Modificación de la actividad metabólica por medio de un dispositivo intraoral en pacientes con hiperplasia condilar confirmada por SPECT / Metabolic activity modification by means of an intraoral device in patients with condylar hyperplasia confirmed by SPECT

Objetivo: Evaluar los efectos de la aplicación de un dispositivo intraoral de uso permanente en el comportamien- to de los cóndilos con hiperplasia condilar (HC) confirmada por tomografía computarizada de emisión por fotón único (SPECT), estableciendo una comparación con un grupo de pacientes con HC que no utilizó el dispositivo. Materiales y métodos: 30 pacientes con una edad promedio de 21,7 años (+/-5,56) con HC confirmada con SPECT fueron asignados al azar a dos grupos: a los del grupo I (n=18) se les colocó un dispositivo intraoral de uso perma- nente para modificar la posición de la mandíbula, mientras que a los del grupo II (n=12) no se les colocó ningún dispo- sitivo. Se realizaron evaluaciones de dolor, del desvío de la línea media, de la apertura máxima y del disconfort al inicio del estudio y a los 2, 4, 6, 10, 12 y 14 meses. A los 19 meses promedio, la actividad osteoblástica (AO) fue reevaluada me- diante SPECT. Resultados: En el grupo I, la AO en los cortes coro- nales y transversales cesó o disminuyó (p<0,001) respecto a la condición inicial, mientras que en el grupo II la AO au- mentó (p<0,001). Los datos fueron analizados utilizando el test de Wilcoxon de rangos signados. Al ajustar un modelo de ANCOVA robusto utilizando el valor inicial como covariable también se observa que el efecto del grupo fue estadística- mente significativo en ambos cortes (p<0,001). Conclusiones: La aplicación de un dispositivo intrao- ral de uso permanente mejora la evolución de la hiperplasia condilar, lo que lo puede convertir en un tratamiento de uti- lidad para el tiempo que se aguarda para realizar una condi- lectomía alta de cuello de cóndilo, o incluso para evitar este procedimiento (AU)

Objective: To evaluate the effects of the application of an intraoral device for permanent use on the behavior of con- dyles with condylar hyperplasia (CH) confirmed by single photon emission computed tomography (SPECT), establish- ing a comparison with a group of patients with CH that did not use the device. Materials and methods: Thirty patients with an aver- age age of 21.7 years (+/-5.56) with CH confirmed by SPECT were randomly divided into two groups: the ones in group I (n=18) received an intraoral device for permanent use to align the mandible, while those in group II (n=12) did not get any device. Pain, midline shift, maximum opening, and discomfort were evaluated at the beginning of the study and at 2, 4, 6, 10, 12, and 14 months. At an average of 19 months, osteoblastic activity (AO) was reassessed by SPECT. Results: In group I, the AO in the coronal and trans- verse sections ceased or decreased (p<0.001) in comparison to the initial condition, while in group II the AO increased (p<0.001). The data was analyzed by the Wilcoxon signed rank test. Adjusting a robust ANCOVA model using the ini-tial value as a covariate made it possible to observe that the effect of the group was statistically significant in both cuts (p<0.001). Conclusions: The application of an intraoral device for permanent use improves the evolution of condylar hyperpla- sia, which can make it a useful treatment until a high condylectomy of the neck of the condyle is performed, or even to avoid this procedure (AU)

Effectiveness of low-intensity pulsed ultrasound on osteoarthritis of the temporomandibular joint: A review.

