SEMINAR ON ADULT ORTHODONTICS

Biomechanical modifications made to accommodate orthodontic treatment of adult dentitions are generally minor and adhere to the basic laws of physics as they apply to orthodontic tooth movement.

Some adult presentations necessitate changes in treatment strategy from what would otherwise be employed in adolescent patients to achieve similar goals.

In other cases, objectives themselves may need to be modified because of lack of growth potential, constraints of treatment mandated by the patient or the presence of multiple missing or compromised teeth.

1. Adult orthodontics DR SHEHNAZ JAHANGIR FINAL YEAR MDS DEPT. OF ORTHODONTICS NICDS

2. Introduction History Difference Between The Adolescent And The Adult Limitations Of Treatment In Adults Diagnosis And Adult Orthodontics Treatment Planning For Adult Patients Biomechanical Considerations In Adult Orthodontics

3. Bonding in adults Adjunctive Treatment Procedures Comprehensive Treatment For Adults Surgical Orthodontics Psychological considerations for Adults Finishing in adults Retention plan for adults Conclusion References

4. Introduction The frequency of malocclusion in adults is equal or greater than that observed in children and adolescents. ( Stenvik EJO 1997) Studies in Sweden and Holland reported that the prevalence of malocclusion ranged between 40% and 76% in adults ( Salonen EJO 1992)

5. During the past 20-30 yrs, there has been an increase in the number of adults seeking orthodontic treatment. Before 1970, approximately 5% of the American orthodontic patients were adults. By 1980’s , adults were estimated to account for 20 -25% of orthodontic patients.

6. Increased interest of the adult patient Melsen et al - Innovations in appliance placement techniques – Direct bonding, lingual/invisible appliances. Innovations in material research – ceramic brackets & tooth coloured wires.

7. Role of family dentist - Increased desire of restorative dentists and patients for treatment of dental mutilation problems using tooth movement rather than prostheses. Role of media, visual as well as print - Articles in magazines, news paper as well as community programs have increased patient awareness towards health & esthetics . Better management of TMJ dysfunction.

8. More effective management of skeletal jaw dysplasias with advanced orthognathic surgical techniques. Reduced vulnerability to periodontal breakdown as a result of improved tooth relationships and occlusal functions. A broader understanding of the biology of the tooth movement especially with regard to age changes. Ingenious approaches to anchorage management such as implants.

9. HISTORY Kingsley (1880) suggested that there were hardly any limits to the age of when tooth movement might not succeed. In contrast Mac Dowell (1901 ) was of the opinion that after 16 years of age, orthodontic treatment was also impossible owing to the development of the glenoid fossa , the density of the bones and muscles of mastication.

10. Lischer (1912) believed that the period between 6–14 years was a golden age of treatment. Case (1921) demonstrated treatment possibilities in aged and periodontally affected patients. Reidel & Dougherty (1976) predicted the status of adult orthodontic treatment today and stresses the need for adjunctive orthodontic services provided by periodontist and restorative dentist.

11. Indications Improvement of tooth-periodontal tissue relationship. Establishing an improved plane of occlusion to distribute the forces of occlusion better. Balancing the existing space for better prosthetic replacement. Improve occlusion and coordination between the muscle and TMJ. Improve patient esthetic.

12. Contraindications Severe skeletal discrepancies. Advanced local or systemic disease. Excessive alveolar bone loss. Poor stability prognosis – tooth movement into unfavorable positions. Lack of patient motivation & co-operation, resistance to wear the appliance.

13. Inability to prevent excessive hard/soft tissue destruction. Inadequate space for tooth movement. Movement of teeth against occlusal opposition or into occlusal trauma. No improvement in PDL health, function/esthetics. Negative anchorage potential – movement of teeth against inadequate anchorage.

14. Classification: Adult patients fall into 2 different groups ( Proffit ) Younger adults - A ge 20s to early 40s An older group – 40s to 60s

15. Younger Group Goal – Comprehensive treatment &maximum possible improvement; improved quality of life .

16. Reasons for not receiving orthodontic treatment early 1) Did not desire treatment. 2) Were not aware of orthodontic treatment. 3) Parents could not afford. 4) Were not given proper advise by family dentist. 5) No orthodontist located in the vicinity.

17. Incomplete orthodontic treatment when younger or were uncooperative. Had orthodontic treatment as children but relapse occurred. More conscious of appearance with age. Anterior teeth started to crowd or minor crowding becomes worse. Dis -satisfaction with the outcome of previous treatment.

18. Older Group Goal - Maintain proper dental health. For easy & effective control of disease & restoration of missing teeth. As an adjunctive procedure to the larger periodontal & restorative goals ; not necessarily interested in the ideal result.

19. Reasons for seeking orthodontic treatment: 1) Malposed teeth contributing to PDL disease. 2) Increased difficulties with mastication. 3) Anterior spaces enlarging or new ones developing. 4) For better tooth positioning prior to prosthetic preparation. 5) Tooth interferences & mandibular slide causing TMJ problems.

20. Difference Between The Adolescent And The Adult Growth Factors Adolescents : Growth is left - orthopedic treatment option is available - stable correction of skeletal discrepancy is possible. Adults: No growth - surgical procedures - Moderate to severe skeletal disharmonies Dental camouflage - Mild skeletal problems.

