Evaluation of SPECT/CT in the assessment of inflammatory jaw pathologies.

PURPOSE: Since accurate diagnosis of inflammatory jaw diseases is still challenging, this study investigated the performance of three phase bone scintigraphy including SPECT/CT in the assessment of correct diagnosis and size of the affected bone tissue. METHOD: This retrospective study contained 31 patients with suspected jaw-related osteoradionecrosis, osteomyelitis or medication-related osteonecrosis of the jaw, which underwent 3-phase bone scintigraphy including SPECT/CT. Results were reviewed by two nuclear medicine physicians. Positive cases received surgery; negative ones were followed-up for six months. Both served as reference standard. Inflamed bone length was measured in the SPECT/CT images and postoperatively by a pathologist. RESULTS: 19 out of 20 positive cases and 10 out of 11 negative ones were classified correctly by SPECT/CT (sensitivity 95 %, specificity 91 %, accuracy 94 %, positive predictive value 95 %, negative predictive value 91 %). Regarding the length of affected bone, no significant difference (p = 0.23) could be observed between SPECT/CT and postoperative obtained values. Both correlated significantly (r = 0.86, p = 0.0001). CONCLUSION: SPECT/CT can safely detect different kinds of inflammatory jaw pathologies compared to other conventional imaging modalities. Lack of specificity of conventional scintigraphy ranging from 17 % to 71 % in earlier studies could be improved by adding CT-analysis. Additionally, SPECT/CT assists the surgeon in determining the expansion of the process (with focus on the length) preoperatively and thereby optimizing surgery planning.

Assessment of simulated osteoporosis in alveolar bone using optical coherence tomography.

Steoporosis is a skeletal disorder that compromises bone resistance and its diagnosis is usually performed using dual energy X-ray absorptiometry. Thus, the search for efficient diagnostic methods that do not involve the emission of ionizing radiation is necessary. This study proposed to use the Optical Coherence Tomography (OCT) to evaluate osteoporosis in alveolar bone. Osteoporosis lesions is simulated in vitro in porcine bones, and imaging is performed by OCT and micro-computed tomography (micro-CT). A developed algorithm is proposed to calculate the optical attenuation coefficient ( µ t ), mean optical attenuation coefficient ( µ¯t ), integrated reflectivity (ΔR) and bone density ( BD). The µ¯t , ΔR and BD parameters shows a good correlation to micro-CT parameters (bone volume/tissue volume and total porosity). The µ t and µ¯t methods are negatively impacted by non-uniform intensities distribution in osteoporosis images. In conclusion, BD and ΔR analysis demonstrates to be potential techniques for diagnosis and monitoring of osteoporosis using OCT.

Comparative Assessment of Facial Asymmetry in Malocclusion using Posteroanterior View.

AIM: The study was conducted to assess facial asymmetry in various dental malocclusions and to determine asymmetry in lower, mid, and upper face and jaws using posteroanterior cephalometric analysis. MATERIALS AND METHODS: Overall, 120 posteroanterior cepha-lograms were taken of individuals between 12 and 25 years of both sexes, and were divided into four groups: Angle's class I excellent occlusion, Angle's class I malocclusion, Angle's class II malocclusion, and Angle's class III malocclusion. These cepha-lograms were traced and Grummon's analysis was performed. RESULTS: In Angle's class I occlusion and Angle's class II malocclusion, the results obtained showed asymmetry present in the upper face. Correlation was found between occlusion, maloc-clusion, and facial asymmetry. CONCLUSION: Facial asymmetry was found in all dental occlusions whether excellent or malocclusion group, with maximum asymmetry having upward trend toward upper face starting from lower. CLINICAL SIGNIFICANCE: For the success of the orthodontic treatments in various types of malocclusion and to determine the facial asymmetry, posteroanterior view can be very helpful, as it gives additional information which can be utilized to augment treatment planning and improve prognosis in terms of relapse prevention.

Assessment of jawbone trabecular bone structure amongst osteoporotic women by cone-beam computed tomography: the OSTEOSYR project.

OBJECTIVE: To assess the trabecular bone structure of jawbones and the dens (the odontoid process of the second cervical vertebra) amongst osteoporotic and nonosteoporotic women using cone-beam computed tomography (CBCT). Analysis of the dens trabecular bone structure aimed to test the validity of CBCT in such analysis. METHODS: Thirty-eight women who went under dual-energy X-ray absorptiometry (DXA) examination were scanned by CBCT. Cuboids from different areas of jawbones and the dens were extracted from each scan. Trabecular thickness (Tb.Th), trabecular separation (Tb.S), bone volume fraction (BV/TV), specific bone surface (BS/TV) and connectivity density were calculated. Student's t-test, Pearson correlation, and logistic regression analysis were used to explore differences in these measures between groups. RESULTS: Jawbone-derived measures showed insignificant differences (P > 0.05) between osteoporotic and non-osteoporotic groups, and weak correlations with femoral neck and lumbar vertebrae T-scores (r ≤ 0.4). Dens-derived measures, however, resulted in the opposite (r = 0.34-0.38 [P value = 0.02-0.036] and r = 0.48-0.61 [P value ≤ 0.003]) and the highest accuracy of osteoporosis prediction: 84.2% and 78.9% respectively. CONCLUSION: Trabecular bone structure of the mandible and maxilla is not affected in osteoporosis as assessed by CBCT. Dens trabecular bone analysis revealed the opposite, so some trabecular bone measures may be assessed by CBCT, which may aid in predicting osteoporosis.

