21 research outputs found
Влияние изменения тиреоидного статуса на активность центральной стресс-лимитирующей системы
ТИРЕОИДНЫЕ ГОРМОНЫЙОДСОДЕРЖАЩИЕ ТИРЕОИДНЫЕ ГОРМОНЫСТРЕСССТРЕСС-ЛИМИТИРУЮЩИЕ СИСТЕМЫТИРОКСИНГИПЕРТИРЕОЗГИПОТИРЕОЗЭКСПЕРИМЕНТЫ НА ЖИВОТНЫХБИОМЕДИЦИНСКИЕ ИССЛЕДОВАНИЯКРЫС
DEGENERATIVE CHANGES OF THE HUMAN TEMPOROMANDIBULAR JOINT: A radiological, microscopical, histomorphometrical and biochemical study.
In five autopsy specimen studies human temporomandibular joints were investigated by conventional tomography, macroscopy, and microscopy for degenerative changes, in particular erosive hard-tissue changes.In the microscopical evaluation special attention was paid to the calcified cartilage. The calcified cartilage was outlined by a flat or gently undulating basophilic tidemark and an irregular osteochondral junction. A significant correlation was found between the thickness of the calcified cartilage and that of the total articular cartilage. Two types of erosive changes were found; an extensive type with complete loss of overlying cartilage and a local type with retained cartilage. The erosive changes were generally more extensive in the condyle. Microscopically, the erosive changes in the condyle were evenly distributed. In the temporal component there was a slight predominance of these changes located to the lateral part of the tubercle. Tomography underestimated both the presence and the extent of the erosive changes. Positive predictive values and negative predictive values were 0.70 and 0.83, respectively, for changes in the condyle and 0.91 and 0.68 for changes in the temporal component. The likelihood ratio for a positive test was 10.6 in the temporal component and 5.6 in the condyle. The likelihood ratio for a negative test was comparable in the two joint components 0.49 and 0.47 respectively. Three different techniques of computer-aided bone histomorphometry (manual, automatic and semi-automatic) were assessed. The variation when assessing the total and trabecular bone volume was evaluated. Good reproducibility in the assessment of the total and trabecular bone volume was achieved with the aid of a single observer and a semi-automatic technique. This technique was therefore used to assess the total and trabecular bone volume in condyles and temporal components of joints with and without microscopically verified erosive changes. Condyles with erosive changes demonstrated both a higher trabecular bone volume (P< 0.05) and higher total bone volume (P< 0.01) than condyles without erosive changes. In a clinical study on patients undergoing diskectomy, the two cartilage matrix macromolecules aggrecan and cartilage oligomeric matrix protein (COMP) were quantified by enzyme-linked immunosorbent assay in lavage fluids from temporomandibular joints before and six months after surgery. The aggrecan/COMP ratio was higher in the lavage fluid of all joints at follow-up as compared to preoperatively. All joints developed radiographic changes indicative of degenerative changes (osteoarthrosis) during the postoperative period
Letter to the editor concerning Parrott LA, Ng SY. A comparison between bitewing radiographs taken with rectangular and circular collimators in UK military dental practices : a retrospective study published in Dentomaxillofacial Radiology (2001;40:102–109).
Ultraljudsundersökningar i huvud- och halsregionen
Sampublicering även i norska och finska tandläkartidningarna.</p
PET/MR versus PET/CT for locoregional staging of oropharyngeal squamous cell cancer
Background: The value of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for TN staging in head and neck cancer (HNC) has been proven in numerous studies. A few studies have investigated the value of FDG-PET/magnetic resonance imaging (MRI) in the staging of HNC; the combined results indicate potential for FDG-PET/MRI, but the scientific evidence remains weak. Purpose: To compare performance of FDG-PET/CT and FDG-PET/MRI for locoregional staging in patients with oropharyngeal carcinomas. Material and Methods: Two radiologists independently of each other retrospectively reviewed primary pre-therapeutic FDG-PET/CT and FDG-PET/MRI examinations from 40 individuals with oropharyngeal carcinomas. TN stage and primary tumor size were noted. The results were compared between observers and modalities and against TN stage set at a multidisciplinary conference. Results: For nodal staging, PET/MRI had slightly higher specificity and accuracy than PET/CT for the most experienced observer. Both methods demonstrated excellent sensitivity (≥ 0.97 and 1.00, respectively), as well as high negative predictive values (≥ 0.95 and 1.00, respectively). No significant differences were found for tumor staging or measurement of maximum tumor diameter. There was a weak agreement (κ = 0.35–0.49) between PET/CT and PET/MRI for T and N stages for both observers. Inter-observer agreement was higher for PET/MRI than for PET/CT, both for tumor staging (κ = 0.57 vs. 0.35) and nodal staging (κ = 0.69 vs. 0.55). The agreement between observers was comparable to the agreement between methods. Conclusion: PET/MRI may be a viable alternative to PET/CT for locoregional staging (TN staging) and assessment of maximal tumor diameter in oropharyngeal squamous cell cancer
Pre-operative radiographic evaluation of lower third molars with computed tomography
