Orthodontics and Orthodontology Commons^™

An Analysis Of Orthodontic Treatment Results Employing Class Ii Armstrong Adjustable Intermaxillary Springs, Michael E. Shumate

Loma Linda University Electronic Theses, Dissertations & Projects

A study of orthodontic treatment results employing Class II Armstrong Adjustable Intermaxillary Springs was made on twenty-eight randomly selected patients which were treated by Dr. Maclay Armstrong.

The skeletal and dental changes observed during treatment with the Class II springs was compared with those results observed when comparable type malocclusions were treated with Class II elastics. A list of changes which were observed during treatment with Class II elastics was compiled from the literature using individual studies published by Ricketts, Creekmore and Hanes.

The study was based on the findings observed in the initial and final cephalometric radiographs. A statistical …

Masseter Muscle Position Relative To Skeletal Open Bite And Skeletal Closed Bite, Alonzo David Proctor

Loma Linda University Electronic Theses, Dissertations & Projects

Modification of cephalometric roentgenographic procedures provided a means to identify the anterior borders of the right and left masseter muscles and relate them to surrounding dentoskeletal elements. Attachment of short, stiff, wires to the cheeks in a position superficial to the anterior borders of the muscles, subsequent to palpation and prior to exposure of the roentgenographic film, was the procedure used. The bi-lateral images projected on the film were averaged and traced along with dentoskeletal elements including those associated with skeletal type. This line representing the anterior border of the musculature was used to assess muscle position in the vertical …

The Advantages Of A Condyle-Gnathion Reference Line In Roentgenographic Cephalometry, Ernest N. Chan

Loma Linda University Electronic Theses, Dissertations & Projects

Evaluation of the cephalograms of 150 patients showed a wide range in the angulation of the lower border of the mandible to the various facial planes. The degree of this angulation did not always correspond with the severity of malocclusion. Group I represents normal occlusions, Group II comprises malocclusions.

A new reference line is submitted for the investigation of its advantages in cephalometric roentgenography. The mandibular radius drawn through the geometric center of the condyle to the point gnathion is correlated with several indices of facial growth, namely (1) ANB difference, (2) upper facial:lower facial height and (3) PoNB distance …

The Development Of An Instrument For Three Dimensional Analysis Of Micron Quantities Of Tooth Movement, M. Clark Lamberton

Loma Linda University Electronic Theses, Dissertations & Projects

In order to quantitate initial tooth movement in response to forces applied to the tooth crown, an instrument for intraoral use has been developed. The photomicrometer consists of nine photosensitive cells mounted in an assembly of two layers. Eight of the cells were mounted to form X and Y axes, top layer and bottom layer, to measure horizontal movements. The ninth cell was mounted in the center of the bottom layer and was used for alignment and for measurements in the Z or vertical axis. The photocell assembly was approximately 10 mm diameter and 6 mm high. This assembly when …

Sex Determination By Cephalometry And Odontometry, Clair R. Hopkins Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

Plaster casts of teeth and lateral cephalometric roentgenograms were studied to see with what degree of accuracy sex could be determined. The sample considered was made up of one hundred and forth-four individuals--50 males and 94 females--being treated in the Graduate Orthodontic Department of the Loma Linda University School of Dentistry. The age range for the boys was from 15 to 19 and for the girls, from 14 to 20. Data was obtained for the following variables from tracings of the roentgenograms and from the dental casts:

1. Glabello-occipital length
2. Articulate to nasion
3. The gonial angle of the mandible
4. Prosthion to …

Mandibular And Alveolar Growth In Dog Following Infusion Of 5-Fluorouricil, Richard D. Pfeiffer

Loma Linda University Electronic Theses, Dissertations & Projects

The action of a chemotherapeutic agent as a tool in studying its effect upon a primary growth center, the mandibular condyle, was investigated. So far as can be ascertained, no studies have been reported where these growth sites have been eliminated or modified by the use of chemotherapeutic growth inhibitors.