Loading is indispensable for the growth, development, and maintenance of joint tissues, including mandibular condylar cartilage, but excessive loading or reduced host adaptive capacity can considerably damage the temporomandibular joint (TMJ), leading to temporomandibular joint osteoarthritis (TMJ-OA). TMJ-OA, associated with other pathological conditions and aging processes, is a highly degenerative disease affecting the articular cartilage. Many treatment modalities for TMJ-OA have been developed. Traditional clinical treatment includes mainly nonsurgical options, such as occlusal splints. However, non-invasive therapy does not achieve joint tissue repair and regeneration. Growing evidence suggests that low-intensity pulsed ultrasound (LIPUS) accelerates bone fracture healing and regeneration, as well as having extraordinary effects in terms of soft tissue repair and regeneration. The latter have received much attention, and various studies have been performed to evaluate the potential role of LIPUS in tissue regeneration including that applied to articular cartilage. The present article provides an overview of the status of LIPUS stimulation used to prevent the onset and progression of TMJ-OA and enhance the tissue regeneration of mandibular condylar cartilage. The etiology and management of TMJ-OA are explained briefly, animal models of TMJ-OA are described, and the effectiveness of LIPUS on cell metabolism and tissue regeneration in the TMJ is discussed.

Reabsorción Condilar como Complicación Postoperatoria en Pacientes Sometidos a Cirugía Ortognática. Revisión Narrativa / Condylar Resorption as a Postoperative Complication in Patients Undergoing Orthognathic Surgery. Narrative Review

RESUMEN: La reabsorción condilar como complicación postoperatoria en cirugía ortognática es una causa frecuente de recidiva de anomalías dentomaxilares, existiendo diversos factores que se relacionan con su aparición. El objetivo de este estudio fue describir mediante una revisión narrativa la reabsorción condilar como complicación postoperatoria en cirugía ortognática. Se realizó una búsqueda electrónica de la literatura en las bases de datos electrónicas PubMed, EBSCO, TripDatabase y Epistemonikos sin límite de años, en idioma inglés y español, incluyendo revisiones sistemáticas, ensayos clínicos y estudios observacionales. Se excluyeron reportes de casos, estudios en animales y aquellos que no relacionaran la complicación con cirugía ortognática. Se evaluaron los estudios según grado de recomendación y calidad de reporte. Veintiún artículos fueron seleccionados según los criterios de selección establecidos en esta revisión. La literatura reportada sugiere que la reabsorción condilar es una patología de frecuencia relativa en pacientes postoperados de cirugía ortognática (1,4-32 % de los casos) y que está asociada a factores de riesgo preoperatorios tales como género, edad, tipo de anomalía dentomaxilar y técnica quirúrgica utilizada. La reabsorción condilar es una complicación postoperatoria a cirugía ortognática que debemos considerar en la planificación del tratamiento e identificar pacientes con factores de riesgo. Luego de la intervención quirúrgica es de vital importancia realizar un seguimiento estricto a este tipo de pacientes e identificar de forma temprana cambios clínicos y radiográficos. Finalmente, es importante seguir investigando sobre esta materia para establecer criterios de prevención y diagnóstico, con mayor claridad.

ABSTRACT: Condylar resorption as a complication following orthognathic surgery is considered to cause dento-facial anomalies, relating to different pre and intra-operative factors. The aim of the research was to describe condylar resorption as a postoperative complication after orthognathic surgery. A review of the literature was made in four databases: PubMed, EBSCO, Trip database and Epistemonikos. The search was carried out without year limiting, articles in English and Spanish, including systematic reviews, observational studies and clinical trials. Exclusion criteria were applied for report cases, animal studies and articles that do not relate condylar resorption with orthognathic surgery. Quality of evidence and strength of the recommendations were assessed for the chosen studies. For this study 21 articles were selected following the inclusion criteria. The literature found reported that condylar resorption is a relatively frequent complication following orthognathic surgery (1.4-32 % of frequency) and that it can be associated with several factors such as genre, age, dento-maxillary anomaly and surgical technique. Condylar resorption is a complication that we must consider in the planning of orthognathic surgery, in order to identify risk factors and patients who are more likely to present this post-surgical complication. Following surgery, strict follow-up is a key factor to determine early clinical and radiographic changes. Finally, further research is needed to establish stronger prevention and diagnostic criteria.

Investigating possible correlation between condylar asymmetry and clinical dysfunction indices in patients with temporomandibular dysfunction using Cone-beam computed tomographic.

