Browsing by Subject "Dental Arch"

Now showing 1 - 9 of 9
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    A Study of the Relationship of the Dental Arch to its Supporting Structure
    (1964) Lampros, Leo Nicholas
    Using 19 human caucasian skulls, a radiographic technique was developed to study the relationship of the dental arch to its supporting structure. All skulls were oriented to occlusal plane and x-rayed from a distance of five feet. The highest positive linear correlation recorded was between mandibular second molar width and apical base width in the second molar region. In the maxillary arch, high correlations were found to exist in both the cuspid and molar regions between dental arch width and apical base width. Correlations were lacking in the mandibular cuspid region between dental width and apical base width and between maxillary and mandibular dental and apical base depth. The central tendency and dispersion was calculated, as well as the standard error of the mean and coefficient of variation for all groups of measurements which included arch widths, apical base widths, arch depths and apical base depths. A generalized description of the position of the dentition to its supporting structure was presented; this indicated that the buccal segments in most cases showed less variation in their position over their supporting structure than the anterior segments. Each dental arch was descriptively classified using the terms ovoid, square, tapering and combinations of these.
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    An Investigation of Dental Arch Form in a Sample of Malocclusions
    (1975) Page, Robert M.; Garner, LaForrest D.; Shanks, James C., Jr.; Dirlam, James H.; Potter, Rosario H.; Barton, Paul
    The objective of this study was to investigate the geometric arch forms found in a sample of malocclusions. The specific objectives were to determine if there was a basic geometric arch form which described all of the sample, to identify the typical arch form in each of the classes of malocclusion, and to determine if there was a statistical difference in form among the various classes in each arch. A sample of 99 maxillary and mandibular plaster casts were collected from the Department of Orthodontics, Indiana University School of Dentistry, and classified according to Angle's classification of malocclusion. Occlusograms were taken of all casts. The center of incisal edges, cusp tips of cuspids and bicuspids, and bifurcation of molars were marked and traced on acetate tracing paper from the occlusogram). A straight line was drawn between these points giving the final dental arch form. A coordinate· system was established on each arch form which allowed the classification of the arch form by Hayashi's method 60. The results showed that no basic arch form described the sample. The average arch form for each classification of malocclusion varied between classes and between arches. Statistically, maxillary arch form of the Class II division 2 differed significantly from maxillary Class I, Class II division 1, and Class III malocclusions. Class II division 2 mandibular arch form differed significantly only from the mandibular Class I malocclusion.
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    Assessment of Dental Asymmetry Utilizing Orthodontic Study Casts Comparing Tooth Positions to the Midpalatal Raphe and Tooth Size Among Antimeres
    (2002) Sprowls, Matthew W.; Hartsfield, James K., Jr.; Baldwin, James; Everett, Eric T.; Hathaway, Ronald; Shanks, James C.; Ward, Richard E.
    Several studies have been conducted in relation to the treatment and etiologies of craniofacial and dental asymmetries in the orthodontic scientific literature. However, limited research has attempted to correlate asymmetry in dental traits to each other. The purpose of this research study was to develop a better understanding of the correlations between dental arch asymmetry and dental tooth size asymmetry and their underlying causes. Understanding asymmetries is essential in orthodontic diagnosis and treatment planning. An orthodontist cannot obtain an optimal occlusal and functional result without properly balancing skeletal and dental relationships. Pretreatment dental study casts of 86 sequential patients from the postgraduate orthodontic clinic at the Indiana University School of Dentistry were used for the analysis. Each patient was analyzed in a single blind fashion to minimize bias. The Adobe Photoshop® ruler and Chicago® brand electronic digital calipers accurate to the nearest tenth of a millimeter were used for digital measurements. Measurements were made to determine the amount and direction of asymmetry along the dental midlines relative to the median palatine raphe. Transverse and sagittal measurements were made to record asymmetries in canine and molar positioning. Furthermore, three sets of antimeric maxillary teeth were measured for length and width. These included the central incisors, the canines, and the first molars. Fluctuating asymmetry was present in all measurements, except molar distance to median palatal raphe. This was found to be directional to the left in the entire sample group. Statistical analysis was subsequently performed and the results showed significant correlations in the individuals in the subsample dentition group. Subjects belonging to this group with a measurable degree of fluctuating asymmetry had a greater tendency toward transverse maxillary discrepancies as measured from the canines and first maxillary molars relative to the median palatal raphe. Moreover, individuals in the subsample group with above average total weighted fluctuating asymmetry values according to the parameters analyzed in this study appeared more likely to have decreased developmental stability leading to the clinical expression of more severe malocclusions.
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    A Comparison of Maxillary Arch Form and Dento-Skeletal Patterns in Japanese and Caucasian American Individuals Exhibiting Class II Div. 1 Malocclusions
    (1960) Bell, S. Wallace
    A study was made comparing Japanese and Caucasian American Class II, Div. 1 malocclusions with respect to maxillary arch form and dento-skeletal patterns. For the arch form study, the maxillary casts of twenty Caucasian and eighteen Japanese individuals of comparable ages were evaluated. Dental arch indices were calculated for each individual and the mean values of the two groups were tested for significant difference. The Caucasian arches exhibited a more narrow tapering form than did the Japanese. In the second part of the study, eighteen Japanese and eighteen Caucasian American Class II, Div. 1 malocclusions were evaluated for differences in dento-facial architecture. Downs' radiographic cephalometric analytical procedure was used. Mental prominence was also measured using a technic which was described. It was found that the facial plan angle and mandibular plane angle in the Japanese group was more obtuse. The mental prominence in the Caucasian group was larger than in the Japanese group.
