Long term effects of orthodontic treatment /certified fixed orthodontic courses by Indian dental academy


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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call

The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call

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Long term effects of orthodontic treatment /certified fixed orthodontic courses by Indian dental academy

  1. 1. LONG TERM EFFECTS OF ORTHODONTIC TREATMENT INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. CLASS II CORRECTION Orthopedic appliances CLASS III CORRECTION Temporomandibular joint INTERNAL DERANGEMENT JOINT SOUNDS CLICKING Condyle fossa relationship www.indiandentalacademy.com
  3. 3. •Orthognathic surgical procedures •Periodontal tissues •Profile changes in extraction and non extraction cases Single jaw surgery Double jaw surgery www.indiandentalacademy.com
  4. 4. Arch length •Arch form considerations Arch perimeter Arch width Arch expansion •Retention and stability www.indiandentalacademy.com
  5. 5. Long term periodontal changes associated with orthodontic treatment www.indiandentalacademy.com
  6. 6. • It is well established that orthodontic therapy can produce a more esthetic dentofacial complex and a superior functional occlusion. • However, it remains unclear as to whether long-term periodontal health is better or worse as a consequence of the patient having undergone orthodontic therapy in adolescence. www.indiandentalacademy.com
  7. 7. • The literature regarding the relationship between crowding of teeth, plaque accumulation, and degree of periodontal disease is conflicting. • Several studies report that there is a positive relationship among these factors, while other studies report no relationship. www.indiandentalacademy.com
  8. 8. • It is widely believed that an important rationale • for performing orthodontic treatment is to promote the health of the periodontium, thereby enhancing longevity of the dentition.1,2 It is therefore assumed that adults with untreated malocclusions would be subject to a greater prevalence of periodontal disease than if their malocclusions had been corrected orthodontically. www.indiandentalacademy.com
  9. 9. • Conversely, it has been maintained that orthodontic treatment may have some adverse effects on the gingival and periodontal tissues which may hasten or promote periodontal breakdown in later life. www.indiandentalacademy.com
  10. 10. • Clinicians also differ in their opinions regarding • relationships between orthodontic treatment and periodontal status; several investigators maintain that there is no permanent damage to a healthy periodontium as a result of orthodontic treatment, whereas others believe that orthodontic treatment may initiate the first stage of marginal periodontitis. In addition, the periodontal remodeling associated with orthodontic therapy may become a significant factor with age. www.indiandentalacademy.com
  11. 11. • A relationship may exist between orthodontic • • therapy and conversion of gingivitis into periodontitis— for example, orthodontic bands may increase subgingival plaque retention. Furthermore, orthodontic movement resulting in tooth intrusion may shift supragingival plaque into a subgingival location and predispose toward destructive periodontitis. In this respect small but statistically significant loss of connective tissue attachment has been reported shortly after completion of orthodontic therapy www.indiandentalacademy.com
  12. 12. • Polson AM et al (ajo 1988) evaluated the clinical periodontal status of persons who had completed orthodontic therapy at least 10 years previously (study) and compared the findings to those of adults with untreated malocclusions (control). www.indiandentalacademy.com
  13. 13. • Subjects in the study (n = 112; 63 female subjects, 49 male subjects; mean age 29.3 ± 4.2 [SD] years) and control (n = 111; 62 female subjects, 49 male subjects; mean age 32.9 ± 6.5 years) populations underwent a comprehensive periodontal examination www.indiandentalacademy.com
  14. 14. • periodontal examination consisted of • • • • • • measurements taken at six points around the circumference of each tooth: (1) plaque, (2) visual inflammation, 3) bleeding after probing, (4) pocket depth, (5) gingival recession, and (6) loss of connective tissue attachment www.indiandentalacademy.com
  15. 15. Plaque and inflammation • The degree of inflammation corresponded with the distribution of plaque and indicated that clinical signs of inflammation (color changes and bleeding) related to the presence or absence of plaque , rather than a history of orthodontic treatment www.indiandentalacademy.com
  16. 16. Gingival margin • Gingival margin location was measured as an indication of gingival recession. Contrary to expectations, the orthodontically treated group consistently showed a more coronal gingival margin location than the control group www.indiandentalacademy.com
