Liogi Iwaki Filho

Comparative Study of the Mechanical Resistance of 2 Separate Plates and 2 Overlaid Plates Used in the Fixation of the Mandibular Condyle: An In Vitro Study

PURPOSE The objective of this study was to carry out a comparative evaluation of the mechanical resistance of 2 rigid internal fixation techniques for fractures of the mandibular condyle using miniplates. MATERIALS AND METHODS Forty polyurethane resin replicas of human hemimandibles were used. The hemimandibles were sectioned to simulate a high subcondylar fracture and then stabilized with 2 fixing techniques using 2.0-mm system plates and screws. The fixation techniques were 2 separate 4-hole plates with 8 screws, and 2 overlaid 4-hole plates with 4 screws. Each system was submitted to load tests, with the application of the load in mediolateral and anteroposterior directions in an Instron 4411 universal assay machine (Instron, Norwood, MA). RESULTS Load values and peak displacement were measured. Means and standard deviations were evaluated by analysis of variance (P < .05) and Tukey tests, in which it was verified that the antero-posterior peak load value was affected by the arrangement of the plates on the models, although no differences were observed between the groups for the mediolateral peak load. The arrangement of the plates did not have any influence on peak displacement. Similarly, the final value of the mediolateral load was not affected by the arrangement of the plates on the model. CONCLUSION The experimental model with 2 separate plates was statistically superior to the model with 2 overlaid plates only in relation to anteroposterior peak load. Despite showing superiority in mediolateral peak load and peak displacement, there was no statistical difference between the groups for these parameters.

Interdisciplinary treatment for a patient with open-bite malocclusion and amelogenesis imperfecta

Amelogenesis imperfecta (AI) comprises a clinically and genetically heterogeneous group of conditions that affect the dental enamel, occasionally in conjunction with other dental, oral, and extraoral tissues. The aim of this case report is to describe an interdisciplinary treatment of hypoplastic AI associated with a severe open bite. The treatment consisted of surgical, orthodontic, periodontal, prosthetic and restorative management, establishing good chewing function, dental esthetics and facial harmony.

Different Surgical Approaches for Multiple Fractured Atrophic Mandibles

Atrophic edentulous mandible fractures in geriatric patients have low incidence but present several biological and biomechanical peculiarities that produce a nonunion rate of around 20%. Surgical extraoral approaches for internal fixation of these fractures can be transcervical or by one or two submandibular incisions. Two patients sustaining multiple fractures in atrophic edentulous mandible are presented: the first patient was 72-years-old, treated by two submandibular incisions, and the second was 81-years-old, treated by transcervical approach. We discuss the advantages and drawbacks of each approach and their indications according to the Luhr et al (1996) atrophy index.

Estudo laboratorial de teste de resistência ao tracionamento da resina composta fotopolimerizável Fill Magic® destinada à colagem de braquetes para tracionamento ortodôntico de dentes retidos

OBJETIVO: Avaliar a resistencia a tracao de duas resinas utilizadas para colagem de acessorios para tracionamento dentario. METODOLOGIA: o presente estudo comparou a adesividade e praticidade de duas resinas destinadas ao tracionamento ortodontico de dentes impactados: a Concise® da 3M®, presente no mercado ha alguns anos e tida como referencia na realizacao deste procedimento; e a Fill Magic® da Vigodent®, cuja tecnica e julgada mais simples pelo fabricante. Foram incluidos 40 terceiros molares em corpos de prova e estes divididos em dois grupos de 20, um para cada resina. Uma vez colados os braquetes, os corpos de prova foram submetidos a forca de tracao horizontal (10 de cada grupo) e vertical (10 de cada grupo), ate que os braquetes se soltassem. Os valores obtidos na maquina universal de ensaios foram registrados e comparados por meio de medias para que fosse possivel estabelecer as vantagens e desvantagens de cada resina. RESULTADO E CONCLUSAO: apesar dos valores obtidos com a resina Fill Magic® terem sido menores que os da resina Concise®, comprovou-se que eles sao suficientes para a realizacao do tracionamento ortodontico.

Mouth floor enlargements related to the sublingual glands in edentulous or partially edentulous patients: a microscopic study

Mouth floor enlargements (MFE) are observed in edentulous and partially edentulous patients, impairing denture fitting, and have recently been described in the literature as hyperplasias of the sublingual glands. Objective: This study aims at describing the microscopic aspects of MFE that contribute to their final diagnosis. Methods: Twenty-four specimens were surgically removed from the enlarged mouth floor of 19 patients (15 females and 4 males). Patient age ranged from 48 to 74 years, with a mean of 57 years. The main surgical indication was to permit or improve the fitting of dentures. Six patients were completely edentulous and 13 were partially edentulous. The material was processed for microscopic examination and stained with hematoxylin-eosin, Mallorys trichrome and periodic-acid Schiff (PAS). Results and Conclusions: The epithelium of the mouth floor was normal in 17 cases, hyperplastic in 4 and atrophic in 3. Six of the 24 sublingual glands removed were microscopically normal, while the other specimens presented acinar atrophy with hyperplasia of duct-like structures. Interstitial fibrosis was observed in 18 cases and was accompanied by adipose tissue infiltration in 15. Decreased lymphoid tissue was observed in 16 samples and oncocytosis was present in 5 cases. We suggest that MFE in edentulous or partially edentulous patients should be considered as an entity for the text books.

