Hamular bursitis as a cause of orofacial pain. A case report.

Pterygoid hamular bursitis is an infrequent cause of orofacial pain due to a hypertrophic pterygoid hamulus. The pain is often referred to the pharynx, temporomandibular region and facial zone, and requires a differential diagnosis with other craniofacial entities. This paper describes a patient with pterygoid hamular bursitis that presented pain of neuropathic characteristics in the left retromolar region, associated with odynophagia and temporomandibular joint disorders. Based on the clinical and radiological findings, a surgical resection of the pterygoid hamulus was decided. After the surgical procedure the patient still reported symptoms so additional specific treatments such as peripheral nerve block and infiltration were performed. Four months later, the patient developed a squamous cell carcinoma on the left margin of the tongue, which was surgically treated. At present (thirty months follow-up), the patient has no pain or signs of tumor relapse. Key words:Pterygoid hamular bursitis, orofacial pain, oral carcinoma, temporomandibular joint disorders, radiofrequency, neuropathic pain.

Comparison of the Masticatory Force (with 3D Models) of Complete Denture Base Acrylic Resins with Reline and Reinforcing Materials.

The reinforcement of acrylic denture base remains problematic. Acrylic prosthesis fractures are commonly observed in prosthodontic practice and have not been reliably resolved. This study compared the resistance to masticatory force of acrylic bases of removable complete conventional prosthesis in 3D upper models. Forty acrylic base test specimens containing two types of reinforcement meshes (20 with glass fiber meshes (FIBER-FORCE®- Synca, Bio Composants MédicauxTM, Tullins, France), 20 with metal meshes (DENTAURUM®-Ispringen, Germany)), 20 with a conventional PMMA acrylic base (LUCITONE 199®-Dentsply Sirona, York, PA, USA), and 20 using a permanent soft reline material (MOLLOPLAST-B®-DETAX GmbH & Co. KG, Ettlingen, Germany) were tested-a total of 80 specimens. Half of the specimens were made for a low alveolar ridge and half for a high alveolar ridge. The data were analysed using one-way analysis of variance and Student's t-test for independent test specimens. In the high-alveolar-ridge group, the prosthesis reinforced with the glass fiber mesh was the most resistant to fracture, while in the low-alveolar-ridge group, the non-reinforced prosthesis showed the highest resistance masticatory force. Prostheses with the permanent soft reline material showed the lowest resistance to fracture in both high and low-alveolar-ridge groups. The results show that the selection of the right reinforcement material for each clinical case, based on the height of the alveolar ridge, may help to prevent prosthesis fractures.

Comparison of CAD-CAM and traditional chairside processing of 4-unit interim prostheses with and without cantilevers: Mechanics, fracture behavior, and finite element analysis.

STATEMENT OF PROBLEM: How processing by computer-aided design and computer-aided manufacturing (CAD-CAM) or traditional chairside fabrication techniques affects the presence of defects and the mechanical properties of interim dental prostheses is unclear. PURPOSE: The purpose of this in vitro study was to compare the effects of CAD-CAM versus traditional chairside material processing on the fracture and biomechanical behavior of 4-unit interim prostheses with and without a cantilever. MATERIAL AND METHODS: Two types of 4-unit interim prostheses were fabricated with abutments on the first premolar and first mandibular molar, one from a prefabricated CAD-CAM block and one with a traditional chairside polymer-monomer autopolymerizing acrylic resin (n=10). Both groups were assessed by compressive strength testing and additionally with or without a cantilevered second molar by using a universal testing machine with a 5-kN load cell. A finite element model (FEM) was built by scanning both prosthesis designs. Finite element analysis (FEA) replicated the experimental conditions to evaluate the stress distribution through the prostheses. RESULTS: Interim fixed prostheses manufactured by CAD-CAM showed significantly higher mean fracture loading values (3126 N to 3136 N) than for conventionally made interim fixed prostheses (1287 N to 1390 N) (P=.001). The presence of a cantilever decreased the fracture loading mean values for CAD-CAM (1954 N to 2649 N), although the cantilever did not influence the traditional prostheses (1268 N to 1634 N). The highest von Mises stresses were recorded by FEA on the occlusal surface, with the cantilever design, and at the transition region (connector) between the prosthetic teeth. CONCLUSIONS: Interim partial prostheses produced by CAD-CAM had a higher strength than those manufactured traditionally. The presence of a cantilever negatively affected the strength of the prostheses, although the structures manufactured by CAD-CAM still revealed high strength and homogenous stress distribution on occlusal loading.

Torsion Resistance of the Ball Head System Screw and Screwdriver for Angled Screw Channels on Implant Prosthetics.