PURPOSE: Temporomandibular disorder (TMD) is a common problem in modern societies. Causes of TMD, as a consequence of condylar asymmetry index (CAI), are still a subject of controversy. The aim of the present study was to determine the possible correlations between the degree of condylar asymmetry and clinical dysfunction indices. MATERIALS AND METHODS: In this cross-sectional study, we used the Habets method to measure the CAI in 42 TMD patients. The participants' age and sex were matched in the control group. Patients were divided into mild, moderate and severe dysfunction groups based on Helkimo's clinical Di. The data were analyzed using Mann-Whitney U and Kruskal-Wallis tests. Also, the study attempted to assess the possibility of correlation between age and CAI. RESULTS: The CAI values of TMD patients were significantly higher than those of the control group (P = 0.001). However, CAI was not significantly different among TMD patients with different dysfunction index. There was no significant correlation between CAI and age (Spearman r = 0.655, P = 0.23). CONCLUSION: Based on the findings of the present study, patients with condylar asymmetry index are more susceptible to TMD. However, degree of the condylar asymmetry is not a criterion for TMD signs and symptoms.

Protective Effects of Low-Intensity Pulsed Ultrasound on Mandibular Condylar Cartilage Exposed to Mechanical Overloading.

The aim of this study was to assess the effect of low-intensity pulsed ultrasound (LIPUS) application on rat temporomandibular joints (TMJs) with early-stage of osteoarthritis-like conditions induced by mechanical overloading. Fifteen-week-old male Wistar rats were divided into two experimental groups and a control group (n = 10 each). Both TMJs of all rats in one experimental group were subjected to mechanical overloading for 5 d, and those in the other experimental group were exposed to LIPUS for 20 min/d after overloading. Condyles were assessed using micro-computed tomography, histology and histomorphometry. LIPUS treatment attenuated cartilage degeneration, decreased the number of osteoclastic cells and restored the expression of aggrecan after an initial decrease induced by mechanical overloading. These results indicate that LIPUS may have a protective effect on the early progression of TMJ osteoarthritis.

Condylar head remodeling compensating for condylar head displacement by orthognathic surgery.

The purpose of this study was to evaluate the association between kind of condylar displacement due to orthognathic surgery and the subsequent adaptive condylar head remodeling. The sample in this retrospective cohort study consisted of 30 patients (12 female and 18 male; mean age 22.7 y) with skeletal Class III malocclusion who underwent bilateral sagittal split ramus osteotomy (SSRO). Three-dimensional superimpositions of cone-beam computed tomography (CBCT) scan derived images from immediately after and 6 months after surgery were to reveal the type of remodeling, while images from before and immediately after surgery were to identify the type of condylar displacement. Laterally displaced condyles showed bone resorption on the lateral surfaces and deposition on the medial surfaces, whereas the contrary was found in medially displaced condyles. Anteriorly displaced condyles showed resorption on the anterior surfaces and deposition on the posterior surfaces, whereas the contrary was found in posteriorly displaced condyles. Superior surfaces of the condyles showed bone resorption regardless of displacement direction. The results indicate that condylar remodeling patterns (resorption/deposition) are determined by the direction of condylar displacement during surgery. However, condylar displacement by surgery is not completely compensated by condylar head remodeling, especially in case of downward displacement.

Alterations of mandibular movement patterns after total joint replacement: a case series of long-term outcomes in patients with total alloplastic temporomandibular joint reconstructions.

According to recognized guidelines, a total alloplastic replacement may be indicated to resolve temporomandibular pain and functional limitations in cases where conservative and less aggressive surgical management strategies have failed. It is broadly believed that, as a result of the surgical procedure, the function of the lateral pterygoid muscle is lost and so are the laterotrusive and protrusive jaw movements. Furthermore, the joint prosthesis design may not be conducive to lateral and protrusive movements. Using a dynamic stereometry technique, it was possible to perform a quantitative analysis of kinematics in TJR patients. The cases of four patients who showed preserved lateral and/or protrusive motion are presented here. During mouth opening, prosthetic condyle translation ranged from 3.18mm to 10.09mm and it was also possible to observe this clinically. It has been suggested that changes in prosthesis design may have improved postoperative jaw kinematics. Considering the large diversity in treatment outcomes, it is recommended that the individual prognosis should always be discussed with the patient prior to surgery.

