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Biomedical subjects

K K Virtanen

Publications and source records attributed to K K Virtanen.

At least 19 recordsLinked to original sources
PubMed1994

Occlusion and craniomandibular function among patients treated with removable partial dentures.

Forty patients treated with removable partial dentures (RPDs) at the Institute of Dentistry, University of Oulu, were selected for this study. The type of occlusion, horizontal and vertical overlap, the slide between retruded contact position and intercuspal position, and the occlusal interferences were investigated as occlusal parameters. Helkimo's anamnestic and clinical indices were used to measure the craniomandibular function and the clinical index score was used to compare the differences between different groups. The RPD-generated occlusal interferences seemed to cause most harmful effects in point centric, interference free occlusions, when the damage was directed at the temporomandibular joint. These interferences were most frequently found in the retruded contact position and caused by the RPD teeth.

Adult↗
PubMed1994

Clinical and radiologic assessment of possibilities for endosseous implants and osseointegrated prostheses in 55-year-old edentulous subjects.

To determine how many 55-year-old edentulous subjects were suitable candidates for implant-retained overdentures of fixed implant bridges and how many of them might be interested in such treatment, case histories were reviewed, and clinical and radiologic examinations were performed on 146 subjects (100 women, 46 men) in a medium-sized city in northern Finland. Numbers and lengths of implants required in altogether 16 regions in the upper and lower jaw were evaluated. The commonest implant length was 8 mm in the upper jaw and 16 mm in the lower jaw. Construction of an implant-retained fixed bridge would have been possible in the upper jaw in 121 subjects (83%) and of an overdenture in all lower jaws. Information about the benefits of the treatment is important because, although the percentage of subjects who were suitable candidates for implant-retained prostheses was high, few subjects were aware of or interested in this type of treatment.

Alveolar Bone Loss↗
PubMed1988

Free amino acids in human palatine gland secretions.

Human palatine gland saliva (HPS) was collected from young adult subjects (mean age 22 yr) of both sexes by gentle mechanical stimulation. The HPS contained 9-13 of the common amino acids within the range of 2-850 nmol/ml, but most samples had low or no concentrations of arginine, tryptophan and proline. Methionine and cysteine were not reliably detected. The molar ratios of most amino acids varied between subjects, but the ratio of leucine to isoleucine was remarkably constant (mean +/- SD = 1.86 +/- 0.28; n = 28). The minimum average secretion rate of HPS, using gentle mechanical stimulation, was estimated to be about 25 mg/min (wet weight).

Adult↗
PubMed1988

Time estimates for dental treatment in four age cohorts of an adult population.

Needs for tooth extractions, conservative dental treatment--including periodontal and caries treatment--and occlusal rehabilitation--including stomatognathic and prosthetic treatment or a combination of these--in a Finnish adult population were summarized and time estimates for the treatment calculated. The study population consisted of 1,275 adults in four age cohorts--25, 35, 50, and 65 years. A decrease was observed from five hours of total dental treatment time needed at ages 25 and 35 years to four hours at age 50 years and three hours at 65 years. At the age of 25 years, 86 percent of the treatment time (255 min) was needed for conservative therapy, the corresponding figures at 65 years being 35 percent (66 min). On the other hand, a fivefold increase (from 13% to 62%) in the proportion of time needed for occlusal rehabilitation was observed between age 25 and 65. A combination of stomatognathic and prosthetic treatment was most frequently needed. The percent of time needed for tooth extractions varied from 1 to 3 percent among the four age cohorts.

Adult↗
PubMed1986

Densities and sizes of the main masticatory muscles in computed tomography compared with clinical findings related to temporomandibular joint (TMJ) dysfunction.

Computed tomography (CT) has a good resolution capacity and is an excellent method for measuring tissue densities. The aim here was to compare the densities and sizes of the main masticatory muscles, the masseter, medial pterygoid and lateral pterygoid muscles, as obtained with CT, with clinical findings in patients with TMJ dysfunction (25) and controls (29). The densities of the masseter muscles and the medial pterygoid muscles showed no statistical difference between the patients and controls, while the lateral pterygoid muscles of the patients had densities that were only almost significantly higher than those of the controls. The masseter muscles on the patients who more often had signs of bruxism in their dentition were statistically significantly thicker than in the controls, but the widths of the medial pterygoid muscles gave no statistical difference between the groups. The results seem to indicate that in addition to the bone density changes associated with functional disorders of the masticatory system, there may be also density and size changes in the masticatory muscles which are detectable by CT.

Adolescent↗
PubMed1985

Partial purification and characterization of arylamidases from human palatine secretions.