  17. 17. • There are two possibilities that may be responsible for the more coronal gingival margin in the orthodontically treated group. • First, orthodontic appliances result in gingival inflammation and enlargement, independent of the presence of supragingival plaque. Generally, however, the gingiva returns to normal after bands have been removed. www.indiandentalacademy.com
  18. 18. • The second possibility relates to the gingival bunching that may occur with orthodontic relocation of the teeth. The incidence of gingival bunching and clefting has been reported primarily in association with orthodontic closure of extraction spaces www.indiandentalacademy.com
  19. 19. Pocket depth • Examination of pocket depths showed no • statistical difference between study and control groups; however, the pocket depth values for all tooth types and surface locations were always greater in the orthodontically treated group. Although one tends to associate deeper periodontal pockets with destructive periodontal disease, this is not necessarily the case since the critical clinical variable relating to periodontal destruction is the loss of connective tissue attachment www.indiandentalacademy.com
  20. 20. • The lack of difference between the groups regarding loss of attachment means that the increased pocket depth tendency in the study group did not represent greater periodontal destruction. • Consequently, the tendency for deeper pocket depths in the study group resulted from a more coronally positioned gingival margin, rather than from increased periodontal destruction at the. base of the pocket. www.indiandentalacademy.com
  21. 21. • Residual tissue bunching would result in coronal positioning of the gingival margin and an associated increase in pocket depth, and may have been responsible for the greater pocket depth tendencies in the study group www.indiandentalacademy.com
  22. 22. • It is reasonable, however, to consider that gingival tissue bunching could also occur in other locations where tooth position is changed by orthodontic movement. Although studies have indicated that tissue bunching is transient and resolves with time, www.indiandentalacademy.com
  23. 23. • the tendency for a more coronal gingival margin location has been reported on a long-term basis after tooth movement into extraction spaces. • A similar generalized effect throughout the dentition would result in a tendency toward the more coronal gingival margin in the orthodontically treated group in this present study. www.indiandentalacademy.com
  24. 24. Attachment loss • It is probable that the connective tissue • attachment level is the single most important variable when assessing the progression of marginal periodontitis. The lack of difference in attachment levels between study and control groups in the present study implies no adverse long-term effect after orthodontic treatment in adolescence. www.indiandentalacademy.com
  25. 25. • . There was no correlation between various incisal movements and the degree of gingival recession. • it was concluded that orthodontic treatment during adolescence had no discernible effect upon later periodontal health. www.indiandentalacademy.com
  26. 26. • Trossello and Gianelly (J. Peridontol. 1979). also reported only minor differences in the health of the periodontal tissues and alveolar bone in a group of thirty female patients between 18 and 25 years of age at least 2 years after orthodontic treatment, as compared to a similar group of subjects who had never received orthodontic therapy www.indiandentalacademy.com
  27. 27. • In Zachrisson's study (AO 1973) however, after 2 years of posttreatment follow-up, the orthodontic group demonstrated a slightly increased loss of periodontal attachment and alveolar bone as compared to the untreated control group, but this was considered to be within acceptable limits. www.indiandentalacademy.com
  28. 28. • However, approximately 10 percent of the orthodontic patients demonstrated a more significant amount of loss of attachment and marginal alveolar bone loss. • It should be realized that the cases studied involved severe malocclusions requiring extensive tooth movement www.indiandentalacademy.com
  29. 29. Long term changes on arch form due to orthodontic treatment www.indiandentalacademy.com
  30. 30. • It is well established that increases in dental arch length and width during orthodontic treatment tend to return toward pretreatment values after retention. • These dimensional changes may affect arch form as well. The majority of studies pertaining to arch form have focused on attempts to find the single shape that would best describe the dental arches of a particular sample. www.indiandentalacademy.com
  31. 31. • It is a commonly held view that minimal alterations to the original arch form during treatment may result in minimal postretention changes. • However, there are certain patients in whom arch form is purposely changed with treatment. www.indiandentalacademy.com
  32. 32. • Patients with Class II, Division 1 malocclusions maxillary arches with tapered shapes, flared incisors, and constricted intercanine widths are often changed during treatment to coordinate it with the mandibular arch. The long-term consequences of this change in arch form are not known www.indiandentalacademy.com