Micro-CT observation of in vivo temporal change in mandibular condyle morphology in BMAL1 knockout mice.

Brain and muscle Arnt-like protein-1 (BMAL1) knockout mice exhibit accelerated aging, abnormal glucose metabolism, and impaired adipocyte differentiation, among other phenotypes, which are effects associated with the BMAL1 gene. No study has investigated temporal changes in the deformation of the mandibular condyle and the presence of calcification in areas surrounding the mandibular condyle. In a study of 12 C57/BL strain mice under inhalation anesthesia, we collected images of the mandibular condyle at 6 weeks after birth and then every 5 weeks from 10 to 25 weeks after birth. At 25 weeks, deformation of the mandibular condyle was seen in 8 of 12 joints in BMAL1 knockout mice and in 2 of 12 joints in wild-type mice. At 20 and 25 weeks, deformation in areas surrounding the mandibular condyle, which are known to undergo calcification, was seen in 2 of 12 joints in BMAL1 knockout mice and in 0 of 12 joints in wild-type mice. BMAL1 knockout mice exhibited premature aging of the mandibular condyle, which suggests that circadian rhythms affect mandibular condyle morphology.

Three-Dimensional Analysis of Perioperative Condylar Displacement After Mandibular Setback Surgery With Intended Manual Condylar Positioning.

PURPOSE: The purpose of this study is to investigate the effect of orthognathic surgery with intended manual condylar positioning on condyle by examining a change in its position. METHOD: About 18 patients with mandibular prognathism who underwent orthognathic surgery with intentional manual condyle positioning were included. Condyle displacement was analyzed through 3D cone-beam computed tomography before and after operation. The patients were categorized into 2 experimental groups: group A (1-jaw) and group B (2-jaw). The experimental groups were examined before surgery (T0), 3 days (T1), and 6 months (T2) after surgery. Condylar displacement direction was investigated in terms of bodily shift and rotational movement. RESULTS: Downward bodily shift of condyle after surgery was significantly apparent from all of the patients. Condylar bodily shift in other directions was statistically insignificant. Gross bodily shift of condyle right after surgery was anterolateral-inferior direction. In perspective of rotational movement, condyle rotated in infero-medial direction right after operation, but no significant change was presented afterwards. In addition, no significant difference in the amounts of condylar shift and pattern existed between groups A and B. CONCLUSION: Intended manual condylar positioning may minimize postoperative displacement of condyle while accomplishing skeletal stability.

Impact of Bone Volume Upon Condylar Activity in Patients With Unilateral Condylar Hyperplasia.

PURPOSE: Unilateral condylar hyperplasia or hyperactivity (UCH) is a bone overgrowth disorder affecting the mandible. The purpose of this study was to determine the relations among age, condylar bone structure, condylar bone volume, and condylar bone activity on single-photon emission computed tomographic (SPECT) scans in patients with UCH. MATERIALS AND METHODS: This study included 20 patients with a clinical presentation of progressive mandibular asymmetry and a positive bone SPECT scan. A bone SPECT-derived standardized uptake value (bSUV) for the condylar region was determined. All patients underwent condylectomy to arrest further progression of the disease. The resected condyles were scanned with a micro-computed tomographic scanner (18-µm resolution). Bone architectural parameters were calculated with routine morphometric software. RESULTS: The mean bSUV of the condyle on the affected side was 15.32 (standard deviation [SD], 8.98) compared with 9.85 (SD, 4.40) on the nonaffected side (P = .0007). For trabecular bone structure, there was a nonsignificant correlation between the SUV of the affected condyle and the measured bone volume fraction (r = 0.13; P = .58) and trabecular thickness (r = 0.03; P = .90). CONCLUSION: No meaningful relation was found between condylar bone volume fraction and condylar activity on bone scan; therefore, the impact of bone volume fraction on the results of bone scans is limited. The measured condylar activity on SPECT scan seems to be primarily a reflection of the remodeling rate of bone.