21. Dentofacial esthetics Adolescents: Reasonable concern, frequently matched to severity of the condition. Adults: seek treatment more often for esthetic reasons and hence is likely to have unreasonable expectations about the outcome of the treatment. Periodontal susceptibility Adolescents : More resistant to bone loss as a result of periodontal disease; but highly susceptible to gingival inflammation. Adults: high degree of susceptibility to bone loss as a result of periodontal disease .

22. Neuromuscular Maturity Adolescents: Significant potential for adaptability of the stomatognathic system, allowing variety of biomechanical choices. Adults: Mechanical options are limited due to lack of neuromuscular adaptability; also tendency toward transitional occlusal trauma, coinciding with orthodontic occlusal changes. Rate of tooth movement Adolescents: Predictable and rapid, particularly during eruptive stages when permanent root development is not yet completed. Adults: Initially somewhat slower, but more rapid and predictable after initial movement has begun.

23. Extractions Adolescents: Four premolar extractions frequently carried out to resolve crowding symmetrically; space gaining techniques are also available. Adults: Four first premolar extractions are used less frequently to resolve crowding; asymmetric extractions and stripping of over bulked restorations is carried out. Irreversible damage to periodontal tissues or to adjacent teeth may force orthodontist into unusual treatment plans for adults; careful analysis may lead to strategic extraction to solve alignment problems, as well as to eliminate existing damaged teeth.

24. Orthodontic anchorage Anchorage Potential Adolescents: More frequent incorporation of headgear to maximize anchorage and retraction of anterior teeth. Adults: Greater anchorage potential because of completely erupted first and second molars, the use of implants and several molar distalization techniques can be used as an alternative.

25. Missing Teeth Adolescent: Early treatment control during eruption stages facilitates space closure without prosthesis. Adults: Frequent problems involving anterior and posterior teeth require restorative commitment for treatment planning and temporary tooth replacement during fixed appliance therapy, implants can be used as restorative option.

26. Patient compliance Lack of compliance and cooperation in a child patient is a common problem. Psychologically, adults are well motivated, appreciative and compliant during orthodontic treatment, more cleaner, more careful, more punctual, prompt paying. Some adult patients may, however, have unreal expectations about the outcomes of orthodontic treatment. Both limitations and reasonable outcomes must be clearly communicated to such patients prior to initiation of the treatment to prevent disappointment at the conclusion of the treatment.

27. Comparison Factors Adolescents Adults Dental caries More susceptible Recurrent decay restorative failures, root decay& pulpal pathosis PDL disease Resistance to bone loss Susceptible to gingival inflammation Susceptible to bone loss TMJ adaptability High Symptoms with dysfunction Occlusal wear Infrequent Increased enamel wear with adverse change in supporting tissue.

28. Limitations Of Treatment In Adults There are two categories of factors:- A. Intrinsic - Biological B. Extrinsic - Biomechanical The marked intrinsic limitation is the lack of growth in adults; skeletal discrepancies can therefore be corrected by Orthognathic surgery. Since orthodontic tooth movement is a result of cellular reaction to a mechanical stimulus, the cellular response may vary with the health and age of the individual

29. Periodontium Reitan 1954 found Bone apposition on the tension side after the application of 50 gm of continuous force in a 39-year-old man, however, was evident only after 8 days of force application. This lag in bone apposition did not occur in a 12-year-old boy subjected to the same regimen. Reitan concluded that there is a measurable delay in bone formation in the adult that is not observed in the child.

30. According to Norton insufficient source of progenitors cells due to less vascularity with increasing age account for the delayed response to mechanical stimulus. Histologic response in the adult - begin more slowly, but once proliferation of connective tissue cells and vascularity has occurred - tooth movement is appear normal. Graber - adults are more prone to root resorption - their reduced vitality (as compared with the young growing child) and lack of ability to deposit new cementoid layer and protect the resorbing root surface.

31. Alveolar bone Cortical bone becomes denser while the spongy bone reduces with age and the structure of bone changes from that of a honeycomb to a network. (Liu et al 1977 J Dent Res)

32. Apical displacement of the marginal bone level is a local factor that influences the biological backgrounds for tooth movement in adults. The marginal bone loss is age related but is also the result of progressive periodontal disease. Teeth Adults are also more likely to have missing teeth, teeth reduced in dimension due to attrition as well as teeth with large restorations.

33. Extrinsic Limitations Invariably caused by our inability to adapt the force system to produce the desired stimulus. Since the adult patient posses so many problems to the orthodontist, Barrer and Chasens et al suggested that it was advisable to defer orthodontic treatment when faced with the following situation. Uncontrolled/advanced local or systemic disease. Excessive alveolar bone loss. Severe skeletal discrepancy. Inability to prevent excessive hard/soft tissue destruction. Movement of teeth against occlusal opposition or into occlusal trauma. No improvement in periodontal health, function or esthetics possible.

34. Diagnosis And Adult Orthodontics Careful diagnosis and treatment planning on a multidisciplinary basis is required to treat adult patients. Adult may exhibit a potential for such pathological changes as knife-edge ridges, increased cortical thickness, buried roots, impactions, periodontal breakdown, TMJ problems. Osteoporosis, diabetes mellitus, hormonal, vitamin or systemic disorders common to the adult, necessitate more careful and extensive diagnosis evaluations.

35. The standard diagnostic aids such as case history, clinical examination and study casts, radiographs and photographs are mandatory. The problem oriented diagnostic approach as described by Proffit and Ackerman is strongly recommended to ensure that no aspect of the patient need is neglected.

36. Periodontal Diagnosis Assess the patients potential for bone loss and gingival recession during orthodontic tooth movement. Patient should be screened for the risk factors of periodontal disease. Pre treatment consultation with the periodontist should be routine and orthodontic objectives be altered according to his advice. Movement of teeth in the presence of periodontal inflammation will result in an increased loss of attachment and irreversible crestal loss.

37. Temporomandibular Disorder Diagnosis Signs & symptoms of Temporomandibular Disorder often increase in frequency and severity during adult treatment. So it is imperative for the orthodontist to be familiar with their diagnostic and treatment parameters. Adult patients especially females with TMJ sign and symptoms should be evaluated regarding exposure to stress and her handling of stress.

38. In a prevalence study, Schiffman and Friction found that the group of patients whom they treated for TMD problems were divided into several types: Muscle disorders - 23% Joint disorders - 19% Muscle–joint combinations - 27% Normal - 31%

39. Treatment Planning For Adult Patients Musich 1986 studied 1400 adults and demonstrated the scope of treatment planning considerations. About 70% to 75% of the sample required multidisciplinary management to attain optimal treatment outcomes. SPG – solo provider group (Orthodontist alone) DPG – dual provider group (Orthodontist & Restorative dentist) MPG – multiple provider group

40. Factor in selection of treatment plan Existing oral pathology Skeletal relationship Biological considerations Therapeutic approaches available Extraction (v/s) Non extraction therapy Anchorage requirements Missing teeth (Dental mutilation)

41. Existing oral pathology : include recurrent decay, restorative failures, root decay with pulpal involvement periodontal bone loss, TMJ symptoms and retained roots. These conditions should be treated first before proceedings to orthodontics with a multi-disciplinary approach. Skeletal Relationships : No growth with minimal skeletal adaptability. Therefore surgical procedures are frequently required to correct moderate to severe skeletal disharmonies.

42. Biological Considerations : Neuromuscular maturity – mechanical options for an adult are limited because of lack of neuromuscular adaptability. There is a tendency towards iatrogenic transitional occlusal trauma, coinciding with orthodontic occlusal changes. Periodontal susceptibility – higher degree of bone loss as result of periodontal disease can be evidenced during orthodontic therapy. Therapeutic approaches available : Restorative dentistry : frequently required. Orthognathic surgery : needed in 10 to 20% of adults.

43. Extraction v/s Non Extraction Therapy Classical 4 premolars extraction to resolve crowding rarely done. Upper premolars extraction alone is a common alternative. Anchorage requirements Adults have greater anchorage potential because of completely erupted 1st, and 2nd molars On the other hand 40% of the adults patient are partially edentulous.

44. Implants for orthodontic anchorage - plays an important role in their treatment. Osseo integrated implants, Onplants , Zygoma ligatures, Titanium miniplates and Titanium Miniscrews can be used efficiently in adults. Missing teeth (Dental mutilations) In adults, most of these spaces cannot be closed without a prostheses either a temporary tooth replacement during Fixed appliance therapy or fixed prostheses later. Implants have become a reliable alternative. Therefore a multidiscipilinary team approach is required for their comprehensive rehabilitations.

45. Treatment Objectives According to ACKERMAN , adult orthodontics is concerned with a striking balance between “achieving optimal proximal and occlusal contacts of the teeth, acceptable dentofacial esthetics, normal function and reasonable stability”. Jackson’s Triad of traditional objectives ( ie ) esthetics, function and structural balance are neither realistic nor always necessary for all adult patients. Class I occlusal goals can be considered over treatment for patients under multiple provider group.

46. Orthodontist commonly tries to achieve the following objectives when treating adult patients: Parallelism of abutment teeth Permits insertion of multiple unit replacements and does not require excess cutting or devitalizations during abutment preparation.

47. Most favorable distribution of teeth Teeth should evenly distributed for replacement of fixed and removable prostheses in the individual arches. Adequate embrasure space and proper root position It allows for better placement of restorations and Interproximal cleaning becomes easier.

48. Adequate occlusal plane and potential for incisal guidance at satisfactory vertical dimension In a mutilated dentition with bite collapse, adequate occlusal plane can be established by giving Hawley bite plane with the platform of anterior plane adjusted at right angles to long axis of lower incisors. This allows centric relations at an acceptable Vertical dimension. Bite plane also allow simultaneous Bilateral neuromuscular activity. Curve of spee should be mild to flat bilaterally. This is difficult to achieve if there are supraerupted molars.

49. Better lip competency and support In cases requiring anterior restorations, retraction is recommended to achieve lip competency. Lower incisors extending 1 to 2mm into the palatal mucosa (Class II Div 1 cases) cause soft tissue irritations. So their IMPA is increased (105° to 120°) to establish incisal guidance. Adequate lip support is created to prevent wrinkling which makes the face prematurely aged.