  33. 33. • Cruz R ,Paul Sampson, Robert M. Little,et al (AJO 1995) did a study to evaluate the long term changes on arch form due to orthodontic treatment www.indiandentalacademy.com
  34. 34. • Dental casts were evaluated before treatment, after treatment, and a minimum of 10 years after retention for 45 patients with Class I and 42 Class II, Division 1 malocclusions who received four first premolar extraction treatment. Computer generated arch forms were used to assess changes in arch shape over time. • Extraction patients were selected for the study, since it was likely that their arch forms were changed more during treatment than nonextraction patients. www.indiandentalacademy.com
  35. 35. • Each patient had complete records including dental casts and cephalometric radiographs at three time periods • pretreatment (T1), • At the end of active treatment (T2), and • A minimum of 10 years after removal of retainers (T3). www.indiandentalacademy.com
  36. 36. • In the current study, a general pattern of postretention relapse of the treatment changes in arch form was exhibited by patients with Class I and Class II malocclusions. However, a high degree of individual variability was prevalent. www.indiandentalacademy.com
  37. 37. • Results showed that changes in arch form that occurred after retention were moderately associated with changes that occurred as a result of orthodontic treatment. • This seems to indicate a tendency for small treatment change to result in minimal postretention change, whereas large postretention change resulted in cases with large treatment change. www.indiandentalacademy.com
  38. 38. • This would also seem to agree with claims made by several investigators that minimal changes in the dental arch form may enhance long-term stability www.indiandentalacademy.com
  39. 39. • The Class II maxillary arches demonstrated the highest mean change in shape during orthodontic treatment. When compared with the Class I sample, • it was expected that the Class II sample would have demonstrated more postretention change. However, results did not support this assumption. The Class II arches underwent a similar variety of postretention change. www.indiandentalacademy.com
  40. 40. • Change in arch length, intermolar width, intercanine • width, and Irregularity Index were in agreement with findings of Little et al (.AJO 1981) In general, arch width and arch length decreased in the postretention period and crowding increased, irrespective of whether the original intercanine width was maintained or increased during treatment. www.indiandentalacademy.com
  41. 41. • In the present study, the largest treatment change in arch form was observed in the Class II group, but no difference was found in the magnitude of postretention change when compared with the Class I arches. www.indiandentalacademy.com
  42. 42. • This could suggest that the clinician should not expect greater relapse when altering the maxillary arch form of a patient with Class II, Division 1 malocclusion. www.indiandentalacademy.com
  43. 43. • In fact, both Class I and Class II cases had marked relapse, and Class II cases did not respond with more relapse than the Class I cases even though they were changed more during treatment. • Since the treatment versus postretention correlation was low for the Class II cases, another interpretation of the data is that Class II maxillary arches had more variation in response. www.indiandentalacademy.com
  44. 44. CLINICAL APPLICATION • Arch form may be changed during treatment if the clinician understands that the change may or may not be stable. Retention should certainly be an important consideration when planning treatment for these patients. www.indiandentalacademy.com
  45. 45. RAPID MAXILLARY EXPANSION • I nterest in rapid maxillary expansion (RME) has increased markedly during the past 2 decades. • The correction of transverse discrepancies and the gain in arch perimeter as potential nonextraction technique appear to be the most important reasons underlying this increased interest. www.indiandentalacademy.com
  46. 46. • There have been few well-designed investigations of the long-term craniofacial adaptations to RME therapy. www.indiandentalacademy.com
  47. 47. • the long-term effects of RME was performed by Haas (AO 1980). The study presented longterm data from 10 subjects. After expansion, the average increases initially were 9 mm in apical base width and 4.5 mm in nasal cavity width. • None of the 10 subjects underwent a loss in either dimension at the time of reevaluation (614 years postretention) www.indiandentalacademy.com
  48. 48. • In another long-term cephalometric study that incorporated metallic implants, Krebs examined 23 patients with bilateral cross bites over a 7-year period after RME. • He found that increments in both nasal and maxillary width were relatively stable. The width of the dental arch was increased significantly by RME therapy, but the gain in many instances was not stable, with a steady decrease being recorded up to 4 or 5 years after the treatment. www.indiandentalacademy.com
