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Biomedical subjects

S Kopp

Publications and source records attributed to S Kopp.

At least 127 records · Page 7Linked to original sources
PubMed1989

The sufficiency of blood flow in human masseter muscle during endurance of biting in the intercuspal position and on a force transducer.

Blood flow changes caused by endurance of voluntary isometric muscle contraction and the sufficiency of flow during contraction were assessed by measuring 133Xe clearance. Aiming at 50% maximum voluntary contraction (MVC), 9 healthy persons sustained biting in the intercuspal position (ICP group) at an actual medium EMG activity level of 55% MVC, while receiving a visual feedback of the average-integrated EMG activity. Eleven persons sustained unilateral biting (UBF group) on a force transducer at 40% MVC, receiving feedback of the force output. The significantly lower % MVC for the UBF group was due in part to a decrease in the EMG activity during endurance, while force was constant. Blood flow changes over time were significant; however, the changes differed significantly between groups during endurance: the ICP group had a median reduction in blood flow to 0.4 of the initial resting value, and the UBF group had a 0.2-fold median increase. Following endurance, flow changes integrated over 3 minutes were about 43-fold the initial resting values of both groups. This similarity was probably a result of their equivalent effort. The endurance flow accounted for 1% of the total change for the ICP group and 5% for the UBF group. Overall, the proportion of the total flow that took place during endurance decreased logarithmically with greater level of contraction and masseter effort. Therefore, sufficiency of blood flow to maintain muscle fibre homeostasis is less when the rate of metabolic turnover is greater, thus contributing to an earlier onset of masseter fatigue, pain and exhaustion at high contraction levels.

Adult↗
PubMed1989

[Value of bite-guard splints for dysfunctions of the masticatory system].

Based on a clinical post-treatment evaluation of 184 patients, the value of bite-guard splints in the treatment of dysfunctions of the masticatory system was assessed. The results clearly showed that successful results (83-89%) could be achieved, if the indications were considered with differentiation. Intracapsular joint diseases could be successfully treated with bite-guard splints, while other treatment concepts had to be applied for myalgia, bruxism and condylar displacement or dislocation.

Adult↗
PubMed1989

[Perioperative treatment of patients with chronic TMJ diseases].

The concept of perioperative diagnosis and treatment of patients with chronic TMJ disease has been confirmed by a follow-up examination of ten female patients after surgical treatment. Eight of the ten patients were pain-free after observation periods of 3 to 20 months. Following an initial bite-guard splint therapy, instrumental functional analysis, MR tomography and arthrographic visualization of dynamic movement profiles are indispensable. The results have also shown that, depending on the intraoperative finding, a postoperative splint therapy should be performed for six months.

Adult↗
PubMed1989

[Instant-picture motography in dentistry].

In technical applications instant-picture motography is used for recording motion traces. The process involves a photographic pulse light procedure based on the Polaroid instant-picture technique. Its applications include, among others, robot motion analysis in developing ergonomic workplaces and, recently, functional diagnosis in dentistry. The advantages lie in the touch-free representation of mandibular movements involving minimal recording weight. Functional disorders can be detected immediately. The results obtained provide a first information basis for the dentist to decide on the proper treatment concept. The experiments on the diagnostic and therapeutic utilization of the recorded border movements have not been concluded yet.

Dental Articulators↗
PubMed1989

[Pilot study on the clinical use of instant-picture motography].

Articulator experiments using instant-picture motography (Bumann et al. 1988) have shown that the extent and form of mandibular border movements can be recorded with a coefficient of variation of less than 5% in a "model", when recorded close to the axis. Within the framework of the pilot study the reproducible accuracy of +/- 2 degrees was within the range of the adjustment accuracy of the articulators, as compared with the Meyer reference system (1986). It is not until the evaluation of a large-scale clinical study that we will know if programming individually adjustable articulators is permissible or not.

Bite Force↗
PubMed1989

[Effects of different sterilizing techniques on osseous regeneration of grafted lyophilized cartilage].