50. Improved crown / root ratio : If bone loss is isolated on a single tooth, length of clinical crowns is reduced and tooth can be erupted orthodontically thereby improving the crown / root ratio.

51. Improvement or correction of mucogingival and osseous defects. Repositioning of prominent teeth will improve the gingival topography. In adults the goal should be to Level the crestal bone between adjacent cemento -enamel junction: favorable osseous and soft tissues changes will diminish the need for muco -gingival surgery.

52. Bonding In Adults Today’s orthodontic practice includes a larger proportion of adult patients and it is possible that crowns, bridges (porcelain, gold, non-precious metals) or restorations (amalgam, composite) may require to be bonded

53. For metal brackets and amalgam restorations: Microetching (for about 3 seconds with 100 μm aluminium oxide powder) is essential for bonding to large amalgams, gold or other non-precious metals. The abrasive particles create a retentive surface to which bonding with highly filled composite is greatly enhanced, at least 300%.

54. For bonding to porcelain surfaces conventional acid etching is ineffective for mechanical retention of brackets: the most commonly used etchant is 9.6% hydrofluoric acid in gel form for 2–4 minutes. The hydrofluoric acid prepares all porcelain surfaces for the application of selected conditioner and adhesive (micro-mechanical bond). The use of a heavily filled resin adhesive after microetching , with the application of hydrofluoric acid and silane primer (chemical bond), provides the highest shear bond strength.

55. BiomechanicalConsiderations In Adult Orthodontics A precise biomechanical control of tooth movement is necessary to achieve correction of malocclusion in all 3 dimensions. The forces used in the adults should be at a lower level than those used in children. The initial forces should further be kept low because the immediate pool of progenitor cells available for resorption are low.

56. In adults with periodontal involvement where bone has been lost, Periodontal ligament area decreases with the results that the same force against the crown would produce greater pressure in the Periodontal ligament. The absolute magnitude of force must therefore be reduced. Marginal bone loss results in crest being displaced apically so greater will be the tipping moment for same force. A counter COUPLE is necessary to affect BODILY movement.

57. Force levels should be decreased but the magnitude of the couple applied to counteract the tendency to tip should not be decreased proportionally. In the presence of marginal bone loss, light continuous intrusive forces should be maintained.

58. Classification of Adult Patients (based on treatment)

59. According to Proffit , adult orthodontic procedure can be conveniently classed into three categories Adjunctive treatment Comprehensive treatment Surgical-orthodontic treatment

60. Adjunctive Treatment Comprehensive Treatment Goal To facilitate disease control To achieve ideal occlusion and restoration of function Extent of Appliance Less than full arch One or both arches Time Frame Six Months or longer Eight to 36 months Type of problem Extrusion Open Bite Molar uprighting Deep Bite Space Redistribution Class II/III Malocclusion Incisor Alignment Skeletal excess/ deficiency

61. Adjunctive Treatment Procedures Definition: Tooth movement carried out to facilitate other dental procedures necessary to control disease & restore function. Goals of Adjunctive Treatment Procedures Facilitate restorative treatment Improve Periodontal ligament health Favorable crown : root “Goal of Adjunctive Treatment Procedures is to provide a physiologic occlusion & facilitate other dental treatment & has little to do with Angle’s concept of an ideal tooth relationships.”

62. Timing & sequence of treatment Active disease Disease control Establish occlusion Definitive restorative Rx Maintenance Re-evaluate stabilize

63. Biomechanical considerations Control of anchorage requires that anchor teeth not be allowed to tip. This is major reason that adjunctive treatment usually requires a fixed appliance. Edgewise appliance brackets of 0.022 slot dimension are used preferably . Twin bracket prevents undesirable rotations and tipping. Larger slot allows the use of stabilizing wires which are stiffer.

64. Bracket are placed in an ideal position only on teeth to be moved, remaining teeth incorporated in the anchor system and are bracketed so the archwire slot are closely aligned. Passive engagement of the wires to anchor teeth produce minimal disturbance of teeth.

65. Various Adjunctive Treatment Procedures Uprighting of the posterior teeth Loss of a lower molar can lead to tipping and drifting of adjacent teeth, poor interproximal contacts, poor gingival contour, reduced interradicular bone, and supra eruption of unopposed teeth. Since the bone contour follows the Cemento -Enamel Junction, pseudopockets form adjacent to the tipped teeth.

66. The decision is to be made whether to upright the tipped teeth by distal crown movement or by mesial root movement. The decision will depend on the position of the opposing teeth, the occlusion desired, the anchorage available, and most importantly the contour of the bone in the edentulous ridge area.

67. Appliances for molar uprighting

68. Duration Distal crown tipping faster than mesial root movement usually 8-10 weeks . Occlusal interferences –prolong Rx time Up righting 2 molars with mesial root movt may take 20-24 wks. Retention

69. Forced Eruption 1 st described in 1973 by Heithersay . Teeth with defects in the cervical third of the root. Isolated tooth with one or two walled vertical periodontal defects. Result of horizontal or oblique fracture internal or external resorption Decay pathologic perforation or periodontal disease.

