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Biomedical subjects

E A BeGole

Publications and source records attributed to E A BeGole.

At least 37 records · Page 2Linked to original sources
PubMed1997

Bond strength of visible light-cured glass ionomer orthodontic cement.

In this in vitro study, tensile strength tests were conducted with a visible light-cured glass ionomer cement (Fuji Ortho LC, GC America Inc.) bonded to extracted teeth under six different enamel surface conditions: (1) dry nonetched, (2) moist etched, (3) moist nonetched, (4) moist nonetched rebonded, (5) moistened with saliva substitute, and (6) moistened with human saliva. Two resin adhesives (Rely-A-Bond and Phase II, Reliance Orthodontic Products) were applied to dry and etched enamel and served as control agents. The glass ionomer cement approached the strength observed for resin adhesives and required the presence of moisture on the enamel surface for optimal performance.

Acid Etching, Dental↗
PubMed1997

National survey of endodontists and selected patient samples: infectious diseases and attitudes toward infection control.

A survey was conducted of 591 patients from endodontic practices located in six large municipalities in the United States. A comparison was made between the self-reported incidence of transmissible diseases from patients medical histories to national statistics for the incidence of hepatitis B, herpes, tuberculosis, and HIV/AIDS. A national survey of 422 endodontists was also conducted. This survey was used to determine the beliefs and attitudes of practicing endodontists toward infection control techniques and infectious diseases. Compared with previous surveys, a trend toward increasing use of the hepatitis B vaccine, gloves, and greater acceptance of medically compromised patients was found.

Attitude of Health Personnel↗
PubMed1995

An evaluation of mandibular asymmetry in adults with unilateral posterior crossbite.

A retrospective study was conducted to determine whether mandibular symmetry in adults with untreated unilateral posterior crossbite was different from that found in adults with untreated Class I malocclusions. Thirty adults, 18 years or older, with a unilateral posterior crossbite were compared with 30 adults exhibiting Angle Class I malocclusions. Skeletal and dental symmetry were assessed with submentovertex (SMV) radiographs, whereas condylar position within the glenoid fossa was analyzed with horizontally corrected tomograms. Relative to a mandibular coordinate system, the mandibular first molar on the crossbite side was found to be more lateral and relatively distal in comparison to the contralateral side. Skeletally, the mandible showed no asymmetry. Relative to the cranial floor, the mandible was "rotated" so that the condyle on the crossbite side was positioned relatively posteriorly in comparison to the contralateral side. A relative posterior positioning of the glenoid fossa was inferred, since there was no demonstrable mandibular skeletal asymmetry or condylar displacement within the fossa as shown on corrected tomograms in the crossbite group as compared with the Class I group. The results question whether it is appropriate to correct unilateral posterior crossbites in adults by orthodontic tooth movement alone, given the skeletal remodeling in the temporomandibular joint, which may have already occurred.

Adolescent↗
PubMed1994

Mandibular skeletal and dental asymmetry in Class II subdivision malocclusions.

Mandibular symmetry was compared between a group of 28 subjects exhibiting Class II subdivision malocclusions and 30 subjects with Class I malocclusions who served as the control group. With submentovertex radiographs, symmetry was assessed by measuring the relative difference in spatial position of mandibular landmarks in both anteroposterior and transverse dimensions as determined by coordinate systems representing the cranial floor, mandible, and mandibular dentition. Only those variables representing the anteroposterior difference between right and left mandibular molar positions showed a statistically significant difference between the groups. Whether the position of the mandibular molars was measured relative to the cranial floor or within the mandible itself, the mandibular first molar was located more posteriorly on the Class II side of the subdivision malocclusion within a mandible that exhibited no other unusual asymmetry.

Adult↗
PubMed1994

Long-term stability after orthodontic treatment: nonextraction with prolonged retention.

