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Biomedical subjects

T Strömberg

Publications and source records attributed to T Strömberg.

At least 19 recordsLinked to original sources
PubMed1992

Vibrotactile perception threshold measurements for diagnosis of sensory neuropathy. Description of a reference population.

Recognition of the fact that impairment of the tactile sense may occur independently of other disturbances in the vibration syndrome has rekindled an interest in developing a diagnostic method for early detection of vibration-induced neuropathy. There is also evidence suggesting that vibrotactile measurements represent a valuable diagnostic tool in compressive neuropathies, such as the carpal tunnel syndrome. The method may also become useful for diagnosing sensory neuropathies caused by other factors, such as solvents, pesticides, heavy metals, alcoholism, and diabetes. However, before vibrotactile measurement can be accepted and established as a tool for clinical diagnostic purposes, for screening, and in research, the level and the shape of the normal threshold curve have to be specified. With the purpose of assembling normative data, the vibrotactile perception thresholds (8-500 Hz) of the right index fingertip were measured in 171 healthy males (19-75 years) not exposed to vibration. A Békésy audiometer was modified to operate in combination with a vibration exciter, instead of headphones, at frequencies lower than usual (8-500 Hz). The results showed that the perception thresholds increased from about 100 dB to about 140 dB (rel. 10(-6) m/s2rms) as a function of frequency and age. The frequency-dependent changes were not linear, however, but displayed a peak in sensitivity at 125 Hz. Threshold changes due to aging were most pronounced at the highest frequencies. It is of the utmost importance that these natural changes are taken into account when making comparisons between groups or individuals.

Adult↗
PubMed1992

Quantitative radioactive analysis of microleakage of four different retrograde fillings.

Sealing properties of four different retrograde filling materials were investigated in vitro. Radioactive isotopes were applied in the root canal, and leakage into an extraradicular fluid was measured at regular intervals. The method permitted repeated observation of the specimens over prolonged periods of time. Forty single-rooted human teeth were biomechanically instrumented and obturated using calcium-hydroxide paste. Following obturation, an apicectomy was performed and retrograde cavities were filled with four different materials: group 1, non gamma 2 amalgam (Amalcap); group 2, glass ionomer cement (Ketac Silver); group 3, calcium-hydroxide-based root canal sealer (Sealapex); group 4, composite resin (Palfique Light-S). After removal of the calcium hydroxide, the teeth were immersed in a fluid. An isotope solution was then placed in the root canals. Samples were taken from the fluid at 0, 3, 7, 28, 56, 105, 210, 285 and 376 days to determine the radioactivity. It was found that Sealapex and Palfique Light-S showed significantly less leakage than amalgam and glass ionomer cement, which had the highest apical leakage.

Analysis of Variance↗
PubMed1992

Vibrotactile function of the hand in compression and vibration-induced neuropathy. Sensibility index--a new measure.

The perception thresholds for vibration stimuli of the hand at seven frequencies (8-500 Hz) were evaluated in 300 patients referred to the Department of Hand Surgery in Malmö during the years 1985-1990 for various types of neuropathy (carpal tunnel syndrome, vibration-induced neuropathy, cervical rhizopathy, brachialgia, ulnar neuropathy, radial tunnel syndrome, and polyneuropathy). A sensibility index was calculated by dividing the integrated area under the obtained vibrogram curve of each object tested (areaT) by that of the corresponding area under a superimposed and age matched reference curve (areaR). Sensibility index of less than 0.8 was regarded as the cut off value. The index and little fingers bilaterally were tested to reflect median and ulnar nerve function. There were considerable variations in patterns of pathology among the various groups of patients. In patients with unilateral carpal tunnel syndrome only 10 patients (23%) had abnormalities limited to one recording, while 21 patients (47%) showed abnormalities in all four recordings. This indicates that an isolated carpal tunnel syndrome may reflect more generalised disease of the peripheral nervous system.

Carpal Tunnel Syndrome↗
PubMed1989

Trochanteric fractures--a clinical and radiologic evaluation of McLaughlin, Ender, and Richard's osteosynthesis.