The primary objective of this study was to determine the torsion resistance of the Ball Head System (BHS) screw and screwdriver set at 0°, 20°, and 30° angulations. The secondary objective was to compare the BHS set with the 1.3-mm hexagonal screwdriver system (HexS) at 20° and analyze the condition of the BHS after 10 and 30 iterations with 30 N·cm torque at 30° angulation. A workbench made from type 4 plaster with 6 steel implant replicas (external hexagon, 4.1 mm) inserted at 0°, 20°, and 30° angulation was designed. An analogical torque meter was used. The deformations produced on the whole set were examined by field emission scanning electron microscopy. A descriptive analysis was performed. The maximum torque performance for BHS at 30° angulation was 54 ± 12 N·cm. Most screws could be removed despite the deformations produced. At 20° angulation, the BHS set achieved an average torque resistance of 67 ± 12 N·cm, whereas the HexS failed at 45 ± 2 N·cm. Although the iterations performed at 30 N·cm torque and 20° angulation produced some deformations on BHS sets; these could be tightened and unscrewed. The BHS allows tightening at a torque of up to 54 N·cm. Under the same conditions, BHS showed more torque resistance than HexS. Deformation of BHS sets was directly related to the number of iterations.

Novel Ball Head Screw and Screwdriver Design for Implant-Supported Prostheses With Angled Channels: A Finite Element Analysis.

The primary objective of this study was to design the optimal geometry of a novel screwdriver, create the grooves on a ball head screw, and demonstrate its resistance to a torque of up to 40 Ncm at angulations of 0°, 15°, and 30° by using nonlinear finite element analysis. A secondary objective was to create a foolproof, easily recognizable system. The grooved ball head screw and geometry of the screwdriver, functioning from an angulation of 0° to 30°, was generated using Pro-ENGINEER Wildfire 5.0 software. Static structural analyses among bodies in contact were performed at different angles of 0°, 15°, and 30° at a torque of 20 Ncm and 40 Ncm using nonlinear finite element simulation by means of ANSYS 12.0. The maximum stress supported by the ball head screw and screwdriver was similar at 20 Ncm and 40 Ncm. Although greater deformations were found at 40 Ncm, these were small and might not affect the performance of the system. Further, the rupture torque value for the M2 connection was 55 Ncm for 0° and 30°, and 47.5 Ncm for 15°. Numerical simulation showed that the ball head system design can achieve the mechanical strength requirements expected for screws used in implant-supported restorations at an angulation of up to 30°. Finite element analysis showed this novel ball head screw and screwdriver system to be a good solution for angled screw channels in implant-supported prostheses.

Effect of abutment angulation in the retention and durability of three overdenture attachment systems: An in vitro study.

PURPOSE: This in vitro study investigated and compared the durability and retention of three types of attachments. MATERIALS AND METHODS: Three commercially available attachments were investigated: Clix®, Dalbo-Plus® and Locator®. In total, 72 samples of these attachments were placed in the acrylic resin forms and subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH 7 and 37℃. The abutments were placed at angulations of 0°, 10° and 20°. The retention force was recorded at the beginning and after 540, 1080, 2160, 3240, 4320 and 5400 insertion-removal cycles. RESULTS: The results revealed that there were significant differences in the average values of the insertion/removal force due to angulation (F (2.48) = 343619, P<.05) and the type of attachment (F (7.48) = 23.220, P<.05). CONCLUSION: Greater angulation of the abutments was found to influence the retention capacity of the attachments, and the fatigue test simulating 5 years of denture insertion and removal did not produce wear in the metal abutments.

Load-Bearing Capacity of Fiber-Reinforced Composite Abutments and One-Piece Implants.

Fiber-reinforced composites (FRC) can potentially help in a physiologic stress transmission due to its excellent biomechanical matching with living tissues. Novel one-piece FRC implants and abutments with two different fiber orientations were loaded until failure to assess the load-bearing capacity, fracture patterns, and precision of fit. The one-piece FRC implants showed significantly higher load-bearing capacity compared to FRC abutments regardless of the fiber orientation (p < 0.001). For FRC abutments, bidirectional abutments showed significantly higher loads compared to unidirectional abutments (p < 0.001). The type of structure and fiber orientation are strong determinant factors of the load-bearing capacity of FRC implants and abutments.

Useful surface parameters for biomaterial discrimination.