70. Advantages : a good access for endodontic and restorative procedures or to reduce pocket depth. Crown margins can be placed on sound tooth structure. Uniform gingival contour maintained-improved esthetics . Alveolar bone height & bony support of adjacent teeth is not compromised. Apparent crown length is maintained. Maintains biologic width.

71. The distance the tooth to be extruded is determined by: Location of the defect Space to place the margin of the restoration so that it is not at the base of the gingival sulcus ( at least 1mm above the base of sulcus ) Allowance for the biological width of the attached gingiva (2mm) crown-root ratio at the end of treatment should be 1:1 or better.

72. Correction of Crossbite If only one or two teeth are involved, the crossbites usually results from displacement of crowded teeth or ectopic eruption. If a group of teeth are involved it is more likely that crossbite is a skeletal problem and will not respond to limited orthodontic treatment.

73. Through the bite" or cross elastics produce both horizontal and vertical forces and will extrude the teeth while moving them buccolingually .

74. Comprehensive Treatment For Adults Comprehensive orthodontic treatment aims at making the patient’s occlusion as ideal as possible, repositioning all or nearly all the teeth in the process. Comprehensive treatment is possible for adults, but it poses some special problems that do not exist for younger patients. The following considerations should be kept in mind while treating adults Lack of growth. Heightened possibility of periodontal disease. Different motivations for seeking orthodontic treatment.

75. While treating adults- Appliance should be simple in order to elicit maximum patient cooperation. Appliance should exert light forces for best physiological response. Appliance should be long acting to decrease the number of appointments. Appliance should be invisible as possible .(plastic, ceramic brackets, fixed lingual appliances) Appliance should be better retained . (fixed)

76. Periodontal Aspects Of Adult Treatment There is no contraindications to treating adults with periodontal disease as long as the disease is under control. Three risk groups are identified in the population Those with rapid progression (10%) Those with moderate progression (80%) Those with no progression despite the presence of gingival inflammation (10%).

77. Minimal Periodontal Involvement Bacterial plaque - main etiological factor - periodontal breakdown For adults orthodontic patient’s gingival recession is to be prevented rather than to try correcting it later. According to the present concept, gingival recession occurs secondary to alveolar bone dehiscence; if overlying tissues are stressed. Stress can be due to Tooth brush trauma Plaque induced inflammation Stretching and thinning of gingiva created by labial tooth movement

78. Moderate Periodontal Involvement Disease control: Preliminary periodontal therapy is preformed which includes meticulous root surface preparative and curettage and patient kept under observation to watch whether the disease is controlled. Treatment procedures like osseous contouring or repositioned flaps to compensate areas of gingival recession are best deferred until final occlusal relationships have been established. Disease control also requires endodontic treatment of any pulpally involved teeth. Temporary restorations (composite resins) are placed to control caries and definitive restorative procedures (cast restoration) are delayed after orthodontic phase of treatment.

79. Fully bonded orthodontic appliance is recommended. Steel ligatures or self ligating bracket are preferred for periodontally involved patients rather than elastomeric rings to retain arch wires. During comprehensive treatment, patient with moderate periodontal problems should be on a maintenance schedule (2 – 4 months interval) . Hygiene aids: Electric tooth brushes, rubber interdental stimulators, proximal brushes and adjunctive chemicals ( eg . Chlorhexidine ) should be considered.

80. Severe Periodontal Involvement The general approach is the same as outlined earlier but Periodontal maintenance schedule is at more frequent intervals (every 4 to 6 weeks). Orthodontic goals modified and forces kept to absolute minimum, because of the reduced area of PDL.

81. Muco -gingival Corrections Attention if paid to 3 factors prior to orthodontic therapy can make the treatment easier and more predictable. Thick tissue gets bunched up and can slow down tooth movement considerably. While uprighting a second or a third molar, these tissue moves coronally on the tooth and a pseudopocket develops. This can become a nidus for bacteria and a potential locus for the apical migration of the attachment. If there is a minimal band of keratinized tissue and the roots move out of the alveolus, there is bound to be recession. Frenal attachments that prevent or slow down tooth movements may be removed during or before tooth movement.

82. Orthodontic Treatment Of Periodontal Defects Advanced Horizontal Bone Loss: One of the most important factors that determines the outcome of orthodontic therapy, is the location of the bands and brackets on the teeth. In a periodontally healthy individual, the position of the bracket is usually determined by the anatomy of the crown of the tooth However, if a patient has underlying periodontal problems and significant alveolar bone loss, the bone level may have receded several millimeters from the CEJ. As this occurs, the crown to root ratio will become less favorable.

83. The orthodontist can correct many of these problems by using the bone level as a guide to positioning the brackets on the teeth. In these situations, the crowns of the teeth may require considerable equilibration. If the tooth is vital, the equilibration should be performed gradually to allow the pulp to form secondary dentin to insulate the tooth during the equilibration process. The goal of equilibration and creative bracket placement is to provide a more favorable bony architecture as well as a more favorable crown to root ratio.

84. Hemiseptal Defect Adult patients may have marginal ridge discrepancies caused by uneven tooth eruption before orthodontic treatment. In these situations, it is important for the orthodontist to assess bite wing or periapical radiographs of these teeth in order to determine the bone level interproximally . If the bone level is oriented in the same direction as the marginal ridge discrepancy, then leveling the marginal ridges will level the bone. However, if the bone level is flat between adjacent teeth, correction of the marginal ridge discrepancy orthodontically will produce a hemiseptal defect in the bone.

