Preimplant guided bone regeneration in the anterior maxilla

Guided bone regeneration is a clinical procedure aimed at promoting bone formation at sites where there is severe bone loss. The purpose of this article was to demonstrate reconstruction of deformations of the alveolar process resulting from traumatic injuries to maxillary incisor teeth by guided bone regeneration procedures followed by insertion of dental implants. In both cases, submembranous space-making was stabilized by human demineralized freeze-dried bone. Implant insertion at the sites of bone augmentation resulted in successful restorations. Histologic examination of biopsy samples from the submembranous hard tissue revealed particles of demineralized freeze-dried bone allografts partially surrounded by uninflamed connective tissue and by vital bone adjacent and adhered to the demineralized freeze-dried bone allograft particles.     

The surgical correction of a deviated anterior maxilla in a horse

The surgical correction of facial deformities of the horse have rarely been undertaken. The surgical and medical management of submucous clefting of the anterior maxilla in a young colt is described.     

Mandibular erosion from silastic implants: evaluation with a dental CT software program

Silastic implants used to augment the chin during cosmetic surgery may cause erosive bone changes and complications. We describe the radiologic appearance of these changes and the dental CT reformatting programs by which they may be assessed. Multiplanar CT scans of four patients with Silastic chin implants were evaluated retrospectively for implant density, presence and size of bone defects, relationship of defects to root apices, relationship of defects to mental foramen, and associated findings. The dental CT software program was instrumental in delineating the relationship between the bone defects and the root apices.     

A new angle on restoring anterior teeth with root-form implants: clinical report

Root-form implants may be indicated for the replacement of missing anterior teeth. Occasionally fixtures are placed in a position inconsistent with proper tooth alignment. The new PreAngled Abutment (Dentsply/Implant Division, Encino, CA) addresses this problem and was used to successfully restore missing tooth numbers 7 and 8 for a patient that had two malpositioned implants.     

Hard-tissue augmentation for the placement of anterior dental implants

Dental implants have become a popular alternative for replacing missing teeth in every region of the oral cavity. In the anterior zone, special esthetic concerns require not only a stably anchored implant for long-term success, but also the presence of adequate hard and soft peri-implant tissues. Anterior tooth loss is often accompanied by considerable loss of alveolar bone, so augmenting hard tissue before or in combination with implant placement becomes a critical part of therapy. One of the most successful augmentation techniques is guided bone regeneration (GBR). Thus far, augmentation procedures using expanded polytetrafluoroethylene membranes (ePTFEa) have proved to be the most efficient and predictable surgical technique to enhance deficient bone sites. This article discusses some critical biological and clinical/technical aspects of GBR and describes techniques for anterior hard-tissue augmentation with the photographic documentations of three clinical cases.     

Challenging the anterior attentional system with a continuous performance task: a functional magnetic resonance imaging approach

Combining the Continuous Performance Test (CPT) with a modern functional imaging technique provides a powerful tool for investigating neurophysiological processes in the human brain. There is increasing evidence from single photon emission tomography (SPECT), positron emission tomography (PET) and presently also functional magnetic resonance imaging (fMRI) studies proposing the existence of a distributed large-scale attentional network, mediated by the dorsolateral prefrontal and mesial frontal cortex, thalamus, basal ganglia and posterior parietal and superior temporal lobe. The aim of this study is to show that fMRI is a useful tool for in vivo localization of attentional tasks and to compare the results with established imaging techniques. Functional MRI was performed on a clinical 1.5-T system using gradient-echo acquisition. For data processing, the Statistical Parametric Mapping (SPM96) package was used. A right lateralized activation pattern in the dorsolateral prefrontal and mesial frontal cortex, the thalamus and the basal ganglia was found in a group of 12 male subjects. These findings support theories suggesting right hemispheric dominance of human attention.     