The secretions (HPS) contained an arylamidase-like enzyme discovered by chromatography on Sephadex G-100 Superfine columns using N-L-alanyl-2-naphthylamine (2NA) as substrate. The enzyme was fractionated in the void volume, suggesting that its molecular weight was 150,000 or higher. It hydrolysed, with decreasing rates, the 2NA of L-alanine, L-leucine, L-methionine and L-phenylalanine, the pH optimum for the best substrate (ala-2NA) being 8.0, alpha-Benzoyl-DL-arginine-2NA was not hydrolysed. p-Chloromercuribenzoate, EDTA, Ca2+ and Zn2+ were inhibitory, whereas chemical modification with typical tyrosyl group reagents did not significantly inactivate the enzyme. Treatment of HPS with Triton X-100 revealed two further arylamidase-like enzymes with lower mol. wt (90,000 and 40,000, respectively). Inhibition characteristics and Cl- effects suggest that one of these enzymes resembles aminopeptidase B (EC 3.4.11.6). HPS also contains endopeptidase activity over a wide pH range (6-9). The number of enzymes in HPS is thus small and most of the peptidolytic activity of HPS in vitro is due to one major enzyme with arylamidase activity.

Adult↗
PubMed1985

Density of the caput mandibulae in computed tomography compared with clinical findings related to TMJ dysfunction.

Computed tomography (CT) is an excellent method for evaluating the temporomandibular joint, since it shows the bone structures and soft tissues at the same time and constitutes the most practical method for measuring tissue densities in vivo. The aim of this work was to compare densities of the caput mandibulae obtained by CT with the clinical findings in patients with TMJ dysfunction (25) and controls (29). The densities in the patient group were higher than in the controls and seemed to correlate with the clinical symptoms and signs of TMJ dysfunction, especially with muscle pain and deviation in the mouth opening movement.

Adolescent↗
PubMed1985

Effect of xylitol-, sucrose-, and water-rinses on the composition of human palatine gland secretions.

The chemical composition of stimulated human palatine secretions (HPS) was studied after rinsing with aqueous solutions of sucrose or xylitol, or with water only. Stimulation with water was associated with increased concentration levels of protein. The levels of sialic acids (per mg protein) and the specific arylamidase activities were simultaneously increased, within the physiologic range. In contrast to a previous report, these results indicate that HPS does contain arylaminopeptidases the activity of which is strongly increased by Cl-. The Cl(-)-dependent activity was revealed when using N-L-arginyl-2-naphthylamide as substrate. The filter paper method used is recommended for collecting HPS for chemical analyses. In spite of the use of a relatively effective and versatile stimulation procedure, only one third of the subjects produced detectable HPS. Very poor secretion of HPS should perhaps be considered in subjects wearing total dentures.

Adult↗
PubMed1983

Composition of human palatine gland secretions and evidence for the presence of specific arylamidases.

After mechanically stimulating the surface of palatine mucosa of adult human subjects, 10-25 microliter of saliva secreted from the openings of the palatine glands were directly collected into graduated glass capillaries. The saliva samples contained large amounts of carbohydrates, sialic acids and hexosamines as a result of the high glycoprotein content of the secretions. The saliva did not show activity from amylase, peroxidase, lysozyme and other typical mixed saliva enzymes, but contained arylamidases at concentrations much higher than mixed saliva from the same subjects.

Adult↗
PubMed1978

Effect of 4.5--year use of xylitol and sorbitol on plaque.

The pH values of xylitol-containing plaque suspensions of persons who habitually used xylitol and sorbitol during 3.2 to 4.5 years did not significantly differ from those observed with suspensions containing no added carbohydrates. Sorbitol produced in 22-hour incubations pH values as low as 3.9 to 5.5. The activity of plaque xylitol dehydrogenase was almost nil, whereas sorbitol dehydrogenase activity was higher. The nonacidogenic nature of xylitol in relation to plaque did not change in prolonged use of xylitol.

Adolescent↗
PubMed1977

Activity of arginine aminopeptidases and phosphatases in inflamed palatal mucosa in denture stomatitis: a histochemical and biochemical study.

Aminopeptidase and phosphatase activity of denture stomatitis mucosa was studied histochemically and biochemically. Stomatitis clearly increased the activity of these enzymes. An enzyme resembling the chloride-activated aminopeptidase B, usually involved in inflammatory processes, was recognized in the inflamed tissue in higher concentrations than in the control tissue.

Acid Phosphatase↗
PubMed1976

Aminopeptidase B in human serum.

The activity of arginine aminopeptidases in human serum was studied with special reference to the possible involvement of enzymes resembling aminopeptidase B (APB). The serum samples were obtained from 10 patients with various acute inflammatory processes, both during the acute phase and after treatment with penicillin. The administration of penicillin to the patients did not result in noticable changes in the chromatographic pattern of the APB-like enzyme. The disappearance of the acute symptoms did not significantly affect the overall specific activity of arginine aminopeptidases in serum. The results showed that human serum does contain, contrary to earlier reports, an enzyme corresponding to APB, even though in very low concentrations. The low enzyme activity was revealed by prolonged reaction times and by the use of larger samples in chromatography than earlier. The APB-like enzyme in serum may have derived from blood cells.

Abscess↗