Radiolucent Space Research Articles

The Radiographic "Air Sign" in Neonatal Mandibular Distraction Osteogenesis.

Timing of extubation on post-mandibular distraction osteogenesis (MDO) surgery is critical, given that at baseline these infants have difficult airways and failed extubation requires either re-intubation of an already complex airway with a fragile, recently osteotomized mandible, or adjunctive airway measures such as CPAP that may apply unwanted pressure to the surgical site. Thus, the goal is to plan extubation when the risk of failure is minimal. Currently, there is a void in the literature addressing the timing of extubation post-MDO and no objective sign of extubation readiness has been elucidated. This study describes a simple clinical pearl to assist in the evaluation of extubation readiness in these patients. Postoperatively, we obtain weekly radiographs to assess distractor stability and advancement, and to assess for the "Air Sign". The Air Sign describes a radiolucent space (air) visualized in the oropharynx on lateral radiographs, likely indicating that the tongue based airway obstruction has been relieved by mandibular advancement.

Atypical presentation of achalasia cardia: A case report

Background: Primary achalasia is a disease of unknown etiology in which there is a loss of peristalsis in the distal esophagus and a failure of lower esophageal sphincter to relax with swallowing. Typical Clinical manifestations including dysphagia for solids (91%) and liquids (85%) and regurgitation food (76 to 91%) are the most frequent symptoms in patients with achalasia. Regurgitation may also result in aspiration (8%). However, atypical presentation of achalasia may cause delayed diagnosis and mismanagement. Objective: This case report presents atypical presentation of achalasia in which patients presenting primarily with prolonged cough. This case report discusses possible mechanisms explaining the atypical presentation of achalasia including chronic cough. Methods: We report a 45-year-old female patient presented to Emergency Department at Al Wakra Hospital with a history of cough and shortness of breath for more than two weeks. Oxygen saturation was 90% on room air with no history of vomiting, fever, hemoptysis, hematemesis or weight loss. Additionally, there was no significant past medical history except for recent diagnosis with bronchial asthma. In ED, patient was managed as a case of bronchial asthma exacerbation and received beta-2 agonist nebulization, intravenous corticosteroid and oxygen mask. Minimal improvement in the her condition was noted after treatment. Initial investigations were conducted including complete blood count, comprehensive metabolic panel and chest X-Ray. A radiolucent space in upper mediastinum with a query of pneumomediastinum was determined. Further imaging was conducted using computed tomography which showed diffuse dilatation of the esophagus. Conclusion: Chronic cough could be the only presentation in achalasia cardia.This a typical presentation may cause misdiagnosis or delayed treatment and should be considered in differential diagnosis.

Bacterial Plaque Colonization Around Dental Implant Surfaces

To examine the distribution of bacteria into the internal and external surfaces of failed implants using histologic analysis. There were 10 failed pure titanium and 5 failed hydroxyapatite-coated titanium implants consecutively removed various years after their placement. Criteria for fixture removal were peri-implant radiolucency and clinical mobility. The mobile fixtures were retrieved with the patients under local anesthesia. Fixtures were removed maintaining the abutments with the aim to observe the bacterial infiltration at the level of abutment/implant interface and on the implant surface. A thin radiolucent space was always present around all the failed implants. The abutments screws were tightly secured in all clinical cases. The bacterial cells were composed of cocci and filaments, which were adherent to the implant surface with an orientation perpendicular to the long axis of the implant. All the specimens included in this study showed bacteria at the level of implant/abutment interface. Histologic analysis at the level of abutment/implant interface in 2-stage implants identified heavy bacterial colonization. These findings appear to support those studies showing bacteria penetration at the level of the micro-gap, which can legitimate the hypothesis that the micro-gap at the bone level could present a risk for bone loss caused by bacterial colonization.

