摘要:

The use of a camera for metrical purposes presupposes a knowledge of errors affecting the photograph. The aim of the present study was to test stereomodels of defined test objects with regard to inherent deformations. Three different test objects were used, a fine-lined grid and two test models resembling the teeth and the surrounding labial gingiva. The accuracy as given by the standard error of unit weight of absolute orientation was 0.018 mm (precision grid), 0.066 mm (convex surface) and 0.115-0.139 mm (jaw model). The precision under the test conditions as judged from the comparison of stereomodels from repeated exposures of the same object (jaw model) was between 0.009 and 0.032 mm. Since the stereomodel was deformed in a similar way irrespective of the test object used, it was concluded that part of the total error could be interpreted as a systematic deformation of the stereomodel. For furtherin vivoapplication of the method, with difficulties to identify reference points on the gingiva from repeated exposures, a simple way to estimate the accuracy of gingival measurements was derived by extrapolation from the standard error of the reference points on the teeth.

ISSN:0001-6357    

DOI:10.3109/00016357409026339

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

With the aid of a stereomicroscope fitted with two cameras, changes in the topography of the gingiva in vivo has been quantitativly evaluated. During the exposures the patient was fixed to the camera system by means of a biting plate. The changes in gingival topography were studied during a 180-day observation period in six cases after mucoperiosteal flap operation and gingivectomy. The gingival topography was evaluated in the direction of photography, the depth, and also in a plane perpendicular to it. The postsurgical swelling was most pronounced after three days. Expressed as volume increase per unit area it amounted on average to 0.6 mm3per mm2. The subsidence of swelling was slower following the flap operation. During the subsequent period of observation (30 to 180 days) a gingival remodelling was observed which, interdentally, involved a coronally directed remigration of the gingival margin by nearly 50 per cent.

ISSN:0001-6357    

DOI:10.3109/00016357409026340

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

The aim of the study was to ascertain whether substitution of sucrose in candy by Lycasin can influence the incidence of dental caries in a group of children. The caries increment in the primary dentition in three to six year old children using Lycasin candy as a substitute for conventional candy was observed for 1½to 2½years. Initially 225 children took part in the study, which started with a 6-month observation period. For various reasons many of the children dropped out, especially in the Lycasin group. Of the children, 173 were observed for one year and 113 for two years. A coupon system showed that the substitution in the Lycasin group had been only partial. Statistical analysis of the findings, which included the ordinary t-test between the Lycasin group and the contrast group as well as an intraindividual comparison between the observation period and the substitution period, showed a tendency towards a difference in caries increment between the Lycasin group and the control group and the presubstitution and the substitution periods, respectively. Thus, a reduction in dental caries increment (d.m.f.s. and d.m.f.t.) of about 25 per cent was probable.

ISSN:0001-6357    

DOI:10.3109/00016357409026341

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

This paper gives the age- and sex distribution of symptoms of dysfunction of the masticatory system in 321 Lapps in Northern Finland. According to both an anamnestic and a clinical dysfunction index roughly the same prevalence of dysfunction was found among men as among women. The few sex differences which were found were small. Women had a significantly higher frequency of headache, pain in the neck and shoulders and fatigue of the jaws. On the average women had a worse dental state than men, who on the other hand reported luxations of the TMJ and some biting para-functions more frequently than women. The age distribution was remarkably even for most of the recorded symptoms. General symptoms as headache, general joint and muscle symptoms, however, increased in frequency with age. For some of the anamnestic variables (oral parafunctions, feeling of fatigue of the jaws and facial pain) the age group 35-44 years showed the highest frequencies. The lowest frequencies of both anamnestic and clinical symptoms were found in the youngest age group (15-24 years). The findings in this study differ markedly from earlier studies on clinical materials reporting a skewed sex- and age distribution. The conclusion is that results from studies concerning age- and sex distribution of patients with functional disorders of the masticatory system, are not representative for the distribution of such symptoms in the general population.

ISSN:0001-6357    

DOI:10.3109/00016357409026342

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

This study was carried out in order to observe the changes in amino-peptidase activity which might occur in the palatal mucosa and gingiva of the rat in the initial phase of healing after tooth extractions. The material consisted of 115 male Sprague-Dawley rats. Amino-peptidase activity was studied at time intervals of 30 min., 1, 2, 4, 8, 16 hours and 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 days after the extractions. The azocoupling principle was used for the histochemical demonstration of enzyme activity. However, the incubation solution was in gel form. A semipermeable membrane was placed between the tissue sections and the incubation medium in order to prevent enzyme diffusion and dissolving of enzymes into the incubation medium. The substrates used wereN-aminoacyl 2-naphthylamines of L-leucine and L-arginine. Histological investigations were carried out simultaneously with the histochemical study. The principal increase in aminopeptidase activity occurred relatively late after the tooth extractions. The most intense staining was observed in 4- to 7-day wounds. During the same period the most active fibroblastic proliferation was observed histologically. The changes were demonstrable using both of the substrates. However, the staining was more intense whenN-L-leucyl-2-naphthylamine was used as the substrate. By usingN-L-arginyl-2-naphthylamine as the substrate, chloride ions caused a marked increase in staining intensity. It was thus assumed that aminopeptidase B would also be activated during the healing.

ISSN:0001-6357    

DOI:10.3109/00016357409026343

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

This work describes the variations in craniofacial morphology in individuals with congenially missing permanent teeth with relation to facial prognathism, jaw development and inclination of the incisor teeth. Both sexes displayed significantly less upper jaw prognathism in individuals with hypodontia compared to the controls, and a less maxillary length as well. This finding was independent of whether the congenitally missing teeth were situated in the upper or the lower jaw. The upper incisors displayed greater anterior inclination in the individuals with hypodontia of both sexes.

ISSN:0001-6357    

DOI:10.3109/00016357409026344

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor