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Biomedical subjects

L Hollender

Publications and source records attributed to L Hollender.

At least 19 recordsLinked to original sources
PubMed1992

Image resolution in the midsagittal plane of the Orthopantomograph-10 using Lanex regular and T-Mat G screen-film combination.

Image resolution was measured in the midsagittal plane of the Orthopantomograph-10 with the use of Lanex regular and T-Mat G screen-film combination. A thin platinum edge phantom was used to obtain images for calculation of the edge response functions. Subsequently, line spread functions and modulation transfer functions of the system were calculated. Noise equivalent passband values, which were expressed in line pairs per millimeter, were derived to describe the image resolution. The noise equivalent passband values derived in this study were generally smaller than those reported in a previous study. The width of the image layer was found to be uniform at different vertical levels.

Humans↗
PubMed1992

Decision making in radiographic imaging.

In 1987, the U.S. Department of Health and Human Services issued guidelines for prescription of dental radiographic examinations, and although these recommendations have been reprinted in several widely circulated publications, it seems that the adoption of these guidelines is far from common, even among U.S. dental schools. The recommended criteria are founded on the existing knowledge of prevalence and progression of the most common dental diseases and on the fact that occult diseases within the jaws are uncommon. There are, however, other factors that may influence the decision on the time and extent of a radiographic examination, which may lead to deviations from the suggested guidelines. These factors include: education, peer influence, patient's preference, legal considerations, the dentist's field of interest or specialty, the training of the staff, and practice routine. The diagnostic interpretation of radiographs is far from a completely objective process, even if it is a question as simple as the presence and/or extent of a carious lesion. Numerous studies have shown a large variation among observers, both with regard to the occurrence and extent of carious lesions, in bite-wing radiographs. Caries diagnosis is only one example of many situations where significant observer variation is found. The more complex the diagnostic task, the more variation can be expected. The effect of observer variation on treatment decisions regarding carious lesions is used as an example of the problems encountered daily in the dental practice.

American Dental Association↗
PubMed1991

Agreement between panoramic and intra-oral radiography in the assessment of marginal bone height.

Panoramic and intra-oral radiographs from 400 consecutive patients were evaluated for the assessment of the marginal bone height. Two hundred panoramic radiographs were exposed with the rotational technique and 200 with the intra-oral X-ray tube technique. Measurements of the approximal marginal bone level were independently performed by two observers. Complete agreement between panoramic and intra-oral radiographs was, on average, obtained in 55% and 49% of the sites, respectively. When the criterion for agreement was widened to include recordings with a difference of +/- 1 mm, the agreement was on average 87% irrespective of the techniques compared. The agreement varied with tooth type and severity of the marginal bone loss. Angular bony defects and furcation involvements were recorded separately. For angular bony defects there was a variation in agreement from 33% to 46% for the rotational technique and from 35% to 51% for the intra-oral X-ray tube technique depending on localization. Furcation involvements of the molars were equally recorded in 60% and 59%, respectively, but in only 12% and 28% for the upper premolars. Interobserver agreement was 58% for the intra-oral radiographs, 60% and 59% for the two panoramic techniques. Mean intra-observer agreement was 68%, 66% and 68%. It is concluded that panoramic radiography can often be used for the assessment of marginal bone loss alone, supplemented when necessary by intra-oral radiographs.

Adolescent↗
PubMed1979

Dental caries and restoration. IV. A six-year longitudinal study of the caries increment of proximal surfaces.

In order to study the progression of proximal caries lesions and the quality of restorations, a sample of individuals in Gothenburg, Sweden was radiographically examined at the ages of 16, 19 and 22. By means of an index system every proximal tooth surface was given a diagnosis and differences between examinations were evaluated by a score system. Of all decayed and filled surfaces observed at the age of 22 more than 70% were already established at the age of 16. During the 16--19 year interval more than twice as many new carious lesions were developed than during the 19--22 year interval. The decrease in the number of new lesions during the last interval was accompanied by a slower progression of already existing lesions. Both factors resulted in a lower mean value with regard to scores during the 19--22 year interval compared with the preceding one. However, great individual differences were noted and 22 percent of the individuals exhibited larger score values during the last interval than during the first. Relatively seen the number of restorations with overhanging margins was lower at the final examination than at the previous ones.

Adolescent↗
PubMed1978

Chronic sclerosing osteomyelitis of the mandible. Scintigraphic and radiographic findings.