The role of muscle grafts in temporomandibular joint ankylosis: short-term experimental study in sheep

The temporalis muscle flap can be used as an inter-positional graft placed into a gap arthroplasty site in temporomandibular joint (TMJ) ankylosis. The purpose of this study was to investigate the role of the muscle graft in sheep. Five pure-bred adult Merino sheep were used and ankylosis was induced in all right TMJs. At 3 months, the ankylosis was released by gap arthroplasty and reconstructed with a masseter muscle graft, because the temporalis muscle is short and poorly vasculized in sheep. The sheep were killed at 3 months after muscle grafting. The maximal mouth opening was recorded before and after operation and at death. The joints were examined radiologically and histologically. In 4 sheep mouth opening remained at the pre-operative level. A clear radiolucent space remained between the smooth temporal and ramus stumps. Histologically, the muscle graft remained vital but with some fibrous tissue formation between the bone ends. One sheep developed an infection at the operative site following the muscle graft; this partly resolved with antibiotics, but the TMJ developed a fibrous reankylosis that was demonstrated clinically, radiologically and histologically. These results indicate that an uncomplicated temporalis muscle graft reconstruction with gap arthroplasty is a successful and stable procedure in human TMJ ankylosis.

Cementless fixation of hip prostheses in dogs

Fixation of smooth cementless femoral prostheses was studied in 16 dogs which were killed 2, 3 and 4 months after operation. Rotational stability, examined by hand, was good in 9 cases and all stable prostheses could be extracted. Five out of 6 dogs, who did not bear weight after the operation, had a stable prosthesis compared with 4 out of 10 who walked early. Histology showed close bone apposition in 4, tight fibrous encapsulation in 4 and lack of tissue apposition in 8 which were loose. Bone remodelling in radiographs reflected the histological appearances; narrow radiolucent spaces were associated with dense well organised fibrous tissue, and wide radiolucent spaces with loose connective tissue. Prostheses with stems which fill the femoral canal should improve the fixation of smooth cementless prostheses.

Localised mastocytosis at the bone and porous coated interface of a knee prosthesis

A porous coated tibial plateau component, which was not loose, was removed 6 weeks after operation. An absence of bony ingrowth was demonstrated by histological and microradiographic examination. The radiolucent space was filled by young connective tissue and inflammation was indicated by the presence of a few macrophages or foreign body giant cells; there was also an increased number of mast cells near the metallic beads. Such inflammatory cells have not previously been reported around a firmly fixed joint prosthesis, but they have been associated with metallic particles. Since accumulations of mast cells can interfere with the process of bony ingrowth, further studies of removed porous coated prostheses should be made with adequate histological techniques so that the clinical significance of these cells can be better understood.

歯牙腫の臨床病理学的検索 その２： Ｘ線学的，病理組織学的検討

Fifty-four cases of odontoma were studied radiologically, Of these, 42cases (29 compound and 13 complex types were) studied histopathologically with special emphasis on the growing process.Radiologically, odontoma was surrounded by a thin radiolucent space, but in 2 cases in which this radiolucent space had widenend, a tumorous growth was histologically observed in the capsule.In the parenchyme, proliferation of odontogenic epitheliums and ghost cells were observed. Among those cells, dysplastic enamel, dysplastic dentin and osteoid were produced. Those findings suggested inner growth of the tumor.Concerning the capsule, odontogenic epitheliums and dental hard tissues were scattered in some cases. In two cases of the thickened capsule, many developmental processes to odontoma were observed. Those findings suggested outer growth of the tumor.After completion of contouring of the tumor, odontoma had the tendency to proceed to the inner growth, but it almost stopped the outward growth.

External callus formation of closed femoral shaft fractures treated by medullary fixation.

Various radiographic patterns were observed for external callus formation of closed femoral shaft fractures treated by closed and open medullary Rush pin fixation. Closed pinning tends to form more adequate lateral callus, to have less looping of bridging callus over the cortex, and to form smooth, dense callus. Open pinning tends to form less lateral callus, to have more looping (radiolucent space under callus) of the callus over the cortex and fracture site, and to have areas of exuberant callus with the appearance of myositis ossificans. The circulatory status of the cortex and soft tissues seem to be a factor in these callus patterns. Avascular cortex of shaft fractures is inferred by the radiographic findings of bridging callus loops over the cortex, relative increased density of cortical bone, and resorption of cortical bone.

