare outcome parameters by appliance class and to highlight the rare studies comparing different appliances. CONCLUSIONS: Mandibular appliances are not a homogeneous entity. Common use includes only appliances designed for propulsion (with rods and jacks) and retention. However, the few comparative studies available do not identify which are the most effective types or the types with an optimal efficacy/tolerance ratio. PERSPECTIVES: Further appliance comparison studies are needed to determine the most effective type or with an optimal efficacy/tolerance ratio.

Previously Reported Approach Now Used for Temporomandibular Joint Replacement.

Over time, different techniques have been described to obtain broad access to the temporomandibular joint (TMJ), in order to allow good visibility, minimizing post-operative complications at the same time. Most of these techniques have been very useful to perform joint replacement using custom made prostheses, varying in its extension, aesthetics and functional results. The aim of this study was to present the authors' experience using the Blair approach modified by Fernández in 2015, to replace failed TMJ prostheses, when distortion of the surgical reference points has occurred.

Prevalencia del Síndrome de Combinación y sus factores asociados en la Clínica de la Facultad de Odontología de la Universidad de Cuenca, periodo 2015-2016 / Prevalence of Combination Syndrome and associated factors at Clínica de la Facultad de Odontología, Universidad de Cuenca, 2015-2016

INTRODUCCIÓN: Un conjunto de cambios patológicos en el sistema estomatognático frente a la pre-sencia de una prótesis total maxilar y una prótesis parcial removible mandibular han sido descritos como el Síndrome de Combinación. El objetivo de este estudio fue determinar la prevalencia del sín-drome y si factores como la edad, el sexo o el tipo de edentulismo mandibular están asociados al mis-mo en los pacientes de la Clínica de la Facultad de Odontología de la Universidad de Cuenca período 2015-2016. MÉTODOS: Estudio observacional,transversal, descriptivo y de correlación. La muestra estuvo cons-tituida por 312 pacientes edéntulos. Se estableció la presencia del síndrome de combinación cuando un paciente presentaba un mínimo de tres signos asociados. Se determinó la prevalencia del síndro-me de combinación en la muestra y la asociación entre las variables sexo, edad, tipo de edentulismo con la presencia de síndrome de combinación. RESULTADOS: La prevalencia del SC resultó en un 21.8%. Padecer de edentulismo parcial clase I de Kennedy (3.6 veces mayor probabilidad que los otros tipos de edentulismo) y ser adulto mayor de 60 años (1.8 veces mayor probabilidad), tuvieron asociación con el desarrollo del síndrome de Combinación. CONCLUSIÓN: La prevalencia de SC es del 21.8%, la progresión de la edad y el edentulismo parcial clase I de Kennedy conducen a una mayor probabilidad para desarrollar el síndrome de combinación y deben evaluarse como factores de riesgo.(au)

BACKGROUND: The set of pathological changes in the stomatognathic system in the presence of a total maxillary prosthesis and a removable partial mandibular prosthesis has been described as the Combi-nation Syndrome. The main purpose of this study was to determine its prevalence and if features such as age, sex or type of mandibular edentulism are associated with the syndrome in the patients of the Odontologic Clinic of the of Faculty of Dentistry, Universidad de Cuenca during the academic period 2015-2016. METHODS: Cuantitative, cross sectional descriptive and correlational study. The sample consisted of 312 edentulous patients. The diagnosis of the syndrome in this study was determined by the presence of a minimum of three associated signs. We determine the prevalence of combiantion syndrome and the as-sociation between sex, age and edentulism type and combination syndrome. RESUlTS: The prevalence of combination syndrome is 21.8%. Adults 60 years or older (1.8 times higher probability) and patients who suffer from Kennedy class I partial edentulism (3.6 times higher probability than other types of edentulism), have a higher probability for developing the syndrome. CONClUSION: The prevalence of CS was 21.8%, age and suffering from Kennedy class I partial edentulism should be considered as risk factors for developing the syndrome.(au)