OBJECTIVES: To report radiographic findings of examinations with computed tomography (CT) of impacted lower third molars with an intimate relation to the mandibular canal and to investigate how findings of a dark band across the roots of the lower third molar on panoramic views correspond to the CT findings. METHODS: CT images of 90 lower third molars (64 patients, mean age 34.6 years) in which plain radiography was insufficient to allow determination of the precise anatomical relations were reviewed retrospectively. Panoramic views of 88 teeth existed; these images were interpreted independent of the CT examinations with respect to presence of a dark band across the roots. RESULTS: In 31% of the CT images, the course of the mandibular canal was buccal, in 33% lingual, in 26% inferior, and in 10% inter-radicular. The tooth was in contact with the mandibular canal in 94% and with the lingual cortex in 86%. In 23%, grooving of the root by the canal was judged to be present. In 63% of the cases where a dark band across the roots was observed on panoramic radiographs, CT revealed grooving of the root. CONCLUSIONS: Pre-operative CT of lower third molars is motivated in selected cases when plain radiography is inconclusive. The finding of a dark band across the roots on panoramic radiographs is an indicator of grooving of the tooth by the canal and justifies a pre-operative CT examination. The absence of dark bands on panoramic views does not exclude grooving of the roots
A comparative study of the clinical efficacy of Screw Vent implants versus Brånemark fixtures, installed in a periodontal clinic
The clinical success of 85 Screw Vent and 107 Brånemark implants, consecutively installed in a private periodontal clinic under the same conditions and by the same operator, is compared. Mobile implants were removed and considered as failures. Intra-oral radiographs were assessed for the presence of peri-implant radiolucencies and for analysis of bone loss after functional loading. 85 Screw Vent implants were installed in 31 patients. Of 23 implants installed in 9 mandibles, none failed after 16.8 (range 12-25) months of function. Of 62 Screw Vent implants installed in 23 maxillae, 6 failed at abutment connection, 1 failed after 2 months and 2 after 13 months of function. The absolute failure rate after 13.2 (range 6-24) months was 9/62. Mean loss of bone was 1.47 mm (-1.0- +4) after 12 months of functional loading. 107 Brånemark fixtures were installed in 25 patients. Of 51 fixtures inserted in 12 mandibles, none failed; of 56 fixtures installed in 13 maxillae 1 failed before and 2 failed during abutment connection. The absolute failure is 3/56. All remaining fixtures were immobile after loading. 13 fixtures were more than 6 months in function. Only short-term comparison between both systems is possible because the observation time is longer for the Screw Vent implants. In the 1st year, only 1 implant system was available to the periodontist. Short-term comparison reveals 11.3% versus 5.3% of cumulative failure after 6 months for the Screw Vent and Brånemark implants, respectively. The results indicate that clinical efficacy is as effectively obtained with Screw Vent as with Brånemark implants in the mandible. The outcome of treatment with Screw Vent implants in the maxilla seems less predictable
When Maxillary Sinusitis Does Not Heal : Findings on CBCT Scans of the Sinuses With a Particular Focus on the Occurrence of Odontogenic Causes of Maxillary Sinusitis
Objectives: This study sought to investigate the proportion of patients with suspected sinusitis referred for radiological examination who have radiologically verified sinusitis of odontogenic origin and to describe this type of sinusitis. Study Design: This investigation is a retrospective study. Methods: A total of 303 sinus examinations involving cone beam computed tomography (CBCT) performed at Sunderby Hospital, Lulea, Sweden in 2012 were independently reviewed by two radiologists. The number of cases of maxillary sinusitis and the correlation between maxillary sinusitis and odontogenic infections were determined. Results: Overall, 24% of the verified cases of sinusitis were odontogenic. An odontogenic origin was identified in 40% of unilateral maxillary sinusitis cases but only 6% of bilateral maxillary sinusitis cases (p=0.0015). Forty-nine out of 54 patients with periapical destruction had adjacent mucosal swelling in the maxillary sinus, but only 15 of these patients satisfied the criteria for sinusitis. Conclusion: The present study confirms the close relationship between odontogenic infections and unilateral maxillary sinusitis
The impact of cone beam computed tomography on the choice of endodontic diagnosis
Aim To determine whether the outcome of cone beam computed tomography (CBCT) examinations performed in accordance with the European Commission guidelines in a clinical setting has an impact on choosing diagnoses in endodontics. Methodology A prospective observational study was conducted. Fifty-three consecutive patients (81 teeth) from two different endodontic specialist clinics in Sweden were followed. After performing a thorough clinical examination (based on the history, clinical findings, and diagnostic tests such as intra-oral radiography), the examiner wrote down a preliminary diagnosis before CBCT examination. After the CBCT examination, a new diagnosis was made by the same examiner. Both the pre- and the post-CBCT examination diagnoses were plotted according to patients and teeth. The CBCT examinations were performed using similar equipment and protocols that were standardized amongst the clinics. Results The diagnoses were changed for at least one tooth in 22 patients (41%); overall, the diagnoses were changed for 28 teeth (35%). Conclusion CBCT has a substantial impact on diagnostic thinking in endodontics when used in accordance with the European Commission guidelines