Osseointegrated implants in a patient with osteoporosis: a case report

OBJECTIVE: To evaluate the performance of in situ piezolectric extracorporeal shock-wave lithotripsy (ESWL) in the middle part of the ureter. MATERIAL AND METHODS: 36 consecutive patients presenting with stones of the middle part of the ureter were treated by in situ piezoelectric ESWL (EDAP LT 02). The maximal dimensions of the stones ranged from 5 to 14 mm (m = 7.8). Moderate or severe ureterohydronephrosis was present in 19 cases (53%) and a double J stent had been previously implanted in 6 cases (17%). The ESWL sessions were performed in the ventral supine position without any anaesthesia or systematic premedication, but an IM injection of 100 mg of pethidine was administered during poorly tolerated treatments. RESULTS: The stone was located easily in 23 cases (64%) and with greater difficulty in 13 cases (36%), as an intraoperative intravenous injection of contrast agent was performed in 6 cases (17%). The number of sessions per patient ranged from 1 to 2 (m = 1.16). The complete sucess rate was 75%, with a 64% success rate after a single ESWL session. The performances were statistically independent of stone dimensions and the degree of obstruction of the urinary tract. The complication rate was 5.5%, but no ancillary endoscopic or percutaneous treatment was required. CONCLUSION: In situ piezoelectric ESWL allows effective management of most stones of the middle part of the ureter. However, the treatment of stones with a maximal diameter < 5 mm, especially poorly radiopaque stones, can raise problems of localization. Very large or impacted stones, especially when complicated by urinary tract infection, should be preferably treated by first-line ureteroscopy.     

Clinical evaluation of single-tooth restorations supported by osseointegrated implants: a retrospective study

Unilateral whole lung lavage (UWLL) was performed four times in a patient with pulmonary alveolar proteinosis. PaO2 was 94 Torr even under ventilation with 100% O2. Because of the difficulty in providing adequate arterial oxygenation, extracorporeal membrane oxygenation (ECMO) was indispensable in accomplishing the first right UWLL. During the second left UWLL, the left lung was ventilated with nitrogen (N2) and an attempt was made to predict the lowest PaO2 occurring during lavage in order to establish criteria for the use of ECMO during UWLL. When both lungs were ventilated with 100%. O2, PaO2 rose to 150 Torr. PaO2 fell to 65 Torr after ventilation of the left lung with N2 while the right lung was ventilated with 100% O2 for 7 minutes. The N2 was replaced with 100% O2 and ventilation was continued for another 10 minutes to wash the N2 out of the left lung. When the tracheal tube in the left lung was clamped for 7 minutes for degassing, PaO2 fell to 59 Torr. Subsequently 1,200 ml of physiological saline was injected into the left lung, and PaO2 rose to 155 Torr. A 6 Torr difference was found between the value of PaO2 under ventilation with N2 and that of degassing, but this difference was not statistically significant. The lowest PaO2 occurring during UWLL was considered to be predictable if the unilateral lung was ventilated with N2.     

Aneurysmal bone cysts of the maxilla: a clinicopathologic review

PURPOSE: This study evaluated the significant differences in clinicopathologic features of aneurysmal bone cyst in the maxilla and mandible. MATERIALS AND METHODS: A search of the literature showed 30 recorded maxillary cases, and these together with one previously unrecorded case formed the basis of the study. RESULTS: There were no differences in the age and sex incidence. Only two patients complained of pain, and no patient complained of tenderness. No patient gave a history of trauma. Swelling was present in virtually every patient. In seven cases, there was tooth mobility or migration of teeth. Two patients complained of paresthesia. Four patients presented with proptosis, two of whom complained of diplopia. The radiographic appearance of the aneurysmal bone cyst is suggestive but not diagnostic. CONCLUSION: Although these differences do not enable the clinician to make a definitive diagnosis before biopsy, they have important implications for management.     

The infrapatellar synovail fold: a cause for confusion in the evaluation of the anterior cruciate ligament

The anterior cruciate ligament may be simulated by the normal infrapatellar synovial fold or ligamentum mucosum. With the aid of lateral tomography, the expected course and insertion of the structures can usually be differentiated. This distinction is important, since a torn anterior cruciate ligament can be overlooked and lead to a delay in appropriate therapy.     

The anterior tilt of the acromion: radiographic evaluation and correlation with shoulder diseases

The aim of this study was to test whether the anterior tilt of the acromion can be objectively evaluated on lateral radiographs, and whether there is a relation between this anatomical feature and the most common shoulder diseases. Lateral radiographs of 15 dried scapulas were performed in neutral position and with 5 degrees of caudal, cranial, anterior and posterior angulations. Two hundred and forty-three shoulders, both asymptomatic and affected by chronic and post-traumatic impingement, calcific tendinitis and instability, were examined by conventional radiography. The presence of rotator-cuff tears was investigated by sonography. A method was elaborated to obtain reproducible lateral radiographs and to determine the acromial tilt angle. Inter- and intraobserver and inter- and intraoperator variations in measurements were evaluated. Variations in tube angulation produced changes in tilt-angle values on dried scapulas. The average tilt angle for the chronic impingement and the instability groups were significantly different from the post-traumatic, calcific tendinitis and control groups. Rotator-cuff tears were significantly more frequent in the chronic impingement group and related to a more acute tilt angle. The inter- and intraobserver variability coefficients were 0.95 and 0.98, whereas the inter- and intraoperator variability coefficients were 0.94 and 0.96, respectively. Conventional radiography using fluoroscopy for positioning is a well-reproducible method for the evaluation of acromial tilt. There is a significant difference in tilt-angle values between some groups of subjects examined, but the lack of specificity limits the clinical importance of such measurement.     

CT evaluation of the anterior mediastinum: spectrum of disease

Computed tomography (CT) is the study of choice for evaluating disease in the anterior mediastinum. Mediastinal CT is usually performed with intravenously administered contrast material, and spiral CT is the preferred technique for evaluating a mediastinal mass. CT demonstrates thymic hyperplasia and thymic cysts and can help differentiate thymoma and thymic Hodgkin lymphoma. It is also useful in staging Hodgkin lymphoma and non-Hodgkin lymphoma. In thyroid malignancy, CT can depict mediastinal extension and lymphadenopathy; it also allows detection of goiter and ectopic parathyroid glands. Germ cell tumors such as teratoma and seminoma have characteristic appearances at CT. CT can also demonstrate miscellaneous mediastinal masses, such as lymphangioma, hematoma, those due to fibrosing mediastinitis, and pericardial cysts. Adenopathy due to tuberculosis or sarcoidosis is evident at CT, as is osteomyelitis due to a postsurgical abscess. Finally, CT features can suggest the pathologic origin of metastasis in the anterior mediastinum.     

Histological evaluation of bone reactions to aluminium oxide dental implants in man: a case report

Alumina implants have been shown to possess high biocompatibility. The authors present the case of an aluminium oxide ceramic implant removed because of fracture of the abutment after a 30-month loading period. It was possible to observe microscopically that the implant was covered by highly mineralized mature compact lamellar bone; no connective tissue or inflammatory cells were present at the interface. Osteocytes were observed very close to the bone-implant interface. These features indicate the good biocompatibility of the implant.     

Ultrasonographic evaluation of the anterior recess in the normal hip: a prospective study on 166 asymptomatic children

Bypass graft patency with ultrafast computed tomography (= Electron Beam Tomography, EBT) was examined in 72 bypass grafts (47 saphenous veins, 25 internal mammary arteries) in 30 patients and compared with coronary angiography. Angiography was performed a mean of 4.4 +/- 3.5 months (range 1-13) from the EBT examination. Contrast material (120 ml) was continuously administered via a peripheral vein and 40 axial slices (3 mm slice thickness, 110 ms scan time) without overlap sequences were obtained, ECG triggered with the single slice scanner mode. Imaging of internal mammary artery grafts began at the thoracic inlet, for saphenous vein grafts, at the undersurface of the aorta. Sixty of 63 angiographically patent bypass grafts were determined patent by EBT (sensitivity 95%), 8 bypass grafts could not be detected by EBT, and 9 were angiographically occluded (specificity 89%). Twenty-four of 25 internal mammary artery grafts were patent at EBT and coronary angiography, one was occluded. In 27 of the 30 patients (90%), all of the angiographically patent grafts could be confirmed as open with EBT. Obstructions of 10 grafts could not be visualized with EBT. Graft insertion into native coronary vessels could be visualized in axial slices, although morphologic quantification of graft insertion stenosis (75-90%) in two cases was not possible. Three dimensional reconstruction of the 40 axial slices allowed graft anatomy to be delineated. Visualization of bypass insertion into the native coronary vessel was less successful because of opacification of the left and right ventricle. Electron beam computed tomography is a minimally invasive procedure capable of evaluating the patency of saphenous vein and internal mammary artery grafts. The morphologic quantification of graft obstruction and visualization of the insertion of the bypasses into the native coronary vessels is less successful with present technology and imaging modalities.