orthodontic Bracket variations

orthodontic variations of brackets in different malocclusions are declared

1. Orthodontic bracket variations Prof Dr Maher Fouda Mansoura Egypt

2. Bracket variations Various suggestions have been made regarding bracket choice and positioning to optimize tooth position when teeth are absent or where an attempt is made to overcome a local problem of tooth position. The aim is to reduce the need for archwire adjustments or auxiliaries.

3. More common local bracket variations with associated rationale and indications

4. Careful bracket selection and positioning simplifies the treatment of localized anomalies in the following situations: Class II division 1 malocclusion with lateral incisors palatally displaced; absent lateral incisor: space closure; Class III malocclusions: canine angulation; N palatally displaced canine: labial movement; N absent upper central incisors: space closure; N Class III: incisor inclination. Bracket variations

5. Andrew’s Six Keys to Normal Occlusion Lawrence Andrew, in 1972,12 outlined six keys to normal occlusion after studying 120 non-orthodontic models and comparing them with the best 1150 finished orthodontic cases . The established six keys where not only purposeful due to its presence in all 120 orthodontic normals , but also due to the fact that in treated models, the absence of one of the six was able to predict defective incomplete end result. Normal occlusion

6. Key I: Molar Relationship The first of the six keys is molar relationship. 1. The distal surface of the distobuccal cusp of the upper first permanent molar occluded with the mesial surface of the mesiobuccal cusp of the lower second molar . Key I molar relation. (A) Improper molar relationship. (B) Improved molar relationship. (C) More improved molar relationship. (D) Proper molar relationship

7. Key I: Molar Relationship The first of the six keys is molar relationship . 1. I t is possible for the mesiobuccal cusp of the upper first year molar to occlude in the groove between the mesial and middle cusps of the lower first permanent molar, while leaving a situation unreceptive to normal occlusion. Key I molar relation. (A) Improper molar relationship. (B) Improved molar relationship. (C) More improved molar relationship. (D) Proper molar relationship

8. Key I: Molar Relationship The first of the six keys is molar relationship. 1. The closer the distal surface of the distobuccal cusp of the upper first permanent molar approaches the mesial surfaces of the mesiobuccal cusp of the lower second molar, the better the opportunity for normal occlusion. Key I molar relation. (A) Improper molar relationship. (B) Improved molar relationship. (C) More improved molar relationship. (D) Proper molar relationship

9. 2. The mesiobuccal cusp of the upper first permanent molar fell within the groove between the mesial and middle cusps of the lower first permanent molar. 3. The canines and premolars enjoyed a cusp–embrasure relationship buccally , and a cusp–fossa relationship lingually . Key I: Molar Relationship The first of the six keys is molar relationship . Key I molar relation. (A) Improper molar relationship. (B) Improved molar relationship. (C) More improved molar relationship. (D) Proper molar relationship

10. Key II crown angulation or tip: Long axis of crown measured from line 90° to occlusal plane Key II: Crown Angulation, The Mesiodistal Tip • The term crown angulation refers to angulation (or tip) of the long axis of the crown, not to angulation of the long axis of the entire tooth. .

11. Key II crown angulation or tip: Long axis of crown measured from line 90° to occlusal plane Key II: Crown Angulation, The Mesiodistal Tip • • The gingival portion of the long axis of each crown was distal to the incisal portion, varying with the individual tooth type.

12. Key II: Crown Angulation, The Mesiodistal Tip • The long axis of the crown for all teeth, except molars, is judged to be the mid-developmental ridge, which is the most prominent and innermost vertical portion of the labial or buccal surface of the crown.

13. Key II: Crown Angulation, The Mesiodistal Tip The long axis of the molar crown is identified by the dominant vertical groove on the buccal surface of the crown.

14. Key II crown angulation or tip: Long axis of crown measured from line 90° to occlusal plane Key II: Crown Angulation, The Mesiodistal Tip Crown tip is expressed in degrees, plus or minus . The degree of crown tip is the angle between the long axis of the crown (as viewed from the labial or buccal surface) and a line bearing 90° from the occlusal plane.

15. Key II: Crown Angulation, The Mesiodistal Tip A ‘plus reading’ is assigned when the gingival portion of the long axis of the crown is distal to the incisal portion and a ‘minus reading’ when the gingival portion of the long axis of the crown is mesial to the incisal portion.