The suitability of variably sterilized lyocartilage grafts as potential bone substitutes was investigated in animal experiments with special attention to configurational stability. In 3 Beagles corticocancellous implant beds were prepared by box-type ostectomies and lyophilized costal cartilage blocks sterilized with X-rays,ethylene oxide gas and beta-propriolactone solution were placed into them. Implants sterilized with X-rays and beta-propriolactone appeared to be unsuited for recontouring facial bone defects, since they showed complete loss of configuration after a follow-up time of 125 and 230 days, respectively. By contrast, cartilage implants sterilized with ethylene oxide gas retained their configuration after no less than 328 days. In light of these results, methods for sterilizing other biomaterials should be re-considered.

Animals↗
PubMed1989

[Compression joint as a differential diagnosis in chronic facial pain].

"Costen's syndrome" is generally used to label chronic pain in the periauricular region. This article presents the results of a post-treatment evaluation of 50 patients, 25 of whom were referred to hospital with Costen's syndrome indicated in the diagnosis. As a result of this study it is proposed that the term "compression joint" be used instead of "Costen's syndrome". The importance of proper diagnostic procedures is pointed out.

Chronic Disease↗
PubMed1989

[The present state of knowledge on the problem of the relation between diabetes mellitus and breast cancer].

Although there is a broad consensus on diabetes as a factor frequently associated with breast cancer its causal role has not been proved yet. Some pathophysiological mechanisms and pathways are well investigated (e.g. insulin acts as a growth factor or certain interrelations between endocrine regulation, tumor growth, and differentiation) but important questions remain unsolved like the influence of an altered glucose metabolism on tumor growth or to what extent risk factors for breast cancer interfere. A review is given about the experimental studies on insulin as a growth factor and its influence on the hormone receptors of the cancer cell as well as epidemiologic studies concerning the association between diabetes and breast cancer. Summarizing the results there is no clear evidence for determining diabetes mellitus as a risk factor for breast cancer. Further investigations are necessary for deriving conclusions relevant for cancer control measures.

Breast Neoplasms↗
PubMed1988

Estimation of blood flow by 133Xe clearance in human masseter muscle during rest, endurance of isometric contraction, and recovery.

Sixty-four measurements of 133Xe clearance from the masseters of 9 individuals, who had no facial or oral pain, were used to evaluate changes in intramuscular blood flow (IMBF) caused by endurance of isometric contraction at approx. 50 per cent of maximum voluntary EMG activity. On average, the IMBF during endurance increased by 4.2 times in 6 individuals and decreased 62 per cent of the rest flow in 3 individuals. Overall, the group average of endurance flow was 2.5 times higher than the initial rest flow. The group average of post-endurance hyperaemia was 27 times higher than the initial rest flow and 11 times higher than the endurance flow. IMBF during the final rest was 1.7 times higher than the initial rest flow. The relative IMBF during endurance was negatively correlated to muscle effort, and the post-endurance flow in relation to the endurance flow presented a compensatory positive correlation to the muscle effort. Although the average IMBF tended to increase during endurance, it was insufficient to meet the demand of the much higher relative increase in muscle activity, as indicated by the pronounced post-endurance hyperaemia, especially after long endurance.

Adult↗
PubMed1988

Relationship between clinical and radiologic findings of the temporomandibular joint in rheumatoid arthritis.

The relationship between clinical findings in the craniomandibular system and radiologic findings in the temporomandibular joint was investigated in 101 adults with rheumatoid arthritis. Radiologic changes were correlated with duration and severity of temporomandibular joint symptoms and general joint disease. The radiologic changes were also associated with loss of occlusal support, anterior open bite, and occlusal interferences. Most joints with crepitus exhibited radiologic erosion. Joints with mutilating changes were silent.

Adult↗
PubMed1988

Macroscopic and microscopic appearance of radiologic findings in temporomandibular joints from elderly individuals. An autopsy study.