85. If the bone is flat and a marginal ridge discrepancy is present, the orthodontist should not level the marginal ridges. In these situations, it may be necessary to equilibrate the crown of the tooth. In some patients, discrepancies may not be of equal magnitude. In these patients, orthodontic leveling of the bone may still leave a discrepancy in the marginal ridges. In these situations, the clinician must not use the crowns of the teeth as a guide for completing orthodontic therapy, instead they should level the bone orthodontically and equilibrate any remaining discrepancies between the marginal ridges.

86. Surgical Orthodontics Correction of severe skeletal deformity in an adult is achieved by surgical means. 10 – 20% of adults fall into this category. Orthognathic surgery can be performed in both jaws and in all 3 planes of space.

87. In Anterio -posterior plane Maxillary Surgery The Lefort I downfracture procedure almost always is used now to reposition the maxilla. If the maxilla is advanced, a graft in the retromolar area or at a step created in the lateral wall usually is required.

88. Mandibular advancement Currently the bilateral sagittal split osteotomy (BSSO) of the mandibular ramus , performed from an intra oral approach, is the preferred procedure for most patients who need mandibular advancement. Mandibular Setback The Bilateral Sagittal Split Osteotomy can be used to move the mandible posteriorly as well, because of excellent control of the condylar segments and osteosynthesis screws can be employed for fixation.

89. The Transoral Vertical Oblique Ramus Osteotomy (TOVRO) is limited to mandibular setback and required full-thickness overlapping of the segments. It requires less time than the sagittal split osteotomy and is less likely to produce neurosensory changes, but jaw immobilization after surgery is necessary and control of the condylar fragment can be difficult.

90. Correction Of Vertical Relationships Maxillary Surgery The contemporary surgical approach to the skeletal open bite (long face) deformity involves a LeFort I downfracture of the maxilla, with superior repositioning of the maxilla after removal of bone from the lateral walls of the nose, sinus, and nasal septum.

91. It is important to shorten the nasal septum or free its base so that the septum is not bent when the maxilla is elevated. The overall facial height is shortened as the mandible responds by rotating upward and forward. Excellent stability of the vertical position of the maxilla is observed post-surgically

92. In contrast, when the maxilla is moved downward to increase face height, it tends to relapse back up, post surgically, so that 20% or more of the vertical change often is lost even when rigid fixation is used. Both the use of more rigid graft materials and simultaneous osteotomy of the mandibular ramus have been reported to improve the stability of downward movement of the maxilla.

93. Mandibular Surgery Patients with a skeletal open bite often have a short mandibular ramus . Surgery to reduce to mandibular plane angle by rotating the mandible down posteriorly and up anteriorly has been found to be highly unstable, because this rotation lengthens the ramus and stretches the muscles of the pterygomandibular sling. The instability is attributed primarily to lack of neuromuscular adaptation in these powerful muscles.

94. Patients with a short face (skeletal deep bite) problem are characterized by a long mandibular ramus , square gonial angle and short nose-chin distance. They are treated best by sagittal split mandibular ramus surgery to rotate the mandible slightly forward and down in the gonial angle area.

95. Correction Of Transverse Relationships Constriction of the maxilla rarely occurs without some coexisting vertical or sagittal problem. Maxillary constriction or expansion can be accomplished easily by segmenting the maxilla in the course of LeFort I downfracture surgery to correct other problems, and this is the usual approach. Expansion is done with parasagittal osteotomies in the lateral floor of the nose or medial floor of the sinus.

96. Surgically assisted palatal expansion, using bone cuts to reduce the resistance without totally freeing the maxillary segments, followed by rapid expansion of the jackscrew, is another possible treatment approach.

97. Genioplasty in Orthognathic Treatment: Lack of surrounding anatomic structures gives the surgeon considerable latitude in alteration of chin morphology, and movement of the chin in all three planes of space is possible.

98. Genioplasty Techniques: For most patients, the preferred approach to genioplasty is a lower border osteotomy to free a wedge shaped portion of the symphysis and inferior border that remains pedicled on the genioglossus and geniohyoid muscles. This segment can be advanced to augment chin contour, shifted sideways to correct asymmetry, or down grafted to increase lower face height. Genioplasty can be used as an Adjunct to Non-extraction Orthodontic Treatment.

99. Traction of an impacted maxillary canine with corticotomy in a 53-year-old patient: Case report dos Santos RM et al , SeminOrthodo 2019 (Vol. 25, No. 2, pp. 165-174). WB Saunders. A 53-year-old female patient with compromised esthetic and mastication due to the premature loss of some permanent molars. she had a bone density scan which ruled out need for bone sparing medication. She reported that she is compliant with vitamin D supplementation and weight bearing exercise to prevent further skeletal bone loss.