A sample of 22 previously treated orthodontic cases was studied to evaluate long-term stability. All cases were treated nonextraction with fixed edgewise appliances and were without retainers a minimum of 5 years. Data were obtained from study models, although 14 of the 22 cases had longitudinal cephalometric radiographs. The average retention time with a mandibular fixed lingual retainer was 8.4 years. The irregularity index pretreatment was 8.0 mm in the maxillary arch and 5.2 mm in the mandibular arch; at the end of treatment it was 0.9 mm and 1.0 mm, respectively, and at the postretention stage it was 2.0 mm and 2.4 mm, respectively. Resolution of the lower irregularity index was accomplished without incisor advancement or distal movement of the mandibular molar, however, both arches were expanded transversely. During the posttreatment stage all variables showed relapse except for the expanded maxillary canines and premolars. However, the mandibular anterior segment demonstrated relatively good alignment at the long-term stage, which may be a reflection of prolonged mandibular retention.

Adolescent↗
PubMed1994

Control of the vertical dimension in Class II correction using a cervical headgear and lower utility arch in growing patients. Part I.

A retrospective cephalometric study was performed comparing three groups of 30 growing patients with Class II, Division 1 malocclusions. Group 1 was treated with a cervical headgear/lower utility arch combination (CHG/LUA), group 2 was treated with a cervical headgear alone (CHG), and the third group was untreated. The average treatment time was 1 year, 6 months. No other appliances were used during this period. Maxillary and mandibular dental and skeletal treatment responses were compared with an analysis of variance (ANOVA) and a Scheffe's test. In addition, a multiple stepwise regression was performed to determine whether pretreatment measures of facial pattern were accurate predictors of mandibular rotational response. Both treatment groups demonstrated significant reduction in maxillary protrusion. The CHG-only group showed significantly greater anterior descent of the palatal plane as compared with the untreated group. The maxillary molars showed significant distal movement in both treatment groups without any extrusion beyond that seen with normal growth. The maxillary incisor demonstrated significant retroclination in the CHG-only group. There was no statistical difference among the groups for variables commonly used for measuring mandibular rotation or protrusion. The change in vertical position of the lower molar was not significantly different among the groups. A CHG as used in this study produced maxillary orthopedic and orthodontic changes without upper molar extrusion beyond that seen with normal eruption and in the absence of an opening rotation of the mandible, even in subjects with dolicocephalic facial patterns. The LUA did not appear to influence lower molar eruption or mandibular rotational response. None of the commonly used predictors of facial pattern, such as the Y-axis, XY-axis, or MP angle, accurately predicted mandibular rotational response. Further study would be necessary to ascertain whether this was a result of their invalidation as predictors, or a result of the treatment strategy employed.

Cephalometry↗
PubMed1994

The variability and reliability of two maxillary and mandibular superimposition techniques. Part II.

A retrospective cephalometric study was performed to evaluate the reliability and the validity of various maxillary and mandibular superimposition techniques. In the maxilla, Ricketts' position three and the "best fit" techniques were evaluated. In the mandible, Ricketts' position four and the Björk structural method were studied. All techniques proved to be statistically reproducible and reliable. It could not be determined which technique was most valid since a control, such as implants, was not available in the sample used. Both mandibular techniques yielded comparable descriptive analyses of mandibular dental changes. The maxillary superimposition techniques yielded different descriptions of maxillary dental changes which may be a result of the subjective manipulation required when using the best fit technique. Since none of the approaches appeared to be statistically superior, we recommend positions three and four because of their ease.

Adolescent↗
PubMed1993

Long-term sealing efficacy of four root surface sealing materials used in endodontic leakage studies.

Fifty extracted human maxillary anterior teeth were biomechanically instrumented and divided into five equal groups, four experimental and a control. The teeth in the experimental groups had their root surface coated with one of four sealants; epoxy, casting resin, sticky wax, or nail polish. The roots of the remaining teeth were not coated and served as controls. All of the teeth were mounted in the caps of scintillation vials. Five microliters of [3H]uridine were deposited in the root canal space and disintegration counts were obtained over time periods of 1, 4, 8, 12, and 36 wk. At the conclusion of the experiment, sticky wax was demonstrated to provide a superior seal (p < 0.0001).