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    A comparison of maxillary arch form between groups of cerebral palsied and normal children
    (1971) Dummett, Clifton Orrin, Jr.; Gish, Charles W., 1923-; McDonald, Ralph E., 1920-; Roche, James R., 1924-; Shafer, William G.; Garner, La Forrest Dean, 1933-
    The purpose of this study was to compare the maxillary dental arch form and palatal vault form between 98 cerebral palsied and 76 normal children. All subjects were divided into three categories based on their dental eruption. The cerebral palsy subjects were further divided into the regional classifications of diplegia, paraplegia, hemiplegia, and quadriplegia, and the descriptive classifications of spasticity, athetosis, and mixed. The maxillary dental arch form was described by an index number which reflected intercuspid width, intermolar width, anterior-posterior length, and degree of divergence of the posterior segments. The palatal vault form v1as described by the angle of divergence of the palatal walls at an established reference point from a cross-sectional view. All measurements were made from study models and Xerox photocopies of study model cross-sections. In addition, those occlusal discrepancies that were thought to influence arch form, i.e., posterior unilateral and bilateral crossbite, anterior crossbite, anterior open bite, and posterior dental asymmetry were tabulated. Statistical analysis of the results revealed no significant difference in maxillary dental arch form between the cerebral palsied and normal children. The same held true for palatal vault form. Significant differences did occur between primary, mixed, and permanent dentitions for both cerebral palsied and non-handicapped groups. The results suggest that the neuromuscular handicap has little effect on the form of the maxillary dental arch. On the basis of this study, it appears that there is no particular type of maxillary arch form that is peculiar to cerebral palsy.
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    Computer-assisted analysis of dental crowding and its relationship to tooth size, arch dimension, and arch form in the mixed dentition, utilizing the Apple II personal computer
    (1987) Kamp, Anthony A.; Avery, David R.; Shanks, James C.; Hennon, David Kent, 1933-; Barton, Paul; Jones, James E. (James Earl), 1950-
    The programs developed in this study are examples of how a personal computer can aid the delivery of dental care. The versatility of the computer depends on the availability of a variety of programs specifically developed for dentistry, without which computers will have little impact on treatment. Moyers' analysis adapted for the Apple II and its research modification are computer programs developed specifically for dentistry. Accurately predicting the mesiodistal widths of the unerupted permanent canines and premolars in the mixed dentition can lead to orthodontic treatment that is optimally timed, with desirable facial and dental results. The stage of the mixed dentition constitutes the most intricate period in the development of the occlusion; any small anomaly occurring in this stage can pose complicated problems for the permanent dentition, requiring a more extensive and expensive mechanotherapy. Malocclusion is a developmental problem. Analysis of dental crowding and its relationship to tooth size and arch dimensions yielded the following results for the maxillary and mandibular arches: 1. Statistically different values for tooth size were noted between crowded and noncrowded groups, with crowded individuals having larger teeth. 2. Arch perimeter and arch depth were significantly smaller in crowded groups than noncrowded groups. 3. No significant differences were noted between crowded and noncrowded groups in arch width or symmetry. 4. Significant differences were demonstrated in the eccentricity value of an ellipse for crowded and noncrowded cases. This study suggests that dental crowding is associated with both small dental arches and large teeth. Therefore, greater consideration may be given to those treatment techniques which increase dental arch width, length, and perimeter. This is especially relevant in younger patients whose dentitions are in the deciduous and mixed stages of development. Further investigation into the relationship of dental crowding and arch shape with a larger sample might be productive. The eccentricity of a curve should be used to evaluate pre and post orthodontic treatment. Modifications to the basic computer program could include prediction values for Black Americans, cephalometric value interpretation, and the Bolton and Ponts analysis as a comprehensive diagnostic computer package.
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    Effects of rapid maxillary expansion on the cranial and circummaxillary sutures
    (Elsevier, 2011-10) Ghoneima, Ahmed; Abdel-Fattah, Ezzat; Hartsfield, James; El-Bedwehi, Ashraf; Kamel, Ayman; Kula, Katherine; Department of Orthodontics and Oral Facial Genetics, IU School of Dentistry
    INTRODUCTION: The aim of this study was to determine whether the orthopedic forces of rapid maxillary expansion cause significant quantitative changes in the cranial and the circummaxillary sutures. METHODS: Twenty patients (mean age, 12.3 ± 1.9 years) who required rapid maxillary expansion as a part of their comprehensive orthodontic treatment had preexpansion and postexpansion computed tomography scans. Ten cranial and circummaxillary sutures were located and measured on one of the axial, coronal, or sagittal sections of each patient's preexpansion and postexpansion computed tomography scans. Quantitative variables between the 2 measurements were compared by using the Wilcoxon signed rank test. A P value less than 0.05 was considered statistically significant. RESULTS: Rapid maxillary expansion produced significant width increases in the intermaxillary, internasal, maxillonasal, frontomaxillary, and frontonasal sutures, whereas the frontozygomatic, zygomaticomaxillary, zygomaticotemporal, and pterygomaxillary sutures showed nonsignificant changes. The greatest increase in width was recorded for the intermaxillary suture (1.7 ± 0.9 mm), followed by the internasal suture (0.6 ± 0.3 mm), and the maxillonasal suture (0.4 ± 0.2 mm). The midpalatal suture showed the greatest increase in width at the central incisor level (1.6 ± 0.8 mm) followed by the increases in width at the canine level (1.5 ± 0.8 mm) and the first molar level (1.2 ± 0.6 mm). CONCLUSIONS: Forces elicited by rapid maxillary expansion affect primarily the anterior sutures (intermaxillary and maxillary frontal nasal interfaces) compared with the posterior (zygomatic interface) craniofacial structures.