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Item A Cephalometric Skeletal and Dental Analysis of Children with Excellent Occlusions(1962) Rosenbloum, Malcolm LouisA sample of twenty-five children with excellent occlusions between the ages of eight through eleven was collected. Cephalometric radiographs were taken of these children with the objective of obtaining normal standards for the purpose of compiling a cephalometric analysis especially applicable for diagnosis of malocclusions of the mixed dentition. A statistical analysis were performed on the data to calculate the means, ranges, standard deviations, and standard errors of the mean for each measurement. By the use of “t” tests, males were found to be significantly larger than females with respect to several linear measurements. However, there were no significant differences between males and females fore any of the angular measurements. No significant differences were found between this sample and Reidel’s sample; but, when compared to Downs’ sample, the upper and lower incisors of this sample were found to be significantly more protrusive. A correlation study of several pairs of measurements was also done. Significant positive correlations were found between the length of anterior cranial base and the length of the palate; and also between the lower facial height and the lower dental height. A significant negative correlation was found between the chin prominence and the angle of convexity.Item A Study of the Correlation of Incisive Biting Forces with Age, Sex and Anterior Occlusion(1971) Kotwal, Navroze Shavak; Standish, S. Miles; Chalian, Varoujan A.; Shanks, James C.This study was designed to prove or disprove the fact that incisive biting force can be correlated with the variables chosen which were age, sex and anterior occlusion (overjet, overbite and cuspid relation). The amount of linear contact made by the incisal edges of the upper and lower incisors was also included as one of the variables. One hundred and fifty individuals, 80 males and 70 females, between the ages of 10 and 25 were selected for this study. This was a cross sectional study in which four readings of the maximum biting ability were recorded for every individual just once during the study and an average of the four recordings was taken. An intra-oral force transducer using strain gages was employed to record incisive biting forces. The results indicated that age, sex and amount of linear contact were correlated with biting force when considered singly. When the variables were considered jointly through a stepwise regression analysis overbite also entered as a significant predictor of biting force in addition to the three mentioned variables. Multiple correlation coefficient R was 0.54 for the four entered variables (age squared, sex, overbite and linear contact squared) with biting force. The R squared value was 0.29 so that 29 percent of the variation in incisive biting force of this sample was due to these four variables. The correlated R-squared value indicates a large error of prediction and a low degree of precision in estimating biting force from these four variables. Therefore, a regression equation is not demonstrated.Item A Study of the Intra-Arch Relationships in Normal Human Dentures(1951) Lindquist, John T.Item A Study of the Relationship of the Dental Arch to its Supporting Structure(1964) Lampros, Leo NicholasUsing 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.Item An Investigation of Intermaxillary Tooth Mass Discrepancy: A New Approach(1974) Williams, James E.; Garner; Tomich; Potter; Dirlam; ShanksThis study investigated the incidence, amount, and location of intermaxillary tooth mass discrepancy in a sample of malocclusion cases. Obtaining accurate tooth measurements was a primary concern of the investigation. Interproximal separation was achieved in each case prior to the taking of a silicone rubber impression. Individual tooth dies were then produced from the impression and measured with direct reading instruments. A model of occlusion was adopted as a reference for evaluating tooth mass problems. Each case demonstrated some tooth mass discrepancy. The discrepancies in the posterior segments were generally very minor and of limited clinical significance. Larger discrepancies were found in the anterior segments. Most of these were small enough to be managed by clinical manipulation of tooth position, but approximately one-fifth were large enough to have significant effects on occlusion. The labia-lingual thickness of incisors was found to have considerable potential in affecting the anterior occlusion. Statistical analysis revealed no difference in the amount of tooth mass discrepancy between males and females. Likewise, there was no difference between Class I and Class II malocclusion groups. An anterior ratio and ''Anterior Percentage Relation" were calculated and they compared favorably with the results of the original investigators. The malocclusion cases had a wider range of values than those cases of excellent occlusion. Right-left tooth size asymmetry