  49. 49. • The findings of Cameron et al (AJO 2002)investigation revealed that, in the longterm (about 8 years after expansion), the effects of RME with the Haas appliance followed by fixed appliance therapy can induce a normalization of both dental and skeletal components of the craniofacial complex. www.indiandentalacademy.com
  50. 50. • Therefore it can be concluded that on long term results of RME are stable . www.indiandentalacademy.com
  51. 51. Extraction versus non extraction www.indiandentalacademy.com
  52. 52. • The extraction-nonextraction debate, ongoing for almost 100 years, has often been based more on supposition than fact. • Those who favor nonextraction have often presumed that extraction treatment tends to dish in the face; those who favor extraction, on the other hand, often presume the lips tend to be “blown out” by excessive incisor flaring. www.indiandentalacademy.com
  53. 53. • The extraction-nonextraction debate has also been based on suppositions about what occurs after treatment. www.indiandentalacademy.com
  54. 54. • We now have good data showing only small posttreatment differences between extraction and nonextraction patients. • Extraction patients tend to be 2 to 4 mm flatter, on average, than nonextraction patients at the end of treatment. www.indiandentalacademy.com
  55. 55. • Over the short term, it has been shown that there is little or no difference in how orthodontists and laypeople rate the profiles of extraction and nonextraction patients. • However, these patients were followed for only 2 years, and soft tissue changes take longer to develop in subjects with reduced growth potential. www.indiandentalacademy.com
  56. 56. Clear cut extraction vs non extraction www.indiandentalacademy.com
  57. 57. • Stephens,et al (AJO 2005) did a study to evaluate long-term profile changes in extraction and nonextraction patients- www.indiandentalacademy.com
  58. 58. • Twenty extraction and 20 matched nonextraction patients, with posttreatment and long-term follow-up (average 15 years) records, were selected from a single private orthodontic practice. • Posttreatment and long-term follow-up profile photos of the patients’ nose, lip, and chin areas were evaluated by 105 orthodontists and 225 laypeople, who indicated their preferences and the amount of change they perceived among the 40 profiles. www.indiandentalacademy.com
  59. 59. • The patients had similar dental protrusion, soft tissue profile measurements, and ages at the posttreatment observation • The results clearly showed that the extraction and nonextraction patients were comparable at the end of treatment. www.indiandentalacademy.com
  60. 60. • Both groups had similar amounts of lip protrusion in relation to the esthetic lines, similar amounts of dental protrusion, and similar soft tissue facial convexities. www.indiandentalacademy.com
  61. 61. • Bishara et al (AJO 1995) showed that differences between extraction and non extraction groups in lip position relative to the E-line increased during their posttreatment follow-up, but this was only 2 to 3 years later. www.indiandentalacademy.com
  62. 62. • Although they were not different, both groups • demonstrated significant changes over time. Their lips became significantly more retruded in relation to the E- and S-lines, and their facial convexity decreased considerably over the long term. Similar posttreatment changes have been reported for both extraction and nonextraction patients .(Paquette DE et al AJO 1992, Zierhut EC et al AO 2000, Finnoy JPet al EJO 1987,) www.indiandentalacademy.com
  63. 63. • Because there was no clear relation between treatment modality and the profile preferences of orthodontists and laypeople, it cannot be concluded that one type of treatment produces better, or worse, long-term profiles than the other. www.indiandentalacademy.com
  64. 64. Clinical implication • This simply demonstrates regardless of the treatment modality that some profiles changed for the better, and some changed for the worse. • Whether teeth were extracted had no bearing on whether the profiles got better or worse. www.indiandentalacademy.com
  65. 65. • We, as orthodontists, cannot determine whether a patient will age for the better or for the worse. • The results also showed that just because one’s appearance changes over time does not necessarily mean that it will get worse or better. www.indiandentalacademy.com
  66. 66. Borderline extraction vs non extraction www.indiandentalacademy.com
  67. 67. • Paquette, Beattie, and Johnston AJO 1992 compared the long term changes in the borderline cases in class II patients www.indiandentalacademy.com
  68. 68. • The long-term effects of extraction and nonextraction edgewise treatments were compared in 63 patients with Class ll, Division 1 malocclusions who were identified by discriminant analysis as being equally susceptible to the two strategies. www.indiandentalacademy.com
  69. 69. • A lateral cephalogram, study models, and a self-evaluation of the esthetic impact of treatment were obtained from each of the 33 extraction and 30 nonextraction subjects. www.indiandentalacademy.com
