Israel Chilvarquer

Measurement of buccal bone volume of dental implants by means of cone-beam computed tomography

PURPOSEnThe aim of this study was to evaluate the accuracy of cone-beam computed tomography (CBCT) for measuring the buccal bone volume around dental implants.nnnMATERIALS AND METHODSnThree to six implants were inserted into the anterior maxilla of eight skulls, depending on the availability of bone, and after this, the CBCT was performed. By means of CBCT image, measurements of the bone wall at three points of the implant were obtained, analyzed and compared with those obtained in the plaster skull casting.nnnRESULTSnThe results showed that for the three points of the implants, no statistically significant difference in the measurements was obtained from the plaster model and CBCT images.nnnCONCLUSIONSnCBCT can be a useful tool for assessing buccal bone volume along the implant.

Achados radiográficos, sinais e sintomas nas disfunções da articulação temporomandibular

A study of radiographic findings and of signs and symptoms in temporomandibular joint (TMJ) dysfunction was made. Through TMJ transcranial radiographs, the presence of degenerative alterations as well as the estimate of condylar excursion were examined. Data such as chief complaint, pattern of occurrence of pain, signs of muscular pain, and articular signs of dysfunction were evaluated through clinical examination. The most frequent radiographic findings were the degenerative alterations. The most frequent ones were, in decreasing order, flattening, eburnation and osteophyte. Degenerative alterations were more frequent in the condyle than in the articular eminence. The estimates of condylar excursion were, in decreasing order, normo, hyper and hypoexcursion. No relationship between radiographic findings and specific signs or symptoms was observed

Human identification through frontal sinus 3D superimposition: Pilot study with Cone Beam Computer Tomography.

As a unique anatomical feature of the human body, the frontal sinus morphology has been used for identification of unknown bodies with many techniques, mostly using 2D postero-anterior X-rays. With the increase of the use of Cone-Beam Computer Tomography (CBCT), the availability of this exam as ante-mortem records should be considered. The purpose of this study is to establish a new technique for frontal sinus identification through direct superimposition of 3D volumetric models obtained from CBCT exam, by testing two distinct situations. First, a reproducibility test, where two observers independently rendered models of frontal sinus from a sample 20 CBCT exams and identified them on each others list. In the second situation, one observer tested the protocol and established on different exams of three individual. Using the open source DICOM viewer InVesallius(®) for rendering, Mesh Lab(®,) for positioning the models and CloudCompare for volumetric comparison, both observers matched cases with 100% accuracy and the level of coincidence in a identification situation. The uniqueness of the frontal sinus topography is remarkable and through the described technique, can be used in forensic as an identification method whenever both the sinus structure and antemortem computer tomography is available.

Use of models in surgical predictability of oral rehabilitations.

PURPOSEnTo evaluate the rehabilitation of edentulous mandibles with osseous integrated implants in immediate loading, using models in reverse planning.nnnMETHODSnA prospective study was performed on 14 patients with a total of 56 implants placed. It was proposed a technique for the rehabilitation of edentulous mandible with osseous integrated implants of immediate loading, using anatomical replicas derived from computerized tomography scan linked to the rapid prototyping technique of stereolithography in reverse planning, elaborating the definitive fixed prosthesis, with rigid union of the implants on the same day. The patients mandible models were divided in two groups. In the first one, there were patients with edentulous mandible models and with models elaborated after exodontics procedures (Group 1). In the second (Group 2), patients with dentulous mandible models, which allow an evaluation of difficulty in the surgery.nnnRESULTSnThe proposed technique using anatomical models for the personalization of mandibles in immediate loading had 100% of less difficulty in the adaptation of the surgery guide while the dentulous models had 83,3% of more difficulty.nnnCONCLUSIONnThe proposed technique using the mandible models in the rehabilitation of mandibles is feasible.

Evaluation of mandibular condyles in children with unilateral posterior crossbite

The relationship of mandibular condyle dimensions and its association with unilateral posterior crossbite (UPXB) has been suggested in the literature. The purpose of this prospective study was to evaluate mandibular condyles on the left and right sides and between crossed and non-crossed sides in the sagittal and coronal planes, using cone-beam computed tomography (CBCT). Twenty CBCT images of 40 temporo mandibular joints (TMJs) in individuals in mixed dentition phase, which included 9 males (mean 7.9 years) and 11 females (mean 8.2 years), with unilateral posterior crossbite without premature contacts and functional mandibular shifts and with transverse maxillary deficiency. The criteria for sample exclusion included the presence of painful symptoms, facial trauma history, systemic diseases such as juvenile rheumatoid arthritis, mouth opening limitation (< 40 mm), congenital or genetic anomalies, and skeletal asymmetries that may result in TMJ disorders. Dimensional measurements of the condyles between the right and left sides and crossed and non-crossed sides in sagittal and coronal view were made. There was no significant difference between the measurements of the crossed and non-crossed sides in both sagittal and coronal view. These findings suggest that the presence of unilateral posterior crossbite in children with UPXB did not result in changes between the mandibular condyles in the right and left sides or between the crossed and non-crossed sides in the coronal or sagittal plane.

