Indiana University-Purdue University Indianapolis (IUPUI) / Tooth mobility as it relates to orthodontics has not been thoroughly explored. The immediate aim of this project was to develop and test instrumentation to measure both tooth mobility and instantaneous centers of rotation under forces applied perpendicular to the tooth long axis. Two identical dial micrometers were selected and modified to allow variability in range, calibration, and contact pressure. All forces were delivered by mechanical force meters. A holding device was constructed to permit rigid positioning of a micrometer perpendicular to the long axis of any tooth in the arch and measure mobility at one point on the tooth. With an applied force of 500 gm., mobility measurements were made with the instrument on 44 teeth of six orthodontic patients. By repeating the analyses the instrument reproducibility was demonstrated. The pattern of tooth movement to applied force was explored and related to possible stress levels in tipping movements. A second holding device allowed both micrometers to contact a dental extension which was fixed to a maxillary central incisor. An incisor from each of four preorthodontic and two postorthodontic patients was analyzed. Over 200 clinical centers of rotation were calculated from measurements of tooth movements at two points on the tooth's long axis. Results from the first three patients were erratic. The rotation centers of the last three patients generally remained at midroot and also near the theoretical center of the tooth for all forces applied over 50 gm. More comprehensive studies on tooth mobility are recommended.

Indiana University-Purdue University Indianapolis (IUPUI) / This study was undertaken to histologically evaluate orthodontic tooth movement in hypothyroid and in normal Macaque speciosa monkeys. The experimental animals were rendered hypothyroid by radiosurgically altering the thyroid gland. A clinically acceptable orthodontic force was delivered to the anterior teeth of the monkeys. After the desired movement, a histologic investigation was made to correlate tissue responses with pressure, tension and root resorption. There was no significant difference among the three experimental animals. Likewise, there was no significant difference between the control animal and the three experimental animals. Osteoblastic and osteoclastic activity occurred to a comparable degree in both the experimental and control animals and was within normal limits for the amount of orthodontic tooth movement achieved. Root resorption was evident in both orthodontically treated and non-treated teeth in both the experimental and control animals. The root resorption observed was not significantly different, quantitatively or strategically, between the experimental and the control animals. Repair of root resorption was evident in both the experimental and control animals.

Indiana University-Purdue University Indianapolis (IUPUI) / The main purpose of this investigation was to produce bodily tooth movement. A force system based on the moment to force ratio (m/p ratio) was developed and applied to the teeth by means of springs similar to those used in segmented arch technique. An histologic investigation followed the experimentation. The sample consisted of five adult dogs and a relatively young one, all males. On these dogs, light forces of 165 and 147 gms were used for a period of 17, 30 and 35 days. and heavy forces of 490, 450 and 455 gms were used for a period of 120, 107 and 106 days. An intraperitoneal injection of a vital dye, procion red H8BS, was made before placing the appliance in the mouth and used as a marker between old and new bone. Bodily tooth movement was assessed by measuring new bone apposition on the tension side. Most of the teeth did show pure bodily movement, however, slight tipping was noticed in some instances. Direct bone resorption was recorded in all the teeth moved with light and heavy forces with the exception of very few small areas of hyalinization. The only difference between light and heavy forces was in the severity of root resorption. It was found that the heavier the force, the greater was the anchorage loss. The rate of tooth movement was continuous but not constant.

Thesis (M.S.)--University of Michigan, Ann Arbor, 1976. / Typescript (photocopy). Includes bibliographical references (leaves 76-80). Also issued in print.

Thesis (M.S.)--University of Michigan, 1987.

Thesis (M.S.)--University of Michigan, Ann Arbor, 1976. / Typescript (photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 76-80).

Thesis (M.S.)--University of Michigan, 1987.

Thesis (doctoral)--Goteborgs Universitet, 1974. / Includes bibliographical references (p. 36-40).

Thesis (doctoral)--Goteborgs Universitet, 1974. / Includes bibliographical references (p. 36-40).

Thesis (M.S.)--University of Michigan, 1978.