EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...
EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ... EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...
This inference raises an important question: There are roughly three times as many women as men in the sample (123 versus 43), and it can only be hoped that those men that agreed to be recalled are representative of the sex at large. It is speculated that men are less concerned about their occlusions and, thus, relatively indifferent to undergoing a recall examination. There is, however, no practical way of testing this. This problem is common to all orthodontic-recall studies because there is no way to coerce former patients to participate. Table D-4 lists the 17 variables that exhibit statistically significant sex differences in the amounts of in-treatment change. Most of these variables are dependent on tooth relationships. Except for incisor segment ratio and incisor segment depth, all of these variables (15 of 17) changed more in the boys than the girls. The theme seems to be that those variables that were more deviant in boys at the start of treatment (e.g., overjet, overbite, ANB, AOBO, Curve of Spee) warranted more correction during treatment. These changes are illustrated using the data for the AOBO discrepancy (Figure 4-4). The typical male orthodontic patient has a greater AOBO discrepancy at the start of treatment (perhaps because of differential selection of who actually receives treatment). Boys also experience a significantly greater in-treatment change, which leads to the sex differences noted here. The 14 significant sex differences that occurred after treatment (Table D-5) are of particular interest since they constitute difference in the aging process (in combination with any relapse tendencies). Inter-canine width and inter-molar width, both in the maxilla and mandible, differed between men and women because women experienced greater relapse—where ‘relapse’ is constriction of these widths with age. Average changes were small—less than a millimeter. FMIA increased in both sexes, but significantly more in men. FMA flattened about 2 on the average in men, but the mean change was trivial in women (Figure 4-5). We speculate that this flattening is due to growth at the gonial process due to greater muscle force of the elevator muscles in males, and it may well reflect the continued decrease in FMA seen in childhood and adolescence (Ricketts 1972). SNB—in combination with ANB and AOBO—changed a bit both in men and women, but in opposite directions. The change in SNB was positive in men (~ 0.6), but negative in women (~ 0.3). Since the change in SNA was statistically inconsequential in both sexes (~ 0.0), the increase in SNB (and in ANB) in men discloses that mandibular growth slightly exceeded that of the maxilla, making the skeletal profile a bit less retrognathic by the recall examination. In women, mandibular growth lagged slightly behind, creating a 81
Figure 4-4. Plot of the average values of AOBO at the three examinations, by sex. The point of interest here is that males who actually seek orthodontic treatment tend to have greater AOBO discrepancies than girls. Since the orthodontist is able to correct much of the skeletal discrepancy, the sex difference is considerably less at the posttreatment examination than at the start of treatment. This means that boys experience a significant greater in-treatment change for this variable than girls. 82
- 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 and 48: CHAPTER 3. MATERIALS AND METHODS Sa
- Page 49 and 50: The present sample consisted of the
- 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: 40 35 30 FMA (degrees) 25 20 15 10
- 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
- Page 111 and 112: 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
- Page 121 and 122: 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
- Page 129 and 130: 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?
Figure 4-4. Plot of the average values of AOBO at the three examinations, by<br />
sex.<br />
The point of interest here is that males who actually seek orthodontic treatment<br />
tend to have greater AOBO discrepancies than girls. Since the orthodontist is<br />
able to correct much of the skeletal discrepancy, the sex difference is<br />
considerably less at the posttreatment examination than at the start of treatment.<br />
This means that boys experience a significant greater in-treatment change for this<br />
variable than girls.<br />
82
Change language