Condylar positions before and after bilateral mandibular distraction osteogenesis in children with Pierre Robin sequence.

This study aimed to analyze the changes in mandibular morphology after bilateral mandibular distraction osteogenesis (BMDO) in children with Pierre Robin sequence. The positions of the condyles were analyzed in reconstructed three-dimensional craniomaxillofacial images obtained for 18 children before and 8-12 weeks after BMDO. Differences between pre- and postoperative parameters were assessed using paired t-tests. After surgery, a significant decrease in superior joint space was detected (P<0.05), but no change in anterior joint space or posterior joint space was observed. The ratio of the distance between gonia and distance between condylion points (GoL-GoR/CoL-CoR) (P<0.001) and the distances between the condyle and midsagittal plane (P<0.001) increased after surgery, while the condylar horizontal angle decreased (P<0.05). No change in condylar vertical angle was noted. After BMDO, the condyle displayed an outward and upward shift, as well as outward rotation along the proximal segment. The mandible body exhibited forward movement with a more significant opening range. These changes were consistent with the extent of the newly formed bone tissue and the improvement in coordination and appearance of the children's facial structures. The long-term effects of changes in condylar position on the development of the maxillofacial structures needs to be studied further.

Four-Dimensional Computed Tomography Evaluation of Condylar Movement in a Patient With Temporomandibular Joint Osteoarthritis.

Temporomandibular joint (TMJ) osteoarthritis (OA) is a disease of the bone, cartilage, and supporting tissues of the joint. Patients with advanced TMJ-OA often have symptoms such as pain, swelling, and joint dysfunction, and they sometimes require surgical intervention when conservative treatment is not effective. The etiology of TMJ-OA remains elusive. The usefulness of 4-dimensional (4D) computed tomography (CT) in motion analysis of various joints has recently been reported. This article introduces a novel imaging technique of 4D CT that aims to identify kinematic features that may be associated with the etiology of TMJ-OA. In a 69-year-old female patient with severe TMJ-OA, 4D CT evaluation of condylar movement was performed. During the scan, she was instructed to masticate a cookie normally and her natural condylar movement during mastication was evaluated. The coronal 4D CT motion images showed that the synovial cavity was narrower on the affected side than on the unaffected side. Repeated friction between the articular surface of the condyle and the caudal surface of the articular eminence was observed during natural mastication. Although friction between the condyle and articular eminence has been considered a factor in the initiation and progression of TMJ-OA in previous experimental studies using animals, this is the first study to directly visualize the friction between the atrophic and flattened condylar surface and the articular eminence. Four-dimensional CT is a novel imaging technique with the potential to assess kinematic features that cannot be visualized with other imaging modalities in patients with TMJ disease.

Metrical analysis of disc-condyle relation with different splint treatment positions in patients with TMJ disc displacement

Abstract Objective: To evaluate the effect of bite positions characterizing different splint treatments (anterior repositioning and stabilization splints) on the disc-condyle relation in patients with TMJ disc displacement with reduction (DDwR), using magnetic resonance imaging (MRI). Material and Methods: 37 patients, with a mean age of 18.8±4.3 years (7 male and 30 females) and diagnosed with DDwR based on the RDC/TMD, were recruited. MRI metrical analysis of the spatial changes of the disc/condyle, as well as their relationships, was done in three positions: maximum intercuspation (Position 1), anterior repositioning splint position (Position 2), and stabilization splint position (Position 3). Disc/condyle coordinate measurements and disc condyle angles were determined and compared. Results: In Position 1, the average disc-condyle angle was 53.4° in the 60 joints with DDwR, while it was −13.3° with Position 2 and 30.1° with Position 3. The frequency of successful "disc recapture" with Position 2 was significantly higher (58/60, 96.7%) than Position 3 (20/60, 33.3%). In Positions 2 and 3, the condyle moved forward and downward while the disc moved backward. The movements were, however, more remarkable with Position 2. Conclusions: Anterior repositioning of the mandible improves the spatial relationship between the disc and condyle in patients with DDwR. In addition to anterior and inferior movement of the condyle, transitory posterior movement of the disc also occurred.