The macroscopic and microscopic appearance of radiologic findings in 40 temporomandibular joints (TMJ) taken at autopsy from 20 elderly individuals was investigated. The radiologic signs of erosion and sclerosis were strongly associated with macroscopic articular surface destruction only on the condyle while the soft tissue lining was most often intact in areas with a sclerosis of the temporal component. Radiologic concavity, osteophyte, and flattening presented none or mild macroscopic changes. The microscopic appearance of erosion and cyst formation was characterized by the presence of a cell-rich fibrous and well-vascularized connective tissue. In 4 joints with fibrous ankylosis, an articular soft tissue lining was completely lacking. In areas with radiologic sclerosis, thickening of the cortical and subcortical bone was observed. Both erosions and sclerosis were found in most joints with anterior disc position or disc perforation. It was concluded that radiologic signs of erosion and sclerosis in the condyle are more reliable signs of joint disease than such changes in the temporal component.

Aged↗
PubMed1988

Intra-articular and skin surface temperature of the temporomandibular joint in patients with rheumatoid arthritis.

Intra-articular and skin surface temperatures of the temporomandibular joint (TMJ) were investigated in 34 patients with rheumatoid arthritis (RA). History was taken, and a clinical examination of the stomatognathic system was performed. The intra-articular temperature measurement was made with a thermocouple inserted through a needle, and the skin surface measurement was made with a thermocouple lateral to the condylar pole. The intra-articular temperature was lower for 37% and higher for 30% of the patients, whereas skin surface temperature was lower for 18% and higher for 6%, compared with normal individuals. Intra-articular and skin surface temperatures were positively correlated, and the average difference between skin surface and intra-articular temperatures was 1.6 degrees C. The intra-articular temperature was most strongly and positively correlated to the number of joint regions affected by RA and negatively correlated to the number of tender masticatory muscles, whereas skin surface temperature was most strongly and positively correlated to room temperature and negatively correlated to the number of tender masticatory muscles. These results indicate that pain and tenderness of masticatory muscles in RA are associated with hypothermia of the TMJ.

Adolescent↗
PubMed1988

Short-term effect of physical training on temporomandibular joint disorder in individuals with rheumatoid arthritis and ankylosing spondylitis.

Twenty-eight individuals with rheumatoid arthritis (RA) and 32 individuals with ankylosing spondylitis (AS) with symptoms or signs of temporomandibular joint disorder were studied. For both diseases the individuals were divided into an experimental group (E group) and a comparison group (C group). The study included a questionnaire on dental and medical history, clinical examination of the stomatognathic system, and laboratory tests. A physical training program for the stomatognathic system was administered in the E groups, while the C groups were used as controls. All groups were followed up after 3 weeks. In all four groups the individuals reported less severity of temporomandibular joint disorder at the follow-up study after physical training. The maximum voluntary mouth opening capacity increased, and the clinical dysfunction score of Helkimo decreased in the two E groups but not in the C groups. The short-term results of this study show that physical training of the stomatognathic system improves the mandibular mobility in individuals with RA and AS and reduces the clinical dysfunction extent in individuals with RA.

Adult↗
PubMed1988

Skin surface temperature over the masseter muscle in individuals with rheumatoid arthritis.

Temperature measurements were made on the skin surface over the masseter muscle in 71 individuals with rheumatoid arthritis (RA group) and in 52 individuals without general joint disease or symptoms (C group). The temperature recordings were performed with thermistors in contact with the skin. Symptoms in the stomatognathic system and general joint symptoms were investigated by means of a questionnaire. A clinical examination was made of the stomatognathic system. In addition, a medical examination including clinical articular indices and laboratory tests was made. The skin surface temperature over the masseter muscle was generally decreased for the individuals with RA compared with the C group but increased with duration of temporomandibular joint (TMJ) symptoms, approaching normal values. Duration was also the most important variable among those investigated in determining the skin surface temperature over the masseter muscle. Hypothermia in the RA group was correlated with craniomandibular disorders such as lateral deviation of the mandible on mouth opening and TMJ clicking, whereas individuals with a history of swelling in the TMJ region had a higher temperature than average in this group. The results of this study show that there is a correlation between craniomandibular disorders and decreased skin surface temperature over the masseter muscle in individuals with RA.

Arthritis, Rheumatoid↗