  70. 70. • The average posttreatment interval was 14.5 years. • Although the two strategies produced significant, long-lived differences in the convexity of the profile and the protrusion of the dentition (the nonextraction patients were about 2 mm "fuller"), half of the nonextraction patients and three fourths of the extraction patients ultimately presented with less than 3.5 mm of lower incisor irregularity. www.indiandentalacademy.com
  71. 71. • The two groups showed an essentially identical pattern of posttreatment relapse/settling that was related more to the differential growth of the jaws than to the posttreatment position and orientation of the denture. www.indiandentalacademy.com
  72. 72. • it was noted that because the extraction patients started out with slightly more irregularity and ended up with slightly less), the net change favors premolar extraction www.indiandentalacademy.com
  73. 73. • Authors therefore suggested that it be interpreted provisionally as an argument against the single-sided hypothesis that extraction treatments are generally inferior. (mandibular distal displacement/entrapment ) www.indiandentalacademy.com
  74. 74. • In general, the pattern of relapse was unrelated to the type of treatment or to the posttreatment position and orientation of the denture and, instead, appears to constitute a dentoalveolar compensation produced by the differential growth of the jaws following treatment. www.indiandentalacademy.com
  75. 75. • the more the mandible outgrows the maxilla, the greater the probability that the upper molars and the upper incisors will tip forward, that the lower incisors will tip lingually, and that lower molar anchorage will be preserved www.indiandentalacademy.com
  76. 76. www.indiandentalacademy.com
  77. 77. Clinical implication • several useful conclusions can be drawn . • For example, if growth is the usual long- term source of the molar and the overjet corrections, a decision to extract upper first premolars with an eye toward leaving the molars in a Class II relationship would seem an eminently logical approach to the treatment of a nongrowing adult. www.indiandentalacademy.com
  78. 78. • Moreover, given that much of the relapse seen here took the form of dentoalveolar compensations for posttreatment jaw growth, one might also infer the type and the minimum duration of the retention program required for the average adolescent patient. www.indiandentalacademy.com
  79. 79. Long term effects on retention and stability www.indiandentalacademy.com
  80. 80. • Retention for Life • Based on extensive research conducted at the • University of Washington, Little and colleagues concluded that orthodontic results are more likely to be unstable than to be stable" In these authors‘ opinion, the only way to ensure continued satisfactory alignment after treatment would be to provide retention for life. www.indiandentalacademy.com
  81. 81. • Essam A. Al Yami, AJO 1999; did a study to evaluate stability of orthodontic treatment on long term www.indiandentalacademy.com
  82. 82. • Dental casts of 1016 patients were evaluated for the long-term treatment outcome using the Peer Assessment Rating (PAR) index. • The PAR index was measured at the pretreatment stage (n = 1016), directly posttreatment (n = 783), postretention (n = 942), 2 years postretention (n = 781), 5 years postretention (n = 821), and 10 years postretention (n = 564). www.indiandentalacademy.com
  83. 83. • The mean absolute change as well as the percentage of change per year (relapse) related to the postretention stage was calculated. • An analysis of variance was applied to compare the mean change in the PAR between cases with and without a fixed retainer at the postretention stage and up to 10 years postretention. www.indiandentalacademy.com
  84. 84. • The results indicate that 67% of the achieved orthodontic treatment result was maintained 10 years postretention. • About half of the total relapse (as measured with the PAR index) takes place in the first 2 years after retention. www.indiandentalacademy.com
  85. 85. • All occlusal traits relapsed gradually over time but remained stable from 5 years postretention with the exception of the lower anterior contact point displacement, which showed a fast and continuous increase even exceeding the initial score. www.indiandentalacademy.com
  86. 86. • The mean age at the posttreatment stage was 15.6 ± 3.0 and at the postretention stage 16.7 ± 3.1. • This indicates that there were cases reaching the postretention stage while some potential growth was still present. • This remnant of growth may influence the stability of the result of the orthodontic treatment. www.indiandentalacademy.com
  87. 87. • Sixty-seven percent of the achieved orthodontic treatment result was maintained 10 years postretention. • Relapse should not be contributed to orthodontic treatment alone but also of physiologic and pathologic changes in the dentition and surrounding tissues during those years. www.indiandentalacademy.com
