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Biomedical subjects

M R Marcotte

Publications and source records attributed to M R Marcotte.

13 recordsLinked to original sources
PubMed1997

An evaluation of condyle position in centric relation obtained by manipulation of the mandible with and without leaf gauge deprogramming.

Centric relation records of 19 dental students were obtained with leaf gauges and by mandibular manipulation. The condyle/fossa relationships were subsequently evaluated with enhanced sagittal cephalometry. Both clinical methods of obtaining centric relation revealed considerable variation of the condyle location within the glenoid fossa. Only 10% of the patients showed a condyle position "upward and forward" in the fossa with the leaf gauge method. In the mandibular manipulation technique of obtaining centric relation, 10% of the patients showed an "upward and rearward" position of the condyle.

Adult↗
PubMed1996

A study of maximum bite force during growth and development.

Bilateral bite force was measured in a sample of 457 subjects (231 males and 226 females) from 6 years through 20 years. The mean maximum bite force was found to increase from 78 Newtons at 6 to 8 years to 176 Newtons at 18 to 20 years. While earlier studies have shown adult males have a greater mean bite force than females, this difference is not evident during growth and development. Gender-related bite force difference likely develops during the postpubertal period in association with greater muscle mass development in males.

Adolescent↗
PubMed1995

Rationale of the segmented approach to orthodontic treatment.

Modern orthodontics requires defined treatment goals. To achieve them, known force systems must be used to control the active units (teeth being moved) and the reactive units (anchorage teeth). This article discusses the methods of controlling the force systems through the variables of spring design and anchorage selection. Continuous and segmented arch treatment are contrasted in their ability to achieve optimal and defined force systems with minimal side effects.

Dental Stress Analysis↗
PubMed1995

The centered T-loop--a new way of preactivation.

The force system of a prefabricated and preactivated T-loop used for reciprocal space closure was determined by simultaneously measuring the horizontal and vertical forces, as well as the moments using a computer controlled measuring apparatus. Interbracket distances of 21, 24, 27, and 30 mm were used to mimic typical clinical situations. At a loop activation of 7 mm, the anterior and posterior segments first underwent controlled tipping, then translation, and finally, root uprighting as the moment-to-force ratio increased with deactivation. After the loop has been deactivated to 4 mm, however, it should be exchanged to avoid root abutment.

Analysis of Variance↗
PubMed1995

A study of bite force, part 1: Relationship to various physical characteristics.

A new device for measuring and recording bilateral bite force in the molar/premolar region has been developed. Because this new device is elastic and conforms to the occlusal surfaces of the teeth, and because the sensing element is relatively comfortable, it is believed that experimental subjects are less reluctant to register true maximal forces than in earlier studies. Potential correlations of maximum bite force to gender, age, weight, body type, stature, previous history of orthodontic treatment, presence of TMJ symptoms (jaw motion limitation, clicking with pain, or joint pain), or missing teeth were studied in a sample of 142 dental students. The mean maximum bite force of the sample was found to be 738 N, with a standard deviation of 209 N. The mean maximum bite force as related to gender was found to be statistically significant, while the correlation coefficients for age, weight, stature, and body type were found to be low. Even so, all data scatterplots exhibited relatively positive relationships. Correlations of maximum bite force to an earlier history of orthodontic treatment or to the absence of teeth were not found. Subjects reporting TMJ symptoms did not exhibit a significantly different maximum bite force than subjects without symptoms.

Adult↗
PubMed1995

A study of bite force, part 2: Relationship to various cephalometric measurements.

Maximum bilateral bite force, determined in 129 dental students, was evaluated with regard to six skeletal and eight dental measurements acquired from conventional lateral cephalometric radiographs. Statistically significant correlations for three of the skeletal measurements were found. Maximum bite force increased with regard to decreasing mandibular plane/palatal plane angle and to decreasing mandibular plane angles. Maximum bite force increased with an increasing ratio of posterior facial height to anterior facial height. Significant statistical correlation for only one of the eight dental measurements was found: maximum bite force related directly with increasing maxillary and/or mandibular dentoalveolar heights, and unexpected finding.

Alveolar Process↗
PubMed1977

The instantaneous transverse changes in the maxilla due to different points of force application.

The effects of different sites of an expansile force on the maxillae of three monkeys were studied. A lateral force of five pounds was delivered directly to four locations on each maxilla. Aluminum rods, rigidly attached to the teeth of each buccal segment, were photographed before and after each force application. The data indicated that the pattern of lateral maxillary displacement is related to the position of the lateral force in relation to the center of resistance of each maxilla.

Animals↗
PubMed1976

The use of the occlusogram in planning orthodontic treatment.

A method of planning orthodontic treatment in the transverse plane has been presented. The occlusogram procedure outlined augments other orthodontic records in order to define more specifically the requirements of successful orthodontic treatment. Anchorage requirements, extractions, if any, and arch widths plus the final occlusal relationships can be determined at the outset of orthodontic treatment.

Child↗
PubMed1976

Prediction of orthodontic tooth movement.

Orthodontics is rapidly advancing from the stage of fortuitous success to one of planned success. When appliance design is based on simple concepts of equilibrium, prediction of desirable and undesirable tooth movement becomes possible. The flow chart that has been presented allows the clinician to systematically treat dental discrepancies more effectively in potentially less treatment time, since the number of desirable and undesirable side effects can be known in advance and managed accordingly. Simple laws of equilibrium, based on a knowledge of the force systems required for specific tooth movement, also permit the design of proper preactivation bends for an appliance. The procedure may be enlarged to include treatment of each arch since, once the teeth are ideally positioned and rigidly held within each segment, each arch can be considered to consist of three "large, multirooted teeth."

Dental Stress Analysis↗
PubMed1976

A fourth-year orthodontic elective in an educational group practice.

An educational group practice is described in which a fourth-year dental student actively observes and participates in orthodontic decision making and treatment delivery. The student takes part in patient treatment under the direct supervision of a second-year orthodontic resident. The residents reinforce the skills which the students learn in class and laboratory. In this way an effective learning experience results for both the resident and the fourth-year student. Students also attend patient care conferences, where treatment points of view and sequences are discussed. In this way, students have a first-hand glimpse of what a career in orthodontics might be like.

Education, Dental↗