上下がくに発生した多発性の根せん性セメント質異形成症

Periapical cemental dysplasia is generally regarded as a disease that develops al the apical region of vital teeth as a result of proliferation of the connective tissue of the periodontal membrane. The commonest type of lesion in multiple and occurs most often in middle age females. Though in Europe and America there have been many reports of the disease, there arc very few in Japan.The author encountered a case of multiple periapical cemental dysplasia in a 53-year-old female. Because of the lack of symptoms, this case was detected incidentally on radiological examination. The radiographic findings revealed areas of radiopacity ranging in size from rice grain to the tip of the little finger, located around the apices of 54 45 65421 1267 Except for the region of upper left second biscupid, those radiopaque masses were separated by a thin radiolucent space from the surrounding normal bone and the apices of the involved teeth. The affected part around the apices of upper left second biscupid was partly radiolucent and partly radiopaque. All wisdom teeth showed retention and their roots exhibited hypercementosis-like findings.Bone scanning with 99mTc-MDP revealed deposition in each affected part. The right lower wisdom tooth and the growth attached to the root were removed en block and the tooth was examined following decalcification. The histopathological diagnosis was periapical cemental dysplasia accompanied by hypercementosis of the root of the left lower wisdom tooth.The patient has been observed periodically for four years and there have been no clinical or radiological evidence of change, except for a small radiolucent area at the periphery of the lesion showing radiopacity.

Chest roentgenographic findings in 26 patients with traumatic rupture of the thoracic aorta

The initial 100-cm anteroposterior (AP) supine chest roentgenograms of 26 patients with proven traumatic aortic rupture were reviewed. The 20 male patients and six female patients ranged in age from 12 to 75 years. Distortion of normal aortic contour or blurring of the aortic outline occurred in 23 cases. Opacification of the radiolucent space between the aorta and pulmonary artery was seen in 22 instances. The mean mediastinal width, measured at the superior border of the anterior fourth rib, was 9.4 cm. Obliteration of the medial aspect of the left upper lung field was observed on 13 films. Obliteration of the shadow of the descending aorta, hemopneumothorax, and tracheal shift to the right each occurred in 17, 14, and 12 cases, respectively. This study illustrates that distortion or blurring of the aortic arch contour, opacification of the clear space between the aorta and pulmonary artery, and increased mediastinal width (mean = 9.4 cm) are the most frequently occurring abnormalities on the initial AP supine chest films of patients with traumatic aortic rupture. Such findings should arouse the suspicion of aortic rupture, and warrant aortography.

Mineralization pattern and fluoride distribution of the developing and matured enameloid of the shark

The fact that the enameloid of shark teeth contains fluoride as high as about 3.3 per cent in the form of fluorapatite has been previously pointed out by the several investigators. In the present investigations, the distribution of fluoride in the developing and matured enameloid of the shark (Isurus glaucus, Blue shark, Mako) was investigated by means of the electron microprobe, in order to verify the mechanism of fluoride incorporation into the enameloid.The undemineralized ground sections (about 70 micron thick) including a row of tooth germs (from the early stage to the late stage, of development) and matured tooth were made. They were, at first, microradiographed and, then, were subjected for the electron microprobe analysis. The condition of analysis are shown in Table 1.The enameloid organic matrix begins to mineralize throughout the whole layer immediately after it was fully formed. However, the gradient of mineralization increase is different for the layers in the matrix (Fig.1, left, and Fig.5). It seems that the mineralization of enameloid has been completed before the dentin is formed on the inner wall of the enameloid (Fig.1, middlle and right). The mineralization degree in the fully matured enameloid is highest in the surface layer and decreases gradually towards the enameloid-dentin junction (Fig.6, c-d). The tubles containing the cytoplasmic processes of odntoblasts are observed as radiolucent spaces in the inner-half layer (Fig.6, a-d).The fluoride concentration has been already relatively high in the enameloid (higher than 2 per cent in the middle layer) at the early stage (Fig.7, a). Then, as it approaches to the middle stage, the steep increase of fluoride concentration becomes observable in the outer-half layer (Fig.7, b). Finally, in the fully matured enameloid, the fluoride concentration is highest in the surface layer (higher than 3.5 per cent at the level of incisal one-third) and decreases gradually towards the enameloid-dentin junction (about 1.7 per cent)(Fig.7, c-f). However, in the dentin, the fluoride concentration is very low (lower than 0.5 per cent), even in the erupted tooth. Magnesium concentration is about 4 times higher in the dentin than in the enameloid.In the fully matured and unerupted enameloid, the fluoride concentration in the surface layer is highest at the incisal tip (about 3.7 per cent) and decreases gradually towards the cervical region. On the other hand, the fluoride concentration in the inner-most layer shows almost the same degree throughout all level, except the incisal portion in which it is high as at the surface layer (Fig.8).The results of present investigations seem to suggest that the enameloid forming cells have a peculiar ability to concentrate the fluoride in the enameloid.