Anatomic and radiograph study of the persistence of Foramen of Huschke

AIM: the aim of this study is to assess and locate the Foramen of Huschke. STUDY DESIGN: anatomical. MATERIAL AND METHOD: using contrast material like gutta-percha and barium sulfate, through extraoral radiographs, such as panoramic, submental vertex and corrected saggital linear Temporal Mandibular Joint tomograms in four skulls where we clinically checked the existence of foramen of Huschke. RESULTS: The results proved that the foramen of Huschke can be observed in skulls submitted to contrast using radiographic techniques.AIMnThe aim of this study is to assess and locate the Foramen of Huschke.nnnSTUDY DESIGNnAnatomical.nnnMATERIAL AND METHODnUsing contrast material like gutta-percha and barium sulfate, through extraoral radiographs, such as panoramic, submental vertex and corrected sagittal linear Temporal Mandibular Joint tomograms in four skulls where we clinically checked the existence of foramen of Huschke.nnnRESULTSnThe results proved that the foramen of Huschke can be observed in skulls submitted to contrast using radiographic techniques.

A new technique for imaging the temporomandibular joint with a panoramic x-ray machine: Part I. Description of the technique

A new technique for imaging the temporomandibular joint with rotational panoramic radiography is explained and demonstrated with a tissue-equivalent phantom. In this technique the patient is displaced forward and laterally away from the side under examination. Radiographs made with the proposed technique show the temporomandibular joint with more sharpness and less distortion than do radiographs made with conventional panoramic techniques.

Clinical and Histomorphometric Evaluation of Fresh Frozen Bone Allograft in Sinus Lift Surgery

PURPOSEnThe aim of this prospective clinical study was to evaluate the clinical and histomorphometric data of newly formed bone tissue from fresh frozen human allograft in sinus lift surgery.nnnPATIENTS AND METHODSnThirty-three sinus lift procedures were performed in 20 patients, divided into two groups. The control group (nu2009=u20098) received autogenous bone from the mandibular ramus, and the experimental group (nu2009=u200912) received fresh frozen bone (FFB) allograft in chips. After 6 months, 52 implants were placed and 50 biopsies were collected for histomorphometric analysis. Cone beam computed tomography scans were performed at preoperative, immediate postoperative, and delayed postoperative time intervals to assess the degree of graft volume loss.nnnRESULTSnThere was no statistically significant difference between groups as regards degree of graft volume loss (pu2009=u2009.983), total bone area (pu2009=u2009.191), remaining particles (pu2009=u2009.348), and proportion of active osteoblasts (pu2009=u2009.867). There was a statistically significant difference in the vitality rate between the groups (pu2009=u2009.043). In both groups, all implants were clinically osseointegrated after 4 months.nnnCONCLUSIONnFFB allograft was shown to be a feasible substitute for autogenous bone graft in sinus lift surgery.

Active unilateral condylar hyperplasia

Two cases of active unilateral condylar hyperplasia which were treated with condylectomy alone are presented. The first case was an adult form and the other a juvenile form. Both were classified as active by using 99Tc bone scintigraphy. Clinical and radiographic features of both cases conformed to the hemimandibular hypertrophy type. Satisfactory facial symmetry and dental occlusion were achieved. Histopathological data confirmed the activity of the articular cartilage layers.

The Frontal Sinus Cavity Exhibits Sexual Dimorphism in 3D Cone‐beam CT Images and can be Used for Sex Determination

Few studies have assessed the use of the frontal sinus cavities for sex differentiation. In this study, a new methodology was used to assess the reliability of CBCT images of the frontal sinus cavity for determining sex based on the sexual dimorphism found in this anatomical structure. The survey sample consisted of 130 scans that were reconstructed three‐dimensionally. 3D images of the cavity volume in the frontal, lateral, and basal views were exported in TIFF. The following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity, and Ferets diameter. The methodology demonstrated the existence of sexual dimorphism with an accuracy of 80.0% in the logistic regression model. The basal view had the greatest explanatory power in the final model. This methodology may be used as an alternative way of determining a reliable biological profile during the analysis of skeletal remains.