  88. 88. • It has been shown by Behrents Scholas and Van • • der Linden that considerable craniofacial alteration occurs beyond 17 years of age in human beings. This is accompanied by compensatory changes in the dentition. The orthodontist has little control over these biologic processes The results of this type of studies enable clinicians to inform their patients before treatment about treatment limitations in order to give them more realistic expectations. www.indiandentalacademy.com
  89. 89. • In a recent, comprehensive review of the orthodontic literature regarding relapse, Shah (AJO 2003) found that postretention relapse of the mandibular incisors was often incorrectly attributed to misdiagnosis, improper treatment, or inappropriate treatment mechanics.' www.indiandentalacademy.com
  90. 90. • Mandibular incisor relapse is almost inevitable, he pointed out, regardless of the timing of orthodontic treatment and the techniques employed. • Even the extraction of premolars to alleviate crowding does not appear to make corrections any more stable.". www.indiandentalacademy.com
  91. 91. Factors affecting stability on long term • • • • • • Arch perimeter Arch length Inter canine width Inter proximal force Circumferential Supracrestal Fiberotomy Bone morphology www.indiandentalacademy.com
  92. 92. • The main reason for a relapse of crowding is the tendency for dental arch perimeter or length and intercanine width to decrease and constrict over time. • This pattern has teen found in treated as well as untreated normal subjects'; in fact, as early as 1959, Moorrees demonstrated a reduction in arch length from the mixed dentition through the transitional dentition and into early adulthood." www.indiandentalacademy.com
  93. 93. • Gianelly. and others ( AJO 2006) have argued that the stability of orthodontic treatment can be improved by preserving mandibular intercanine width. • This means that any increase in mandibular intercanine dimension is inherently unstable. www.indiandentalacademy.com
  94. 94. • Blake and Bibby (AJO 1998) listed six major criteria for the stability of finished orthodontic cases; • I. The patient's pretreatment lower archform should be maintained to the extent possible. • 2. The original lower intercanine width should be maintained as much as possible, because expansion of lower intercanine width leads to the most predictable of all orthodontic relapse www.indiandentalacademy.com
  95. 95. • 3. Mandibular arch length decreases with time. • 4. The most stable position of the lower incisor is its pretreatment position; advancing the lower incisors can seriously compromise stability. www.indiandentalacademy.com
  96. 96. • 5. Fiberotomy is an effective means of reducing rotational relapse. . • 6. Lower incisor reproximation can improve long-term post-treatment stability www.indiandentalacademy.com
  97. 97. Inter-proximal force • A 'continuous, compressive inter proximal force (IPF), originating in the periodontium and acting on adjacent teeth at their contact points, may be responsible for some long-term arch constriction. www.indiandentalacademy.com
  98. 98. • Southard and colleagues (AJO 1990) found a significant correlation between mandibular anterior malalignment and IPF, • It has been suggested that if IPF does have an influence on dental alignment, it probably acts in conjunction with lip and cheek forces to collapse the arch. • These forces are opposed by the tongue, which tends to expand the arch. www.indiandentalacademy.com
  99. 99. • It follows that the influence of IPF should be more evident in the anterior segment of the arch, where the contact points are narrower, the crowns more tapered, and the expansive force of the tongue more intermittent than in the posterior regions. • Perhaps for this reason, lower incisor reproximation can counteract‘ IPF by slightly narrowing the teeth and by broadening their contacts to resist contact slippage. www.indiandentalacademy.com
  100. 100. circumferential supracrestal fiberotomy (CSF) • Reorganization of the periodontal ligament occurs over a three-to-four month period, whereas the gingival collagen fiber network typically takes four to six months to remodel, and the elastic supracrestal fibers remain deviated for more than 232 days www.indiandentalacademy.com
  101. 101. • Edwards found circumferential supracrestal fiberotomy (CSF) somewhat more effective in preventing- pure rotational relapse than in reducing labiolingual relapse over the long term, and more successful in the maxillary anterior segment than in the mandibular anterior segment • Significant and unpredictable individual tooth movements were still observed after CSF. www.indiandentalacademy.com
  102. 102. Bone morphology • The effect of the amount and structure of • mandibular bone on mandibular incisor stability has recently been investigated in a case-control study at the University of Washington. After measuring trabecular bone structure and cortical bone thickness in both relapsed and stable subjects, Roth concluded that patients with thinner mandibular cortices are at ! increased risk of dental relapse. www.indiandentalacademy.com