Observation of mandibular and alveolar growth following the infusion into the left external carotid artery of a cancer chemotherapeutic agent, 5-Fluorouricil (Roach-Hoffman), was noted. Comparisons were made between the infused and the uninfused sides of the mandible observing gross growth changes.

Four dogs, aged 75 days, were infused with varying …

A Method To Determine Curved Surface Laminagraphic Width And Position In Panoral Radiography Utilizing The Panorex X-Ray Unit, Gary G. Morikone

Loma Linda University Electronic Theses, Dissertations & Projects

Although the Panorex X-ray unit has been in existence for almost a decade, no information is publicly available relative to the determination of its laminagraphic slice width or position.

In order to utilize the machine most effectively as a research tool, it seems imperative that this width and position be established.

For the purpose of establishing the spatial relationship within the exposure mechanism, the two eccentric rotational axes were first located. Utilizing a positioning device, ten panoral radiographs of a plastic working dummy with metallic implants were exposed at varying exposure readings. The resultant radiographs, revealing varying degrees of accuracy …

Using A Computer Model To Study The Force Distribution On The Root Of The Maxillary Central Incisor, E. Jan Davidian

Loma Linda University Electronic Theses, Dissertations & Projects

A computer model of a human maxillary central incisor was devised to predict the momentary center of rotation of a tooth when a force was applied to the crown. The root of a tooth was divided up into a series of small segments to simulate the resisting forces set up along the root by the periodontal fibers. Each segment was assumed to resist a force in proportion to its area.

To study a tooth in a state of static equilibrium, two conditions must be met. The vector sum of all the forces acting on the tooth must equal zero, and …

An Odontometric Study Of Five Contemporary Western United States Indian And Alaskan Eskimo Groups, John A. Matis

Loma Linda University Electronic Theses, Dissertations & Projects

The morphologic characteristics of the oral cavity in five contemporary Western Indian and Alaskan Eskimo groups have been investigated by the use of study models of the dental archs. The sample consisted of 216 individuals, including 44 Navajos, 43 Apaches, 40 Papagos, 42 Pimas and 47 Alaskan Eskimos.

The first purpose of the study was to determine the extent of investigator error. This was accomplished by remeasuring many morphologic traits of the dentition in 125 Indians which had previously been measured by different investigators using the same study models. It was found that investigator error can be significant, even in …

Root Surface Area Related To Anchorage In The Begg Technique, Donald Copeland Freeman

Theses and Dissertations (ETD)

Almost two hundred years ago Hunter recognized the necessity of extracting teeth to ’’procure room for the others which are to be brought into the arch.” He further noted that, ”To extract an irregular tooth would answer but little purpose if no alteration could be made in the situation of the rest.”¹

Extraction of selected teeth to gain room for the proper placement of the rest, and the subsequent procedures to utilize this space to the utmost advantage, have been integral parts of orthodontic treatment for many years.

Strang and Thompson² stated that the ability to manipulate any …

Development Of A Positioning Device For Use In Conjunction With Panoral Radiography, Ray M. Hymer

Loma Linda University Electronic Theses, Dissertations & Projects

A cephalometric positioning device has been developed for use on the XRM Panorex X-Ray machine. Tests have demonstrated that the variability in producing serial radiographs with this device is comparable to, or less than, that currently accepted in conventional radiographic cephalometry.

Two procedures for obtaining serial radiographs were employed. Two patients were used for the first procedure and three patients were used in the second procedure.

In the first procedure each patient was positioned in the device and two radiographs were taken in sequence without disturbing the patient.

In the second procedure three clinic patients were used as subjects and …

A Cephalometric Comparison Of The Chamula, Mayo And Navajo Indians, Norman C. Bunker

Loma Linda University Electronic Theses, Dissertations & Projects

Lateral head x-rays were obtained on selected samples of 24 Chamula, 29 Mayo and 39 Navajo Indians for cephalometric comparison.

