EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...

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Figure 3-1. All cases (n = 236) available in the Tweed Foundation Study. Cases are arranged by their time out of treatment (i.e., time from T2 to T3). All cases are plotted, but only those (n = 166) that were a minimum of 10 years out of treatment were analyzed in the present study. There were appreciably more women than men in the study. Except for 3 women with records more than 25 years out of treatment, the rest of the sample analyzed here was between 10 and 25 years out of treatment. This subset of the Tweed Foundation Study analyzed here consisted of 43 men and 123 women. 37
The present sample consisted of the remaining 166 cases (Table 3-1). All patients were American whites, with pretreatment ages between 8.26 and 43.36 years. Patients at T3 were a minimum of 10.0 years out of treatment. All fixed retainers were removed approximately 2-3 years after posttreatment. Following removal, no mandibular retention was used, and maxillary retainer wear was left up to the discretion of the patient. Sample Description One part of the sample consisted of 69 subjects (23 males; 46 females) who had been placed in a fixed mandibular canine-to-canine retainer and a maxillary removable retainer (traditional Hawley-type) at the end of active treatment. The other part of the sample consists of 97 subjects (20 males; 77 females) who were placed in maxillary and mandibular removable retainers (traditional Hawleytype). Both groups exhibit a low proportion of males because of men’s lower uptake of orthodontic services plus their reluctance to return for a recall examination. Pretreatment (T1), posttreatment (T2), and recall (T3) records were available for all of these 166 cases (Figure 3-1). Mean initial examination age for the sample was 13.94 years (Table 3-1). Posttreatment records were taken at a mean age of 16.89 years, with the total treatment time for the sample averaging 2.94 years. The interval from the posttreatment to recall examination was on average 16.03 years for the sample, with an average recall age of 32.92 years. Description of Data Entry Steps in the cast analysis (conducted by the Tweed Foundation research group) were this: Landmarks on each cast were marked with a soft lead pencil. Vertical lines were drawn on the maxillary cast on the buccal surfaces of the right and left first molar from the mesial buccal cusp tip to the gum line. On the mandibular cast, a vertical line was drawn one millimeter distal to the mesiobuccal groove on the buccal surface of the first molars (Figure 3-2). Holding the casts in occlusion (maximum interdigitation), the Left Molar Correction and Right Molar Correction values were measured, from the marks made as just described. This method produces a value 1.0 mm greater than commonly obtained (Baume et al. 1973; Harris and Corruccini 2008). The difference occurs because the Tweed Foundation teaches over correction of Class II cases to about 1 mm past traditional Angle Class I occlusion. That is the 38
Page 1 and 2: EFFICACY OF TEMPORARY FIXED RETENTI
Page 3 and 4: DEDICATION This thesis is dedicated
Page 5 and 6: ABSTRACT Instability of the occlusi
Page 7 and 8: CHAPTER 5. DISCUSSION .............
Page 9 and 10: LIST OF FIGURES Figure 3-1. All cas
Page 11 and 12: Figure 4-14. Box plot of the distri
Page 13 and 14: Joondeph and Riedel (1994, p 908) d
Page 15 and 16: Strang (1952, p 794) claimed that
Page 17 and 18: malocclusion must be maintained if
Page 19 and 20: e aimed at maintaining, in most ins
Page 21 and 22: three time intervals: during treatm
Page 23 and 24: mechanical treatment does not neces
Page 25 and 26: elation, the masticatory system wil
Page 27 and 28: exerted on the denture from the buc
Page 29 and 30: In summary, the variance in tongue
Page 31 and 32: Sinclair and Little (1983, p 114) a
Page 33 and 34: Study and 43 orthodontically treate
Page 35 and 36: and Sakols 1982; Vaden et al. 1997;
Page 37 and 38: years postretention. Årtun et al.