The effect of bone mass and architecture on mandibular condyle after mandibular distraction.

OBJECTIVE: Mandibular distraction surgery is a critical treatment for jaw deformity. However, abnormal mandibular condylar bone resorption is often seen as complication after surgery. Our previous study using a rat mandibular distraction model suggested that overloading leads to mandibular condylar resorption. Host factors are also believed to influence the resorption. To understand the relationship between host factors and resorption, we investigated the effect of changing bone mass and architecture on the mandibular condyle using FK506. STUDY DESIGN: FK506, an immunosuppressant, was used to compromise bone mass and architecture in this study. Animals were divided into 4 groups: distraction surgery (Dist), FK506 administration (FK), distraction surgery with FK506 administration (FK + Dist), and no surgery or FK506 administration (Cont). RESULTS: The FK group showed reduced bone mass and impaired bone architecture. The Dist group exhibited abnormal bone resorption on the surface of the condyles, which was slightly exacerbated in the FK + Dist group. Bone defect length decreased over time as a result of bone apposition in the Dist group. However, in the FK + Dist group, the bone defect length remained the same. CONCLUSIONS: These results suggest that bone mass and architecture strongly affect the tolerance to the overloading and adaptation with bone apposition in condylar resorption site.

Surface electromyography before and after orthognathic surgery and condylectomy in active laterognathia: a case report.

BACKGROUND: Condylar hyperplasia is a rare bone disease characterised by excessive development of mandibular condyle, which can lead to the development of asymmetric facial deformity together with malocclusion, mandibular deviation, TMJ and masticatory musculoskeletal system dysfunction. There is not a treatment protocol universally accepted. In order to determine the correct management, treatment and intervention timing of these patients, morphological examinations should be coupled with functional assessments. CASE REPORT: In the present case report, morphological (bone scintigraphy; orthopantomography; posteroanterior and lateral cephalograms; 3D facial photographs) and functional (surface electromyography of masseter and temporalis muscles) quantitative data of a 20-year-old male patient affected by unilateral condylar hyperplasia are presented. The patient underwent a surgical treatment with high unilateral condylectomy associated to a maxillary Le Fort I osteotomy; as well as orthodontic treatment before and after surgery. Facial morphology and masticatory muscles activity were assessed before surgery and followed-up 6, 12 and 24 months after surgery. Twenty-four months after surgery, all electromyographic values were normal, and soft-tissue facial asymmetry was negligible at 3D assessment. CONCLUSION: Surface electromyography joins a set of clinical and morphological diagnostic tests that help the surgeon in planning the operation and managing the post-surgical patient.

The association between condylar bone changes revealed in cone beam computed tomography and clinical dysfunction index in patients with or without temporomandibular joint disorders.

OBJECTIVE: The aim of the present study was to compare cone beam computed tomography (CBCT) findings pertinent to patients with temporomandibular disorder (TMD) and patients without TMD (non-TMD), as well as to investigate the correlation between these findings and the clinical dysfunction index (Di). STUDY DESIGN: In this cross-sectional study, CBCT images of temporomandibular joints (TMJs) were evaluated for condylar bone changes in 84 patients with TMD. The patients were assigned a score using Helkimo's clinical Di, ranging from 1 to 25, and were thereafter subdivided into 3 groups based on the degree of Helkimo's Di. CBCT and clinical records of sex- and age-matched non-TMD patients were used as the control group. RESULTS: There was a significant difference in the prevalence of all types of bone changes between TMD and non-TMD groups (all P < .05), except for loose joint bodies. Furthermore, there was a significant correlation between the total amount of bone change and the Helkimo Di score (P < .001). CONCLUSION: Evaluation of CBCT images in the present study revealed significant differences between TMD and non-TMD condyles. There was also a significant relationship between the Helkimo clinical Di and the total amount of condylar bone change in patients with TMD.

Cone-beam computed tomography evaluation of the maxillofacial features of patients with unilateral temporomandibular joint ankylosis undergoing condylar reconstruction with an autogenous coronoid process graft.