Cephalometric evaluation was carried out by means of the Bjork analysis. Mean values for each of the Indian groups were determined and compared with each other and with the mean values of a group of Swedish conscripts studied by Bjork. The mean values were statistically analyzed and and subjected to the Student's "t" test to determine the significant levels of differences.

Results revealed that in comparing the three Indian groups significant differences do appear. They are few and general concordance …

Electromyographic Analysis Of The Temporal And Masseter Muscles During The Para-Retentional Period In Orthodontic Patients, Thomas L. Thompson

Loma Linda University Electronic Theses, Dissertations & Projects

This study was initiated to compare electromyographically the activity of the masseter and temporal muscles during the early retentional period in orthodontic patients. Electromyographic recordings were taken at the following times: (1) before typical edgewise appliance was removed, (2) at time of retainer insertion, (3) after eight to twelve weeks of retainer wearing, and (4) one day following occlusal equilibration. Electromyograms from the orthodontic group of subjects were compared with electromyograms from a group of subjects with normal occlusion, and a group of subjects with untreated Class II, Division 1 malocclusions. There was a total of thirteen subjects studied: five …

Occlusal Patterns And Tooth Morphology In The Navajo Indians Of Monument Valley, Utah, Leroy C. Trnavsky

Loma Linda University Electronic Theses, Dissertations & Projects

The occlusal patterns and morphology of the dentition of the Navajo Indians were studied and compared to those of populations of known Mongoloid ancestry. Thirteen dento-anthropomorphic characteristics were studied from plaster casts obtained from fifty-four Navajo Indians from the Monument Valley area of Utah. The thirteen characteristics included were:

1. Degree of shovel-shape of the maxillary centrals and laterals.
2. Presence of a winged appearance in the maxillary centrals.
3. Mesiodistal crown diameters of the maxillary centrals and laterals.
4. Type of lingual tubercle on the maxillary centrals and laterals.
5. Cusp pattern of mandibular molars.
6. Cusp pattern of maxillary molars.
7. Frequency of cusp of …

Effects Of Loading Various Wire Configurations Under Simulated Cuspid Retraction Conditions, Carl James Heinrich

Loma Linda University Electronic Theses, Dissertations & Projects

The magnitude, and manner of application of forces effects the whole complex picture of tooth movement. Proper mechanical management in terms of the individual tooth as well as the entire arch, must be kept in mind. When applying forces for producing individual tooth movement as desired in cuspid retraction, we must consider the nature of the biological resistance in terms of the force distribution in the periodontal membrane as well as the force magnitudes necessary for efficient tissue response.

Since the alteration of wire configuration offers the greatest potential in changing the physical properties of a unit of wire, the …

A Study Of The Pattern Of Malocclusion Of The Lower Anterior Teeth In Subjects With Malocclusion And No History Of Orthodontic Treatment, Richard A. Simms

Loma Linda University Electronic Theses, Dissertations & Projects

A study of the pattern of malocclusion of the six lower permanent anterior teeth in subjects with malocclusion and no history of orthodontic treatment was undertaken to determine if the malocclusion of these teeth occurred in a random manner or followed a definite regular pattern.

The problem was approached epidemiologically by studying the positions assumed by the teeth in 408 males and females age 12 to 23. The subjects of this investigation were enrolled as students in the grammar school, academy, college and university system of the Pacific Union Conference of Seventh-day Adventists.

The method of visual assessment of malocclusion …

A Comparative Study Of Two Contemporary Methods Of Cephalometric Analysis, Alden B. Chase

Loma Linda University Electronic Theses, Dissertations & Projects

A comparative cephalometric study was made of nineteen cases, fourteen of which were patients under treatment at the Department of Orthodontics, School of Dentistry, Loma Linda University. The remainder were individuals considered to have normal occlusions.

The review of the literature emphasized the plethora of analyses and the fact that cephalometry is a tool that must be mastered if the orthodontist is to give the best service. Thus the need for a study to compare the methods of analyzing the cephalograph. A study was made to compare two main methods of analysis and to determine whether or not the information …