Page 39 and 40: adjustment, if necessary. This abil
Page 41 and 42: Duration of Retention The premise i
Page 43 and 44: The reduction in tooth structure of
Page 45 and 46: 4. The most stable position of the
Page 47: CHAPTER 3. MATERIALS AND METHODS Sa
Page 51 and 52: Figure 3-2. Illustration of how mol
Page 53 and 54: Figure 3-3. Illustration showing di
Page 55 and 56: Figure 3-5. Illustration showing mi
Page 57 and 58: Figure 3-6. Illustration showing an
Page 59 and 60: Figure 3-8. Illustration showing in
Page 61 and 62: 34. LR3 cusp tip point. 35. Right d
Page 63 and 64: Figure 3-10. Illustration showing o
Page 65 and 66: Figure 3-11. Illustration of Inciso
Page 67 and 68: 3. Go, Gonion (anatomic): The most
Page 69 and 70: Figure 3-13. Depiction of the angle
Page 71 and 72: Figure 3-15. Illustration of the me
Page 73 and 74: Figure 3-17. Illustration of the me
Page 75 and 76: Figure 3-19. Illustration of the an
Page 77 and 78: Figure 3-21. Illustration of the up
Page 79 and 80: Figure 3-22. Illustration of the to
Page 81 and 82: Figure 3-24. Illustration of the po
Page 83 and 84: the “older” Tweed force system,
Page 85 and 86: The null hypothesis is: There was n
Page 87 and 88: Figure 4-1. Distribution of the 166
Page 89 and 90: occlusal issues are tolerated by bo
Page 91 and 92: 40 35 30 FMA (degrees) 25 20 15 10
Page 93 and 94: Figure 4-4. Plot of the average val
Page 95 and 96: larger ANB at the recall examinatio
Page 97 and 98: 21 19 Total Chin (mm) 17 15 13 11 9
Page 99 and 100:
Figure 4-8. Box plot of the distrib
Page 101 and 102:
which a Class I relationship was no
Page 103 and 104:
Figure 4-11. Plot of mean Curve of
Page 105 and 106:
Figure 4-13. Box plot of the distri
Page 107 and 108:
Table A-4 addresses the question of
Page 109 and 110:
Figure 4-16. Bar chart of the avera
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only sample changed significantly m
Page 113 and 114:
3 2 1 0 Canonical Variate 2 -1 -2 R
Page 115 and 116:
8 Anterior Discrepancy (ADisc) 6 4
Page 117 and 118:
40 Incisor Aspect Ratio (IAR) 30 20
Page 119 and 120:
1.5 Incisor Segment Depth (ISD) 1 0
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more stable (i.e., the mean change
Page 123 and 124:
Molar Correction (MC) 10 8 6 4 2 0
Page 125 and 126:
Anterior Segment Width (ASW) 1 0 -1
Page 127 and 128:
final vertical positions. This phas
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decreased in both arches during the
Page 131 and 132:
Figure 5-1. Plot of average Incisor
Page 133 and 134:
Based on the present results, the u
Page 135 and 136:
these variables indicate more anter
Page 137 and 138:
and the hassle associated with plac
Page 139 and 140:
Figure 5-2. Scatter-plot graph refl
Page 141 and 142:
stability?” and “for how long?
Page 143 and 144:
About two-thirds (64%) of the corre
Page 145 and 146:
Baume LJ, Horowitz HS, Summers CJ,
Page 147 and 148:
Case CS. Techniques and principles
Page 149 and 150:
Glenn G, Sinclair PM, Alexander RG.
Page 151 and 152:
Joondeph DR. Retention and relapse.
Page 153 and 154:
Littlewood SJ, Millett DT, Doubleda
Page 155 and 156:
Ormiston JP, Huang GJ, Little RM, D
Page 157 and 158:
Rosenstein SW, Jacobson BN. Retenti
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Steadman SR. A philosophy and pract
Page 161 and 162:
Zachrisson BU, Büyükyilmaz T. Bon
Page 163 and 164:
Table A-1. Descriptive statistics a
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Table A-2. Descriptive statistics a
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Table A-3. Descriptive statistics f
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
APPENDIX B. ANCOVA TESTS OF THE COM
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Table B-1. Continued. Sex Retention
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Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
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Table C-1. Results of ANCOVA tests
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Page 191 and 192:
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Page 195 and 196:
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Table D-1. Descriptive statistics,
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Page 203 and 204:
Table E-1. Two-way ANOVA tests eval
Page 205:
VITA Mark Owens was born on January
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EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...

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