was investigated. The results indicated that the problem is not nearly as great as previously reported.Item Cephalometric Study of Human Mandibular Proportions and Relationships in Normal Occlusion(1947) Stoner, Morris M.Item An evaluation of occlusion of cerebral palsied children(1963) Rosenbaum, Charles Herbert, 1935-The purpose of this study was to provide information concerning occlusion and related problems in cerebral palsied children. A group of 124 cerebral palsied children between the ages of 6 and 12 years were examined at the Cerebral Palsy Dental Clinic, Indiana University. The occlusion was evaluated according to Angle's classification. In addition, a recording was made of overjet, over-bite, open bite, cuspid relationships, crossbite and midline discrepancies. The examination included a clinical evaluation of the swallowing pattern of each child. The cerebral palsy classification and I.Q. scores were recorded for each cerebral palsied child after a comprehensive review of his medical record. These findings were compared with a control group of 141 similar aged non-cerebral palsied children examined at Indiana University, Pedodontic department. The cerebral palsied group had an average increased overjet of 0.8 mm. and an average decreased overbite of 0.5 mm., representing an upward and outward positioning of the maxillary anterior segment. Anterior open bite was present in a similar percentage of both groups, but in the cerebral palsied group the measurement recorded was more than twice as great as that recorded in the control group. Forty-four per cent of the cerebral palsied children exhibited bruxism, more than twice the percentage of cases recorded in the control group. The cerebral palsied children exhibited bruxism most frequently in the day time, and was most common in the athetoid group. Other measurements recorded were not significantly different between the two groups. From this study one can conclude that malocclusion and factors affecting occlusion are not found with greater frequency in cerebral palsied children.Item Force Magnitude and Center of Rotation: Histologic Study in Rhesus Monkey(1964) Atta, Alaá EldinIt is believed that a single force, regardless of its magnitude, tips a tooth around the same center of rotation. This is a histologic investigation of this concept; and an attempt to correlate clinical findings with early and late microscopic changes in the periodontium after light and heavy force application. Five Rhesus monkeys, 3-4 years of age, were used. In one, continuous forces of 40 and 600 gm. were to move a maxillary first bicuspid distally through an edentulous space, with the first molar serving as anchor for 47 days. Both teeth tipped equally toward each other. In four monkeys, light, continuous forces, 10 and 57 gm., and heavy forces, 100 and 200 gm., were used to move the two central incisors lingually over periods of 19, 62, and 66 days. The light force had to be maintained for a period of 4-6 weeks before changing the activation. The 10 gm. force did not move incisors after 19 or 62 days. The 57 gm. force moved the tooth faster than the heavy forces. Hyalinization of the periodontal membrane was recorded during the lag period, but not later. At later stages, the heavy force caused more root resorption than the lighter one. The moment/force ratio determines the center of rotation, not the single value of each. Single forces tipped teeth at the same center of rotation, regardless of their magnitude.Item Force Values and Rate of Movement in Closure of Space Between Maxillary Central Incisors(1962) Levihn, Henry L.A study was conducted to determine the rate of tooth movement, pain response and tooth mobility when closing the space between the maxillary central incisors. Twenty children age 8 to 18 were selected who had a minimum of two millimeters space between the maxillary centrals. The forces used were 10, 20, 50, 75, 125, and 200 grams. It was found that there was a fast initial movement followed by a latent period of varying lengths of time. In most instances the lag period is from seven to ten days, but in three cases it was as high as eighteen to twenty-five days. The five patients in the 50 gram group had the shortest latent period. The three patients with the extended latent periods happened to be the three oldest patients in the sample. That is, they were from 16 ½ to 18 years of age, while the average age for the entire sample was about 11 years. After the latent period, the rate of movement in the 10 and 20 gram groups was slower than the rate of movement with higher force. When the higher forces in the 125 and 200 gram range were used, the rate did not continue to increase but was comparable to the rates in the 50 and 75 gram groups. What was noticed in the higher range of force was an increase in the amount of pain and mobility. From these observations it was felt that for tipping of the maxillary centrals the optimal range of force to be used would be 50 to 100 grams. At these forces the rate of tooth movement was rapid and the patient’s response to pain was at a minimum.