Analysis of Variance↗
PubMed1992

A static occlusal analysis based on ideal interarch and intraarch relationships.

Study models were visually assessed to quantify the number of ideal tooth relationships actually present relative to the potential total. Both intraarch and interarch relationships were used to generate an ideal tooth relationship index (ITRI). Index scores were generated for the entire dentition, which could be divided into anterior, posterior, interarch, and intraarch relationships. Index scores were determined at various time intervals so the longitudinal changes could be studied. Treated orthodontic cases (n = 92) showed an initial total ITRI score of 26% that increased to 52% at the end of orthodontic treatment and continued to improve to 59% during the retention and postretention periods. Anterior segment scores were higher (64%) than posterior segment scores (44%). The intraarch relationships of the anterior segment registered the highest (75%), whereas the lingual cusp relationships of the posterior segment had the lowest scores (35%). Various types of malocclusions exhibited different ITRI scores before treatment but responded equally to treatment showing similar improvement in scores at the end of treatment and the posttreatment period.

Adolescent↗
PubMed1992

A comparison of four root canal obturation methods employing gutta-percha: a computerized analysis of the internal structure.

The purpose of the present investigation was to compare the internal structure of gutta-percha for presence/absence of empty spaces when used in four different obturation methods: thermoplastic, chloroform-softened, thermomechanical, and warm lateral condensations. Each obturation was performed five times in a metal mold representing a root canal system. Following obturation the mold was disassembled and the gutta-percha was freeze-fractured at the 1.0, 3.5, and 6.5 mm levels as measured from the tip of the obturations. The fractured gutta-percha was placed in a scanning electron microscope, the image transferred to a computer, and converted to digital data. The results were subjected to statistical evaluation. The results demonstrated no difference between the obturation methods at the 1 mm level, however at the 3.5 mm level, thermomechanical condensation produced an internal structure characterized by a greater number of empty spaces (p < 0.0007). At the 6.5 mm level, thermomechanical condensation differed only from the chloroform-softened gutta-percha (p < 0.01).

Analysis of Variance↗
PubMed1991

Mandible, tongue, and airway in Pierre Robin sequence: a longitudinal cephalometric study.

The purpose of this retrospective longitudinal cephalometric study was to analyze size, growth, and relations of the mandible, tongue, and airway in the isolated, nonsyndromic Pierre Robin Sequence (PRS) infant. The objective was to understand better the early morphologic changes that occur in these structures. The data were obtained from lateral cephalometric radiographs taken in the first 2 years of life on 17 PRS infants, 26 isolated cleft palate (CP), and 26 normal control (N) infants. Mean values of each variable were compared using a univariate analysis of variance. A multivariate discriminant function analysis (DFA) was also used to characterize group differences. The three groups were distinct throughout the period of study. Differences were greater at the earliest age and the distinction was greater between the PRS and N infants with the CP infant in between, but having more similarity to the PRS infant. Initially, the PRS infant had a shorter tongue and mandibular length, narrower airway, smaller tongue area and the hyoid position was more posterior and inferior as compared to N. The tongue shape and position were specific to the PRS infants. This group distinction diminished with age and resulted from an increased mandibular growth rate in the PRS infant. These findings support the hypothesis of "partial mandibular catch-up growth" in the PRS infant. The increased growth rate in the PRS infant improved the airway dimension, which might be partly responsible for the natural resolution of the respiratory distress. This increased growth rate did not allow for the various structures to reach values equal to normal.

Adult↗
PubMed1990

Factors associated with orthodontic patient compliance with intraoral elastic and headgear wear.