Topographical features of biomaterials' surfaces are determinant when addressing their application site. Unfortunately up to date there has not been an agreement regarding which surface parameters are more representative in discriminating between materials. Discs (n = 16) of different currently used materials for implant prostheses fabrication, such as cast cobalt-chrome, direct laser metal soldered (DLMS) cobalt-chrome, titanium grade V, zirconia (Y-TZP), E-glass fiber-reinforced composite and polyetheretherketone (PEEK) were manufactured. Nanoscale topographical surface roughness parameters generated by atomic force microscopy (AFM), microscale surface roughness parameters obtained by white light interferometry (WLI) and water angle values obtained by the sessile-water-drop method were analyzed in order to assess which parameter provides the best optimum surface characterization method. Correlations between nanoroughness, microroughness, and hydrophobicity data were performed to achieve the best parameters giving the highest discriminatory power. A subset of six parameters for surface characterization were proposed. AFM and WLI techniques gave complementary information. Wettability did not correlate with any of the nanoroughness parameters while it however showed a weak correlation with microroughness parameters.

The influence of saliva pH value on the retention and durability of bar-clip attachments.

PURPOSE: The aim of this study was to compare the durability and retention of 4 types of attachments placed over computer aided design/computer aided manufacturing (CAD/CAM) titanium bars when subjected to different pH conditions. MATERIALS AND METHODS: Four commercially available attachments were investigated: Hader Yellow, Hader Red, Ackerman Gold and Ackerman Stainless Steel. These attachments and Ackerman CAD/CAM titanium bars were placed in 2 vessels containing different artificial saliva solutions (pH 7/pH 4) at 37℃ for one month to simulate corrosion conditions, and they were then subjected to mechanical testing (5400 cycles of insertion and removal). RESULTS: The results revealed that there were significant differences in the average values of insertion/removal force due to the pH (F (1, 24)=9.207, P<.05) and the type of attachment (F (3, 24)=11.742, P<.05). CONCLUSION: More acidic pH values were found to have a negative influence on the retention capacity of the attachments.

Bacterial adhesion efficiency on implant abutments: A comparative study

The attachment of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 28213 onto six different materials used to manufacture dental implant abutments was quantitatively determined after 2 and 24 h of contact between the materials and the bacterial cultures. The materials were topographically characterized and their wettability determined, with both parameters subsequently related to bacterial adhesion. Atomic force microscopy, interferometry, and contact angle measurement were used to characterize the materials’ surfaces. The results showed that neither roughness nor nano-roughness greatly influenced bacterial attachment whereas wettability strongly correlated with adhesion. After 2 h the degree of E. coli attachment markedly differed depending on the material whereas similar differences were not observed for S. aureus, which yielded consistently higher counts of adhered cells. Nevertheless, after 24 h the adhesion of the two species to the different test materials no longer significantly differed, although on all surfaces the numbers of finally adhered E. coli were higher than those of S. aureus (AU)

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Bacterial adhesion efficiency on implant abutments: a comparative study.

The attachment of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 28213 onto six different materials used to manufacture dental implant abutments was quantitatively determined after 2 and 24 h of contact between the materials and the bacterial cultures. The materials were topographically characterized and their wettability determined, with both parameters subsequently related to bacterial adhesion. Atomic force microscopy, interferometry, and contact angle measurement were used to characterize the materials' surfaces. The results showed that neither roughness nor nano-roughness greatly influenced bacterial attachment whereas wettability strongly correlated with adhesion. After 2 h the degree of E. coli attachment markedly differed depending on the material whereas similar differences were not observed for S. aureus, which yielded consistently higher counts of adhered cells. Nevertheless, after 24 h the adhesion of the two species to the different test materials no longer significantly differed, although on all surfaces the numbers of finally adhered E. coli were higher than those of S. aureus.

Pre-Prosthetic surgical alterations in maxillectomy to enhance the prosthetic prognoses as part of rehabilitation of oral cancer patient

Objectives: After maxillectomy, prosthetic restoration of the resulting defect is an essential step because it signals the beginning of patient’s rehabilitation. The obturator used to restore the defect should be comfortable, restore adequate speech, deglutition, mastication, and be cosmetically acceptable, success will depend on the size and location of the defect and the quantity and integrity of the remaining structures, in addition to pre-prosthetic surgical preparation of defect site. Preoperative cooperation between the oncologist surgeon and the maxillofacial surgeon may allow obturation of a resultant defect by preservation of the premaxilla or the tuberosity on the defect side and maintaining the alveolar bone or teeth adjacent to the defect. This study evaluates the importance of preprosthetic surgical alterations at the time maxillectomy on the enhancement of the prosthetic prognoses as part of the rehabilitation of oral cancer patient. Study Design: The study was carried out between 2003- 2008, on 66 cancer patients(41 male-25 female) age ranged from 33 to 72 years, at National Cancer Institute, Cairo University, whom underwent maxillectomy surgery to remove malignant tumor as a part of cancer treatment. Patients were divided in two groups. Group A:Resection of maxilla followed by preprosthetic surgical preparation. Twenty-four cancer patients (13 male - 11female). Group B: Resection of maxilla without any preprosthetic surgical preparation. Forty-two cancer patients(28 male-14 female).Results: Outcome variables measured included facial contour and aesthetic (..)(AU)