Four hundred and thirty femoral trochanteric fractures operated with nail-plate (McLaughlin), Ender, or sliding screw-plate (Richard) osteosynthesis were followed up radiographically and clinically. For each method of osteosynthesis the initial nail position was correlated to the occurrence of late mechanical complications. Unstable fractures were associated with a higher incidence of one or more clinical complications such as repeated surgery, post-operative death, or increased pain. For Ender osteosynthesis correlations were found between several mechanical and clinical complications, while for Richard's osteosynthesis mechanical complications were significantly correlated to repeated surgery only. McLaughlin and Ender osteosyntheses had a higher incidence of reoperations than Richard's osteosynthesis, whereas the mobility and ADL function were the same at 4 months.

Bone Plates↗
PubMed1987

A new principle for assessing vibrotactile sense in vibration-induced neuropathy.

The vibrotactile perception threshold has been evaluated in 20 manual workers not exposed to occupational vibration and in 27 workers using hand-held vibrating tools. Threshold values were evaluated with a Békesy type of vibrometer at frequencies ranging from 8 to 500 Hz. The earliest sign of vibration lesion was a reduction of sensation at frequencies of 125 to 250 Hz, indicating dysfunction in receptors of the fast adapting type II (stage 1 curve), followed in more severe cases by a prominent loss of sensation at all frequencies higher than 65 Hz (stage 2 curve). The stage 3 curve indicated the most severe loss of sensation in which the function of slowly adapting type I receptors, as well as fast adapting type I receptors, was deteriorated; consequently the vibrotactile thresholds at low-, median-, and high-frequency ranges were impaired. The vibrotactile changes corresponded well to numbness and the presence of vibration-induced white finger.

Adolescent↗
PubMed1986

Digital vibrogram: a new diagnostic tool for sensory testing in compression neuropathy.

A Békésy audiometer was modified for use in analysis of vibrotactile sensibility of the hand at frequencies ranging from 8 to 500 Hz. In control subjects the "digital vibrogram" has a typical shape, which differs characteristically in patients with carpal tunnel syndrome (CTS). Changes in digital vibrogram usually parallel or precede abnormalities in neurophysiologic tests, and appear long before changes in two-point discrimination (2PD). One-hundred-thirty-two hands of 76 patients diagnosed as having CTS were tested with a vibrometer. Of 113 hands with normal 2PD, the digital vibrogram showed abnormal in 86 cases. Of 19 hands with abnormal 2PD, the digital vibrogram showed abnormal in all but three cases. Twenty-six hands with neurophysiologically normal appearance had abnormal digital vibrogram in 14 cases, while 53 hands neurophysiologically classified as CTS showed abnormal digital vibrogram in 44 cases. It is concluded that the digital vibrogram is a useful tool for early diagnosis of CTS.

Carpal Tunnel Syndrome↗
PubMed1976

Histochemical demonstration of acid hydrolase activity in internal dentinal resorption.

The enzymes acid phosphatase (E.C. 3.133) and beta-glucuronidase (E.C. 3.2.1.31) have been demonstrated in dentin-resorbing cells by means of histochemistry. Addition of specific enzyme inhibitros revealed that the acid phosphatase of these cells was sensitive to fluride, copper, and m?OLYBDATE BUT RESISTANT TO Tartrate. The same pattern of enzyme activity has previously been found in bone-resorbing cells.

Acid Phosphatase↗
PubMed1976

The use of iodine as a contrast medium in endodontic therapy.

The present study describes the use of 10 per cent iodine in potassium iodide as an intradental x-ray contrast medium in the search for root canals or parts of root canals which were not detected in radiographs or by instrumentation. In most teeth with periapical radiolocencies a passage through the entire root was found by means of the contrast medium, but in the teeth without periapical involvement usually no communication was detected. According to the results of the present study, an intradental contrast medium may be useful in the search for apparently obliterated root canals.

Contrast Media↗