  103. 103. • Boese (AO 1980) found an improvement in post-treatment stability of the mandibular anterior segment, without retention, when fiberotomy and reproximation were used in combination with overcorrection and selective root paralleling. www.indiandentalacademy.com
  104. 104. Consequences of long term wear of retainers www.indiandentalacademy.com
  105. 105. • The consequences of long-term fixed retainer • wear have been a concern. Over a six-month retention Heier et al (AJO 1997) found limited gingival inflammation with either. Hawley type removable or bonded lingual retainers!' Although they noted slightly more plaque and calculus on the lingual surfaces in the fixed retainer group, this did not result in more significant gingival inflammation. www.indiandentalacademy.com
  106. 106. • In a longer-term study, Artun (AJO 1984 ) showed that the presence of a bonded lingual retainer for as long as eight years and the occasional accumulation of plaque and calculus gingival to the retainer wire caused no apparent damage to the hard and soft tissues. www.indiandentalacademy.com
  107. 107. • Some authors have contended that a patient • • with reduced periodontal support may be better off with a fixed retainer. A removable retainer may produce "jiggling" forces that can compromise healing and bone regeneration, whereas a fixed retainer can serve as a periodontal splint. In addition, there is no patient compliance issue with a fixed retainer, and minor settling of the posterior occlusion can occur. www.indiandentalacademy.com
  108. 108. Third molar and mandibular arch stability www.indiandentalacademy.com
  109. 109. • The justification often given for extraction of third molars at age 18 to 22 is the avoidance of mandibular incisor relapse and irregularity. www.indiandentalacademy.com
  110. 110. • Bergstrom and Jensen (Dent Abstr 1961) studied sixty subjects with unilateral molar agenesis and noted greater crowding in the quadrants in which third molars were present than in those in which third molars were missing. www.indiandentalacademy.com
  111. 111. • Sheneman In an investigation of 49 patients a • mean of 66 months after orthodontic therapy, The sample included eleven patients with third molars in bilateral occlusion, thirty-one patients with bilateral third molar impaction, and seven patients with bilateral third molar agenesis • He concluded that patients with third molars congenitally missing showed greater dental stability than those in whom third molars were present. www.indiandentalacademy.com
  112. 112. • Lindquist and Thilander (ajo 1982) evaluated a sample of 23 males and 29 females with bilateral mandibular impaction of third molars. The impacted third molar was removed on one side, and the contra lateral quadrant was used as a control. www.indiandentalacademy.com
  113. 113. • Although they found evidence of less crowding on the extraction side, in 70% of the patients the investigators were not able to use their analysis of variables to predict which persons would react favorably. www.indiandentalacademy.com
  114. 114. • In a longitudinal study of 61 pairs of twins observed at 12 to 15 years of age and again at the age of 26 to 30 years, Lundstrom A (Dent Pract 1969 ) found a reduction of spacing with an increase in crowding with age, but he found no relationship between third molar agenesis and these observed changes in arch dimension www.indiandentalacademy.com
  115. 115. • In 1973 Kaplan (AJO 1974) studied postretention crowding in a group of 75 orthodontically treated patients. • He found that, although some degree of lower incisor crowding occurred in the majority of patients, it was not significantly different in subjects whose mandibular third molars were bilaterally erupted, impacted, or congenitally absent. www.indiandentalacademy.com
  116. 116. • In addition, he found that changes in mandibular arch length, width, and molar and incisor position were not significantly different among the three groups. • In conclusion, Kaplan stated that the presence of third molars does not influence postretention changes in arch dimension, tooth position, or mandibular incisor crowding. www.indiandentalacademy.com
  117. 117. CURRENT VIEWS( JCO 2007) • The concept that mesial pressure exerted by • impacted or erupting third molars may alter mandibular eruption patterns and cause decreases in arch length is not substantiated The clinician should make decisions relative to the timing of third molar extraction on the basis of potential development of pathosis, technical considerations of the surgical procedure, and long-term periodontal implications rather than potential impact on mandibular incisor crowding. www.indiandentalacademy.com
  118. 118. CONCLUSION • Usually, the goal of orthodontic treatment is to • • produce a normal or so called ideal occlusion that is morphologically stable and esthetically and functionally well adjusted. There is, however, a large variation in treatment outcome because of the severity and type of malocclusion, treatment approach, patient cooperation, and growth and adaptability of the hard and soft tissues. Follow-up studies of treated cases have shown that although ‘ideal’’ occlusion and dental alignment have been achieved, there is a tendency for relapse toward the original malocclusion www.indiandentalacademy.com