Rehabilitación protésica en pacientes con pérdida de sustancia mandibular / No disponible

La rehabilitación oral de pacientes con pérdidas de sustancia mandibular es compleja. El tratamiento ideal consistirá en restablecer la oclusión, la función así como una aceptable estética facial. En este artículo se presentan diferentes opciones terapéuticas mostrando la resolución de varios casos clínicos. Se han revisado cuatro casos clínicos de pacientes afectos de carcinoma de células escamosas en cabeza y cuello que fueron tratados mediante resección quirúrgica y/o radioterapia y posteriormente rehabilitados protésicamente. En la rehabilitacón de pacientes hemimandibulectomizados destaca la reconstrucción quirúrgica del defecto y la rehabilitación protésica posterior. Al diseñar el plan de tratamiento se han de tener en cuenta diversos factores como la limitación de apertura, el soporte y sellado labial, espacio interoclusal, estado de los tejidos blandos y la lengua y las limitaciones óseas para la posible colocación de implantes. La rehabilitación protésica dependerá de la retención, que sólo se puede obtener a partir de dientes e implantes. Los pacientes hemimandibulectomlzados precisan de una planificación exhaustiva y multidisciplinar (AU)

The oral rehabilitation of pacients with lost of mandibular substance is complicated. The ideal treatment consists in re-establishing the oclusion, the function and an acceptable facial aesthetic. In this article different therapeutic options are shown in various clinical cases. Four clinical cases of head and neck squamous cell carcinoma affected patients that were treated with surgicaI resection and/or radiation therapy and subsequently rehabilitated with prothesis have been revised. The hemimandibulectomized patient rehabilitation emphasizes the defect surgical reconstruction and the subsequent prosthetic rehabilitation. Factors such opening mouth limitacion, labial support and seal, interoclusal space, soft tissue and tongue state, bone limitations should be kept in mind when an implant rehabilitacion is planed. The prosthetic rehabilitation depends on the retention that only can be achieved from teeth and implants. The hemimandibulectomized patients need an exhaustive and multidisciplinary planification (AU)

La extracción completa o la conservación máxima en el paciente fisurado adulto: a propósito de un caso / No disponible

La fisura palatina es la malformación craneofacial más común en neonatos, existiendo multitud de protocolos de tratamiento desde el neonato hasta la edad adulta. Cuando a través de la cirugía y de la ortodoncia no se obtiene la satisfacción terapéutica se recomienda la prótesis para conseguir una estabilidad oclusal óptima y una estética adecuada. Se presenta un caso clínico de un paciente adulto con fisura labial y fístula oronasal remanente después de la cirugía. Tras el estudio y tratamiento protésico provisional del defecto y de la arcada dentaria, se realiza una sobredentadura superior con coronas telescópicas galvanizadas y bulbo obturador en resina. Consideramos que el tratamiento protésico provisional del defecto es absolutamente necesario para conseguir la estabilización de los tejidos blandos. Además, para poder alcanzar un resultado satisfactorio del tratamiento e integrar a estos pacientes en la sociedad, se requiere una vigilancia coordinada de los distintos especialistas de la salud (AU)

Cleft lip and palate is one of the commonest congenital abnormality in neonate, it exist many different treatment protocols from birth to adulthood. If surgery or orthodontics cannot obtain a good result, prosthetic treatment can provide stability to the maxillary arch and get better aesthetics. This case report describes the prosthetic management of a patient with cleft lip and palate after surgery. An exhaustive assessment and a provisional dental and obturator prosthesis were made. Finally an overdenture with galvano-crowns and a resin obturator was rnade. The provisional prosthetic treatment of the palate cleft is always essential to get the soft tissues's stability. It is also necessary a multidisciplinary team for the management of these patients to obtain an optimal result (AU)

Técnicas fotoelásticas aplicadas al estudio de prótesis sobre implantes / No disponible

