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Biomedical subjects

E F Harris

Publications and source records attributed to E F Harris.

At least 55 records · Page 3Linked to original sources
PubMed1992

Methionine enkephalin-like, substance P-like, and beta-endorphin-like immunoreactivity in human parotid saliva.

These three neuropeptides were measured at daily baseline values by radioimmunoassay. Stimulated parotid saliva was collected from 31 subjects using a modified Carlson-Crittenden device affixed over Stenson's duct. Methionine enkephalin-like immunoreactivity ranged from 6.6 to 11.7 fmol/ml, with a mean of 9.3 fmol/ml. Substance P-like immunoreactivity ranged from 6.1 to 12.6 fmol/ml, with a mean of 9.3 fmol/ml. beta-Endorphin-like immunoreactivity ranged from 1.2 to 3.6 fmol/ml, with a mean of 2.6 fmol/ml. This is believed to be the first documentation of methionine enkephalin- and substance P-like activities in human parotid saliva and the first demonstration of beta-endorphin-like activity in any type of human saliva. Substance P-like activity was significantly higher in morning than evening samples; beta-endorphin-like activity also tended to be higher in the morning samples. Substance P and beta-endorphin-like immunoreactivities covaried in a significant positive manner, suggesting either common control mechanisms or similar responses to physiological variables.

Adult↗
PubMed1992

Microleakage of composite resin and glass ionomer cement restorations in retentive and nonretentive cervical cavity preparations.

Ketac Fil glass ionomer cement (GIC) and Scotchbond 2 dentinal bonding agent (DBA)/Silux Plus composite resin restorations were inserted in cervical cavity preparations of extracted human teeth. After thermocycling, the specimens were invested and sectioned longitudinally and horizontally through the center of the restoration. Microleakage was evaluated as a ratio of the extent of methylene blue dye penetration at the tooth-restoration interface. Although all restorations exhibited leakage, both the GIC and bonded composite resin restorations recorded less leakage in retentive than in nonretentive cavity preparations. Composite resin restorations in nonretentive cavity preparations showed significantly more dye penetration toward the pulpal chamber than the GIC restorations. Ketac Fil GIC restorations inserted without a matrix strip exhibited less leakage than those with a matrix strip. The most desirable results were recorded with Scotchbond 2 DBA/Silux Plus composite resin restorations in retentive preparations.

Acid Etching, Dental↗
PubMed1992

Patterns of incisor root resorption before and after orthodontic correction in cases with anterior open bites.

External root resorption is a frequent iatrogenic consequence of orthodontic treatment, particularly in the maxillary anterior teeth. Since resorption also occurs is a normal function of aging and since altered behaviors such as bruxism and chronic nailbiting accelerate resorption even in the absence of treatment, it was hypothesized that the long-term orthopedic forces of tongue thrusting leading to anterior open bites would also enhance the rates of clastic activity. In a series of 32 adolescents with open bites, the roots of permanent maxillary central incisors were significantly shorter and exhibited higher modal grades of periapical resorption than a matched series with deep bites before treatment. The open bite group also had less facial bony support for these teeth. Both series experienced discernible resorption during full-banded treatment but to comparable extents so that, after active treatment, the open bite series continued to possess significantly greater degrees of resorption. Consequently, the oral forces leading to apertognathia are themselves destructive of root integrity and merit early recognition and interception.

Adolescent↗
PubMed1992

An example of regional variation in the tempos of tooth mineralization and hand-wrist ossification.

Two groups of adolescent orthodontic patients, one from the Midwest and one from the Midsouth, were compared to test the clinical impression that the permanent teeth of southern children form and erupt at significantly later ages. Indeed, a marked difference is documented, with the Midsouth series achieving mineralization stages at least 1 1/2 years later on average. This suggests that regional differences are appreciably greater than previously suspected. Clinical consequences revolve on the use of conventional (generally Northeast-based) norms for tooth formation and eruption and predictive models of facial growth. In contrast, the analysis of rates of hand-wrist development (bone age) of these same subjects disclosed no difference; this further confirms the essential independence of development of the dental and osseous tissue systems.

Adolescent↗
PubMed1992

Enhanced prevalence of ankyloglossia with maternal cocaine use.

A series of 500 term neonates was examined in a well-baby nursery, 68 of whom tested positive for maternal cocaine use. From logistic multiple regression equations, weight and crown-heel length were significantly smaller in the maternal cocaine-use subset of this case-control study. Partial ankyloglossia, with a prevalence of 4.4 percent in the overall series, was significantly more common in males than in females (6.0% versus 2.3%), while race (black or white) had no influence on trait frequency. Controlling for race and sex, ankyloglossia was 3.5 times more likely to occur in the drug-use series, perhaps as a function of diminished mitotic rates.