OBJECTIVE: To evaluate the changes in the jaws and the upper airways of unilateral temporomandibular joint ankylosis patients who underwent condylar reconstruction via autogenous coronoid process grafts using cone-beam computed tomography (CBCT). STUDY DESIGN: The 27 included patients underwent CBCT examinations at three stages: T0 (within two weeks before surgery), T1 (two weeks after surgery), and T2 (an average of 13 months after surgery). Forty items related to the maxillofacial hard tissues and the upper airway collected at the three times and the coronoid process graft volumes after surgery were compared. RESULTS: Some integral items related to the mandibular hard tissues exhibited statistical difference shortly after surgery. Some integral items related to maxillofacial hard tissues changing obviously long period after surgery may result from graft remodeling. Asymmetry-related item regarding local neo-condyle and some airway items were significantly different between T0 and T1. Due to variations in graft remodeling, some related local asymmetry items and airway items differed significantly between T0 and T2. CONCLUSIONS: Anteriorly and inferiorly located neo-condyles and a trend toward the pronation of the mandible were observed and the narrowness of the upper airway was improved shortly after surgery. The grafts remodeled differently and some integral and asymmetry items related to neo-condyle changed. The improvements in the upper airway were slightly reduced.

Use of Mini-anchors and Rehabilitation with 0° Cusp Angle Teeth Complete Denture in Recurrent Condylar Dislocation: Technical Adequacy and Procedure.

AIM: To report a case of association between the surgical treatment of temporomandibular dysfunction and rehabilitation with denture total prosthesis (TP) using nonanatomic teeth (cusp 0°) in patients with anterior recurrent dislocation of the temporo-mandibular joint (TMJ) and persistent uncontrolled mandibular movement, showing a technical adaptation and conduct. INTRODUCTION: There are several treatment approaches available for dislocation of the TMJ. The use of condylar mini-anchors for recurrent TMJ dislocation is a valid option and should be considered since it does not alter the joint anatomy. In edentulous patients undergoing TMJ surgical procedures, prosthetic rehabilitation can be seen as a means of treatment preservation. CASE REPORT: A 73-year-old female patient attended the oral and maxillofacial surgery clinic presenting with joint instability, ligament laxity, and chronic recurrent TMJ dislocations. She had already been through three previous unsuccessful surgical procedures. A treatment plan was done based on the installation of a mini-anchor in the patient's TMJ through the preauricular surgical access. Dislocations were then resolved, but the lack of mandibular control even to a lesser extent after surgery precluded the use of prosthetics even at rest. Thus, it was planned to manufacture two conventional TPs with 0° cusp angle teeth, a clinical protocol shortened to three sessions in an attempt to improve the stability of the prosthesis. CONCLUSION: The use of an individual mini-anchor is simple and effective, and the use of artificial teeth is well suited to the case. CLINICAL SIGNIFICANCE: A multidisciplinary intervention (surgery/ prosthesis) is of utmost importance for the resolution and preservation of the treatment of these complex cases.

Experimental comparison between tractional and compressive stress on temporomandibular joint.

OBJECTIVE: We experimentally compared the effects of compressive and tractional mechanical stress on the temporomandibular joint (TMJ) of rabbits to assess the etiology of progressive condylar resorption. MATERIALS AND METHODS: We performed a cortical osteotomy using custom-made devices that were lengthened by 0.25 mm every 12 h for 1 week after surgery. During this time, the rabbit TMJ was under compressive or tractional mechanical stress. The samples in each group were examined using micro-computed tomography and histological staining. RESULTS: Scores for the area of bone resorption were higher in the compressive group than in the tractional group. Moreover, scores for the depth of bone resorption were higher in the compressive group than those in the tractional group. We observed a significantly higher prevalence of resorption in the subcondylar bone in the compressive group than in the tractional group. There were substantially more cells that were positive for tartrate-resistant acid phosphatase in the compressive group than in the control and tractional groups. CONCLUSIONS: The outcomes here suggest that excessive mechanical stress, particularly compressive mechanical stress, may significantly affect morphological bone change findings in the TMJ.