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Biomedical subjects

D C Johnsen

Publications and source records attributed to D C Johnsen.

At least 37 records · Page 2Linked to original sources
PubMed1985

Innervation of teeth: qualitative, quantitative, and developmental assessment.

Anatomical characteristics of tooth innervation provide insights into functional capabilities as well as limitations of this organ. In this review, innervation will be discussed from two major viewpoints. The first part will present distribution of nerve fibers in the tooth; nerve pathways, both autonomic and sensory, will be discussed mostly from a descriptive standpoint. In the second part, quantitation of neural units along key points of the pathways will be presented at milestones in tooth and organism development and aging.

Adrenergic Fibers↗
PubMed1984

Caries patterns in Head Start children in a fluoridated community.

Assessment of caries experience based on the person rather than on the tooth opens the possibility for qualitative descriptions of caries in a population, as well as for the study of specific factors associated with different caries experiences. The study of a Head Start population in adjacent fluoridated communities was divided into two parts. It was the purpose of part one of the study to determine the prevalence of specific caries patterns (presumably associated with different etiologies). Of the children, 39 percent were caries-free; 32 percent had carious lesions only in pit-and-fissure defects of molars; 6.5 percent had carious lesions in hypoplastic defects; 11 percent had facial-lingual lesions, compatible with "nursing caries"; and 11.5 percent had approximal lesions of molars; no child in the study had rampant caries. The second part compared specific lifestyle variables with specific caries patterns. Statistically significant differences or trends were found between caries-free children and those with smooth-surface lesions for mother's educational level, time spent with grandparents, mother's perceived primary reason for cavities, and mother's tendency to permit the child to eat sweets without restriction. No significant differences or trends were found for lifestyle variables between caries-free children and those having lesions associated only with tooth defects.

Child, Preschool↗
PubMed1984

Dental caries patterns in preschool children.

Management of dental caries as a disease requires the same level of skill and broad perspective as managing many other diseases. Dental caries has several variations, four of which were presented here. Long-term outlook for children with two of the caries patterns (those secondary to fissure defects or hypoplastic defects) is good if the teeth are restored. Management of children with nursing caries often involves dealing with well-intentioned but overindulgent parents. Prevention of nursing caries goes beyond simply informing the parents of potential dangers from excessive feeding with the bottle. Hypoplastic defects can resemble nursing caries; the differentiation is important in treating the child. The child with extensive proximal molar lesions may be the most difficult to manage on a long-term basis. A successful prevention program will mean a change in life style for the parent and child. The child with a cleft lip and/or palate has the disadvantages of enamel defects and a significant medical condition inviting overindulgence.

Bottle Feeding↗
PubMed1984

Dental caries of primary incisors in children with cleft lip and palate.

Visual dental examinations were performed on 64 children ages 18 months through 4 years presenting at a Craniofacial Defects Team charged with diagnostic and referral services. Of the 41 children with cleft lip and/or cleft palate, 13 (32%) had dental caries of one or more maxillary primary incisors. One of the remaining 23 children examined experienced caries of the maxillary primary incisors. In incisors of children having clefts of the alveolus, caries tended to correspond to sites of enamel deficiency in caries-free children with alveolar clefts. Caries patterns in children with clefts involving only the palate resembled "nursing carries". Children with clefts are at significant risk for caries of the primary incisors; a dental prevention program is to be emphasized in referring these children for care.

Child, Preschool↗
PubMed1983

Quantitative assessment of neural development in human premolars.

The number of nerve fibers entering a tooth gives an indication of the tooth's capacity to perform a sensory function. Nerve fiber development was quantitated from cross sections of the apical portions of 49 erupted human premolars at various stages of root development and in subjects up to 71 years of age. Neural development was incomplete in immature teeth, greatly variable in young mature teeth, and complete in older teeth. Myelinated axons changed in number but not in size during tooth development. There were significantly fewer myelinated axons in teeth with open and parallel apical foramina than in older teeth. Unmyelinated axons did not change significantly in number with development but fewer large axons were found in older teeth. The number of unmyelinated axons enclosed in a single boundary lamina tended to be lower in older teeth. As a physiologic correlate, threshold responses to electrical stimulation were also determined prior to premolar removal. Threshold stimulation decreased significantly with apical foramen maturation. A significant negative correlation was found between the threshold stimulus and the number of myelinated axons in fully developed teeth, but not in immature teeth.

Adolescent↗
PubMed1980

Instructional alternatives in pediatric dentistry.

In recent years several alternative instructional strategies have been recommended that were departures from traditional approaches. This paper describes several of these alternatives that have been adapted and applied to the curriculum in pediatric dentistry at West Virginia University. They include a systems approach to designing instruction, employment of single conceptual units of instruction, development of instructional objectives, use of audiovisual technology for conveying information, the opportunity for self-pacing, evaluation of students on a mastery model using a criterion-referenced system, and the opportunity for students to learn beyond mastery in programs of self-directed inquiry and contract grading. The methods used for implementing these strategies and the dynamics of their operation are discussed.

Attitude↗
PubMed1977

Development of neural elements in apical portions of cat primary and permanent incisor pulps.

Pulp development was studied with light and electron microscopy in apical portions of cat primary and permanent incisors at various stages of development in order to qualitatively assess hypothesized differences during maturation. Primary and permanent tooth pulps passed through similar stages up to when the primary teeth began to resorb. At that point permanent tooth pulps continued to develop in complexity relative to myelinated axons and developed thin epineurial sheaths. Although the stages were similar in several regards, the time needed by the permanent tooth pulps to reach each stage was considerably greater than for the primary tooth pulps. It is of interest that the young permanent teeth had only a small portion of their final complement of nerves in spite of their relatively complete development. Individual axons, especially myelinated axons, appeared more immature in younger primary and permanent teeth. This suggests a less mature sensory capability for erupting primary teeth as compared to fully developed primary teeth as well as for erupting and young permanent teeth compared to old permanent teeth.

Age Factors↗