Abnormalities, Drug-Induced↗
PubMed1992

Deciduous tooth size standards for American blacks.

Normative standards for tooth sizes are valuable for assessing a given patient's status, both clinically and for evaluating intrinsic (e.g., genetic, chromosomal aberrations) and acquired conditions. There are, however, very few published standards for American Blacks and none for the deciduous teeth. Mesiodistal and buccolingual crown diameters are reported here for a series of 100 Black children. As with the permanent dentition, the primary teeth of Blacks are appreciably larger than Whites, though the amount differs by tooth type. In general, while all teeth are larger than norms for Whites, the posterior teeth (m1, m2) are preferentially larger. Applications of these standards are discussed.

Black People↗
PubMed1991

Heritability of craniometric and occlusal variables: a longitudinal sib analysis.

There has long been interest in the inheritance of malocclusion, but few studies have distinguished between skeletal (craniometric) variables and occlusal, tooth-based variables (e.g., anterior irregularity, rotations, displacements). This study was based on serial assessments of untreated persons in 30 sibships from 4 years (full deciduous dentition) to 20 years of age (full permanent dentition) in the Bolton-Brush Growth Studies of Ohio. Results define a clear dichotomy: craniometric variables (k = 29) typically show significant additive components of variance; correlations increase from age 4 to age 20; and correlations average 0.43 at adulthood. Tooth-based variables of position and relationship (k = 21) reach significance only occasionally; correlations decrease with age to the extent that few variables for subjects at age 20 have a correlation significantly different from zero. In contrast to craniometric variables, which have high heritabilities, almost all of the occlusal variability is acquired rather than inherited.

Adolescent↗
PubMed1991

Age effects on orthodontic treatment: adolescents contrasted with adults.

Skeletodental treatment changes in 30 adolescent girls and 26 women who had Class II, Division 1 malocclusions were contrasted cephalometrically, primarily with the McNamara analysis. The data show that adult treatment does not obligate the practitioner to longer treatment. In this study, both age groups were treated in 2.5 years on the average. Apical base corrections were achieved with equal facility in both groups by the posterior remodeling of point A, and this (in conjunction with unrestrained mandibular growth) is the major source of correction in the adolescents. In adults, in whom growth is trivial, an appreciable source of sagittal correction is the steepening of the occlusal plane. Several sequelae of Class II elastic force occurred as by-products of molar correction in the adults: increased mandibular molar eruption, increased maxillary molar intrusion, increased maxillary incisor eruption, increased mandibular incisor intrusion, and steepening of the occlusal plane.

Adolescent↗
PubMed1991

Age effects on orthodontic treatment: skeletodental assessments from the Johnston analysis.

We have compared differences in treatment outcomes dependent on patient age, either adolescent (means = 12.5 years at start) or adult (means = 27.6). Subjects were female patients whose Class II, Division 1 malocclusions were treated with Tweed edgewise mechanics and four-premolar extractions. Cephalometric records were assessed according to the Johnston analysis. The functional occlusal plane remained stable during mechanotherapy in the adolescents, whereas it steepened considerably in the adults. Differential mandibular growth in adolescents contributed 70% of the total molar correction, with orthodontic tooth movement accounting for the other 30%. Maxillary growth in the adults detracted from the Class II molar correction; tooth movement accounted for virtually all of the correction.

Adolescent↗
PubMed1991

The premaxillary-maxillary suture and orthodontic mechanotherapy.

Even though there has been debate over whether a separate premaxilla exists in the human being, it has been suggested that the premaxillary-maxillary suture remains patent into adolescence and provides an explanation for the action of certain orthodontic and orthopedic appliances. To assess whether this suture is pertinent to an understanding of appliance effects, the skulls of 50 subadult subjects were scrutinized to determine patency with regard to age. Remnants of a premaxillary-maxillary suture may be present on the surface of the palate at all ages studied, and often this suture extends deep to the surface. However, in no case was the suture continuous so as to distinguish a distinct premaxilla. These findings disprove the claim that the premaxillary-maxillary suture system provides an explanation for any form of orthodontic or orthopedic therapy.

Adolescent↗
PubMed1991

Talon cusp: a review with three cases from native North America.

Supernumerary lingual tubercles ("talon cusps") in three North American Indians are reported. These cusp-like structures typically occur unilaterally on permanent maxillary lateral incisors. We speculate that sporadic occurrences of this type probably are induced by trauma or other localized insults affecting the tooth germ. Multiple occurrences in an individual may have a separate etiology, the most severely affected cases being associated with craniofacial syndromes.