Factors related to compliance with the wearing of headgear and intraoral elastics were explored in a sample of 100 university clinic orthodontic patients. Data were gathered by means of a questionnaire that comprised items presumed to be associated with orthodontic compliance. These items were not patient characteristics, but variables of beliefs, attitudes, perceptions, and reasons thought to be associated with compliance. The 58 questions were reduced through alpha factor analysis and the imposition of a coefficient alpha restriction to 12 factors. These 12 factors were named according to the questions they comprised. To assess whether these factors were indeed related to compliance, correlation coefficients were calculated between the factor scores (independent variables) and the criterion of compliance with headgear and elastics (dependent variable). Compliance was rated on a three-point scale. Four factors were found to be weakly, though significantly, correlated with compliance. These factors were combinations of personality type, negative motives (pain, inconvenience, and dysfunction), and positive motives (general health awareness, specific dental knowledge, and personal oral embarrassment). The findings were compared with existing theories of patient behavior.

Cooperative Behavior↗
PubMed1989

The relationship between temporomandibular joint sounds and malocclusion.

The relationship between temporomandibular joint (TMJ) sounds and the occlusion was evaluated in a sample of 226 patients before commencement of orthodontic treatment. TMJ sounds were recorded on videotape, using an audiovisual system, for subsequent classification into various categories. The prevalence of joint sounds was 36.3% (N = 82) of which 50% (N = 41) were categorized as reciprocal clicks. The occlusion (static and functional) and skeletal relationships generally did not appear to be significant factors in contributing to TMJ sounds in patients with malocclusions. However, a larger interincisal angle in the sound-present group, and dental wear and increased overbite in the reciprocal-clicking subgroup may be associated factors.

Adolescent↗
PubMed1989

Apical sealing efficacy of two reverse filling techniques versus cold-burnished Gutta-percha.

The apical seal produced by the cold-burnished gutta-percha method and two amalgam reverse filling techniques was investigated in an in vitro study using 36 extracted human single-rooted teeth. Following root canal obturation, 27 teeth were divided into three experimental groups and each group was subjected to one of the three following filling techniques: (a) cold-burnishing of gutta-percha; (b) amalgam reverse filling; and (c) amalgam reverse filling in conjunction with cavity varnish. The remaining nine teeth served as controls (4). The teeth were placed in methylene blue dye for a period of 1 wk, after which they were retrieved, washed, sectioned, and the apical dye penetration measured. The results showed that amalgam with cavity varnish demonstrated less dye penetration than the other experimental groups. The difference was statistically significant (p less than 0.0001).

Dental Amalgam↗
PubMed1989

Occlusal contacts following orthodontic treatment: a follow-up study.

Occlusal contacts in maximum intercuspation were examined in a sample of 40 patients at the end of active orthodontic treatment and again an average of 21 months later. An increase in the total number of contacts was due to more actual and near contacts on all posterior teeth and more near contacts on anterior teeth. When the results were compared to a previous short term study, continued settling of the occlusion occurred beyond an initial three months of retention. Few contacts changed their location between the occlusal inclined planes and central grooves, suggesting minimal settling of the occlusion in a buccolingual direction.

Adolescent↗
PubMed1988

Facial and dental arch asymmetries in Class II subdivision malocclusion.

The purpose of this investigation was to determine if any significant differences existed with regard to dental arch and facial asymmetries between persons having malocclusions with well-defined asymmetric characteristics, specifically Angle's Class II subdivision malocclusions, and persons having normal occlusions. Secondarily, it was sought to determine the nature of the differences that contributed to the asymmetric occlusal relationship of buccal segments observed in Class II subdivision malocclusions. The sample consisted of 28 subjects in each of the two groups. All possessed a full complement of permanent teeth including first molars. The average age of subjects in both groups was 17 years. Measurements primarily of a linear nature were obtained from posteroanterior and lateral cephalometric radiographs in addition to dental models. Specific measurements were summed to produce various indices of asymmetry. Variables were analyzed with multivariate discriminant analysis. A significant discrimination between the two groups resulted; variables describing asymmetry of the dentoalveolar region of the mandible appeared to be the primary contributors to the difference obtained. Asymmetry of the maxillary dentoalveolar region appeared to make a secondary contribution.

Adolescent↗