Se estudia, mediante métodos fotoelásticos, si el tipo de implante utilizado para soportar una prótesis es un factor que influye en la obtención de una distribución de cargas que minimice las fuerzas soportadas por el mismo. Se utilizan implantes de tres marcas distintas (Steri-Oss, Endopóre y 31), colocados por pares en tres modelos fotoelásticos de características iguales y se coloca un mismo puente de metal-porcelana en cada uno de ellos. Sobre cada modelo, se aplican fuerzas verticales oclusales en al primer molar y oblicuas oclusales en el canino. Se observan los modelos a través de un haz de luz polarizada para obtener las distribuciones de cargas en los mismos. Los análisis cualitativos de cada uno de los patrones cromáticos generados revelan que, en todos los casos, se obtiene una distribución mínima de cargas para el tipo de implantes Steri-Oss. Cuando las fuerzas aplicadas son de poco valor, los modelos con implantes Endopore tienen un peor comportamiento frente al tipo 3I, pero tienden a equiparar su compqrtamiento cuando las fuerzas aplicadas crecen en magnitud, generando patrones de cargas muy similares. Con las limitaciones inherentes a este estudio, se observa que el tipo de implante utilizado en una misma situación protésica, no influye significativamente en la respuesta a las fuerzas aplicadas (AU)

Using photoelastic methods, we study whether or not the kind of implant employed to hold prostheses together is a factor that has an influence on the stress distribution that minimizes the strengths supported by the implant itself. We employ three different brands of implants (Steri-Oss, Endopore and 3D, placed in pairs inside three photoelastic models, all of them with similar characteristics, and we put the same metal ceramic bridge over each one. Each model is subjected to vertical occlusal strengths in the first molar and oblique occlusal strengths in the canine. Models are observed through polarized light to obtain the stress distribution on them. In all cases, qualitative analysis of the chromatic patterns show that the minumum distribution of stress is obtained with Steri-Oss brand implants. When strengths are poor in quality, models with Endopore implants perform worse than models with 3.1 implants, but they tend to perform similarly when strengths are greater in maghitude,creating very similar stress patterns, Despite inherent limitations of this study, we can observe that the kind of implant employed in a prosthetic situation, does not have a meaningful effect on the response to strengths applied (AU)

Análisis fotoelástico de las tensiones generadas con diferentes diseños de prótesis dento-implanto soportadas / No disponible

Diente e implante son elementos que presentan un comportamiento biomecánico diferente debido a la presencia de un ligamento periodontal en uno y no en el otro. Debemos tener en cuenta este hecho cuando diseñemos una prótesis que vaya a ser soportada por estos dos pilares diferentes, para intentar disminuir en lo posible las tensiones que tendrán que soportar tanto los pilares como las estructuras de soporte que los rodean. Para estudiar dichas tensiones, fabricamos un modelo de simulación consistente en . un prisma de resina con propiedades fotoelásticas dentro del cual incluimos un implante y un diente que uniremos con prótesis fijas de tres diseños diferentes. Ejerceremos cargas de intensidades diferentes, sobre tres puntos diferentes de las prótesis, para comparar el patrón dé distribución de tensiones que se genera en cada una de las situaciones recreadas (AU)

Teeth and implants are elements with a different biomechanic behaviour due to the presence of a periodontal ligament around the tooth and its absence around the implant. This must be taken Into consideration whenever we plan to design a tooth-implant supported prosthesis so that the stress generated around the abutments could be reducedas much as posible, A simulation model made of resin with photoelastic properties, with an implant and a tooth included in it and connected by three types of fixed prosthesis, was fabricated to study these tensions. Forces of different intensity will be exerted over three different points of the prosthesis and we will compare the distribution pattern of the generated tensions in each situation (AU)

Electromiografía en la práctica diaria / No disponible

Valoración de la dificultat del registro electromiográfico en cinco pacientes con disfunción craneo-mandibular, se muestran los resultados preliminares. Se realizó el registro electromiográfico del músculo masetero, temporal anterior y posterior además del digástrico. El registro se realizó antes del tratamiento con un equilibrador axial y después. Comparandose la diferencia de registro entre el lado izquierdo y derecho. La conclusión del trabajo es que existe una disminución del registro electromiográfico después del tratamiento; el control electromiográfico requiere de una aparatologia compleja y el tiempo necesario es elevado, observamos una disminución de la diferencia del registro electromiográfico de un lado respecto al otro. Hacen falta más estudios, en este sentido, para saber su trascendencia y el comportamiento de esta variable (AU)

We want to know the dificult of making a electromiography in temporomadibular disorders patients. We made a electromiogrphy of maseter muscle, temporal anterior and posterior, and anterior digastric. The records made before and after tratment with axial equilibrator. We were under control the diference of electromiographyc (DEMG) records between rigth and left side of the body. The condusion was: the elctromiography needs a lot of time to do, we observed a decreasing of electromiography records, finally the preliminay results show as a decreasing of DEMG records. We need more studies in order to know the clinical meaning of that variable (AU)