Fourteen patients with chronic sclerosing osteomyelitis of the mandible were investigated with 99mTc-labeled bone-seeking agents. Scintigraphic findings were compared with radiographic features. High uptake of diphosphonate and polyphosphate was demonstrated in diseased areas. Good agreement was found between radiography and scintigraphy concerning the extent and activity of each process. The use of bone-seeking radiopharmaceuticals in other types of skeletal lesions and differential diagnostic aspects are discussed.

Adolescent↗
PubMed1977

Condylar fractures of the mandible. II. a radiographic study of remodeling processes in the temporomandibular joint.

Remodeling processes in 76 temporomandibular joints were studied on radiographs from 67 individuals sustaining condylar fractures. The indivuduals were ranged into four age groups: 3-11, 12-15, 16-19, and larger than or equal to 20 years of age at the time of fracture. The radiographic examinations were to be performed at the time of the trauma and 3, 6, 12, 24 and 36-48 months after the injury. In the age group 3-11 there was a complete return to normal skeletal relations in 20 of the 27 joints. Joints in teenagers (12-19) did not become normal to the same extent and in adults only minor remodeling was observed. In children the remodeling of the condylar process was extensive but indistinctly outlined. With increasing age there was a shift towards a more distinct apposition of bone on the posterior part of the condylar head visualized as a double contour. This contour first appeared in the late teens. In adults the remodeling processes seemed only to be part of the functional adjustment. Thus, the remodeling processes of the condylar process in a clinical sense may be looked upon as restitutional in children and adjusting or functional in adults. As regards the articular fossa, in children the remodeling processes were first observed as a double contour, of which the new one became more and more distinct, while the original roof gradually disappeared. The final results was a flattened fossa. In adults, a sclerosis of the roof of the fossa was found.

Adolescent↗
PubMed1977

Dental caries and restorations in teenagers. I. Index and score system for radiographic studies of proximal surfaces.

An index and a score system for radiographical longitudinal studies of caries progression on proximal tooth surfaces are presented and compared with the DF-surface system. Generally, a good correlation between DF-surface differences and scores was found in a three-year study on teenagers. However, the score system seems to forward better means for a detailed study of the individual.

Adolescent↗
PubMed1977

Dental caries and restorations in teenargers. II. A longitudinal radiographic study of the caries increment of proximal surfaces among urban teenagers in Sweden.

Within a group of 16 year old school children leaving the regular school dental care, the number of carious lesions and fillings in proximal tooth surfaces was radiographically studied, using an index system. Three years later, the same individuals were re-examined. The results showed that intact surfaces and surfaces with small carious lesions were more resistant to change than others. A minority of the individuals was found to be responsible for a majority of the lesions established during the three year interval. Generally, the progress of caries was slow.

Adolescent↗
PubMed1976

Treatment of non-vital permanent incisors with calcium hydroxide. VI. A clinical, microbiological and radiological evaluation of treatment in one sitting of teeth with mature or immature root.

The purpose of the investigation was clinically, microbiologically and radiologically to assess the effect of calcium hydroxide as a temporary root-filling inserted in the same sitting as root canal debridement in non-vital permanent incisors with mature and immature root, infected or uninfected root canal and with or without radiologically demonstrated periapical bone changes. The material consisted of 141 teeth divided in 3 groups in which mechanical cleansing was accompanied by flushing with sterile saline and sodium hypochlorite solutions giving 0.5% or 5.0% active chlorine, respectively. Microbiological samples were taken from root canals after extirpation of necrotic pulp tissue, after completed cleansing of the root canal and 3 and 6 month after treatment. Results of treatment were evaluated from the radiographs taken before treatment and at the 3 and 6 month follow-ups. Complication, pain and an abscess, occurred in 2 cases, 2 and 5 days, respectively, after treatment. No statistical correlation between occurrence of samples that gave growth, taken from the root canals at 3 (8%) or 6-month control (9%) and 1) bacteriological status of the root canal prior to filling with calcium hydroxide, 2) the development of the root or 3) periapical healing at 3 or 6 month follow-up could be ascertained. Periapical bone healing at the end of 6-months observation period was noted in 61 teeth (46%), regression of periapical bone lesions in 64 (49%) and no periapical healing in 6 (5%). The only difference in healing pattern, statistically significant on 0.1% level, was found in the group of teeth flushed with 5.0% sodium hypochlorite. At 3 month control they showed percentually less cases with regression and more cases with no healing of periapical bone lesions than the teeth in the other two groups. It was concluded that treatment in one sitting can be done routinely, irrespective of the initial status, in all those cases where no other treatment is possible. If the periodontium or the periapical bone are injured during cleansing procedures or if necrotic rests are not pressed out through the apical foramen, no complications after treatment need to be feared.

Adolescent↗