Management of trismus following radiation therapy by cost-effective approach.

Radiotherapy when used in head and neck cancer treatment can produce side effects in patients such as the trismus. If allowed to progress trismus can become so severe that the patient becomes debilitated due to lack of nutrition. Furthermore, trismus and limited oral access present a challenge to the clinician for dental treatment. This article describes a simple and cost-effective appliance for management of trismus.

An exploratory survey of diagnostic methods for bone quality assessment used by Brazilian dental implant specialists.

Bone quality (BQ) has been described as an important predictor for the outcome of dental implant treatment. It is, however, unclear how this factor is assessed in the dental practice routine. The aim of this study was to investigate what Brazilian dental implant specialists know and understand about BQ, if they include BQ assessments in their treatment planning and which methods they use to assess BQ. A questionnaire was posted to Brazilian dental implant specialists, containing open and closed questions about their knowledge and understanding of BQ assessment, and 221 answered the questionnaire. Data were gathered and methods for BQ assessment were grouped using hierarchical cluster analysis. Answers about BQ knowledge and understanding were categorized into quantity of cortical and marrow bone (n = 72), density (n = 55), type of bone (n = 35), bone height (n = 30), bone thickness (n = 27), primary stability (n = 24) and other less common categories. BQ assessment was judged relevant to be considered a selection criterion for implant treatment. Overall frequency analysis showed that methods were roughly divided into usual (n > 170) and unusual methods (n < 9). Cluster analysis grouped BQ assessment methods into four clusters: unusual methods (DEXA, resonance frequency, Periotest and occlusal radiography), perioperative methods (peak insertion torque and tactile perception), sectional imaging (computed tomography) and plain films (periapical and panoramic radiographs). No consensus on BQ understanding or the clinical application of methods to assess BQ was found in this survey. The selection of methods shows a clear natural grouping from basic to advanced strategies for BQ assessment by Brazilian specialists in dental implants.

Jaw-opening muscle contracts more economically than jaw-closing muscle in rat.

Mandibular movement is achieved by coordinated actions of the jaw muscles. To understand the assigned functional role (e.g., motor or postural role) of each jaw muscle, we characterised not only their contractile and energy-consumption properties but also their compositions of myosin heavy chain (MHC) isoforms. The Ca(2+)-dependent isometric tension development and ATPase activity were simultaneously measured in chemically skinned fibers harvested from rat jaw-closing (masseter and temporalis) and jaw-opening (digastric) muscles. After the measurements of isometric tension development and ATPase activity, the MHC compositions in each preparation were determined by SDS-gel electrophoresis. The Ca(2+)-sensitivity of isometric tension development and ATPase activity was significantly (P<0.001) higher in the digastric fibers than in the masseter and the temporalis fibers. The tension cost (ATPase activity/tension) was significantly (P<0.0001) lower in the digastric fibers than in the masseter and the temporalis fibers. The MHCs in the digastric fibers consisted of a mixture of slow type I and fast type II isoforms, while mostly fast type II isoforms in the masseter and temporalis fibers. These results suggest that in rat the jaw-opening muscle contracts more efficiently in terms of the energy use (i.e., more efficient ATP consumption for tension generation) than the jaw-closing muscle.

Assessment of ameloblastomas using MRI and dynamic contrast-enhanced MRI.

We retrospectively evaluated magnetic resonance images (MRI) and dynamic contrast-enhanced MRI (DCE-MRI) of ameloblastomas. MRI and DCE-MRI were performed for 10 ameloblastomas. We obtained the following results from the MRI and DCE-MRI. (a) Ameloblastomas can be divided into solid and cystic portions on the basis of MR signal intensities. (b) Ameloblastomas show a predilection for intermediate signal intensity on T1WI, high signal intensity on T2WI, and well enhancement in the solid portion; they also show a homogeneous intermediate signal intensity on T1WI and homogeneous high signal intensity on T2WI, and no enhancement in the cystic portion. (c) The mural nodule or thick wall can be detected in ameloblastomas lesions. (d) CI curves of ameloblastomas show two patterns: the first pattern increases, reaches a plateau at 100-300 s, then sustains the plateau or decreases gradually to 600-900 s, while the other increases relatively rapidly, reaches a plateau at 90-120 s, then decreases relatively rapidly to 300 s, and decreases gradually thereafter. There was no difference in the CI curve patterns among primary and recurrent cases, a case with glandular odontogenic tumor in ameloblastoma or among histopathological types such as plexiform, follicular, mixed, desmoplastic, and unicystic type.