  119. 119. REFERENCES:1. Polson AM, Subtelny JD, Meitner SW, Polson AP, Sommers EW, Iker HP,-Long-term periodontal status after orthodontic treatment. Am J Orthod Dentofacial Orthop. 1988 Jan;93(1):51-8. 2. Zachrisson B, Alnaes L. Periodontal condition in orthodontically treated and untreated individuals. I. Loss of attachment, gingival pocket depth and clinical crown height. Angle Orthod 1973;43:402-11 www.indiandentalacademy.com
  120. 120. 3. Trossello, V. K., and Gianelly, A. A.: 4. Orthodontic treatment and periodontal status, J. Peridontol. 50:665-671. 1979. Corbett K. Stephens, Jimmy C. Boley, Rolf G. Behrents, Richard G. Alexander, and Peter H. Buschange --Long-term profile changes in extraction and nonextraction patients--- (Am J Orthod Dentofacial Orthop 2005;128:450-7) www.indiandentalacademy.com
  121. 121. 5. Paquette DE, Beattie JR, Johnston LE. A long- 6. term comparison of nonextraction and premolar extraction edgewise therapy in “borderline” Class II patients. Am J Orthod Dentofacial Orthop 1992;102:1-14. Luppanapornlarp S, Johnston LE Jr. The effects of premolar extraction: a long-term comparison of outcomes in “clear-cut” extraction and nonextraction Class II patients. Angle Orthod 1993;63:257-72. www.indiandentalacademy.com
  122. 122. 7. Bishara SE, Cummins DM, Jakobsen JR, 8. Zaher AR. Dentofacial and soft tissue changes in Class II, Division 1 cases treated with and without extractions. Am J Orthod Dentofacial Orthop 1995; 107:28-37. Zierhut EC, Joondeph DR, Årtun J, Little RM. --Long-term profile changes associated with successfully treated extraction and nonextraction Class II Division 1 malocclusions. Angle Orthod 2000;70:208-19. www.indiandentalacademy.com
  123. 123. 9. Andrés De La Cruz R., Paul Sampson, Robert M. Little, Jon Årtun, Dr Odont, and Peter A. Shapiro ---Long-term changes in arch form after orthodontic treatment and retention ---AM J ORTHOD DENTOFAC ORTHOP 1995 May • Volume 107 • Number 5 :518-30.) www.indiandentalacademy.com
  124. 124. 10. Little RM, Wallen TR, Riedel RA.- Stability and relapse of mandibular anterior alignment-first premolar extraction cases treated by edgewise orthodontics. AM J ORTHOD 1981;80:349-63 11. Felton MJ, Sinclair PM, Jones DL, Alexander RG. A computerized analysis of the shape and stability of mandibular arch form. Am J Orthod Dentofac Orthop 1988;92:478-83 www.indiandentalacademy.com
  125. 125. 12.Lee RT--. Arch width and form: a review. Am J Orthod Dentofacial Orthop. 1999;115:305–313. 13. Christopher G. Cameron, et al-Long-term effects of rapid maxillary expansion: A posteroanterior cephalometric evaluation-Am J Orthod Dentofacial Orthop 2002;121:129-35 www.indiandentalacademy.com
  126. 126. 14.Theodosia Bartzelaa; Irmtrud Jonasb-- Long-term Stability of Unilateral Posterior Crossbite Correction-- Angle Orthodontist 2007 , Vol 77, No 2, 237243 15.Geran RG, McNamara JA Jr, Baccetti T, Franchi L, Shapiro LM. --A prospective long-term study on the effects of rapid maxillary expansion in the early mixed dentition.--Am J Orthod dentofacial Orthop. 2006;129:631–640. www.indiandentalacademy.com
  127. 127. 16. Essam A. Al Yami, Anne M. Kuijpers-Jagtman, and Martin A. van ‘t Hof, ---Stability of orthodontic treatment outcome: Follow-up until 10 years postretention-- Am J Orthod Dentofacial Orthop 1999;115:300-4 17. Shah AA –Postretention changes in mandibular crowding- a review of literature—Ajo 2003;124; 298308 18. Gianelly A; -Evidenced based therapy ; an orthodontic dilemma- AJO 2006 ;129 page 596-598. www.indiandentalacademy.com
  128. 128. 19. Blake M and Bibby K- Retention and stability : A review of literature; AJO 1998 ;114; 299-306. 20. Heier et al;-Periodontal implications of bonded versus removal retainers; AJO;1997;112;607616. 21. Årtun--Caries and periodontal reactions associated with long-term use of different types of bonded lingual retainers AJO-DO 1984 Aug Volume 86;112 – 118. www.indiandentalacademy.com
  129. 129. 22.Ades, Joondeph, Little, --A long-term study of the relationship of third molars to changes in the mandibular dental arch -AM J ORTHOD DENTOFAC ORTHOP Volume 1990 Apr (323 - 335): 23.Lindquist B, Thilander B. Extraction of third molars in cases of anticipated crowding in the lower jaw. AM J ORTHOD 1982;81:130-9. www.indiandentalacademy.com
  130. 130. 24. Lundstrom A.. Changes in crowding and spacing of the teeth with age. Dent Pract 1969;19:218-24 25. Kaplan R. Mandibular third molars and postretention crowding. AM J ORTHOD 1974;66:411-30. 26. L. Bondemark; Anna-Karin Holm; Ken Hansen et al --Long-term Stability of Orthodontic Treatment and Patient Satisfaction Angle Orthodontist, 2007 Vol 77, No 1, 181-191. 27. Rinchuse et al- Orthodontic retention and stability-a clinical perspective- JCO March 2007 vol XLI, no.3, 125-132. www.indiandentalacademy.com
  131. 131. Thank you www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com