100. Extraoral examination showed a symmetric face with normal facial height, straight profile, but absence of passive lip sealing. The smile esthetics were compromised due to the diastema between her maxillary central incisors

101. Intraoral evaluation revealed a mutilated dentition with the absence of teeth #16, 13, 26, 37, 36, 46 & 47. Less than 2mm of keratinized tissue was present in the lower molar edentulous areas. Maxillary right deciduous canine was over retained. There was significant spacing on both arches. Periodontal inflammation was treated with deep scaling root planing , oral hygiene instruction and 3 month professional maintenance regimen. To manage the risk of progressing periodontitis , the patient was regulated to maintain less than 10% of sites with bleeding on probing. Mild gingival recession persisted on teeth #35 and 44, however these sites did not Figure 1.

102. OPG showed that the 13 was impacted in a mesially angulated position, fully overlapping the lateral incisor root and up to 50% of the central incisor root. A mild overall bone loss was also observed. CT images showed that tooth #13 was palatally impacted without damaging the adjacent teeth

103. Two interdisciplinary treatment alternatives were offered to the patient. The first option included the surgical removal of the impacted canine and its implant-supported prosthetic replacement. The second option comprised the orthodontic-surgical treatment, which would skeletal anchorage and application of light-forces to bring the canine into its position in the dental arch.

104. Fixed orthodontic appliances (0.022 Х 0.028- in Mini-master series, American Orthodontics, Sheboygan, WI) were bonded from second molar forward on both arches. Leveling and alignment were performed, adequate space for the impacted canine was opened with the mesial movement of both right lateral and central incisors, which also closed the anterior diastema .

105. Surgical exposure of tooth #13 was completed under LA . A full-thickness flap was raised and a button into which a twisted steel-ligature wire was placed was bonded using self-etching primer ( Transbond Plus Self-Etching Primer, 3M/ Unitek , Monrovia, CA). After confirming that adequate bonding was achieved , alveolar corticotomies were performed in the direction the canine would be moved (Fig. 6A).

106. The canine crown was recovered. Sutures were placed and a self-drilling TAD(1,5 Х 8 mm, Morelli , Sorocaba, SP, Brazil) was inserted between the roots of teeth #17and 15. (Figs. 6B and 7)

107. A light-force was immediately loaded into the TAD and since the root of the impacted canine was in a good position, we decided to initially move its crown distally and away from the lateral incisor root. After radiographically confirming that adequate distal movement was achieved, (Fig. 8)

108. a second canine exposure was performed under local anesthesia to change the position of the button and the direction of the traction force, thus we moved the tooth #13 buccally and occlusally . After 10 months of orthodontic traction, the canine erupted with a 90° rotation and it was derotated into the correct position with elastic chains that generated a binary force system (Fig. 9) and the remaining anterior spaces were subsequently closed. In the mandibular arch, leveling and alignment was performed until a 0.019 Х 0.025-in SS was inserted from right to left second premolars, that was used as anchorage for third molars uprighting , which was performed with 0.017 Х 0.025 TMA cantilevers. After teeth #38 and 48 were fully uprighted . Free gingival grafts were performed in the edentulous areas to reduce the long term risks of peri -implant disease. (Fig. 10A) Four months

109. Psychological Consideration less tolerant of discomfort and more likely to complain about pain after adjustments and about difficulties in speech, eating, and tissue adaptation. Often use less visible orthodontic appliances.

110. Children & adolescents – motivation for orthodontic t/t - parent’s desire; not emotionally involved in their own Rx. Adults – seek ortho Rx because they themselves want something, that is not always clearly expressed - hidden set of motivations/unrealistic expectations. Most adults – learning from interacting with other patients . Patient handling – Adolescents - passive acceptance of what is being done. Adults - considerble degree of explanation of what is happening & why; Interest in Rx does not automatically translate into compliance with instructions.

111. Behaviour management of adults- Advanced continuing education courses-Because a larger percentage of adult patients 1. have conditions that require interdisciplinary therapy. 2. require treatment in areas of the emerging knowledge. Refined consultation techniques - patients who require interdisciplinary dental therapy (60% to 70%), it is valuable to employ a consultation format designed to inform and educate. innovative consultation devices (i.e., a before and after photographic bulletin board, videotaped interviews with similarly treated adults) can greatly enhance the patient’s knowledge and confidence.

112. Appliance modifications for adult treatment to reduce concern about appearance Numerous appliances are available to provide for tooth movement within a biologically sound range. Two basic appliances, removable and fixed, are widely used. Incorporation of the skeletal diagnosis, periodontal assessment, and TMJ management lead to the treatment plan and to patient education. Adults demand best treatment results in a short time. Therefore, it is quite important to apprise these patients about the limitations & complexity of the treatment, increased treatment time & high relapse potential.

113. Less Visible Treatment Modalities For Adults Clear brackets and esthetic arch wires Plastic or Ceramic brackets along with tooth colored arch wire are the most esthetic combinations to be used in a conscious adult patients. Lingual Orthodontics Most lingual orthodontics patients are adults and have greater demands and expectations than do labial orthodontic patients, Esthetics is a crucial factor.

