Indiana University-Purdue University Indianapolis (IUPUI) / A method was devised and described to study the tissue response as demonstrated by tooth movement to measured force loads in the range of from 25 to 150 grams force a side or from 50 to 300 grams distributed over the maxillary central and lateral teeth. Investigation was initiated in an attempt to establish the existence or non-existence of threshold force values for anterior tooth movement. Threshold forces are defined in this study as that force necessary to retract the maxillary central and lateral teeth one millimeter. Secondary objectives were to determine whether there is similar tooth movement demonstrated by individuals at given force values, the relation of force and pain response at low force values, whether there is movement of the anchor teeth and whether there is an optical range force for anterior retraction. An optimal range of force would be a range where there was maximum tooth movement with a minimum of pain response. Before and after records were taken on twenty-two children which consisted of models, lateral cephalometric radiographs and before treatment photographs. All the children possessed maxillary protrusions with space distal to the lateral teeth as a criterion for selection for the study. The maxillary central and lateral teeth were branded and brackets were placed at a determined distance from the incisal edge of the central teeth so as to standardize the force at the alveolar crest regardless of root length. The maxillary molar teeth were banded and a soldered lingual bar constructed to extend from light to left molar. Eyelets were welded to the buccal surface of these molar bands as fixed points of reference for measurement of the amount of movement of the maxillary four anterior teeth in relation to the molars. Measurement was made with a Korkhaus Three Dimensional Orthodontic caliper and by superimposition of lateral cephalometric headplates. Measurements were taken at seven, twelve, seventeen, twenty-two and twenty-seven days after activation of .008 X .030 closed coil springs in tension on the right and left side of the appliance. The load deflection of the coil springs was 13 grams per millimeter. The range of forces from 25 to 150 grams a side are termed low force values in this study. At these low force values there is similar tooth movement demonstrated by all individuals in the study. Threshold force values appear to be a range of force values of from 14 to 24 grams distributed to the four maxillary anterior teeth. These low force values of from 25 to 150 grams on the right and left side create no severe or prolonged problems for the patient. In no case was pain described as more than a slight soreness. There appears to be no movement of the anchor teeth as determined by the method used in this study. An optimal range of force values for the retraction of the four anterior teeth is in the range of from 50 to 75 grams a side or from 100 to 150 grams distributed over four teeth.
| Identifer | oai:union.ndltd.org:IUPUI/oai:scholarworks.iupui.edu:1805/34177 |
| Date | January 1959 |
| Creators | Groves, Murray H., Jr. |
| Source Sets | Indiana University-Purdue University Indianapolis |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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