Adult↗
PubMed1990

Delayed dental development in children with isolated cleft lip and palate.

Although most cases of cleft lip and palate are free of other developmental defects, children with isolated cleft lip/palate are at enhanced risk of delayed growth and reduced final size. Three variables were assessed in the permanent dentition away from the cleft site: congenital absence by tooth type (which ranged from 0 to 7%) asymmetry in developmental staging (3 times more common in cleft lip/palate than in controls), and dental age (with a mean delay of 0.9 yr in cleft lip/palate relative to controls). The pervasive nature of these measures of reduced growth potential and developmental control, which were greatest in teeth forming during infancy, suggests that the cause of the compromised growth is the adverse early postnatal environment rather than conditions intrinsic to the individual.

Age Determination by Teeth↗
PubMed1990

Loss of root length and crestal bone height before and during treatment in adolescent and adult orthodontic patients.

It is broadly documented that orthodontic tooth movement enhances the risk of apical root resorption and loss of alveolar crestal bone height, but virtually all studies have focused on the conventional adolescent patient. In this study, samples from adolescent and adult patients were matched for sex, malocclusion, and treatment regimen. In-treatment changes in root length were the same for both groups, whereas loss of crestal bone height was somewhat greater in adults. Major differences, however, were found at the start of treatment: Adults (mean = 28 years) had significantly shorter roots and greater alveolar recession than the young teenagers (mean = 12 years). Consequently, treatment per se does not place adults at greater risk; it is the involvement extant at the start of mechanotherapy that merits careful evaluation.

Adolescent↗
PubMed1990

Age-progressive changes in pulp widths and root lengths during adulthood: a study of American blacks and whites.

The intertwined effects of normal aging processes and time-progressive diseases produce systematic changes in many oral and dental tissues. This cross-sectional study of pulp dimensions and root lengths in sound teeth tested for changes with age in adulthood while controlling for differences in gender and race (black, white). Age was the paramount determinant of pulp size which decreases via the accumulation of secondary dentin. In some instances the rate of change increases in older adults with an inflection point at 35-40 years of age. In contrast, root lengths are statistically independent of age once gender (male greater than female) and race (black greater than white) are controlled. Causes of the lack of association with age are discussed.

Adolescent↗
PubMed1990

Tooth mineralization standards for blacks and whites from the middle southern United States.

Normative standards are provided for permanent tooth mineralization stages for blacks and whites of the middle southern United States. The data cover tooth development from 3.5 to 13 years of age. Females develop more rapidly than males, and blacks are nearly twice as sexually dimorphic (7.2%) as whites (3.7%). Within each sex, blacks achieve mineralization stages significantly earlier, by about 5%, than whites. This complements earlier findings that teeth erupt at appreciably earlier mean ages in blacks.

Adolescent↗
PubMed1989

Small tooth sizes in a nineteenth century South Carolina plantation slave series.

Sub-Saharan African (and derived) populations typically exhibit larger mean tooth crown diameters than whites in spite of considerable population variability. We report on a 19th century series of American black slaves from a single cemetery near Charleston, South Carolina, that possessed notably smaller crown sizes. Analysis identifies a characteristic set of differences compared to caucasians, including retention of large maxillary lateral incisors and disproportionately large premolars and molars. Regression of principal components scores (derived from the mesiodistal diameters) on the sum of all diameters (used here as a measure of overall tooth mass) confirms a basic ethnic difference between black and white odontometrics: significantly more of the tooth mass is apportioned to the cheek teeth (premolars, molars) in blacks than whites. The difference (expressed as residuals from linear regression on tooth mass) holds for the several groups assessed here despite considerable intergroup variability in tooth sizes. Potential explanations for the notably small diameters of this plantation series are speculative, but may involve kin-based divergences and/or reflect the natural intergroup differences extant in the African slave sources.

Adult↗
PubMed1989

Immunoreactive evidence of beta-endorphin and methionine-enkephalin-Arg-Gly-Leu in human tooth pulp.

For the first time, beta-endorphin-like immunoreactivity (BE-LI) has been measured in human tooth pulp. Separation of peptides from pulp tissue was achieved by acid extraction followed by chromatographic separation through a Sep-Pak disposable cartridge. Reversed phase high performance liquid chromatographic (RP-HPLC) was performed on the peptide-rich fractions for further peptide separation. Radioreceptor assay (RRA) data of the HPLC fractions was used to construct a profile of opioid-receptor active peptides. Radioimmunoassay (RIA) data provided further information. Following acute mechanical stress, a monotonic decrease in BE-LI concentrations was evident according to a four bicuspid extraction order.

Adolescent↗