114. Advantages : Labial enamel surface, is preserved which plays an important esthetic role. Susceptibility of this enamel surface to permanent decalcification following chemical insults from etchant materials and to plaque accumulation are prevented. Evaluation of individuals tooth positions can be easily assessed as the labial surface is free of distracting metal (or) plastic brackets Lingual appliances are effective in the following situations Intrusion of anterior teeth. Maxillary arch expansion Combining mandibular repositioning therapy with orthodontic movements Distalisation of maxillary molars

115. The Invisalign System Introduced by Align technologies Santa Clara, California. It is an orthodontic technique that uses a series of clear plastic aligners to move teeth. Worn for a minimum of 20 hours per day. Changed on a 2 weekly basis. Each aligner moves a tooth or a small group of teeth about 0.25 – 0.33 mm. Align technology using computer – aided scanning, imaging and manufacturing technology has pushed this technique into realms of every orthodontic practice.

116. Advantages Ideal esthetics : aligners are relatively invisible, apart from a slight sheen to the teeth in close up. Easy to use for the patient. Comfortable. Simplicity of care and better oral hygiene. Invisalign allows for refinement aligners which can be added at the end of scheduled treatment procedures.

117. Disadvantages Limited control of root movement such as root paralleling, gross rotation correction, tooth uprighting and tooth extrusion. Limited intermaxillary correction : severe skeletal discrepancy cannot be contemplated with invisalign alone. Surgery or a pre- invisalign functional phase would be necessary. Lack of operator control : as the aligners are prefabricated there no chance of altering it.

118. Finishing And Detailing Finishing in adults does not differ significantly from adolescence. Patients with moderate to severe periodontal loss are stabilized with immediately placed retainers as soon as the finishing archwires are removed. Later detailing of occlusal relationship by equilibration should be performed. In Tempromandibular disorder patients undergoing comprehensive treatment, use of interocclusal splint prevents clenching and grinding from recurring.

119. In finishing, we often find that tooth morphology — cusp type, groove direction, number of cusps on the first molar — does not correspond to the skeletal demands of the temporomandibular joint, as the shape of the joint has its influence on the path of the mandible during its chewing cycle. Positioners are less often indicated as finishing devices especially for adults with moderate to severe bone loss.

120. Eventual detailing of occlusal relationships is done in adults by equilibration, tooth reshaping, incisal edge equilibration and also marginal ridge reduction as frequently done procedures. Traditional orthodontic retainer (to allow each tooth to move independently) is not indicated in adults with significant periodontal bone loss & mobile teeth. Splinting may be required either short term being occlusal splint, wraparound retainer, or long term using cast restorations.

121. In selective grinding the “Bull” rule should be consider which means that only the nonfunctional cusps should be modified ( buccal cusp of maxillary denture lingual cusp of mandibular denture). If the functional cusps are indicated for modification, the opposing fossae should be modified or the opposing cusp incline is ground, not the cusp height. The teeth should not be equilibrated at one sitting, but more ideally at several. Heimlich, Albert C. "Selective Grinding as an Aid to Orthodontic Therapy. Angle Orthod 1951;21(2):76-88.

122. If the cuspids are interfering in lateral excursion, it must be relieved. The dotted lines represent the correct path of occlusion. The portion of either tooth that lies between the dotted lines might be removed to allow for acceptable function in lateral excursion. Upper cuspids are grinded usually.

123. In the posterior region on the working side, buccal cusp of upper and lingual cusp of lower is grinded. Untouched upper lingual and lower buccal cusp maintain the maxillo-mandibular opening. When the premature contact exists on the balancing side, correction is made by reducing the steepness of the inclined planes on both the upper and lower molars on the balancing side.

124. Conclusion Biomechanical modifications made to accommodate orthodontic treatment of adult dentitions are generally minor and adhere to the basic laws of physics as they apply to orthodontic tooth movement. Some adult presentations necessitate changes in treatment strategy from what would otherwise be employed in adolescent patients to achieve similar goals. In other cases, objectives themselves may need to be modified because of lack of growth potential, constraints of treatment mandated by the patient or the presence of multiple missing or compromised teeth.

125. By planning treatment and mechanotherapy taking into account the individual circumstances that may affect the patient’s biological response to treatment, realistic goals of orthodontics can be mutually recognized and agreed on by both the provider and the patient before therapy is initiated, resulting in an immensely rewarding experience.

126. References Grabber Vanarsdall . Orthodontics Current Principles and Techniques. 5th edition Mosby, 2012, page no. 837. Proffit WR. Contemporary Orthodontics. 5 th edition Elsevier, 2012, page no. 635. Melsen B. Dr. Birte Melsen on adult orthodontic treatment. Interview by Vittorio Cacciafesta . J Clin Orthod . 2006 Dec;40(12):703-16.

127. Levitt HL. Adult orthodontics. J Clin Orthod 1971;5:130-5. Ackerman JL. The challenge of adult orthodontics. J Clin Orthod 1985;12:43-8. Nattrass , Sandy. Adult Orthodontics : A review. Br. J. Orthod . 1995;22;331- 7. Robb, Cyril Sadowsky , Bernard J. Schneider. Effectiveness and duration of orthodontic treatment in adults and adolescents. Am J Orthod Dentofacial Orthop 1998;113:383-6.

128. Barrer . The Adult orthodontic patient. Am J Orthod 1977;72:619-23. Dyer GS, Harris EF, Vaden JL. Age effects on orthodontic treatment: adolescents contrasted with adults. Am J Orthod Dentofacial Orthop 1991;100:523-30.