Accuracy in the diagnosis of vertical root fractures, external root resorptions, and root perforations using cone-beam computed tomography with different voxel sizes of acquisition

Aim: The aim of this study is to assess the accuracy of images acquired with cone-beam computed tomography (CBCT) in the identification of three different root alterations. Materials and Methods: Forty human premolars were allocated to four experimental groups (n = 10): sound teeth (control), vertical root fracture (VRF), external root resorption (ERR), and root perforation (RP). After the root alterations had been produced, four teeth were randomly assembled into 10 macerated mandibles and submitted to CBCT. Images were acquired with five voxel sizes (0.125, 0.200, 0.250, 0.300, and 0.400 mm) and assessed by three experienced dental radiologists. Sensitivity, specificity, positive and negative predictive values, and the areas under the receiver operating characteristic curve (accuracy) were calculated. The accuracy of imaging in different voxel sizes was compared with Tukey exact binomial test (α=5%). Results: Accuracy with voxel sizes 0.125, 0.200, and 0.250 mm was significantly higher in the detection of ERRs and VRFs than voxel sizes 0.300 and 0.400 mm. No statistical difference was found in terms of accuracy among any of the studied voxel sizes in the identification of RPs. Conclusions: Voxel size 0.125 mm produced images with the best resolution without increasing radiation levels to the patient when compared to voxel sizes 0.200 and 0.250 mm. Voxel sizes 0.300 and 0.400 mm should be avoided in the identification of root alterations.

Single-Needle Arthrocentesis with Upper Compartment Distension versus Conventional Two-Needle Arthrocentesis: Randomized Clinical Trial

The objective of this study was to compare single-needle arthrocentesis with distension of the upper compartment of the temporomandibular joint (TMJ) with the conventional two-needle arthrocentesis. Twenty-six patients with articular disc displacement without reduction (DDWOR) were included in the study and assigned to two groups (n = 13): single-needle arthrocentesis with distension of the upper compartment of the TMJ (1N) and conventional two-needle arthrocentesis (2N). The maximum interincisal distance (MID) and TMJ pain as measured by the visual analog scale (VAS) were compared. MID and VAS data were obtained: before (T1), seven days after (T2), fifteen days after (T3), one month after (T4), three months after (T5), six months after (T6), nine months after (T7), and one year after the arthrocentesis procedures (T8). Considering each group individually, results of the VAS scores and MID measurements showed a significant difference between T1 and T2–T8 (p < 0.001) in both groups. Between two groups, results show no significant differences (p > 0.05). Both techniques tested were effective in reducing pain and increasing MID. Due to the advantages over the conventional two-needle arthrocentesis, single-needle arthrocentesis with distension of the upper compartment should be considered as the first treatment option for patients with painful hypomobilized TMJ of DDWOR.

Evaluation of accuracy of portable fingertip pulse oximeter, as compared to that of a hospital oximeter with digital sensor

CONTEXT The pulse oximeter is a device that noninvasively provides continuous information about the peripheral oxygen saturation (SpO2) rate. This device is utilized in the detection of hypoxemia, due to its able to sense changes in hemoglobin oxygen saturation. AIMS The objective of this study was to verify the accuracy of the Choice® Medical MD300C3 Fingertip Pulse Oximeter, as compared to that of a hospital oximeter coupled with a Drager® Infinity Delta monitor, with the purpose of using this first methodology in dental procedures to monitor the peripheral oxygen saturation (SpO2) of patients submitted to dental treatments. MATERIALS AND METHODS Fifty-five adult patients, both genders, were selected in the Santa Casa Hospital of Maringa, Brazil. The volunteers did not present cardiac problems, prosthetic cardiac valves, pacemakers, or pulmonary diseases, and were not pregnant or children. Each patient received a portable fingertip pulse oximeter (PPO) on the middle finger of the left hand and the hospital oximeter (control device) on the forefinger of the same hand. A total of six measurements were developed. The Pearson correlation coefficient and the Bland and Altman method was used to calculate the statistical analysis. RESULTS No statistically significant difference was found between the measurements taken by the utilized devices. The average of comparative analysis presented by the devices was 0.2337 ± 0.4355 (mean ± SD), suggesting a strong correlation between the obtained results. CONCLUSION According to the methodology of the research, the PPO has similar accuracy to the conventional hospital oximeter with digital sensor. The PPO can be used in dental treatments.

Análise comparativa entre aparelhos de pressão arterial (digital e aneróide) e entre glicosímetros de diferentes marcas na detecção de pacientes hipertensos e diabéticos

Resumen pt: Objetivo: O objetivo do presente estudo foi comparar e testar a confiabilidade e eficiencia de dois aferidores de pressao arterial, aneroide (BD®) e digi...

Continuity resection of the mandible after ameloblastoma – feasibility of oral rehabilitation with rhBMP-2 associated to bovine xenograft followed by implant installation

Recombinant human morphogenetic protein (rhBMP) is a graft alternative for extensive mandibular reconstruction after tumor resections. However, the feasibility of rhBMP-2 to receive osseointegrated implants and prosthetic rehabilitation has been rarely reported. This study reports on a case of an extensive solid ameloblastoma along the mandibular body. The treatment consisted of resection followed by off-label use of rhBMP type 2 associated with bovine bone xenograft. Eleven months postoperatively, the patient was prosthetically rehabilitated with dental implants, without evidence of resorption or complications. The literature on mandibular reconstructions using rhBMP and their feasibility for future osseointegrated implant placement was also reviewed. Based on the presented case, the association between rhBMP-2 and a bovine bone xenograft could be considered a feasible option for the reconstruction and rehabilitation of large mandibular defects after tumor resection. According to the literature, the use of rhBMP as a graft material is encouraging, with good clinical outcome. However, there are no long-term studies demonstrating success and survival rates of implants placed in these grafts. Future investigations will be required to ascertain the long-term survival of implants in areas grafted with rhBMP. Also, there is a lack of information regarding the prosthetic rehabilitation of these patients.