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Biomedical subjects

J J Cunat

Publications and source records attributed to J J Cunat.

16 recordsLinked to original sources
PubMed1989

Physical and mechanical properties of elastomers in orthodontic positioners.

Elastomers for conventional Kesling-type tooth positioners are relatively inelastic and are primarily indicated as finishing devices. However, new materials, first described in the Japanese literature, with claims of a greater range of tooth movement warrant a comparison with conventional materials. Physical and mechanical property testing of positioner elastomers has not been reported in the orthodontic literature. This investigation compared properties of a high temperature vulcanizing (HTV) Japanese silicone (Orthocon) to three traditional polyurethane and vinyl-based polymers and five experimental silicone elastomers. Fourier transform infrared spectroscopy established the definitive chemical composition of the urethane and vinyl materials obtained from a commercial positioner laboratory. Tear strength, tensile strength, tensile stress at selected elongations, and ultimate elongation of all materials were evaluated at 37 degrees C in an aqueous environment. Hardness and water sorption values also were determined and an in vitro force measurement apparatus was fabricated to determine force levels exerted by positioner materials at low displacements. Orthocon was statistically different (Duncan's multiple range test, p less than 0.05) from the traditional commercial urethane and vinyl materials. Orthocon had lower tear strength than the traditional materials. It also demonstrated lower stress values below 100% elongation. The parameters of tensile stress at 50% elongation and ultimate elongation were statistically identical for Orthocon and one experimental silicone material.

Absorption↗
PubMed1985

Reliability and validity of the Orthodontic Locus of Control Scale.

The Orthodontic Locus of Control (OLOC) Scale was developed to assess the ways in which persons perceive and evaluate the events that determine occlusal status and orthodontic treatment. The children's OLOC Scale is a 34-item self-administered inventory with a 6-point response format. The adult measure is a similar, 28-item version of the scale. A 6-item Occlusal Value Scale, was also developed for administration in conjunction with the OLOC Scale. These instruments were given to 51 children and their mothers who applied for treatment at the School of Dental Medicine's Orthodontic Clinic of the State University of New York at Buffalo. For validity studies, children and their mothers completed the Multidimensional Health Locus of Control (HLOC) Scale and the Orthodontic Opinion Poll (OOP) Subscales. The internal consistency estimates for reliability on both the child and parent versions of the OLOC Scales were in the moderate to high-moderate range. Moderate to high-moderate subscale correlations offer promise for the validity and usefulness of the Orthodontic Locus of Control Scale for future research on psychologic and social responses to malocclusion. The implications of the concept of "orthodontic locus of control" for orthodontists and parent-child treatment-related behaviors are discussed.

Adolescent↗
PubMed1983

A dental-facial attractiveness scale. Part I. Reliability and validity.

Since the decision to seek orthodontic treatment is frequently the result of concerns about appearance, assessment of need for treatment should include an impartial evaluation of dental-facial appearance. While some of the standardized techniques for assessing malocclusion have included a consideration of esthetic impairment, they tend to confound this with functional impairment. The purpose of this study was to develop a valid and reliable index that provides relatively objective judgments of dental-facial attractiveness. The subjects in this study were eighth- and ninth-grade children seeking orthodontic treatment and their siblings, and eighth- and ninth-grade children not seeking treatment and their siblings. Photographs of the children were rated for dental-facial attractiveness by lay and dental judges. Children were also assessed for severity of malocclusion by means of the Treatment Priority index. Children seeking treatment were perceived as significantly less attractive than children not seeking treatment. Dental judges rated children seeking treatment as more attractive than did nondental judges. Intraclass reliability coefficients were moderate to high.

Adolescent↗
PubMed1983

A dental-facial attractiveness scale. Part II. Consistency of perception.

A previous report describes the reliability and validity of a scale designed to assess perceptions of dental-facial attractiveness, independent of occlusal function. The purpose of the present study was to assess the consistency of judgments of dental-facial attractiveness (DFA) for sex and race differences in photographed children. Using a five-pont DFA scale, twelve college freshmen (three black females, three black males, three white females, three white males) rated ninety-six photographs of the mouths and jaws of 13- to 14-year-old children (twenty-four black females, twenty-four black males, twenty-four white females, twenty-four white males). No significant mean differences were found between the black and white photographed or between the female and male children photographed. However, means were significantly different for DFA judgments by race and sex of the raters. Black raters judged all photographs to be more attractive than did white raters, and female raters judged all photographs to be more attractive than did male raters. Correlational data are presented describing consistency of perception within rater groups and photographed groups of children.

Adolescent↗
PubMed1982

Reliability and validity of clinical assessments of malocclusion.

The purpose of this research was to determine the reliability and validity of selected clinical judgments of malocclusion, including general evaluations of occlusal status and more specific aspects of dentofacial malrelations. Study casts of twenty-one adolescents planning orthodontic treatment and twenty-nine not planning treatment were examined and rated. The examiners were five dentists in an orthodontic specialty-training program. They completed ratings on six dimensions: (1) need for treatment, (2) degree of malocclusion, (3) potential for tissue loss, (4) negative effect on occlusal stability, (5) negative effect on dental-facial attractiveness, and (6) negative effect on masticatory function. Six weeks later the same five rates scored the fifty casts, using the standardized Treatment Priority Index (TPI). Three weeks later, or 9 weeks after the initial ratings, the casts were again rated on the two general dimensions: need for treatment and degree of malocclusion. Correlations among all the measures were examined. Inter-rater reliability was highest for the ratings of impact on dental-facial attractiveness (r = 0.88). The two general assessments also yielded relatively high rater reliabilities, and the second rating yielded stability coefficients of 0.84 for both of these ratings. Correlations with total TPI scores were 0.70 for the dental-facial attractiveness measure and 0.65 and 0.64, respectively, for assessments of need for treatment and degree of malocclusion. The data indicate that clinical evaluations of the severity of malocclusions are comparable to objective measures in terms of inter-rater reliability. Clinical evaluations are also relatively stable over time. Correlations with the TPI scores also provide evidence of the concurrent validity of clinical judgments.

Adolescent↗
PubMed1981

Variables discriminating individuals who seek orthodontic treatment.

Overall, these results support the view that dental-facial esthetics and self-perceptions of occlusal appearance, as well as attitudes toward malocclusion and orthodontic treatment, are important factors in the individual's decision to obtain orthodontic treatment. The data indicate that psychosocial variables not directly related to occlusal problems and treatment, do not add significantly to the description of differences between those who seek treatment and those who do not. While these analyses did not include a number of variables--such as socioeconomic factors or attitudes of significant others--which may also be important in predicting individual response to malocclusion, they do suggest strongly that psychosocial factors directly related to need for treatment are probably most productively assessed in terms of self-perceptions of occlusal appearance and attitudes regarding dental malrelations and their treatment.

Adolescent↗