16. Normal occlusion is dependent upon proper distal crown tip, especially of the upper anterior teeth since they have the longest crowns. Key II: Crown Angulation, The Mesiodistal Tip

17. The degree of the tip of incisors determines the amount of mesiodistal space they consume and, therefore, has a considerable effect on posterior occlusion as well as anterior esthetics . Key II: Crown Angulation, The Mesiodistal Tip

18. Key II: Crown Angulation, The Mesiodistal Tip In normal occlusion, the crown angulation was positive for all teeth

19. Key II: Crown Angulation, The Mesiodistal Tipaccording to Andrew

20. Key III: Crown Inclination ( Labiolingual or Buccolingual Inclination) Crown inclination refers to the labiolingual or buccolingual inclination of the long axis of the crown, not to the inclination of the long axis of the entire tooth . The inclination of all the crowns had a consistent scheme . Key III crown inclination is determined by the resulting angle between a line 90° to the occlusal plane and a line tangent to the middle of the labial or buccal clinical crown. (A) shows tooth with positive crown torque and (B) shows tooth with negative torque .

21. Key III: Crown Inclination ( Labiolingual or Buccolingual Inclination) Anterior teeth (central and lateral incisors): Upper and lower anterior crown inclination was sufficient to resist overeruption of anterior teeth and also to allow proper distal positioning of the contact points of the upper teeth in their relationship to the lower teeth, permitting proper occlusion of the posterior crowns.

22. Key III: Crown Inclination ( Labiolingual or Buccolingual Inclination) A, Improperly inclined anterior crowns result in all upper contact points being mesial, leading to improper occlusion. B, Demonstration, on an overlay, that when the anterior crowns are properly inclined the contact points move distally, allowing for normal occlusion.

23. Key III: Crown Inclination ( Labiolingual or Buccolingual Inclination) Spaces resulting from normally occluded posterior teeth and insufficiently inclined anterior teeth are often falsely blamed on tooth size descrepancy .

24. Key III: Crown Inclination ( Labiolingual or Buccolingual Inclination) In normal occlusion, the crown inclination for all teeth was negative except maxillary central and lateral incisors

25. Key III: Crown Inclination ( Labiolingual or Buccolingual Inclination) Upper posterior teeth (canines through molars): A lingual crown inclination existed in the upper posterior crowns. It was constant and similar to the canines through the second premolars and was slightly more pronounced in the molars.

26. Key III: Crown Inclination ( Labiolingual or Buccolingual Inclination) Lower posterior (canines through molars): The lingual crown inclination in the lower posterior teeth progressively increased from the canines through the second molars.

27. Tip and Torque The clinical implication of the tip and torque is that they collectively affect the upper anterior crowns and total occlusion. Andrew’s wagon wheel concept. (A, B) Unbent rectangular archwire with vertical wires soldered at 90°, spaced to represent the upper central and lateral incisors. (C–E) As the anterior portion of the archwire is torqued lingually , the vertical wires begin to converge until they become the spokes of a wheel when the archwire is torqued 90° progressively .

28. Tip and Torque In lingual crown torque, for every 4˚, there is 1˚ mesial convergence of central and lateral incisor crowns, at the gingival portion. The ratio is approximately 4:1. Andrew described this phenomenon as the ‘wagon wheel concept’ Andrew’s wagon wheel concept. (A, B) Unbent rectangular archwire with vertical wires soldered at 90°, spaced to represent the upper central and lateral incisors. (C–E) As the anterior portion of the archwire is torqued lingually , the vertical wires begin to converge until they become the spokes of a wheel when the archwire is torqued 90° progressively. Andrew’s wagon wheel concept. (A, B) Unbent rectangular archwire with vertical wires soldered at 90°, spaced to represent the upper central and lateral incisors. (C–E) As the anterior portion of the archwire is torqued lingually , the vertical wires begin to converge until they become the spokes of a wheel when the archwire is torqued 90° progressively .

29. Mini sprint ® II Brackets McLaughlin Bennett 5.0

30. Andrew

31. The orthodontist is often called upon to correct upper lateral incisors which are palatally displaced. Bracket variations 1-upper lateral incisor palatally displaced and/in crossbite

32. Cases with upper anterior crowding on Class 1 or Class III dental bases are liable to have upper lateral incisors which are in crossbite , and it can be difficult to achieve stable root correction.

33. upper or lower lateral incisor palatally or lingually displaced

34. upper lateral incisors palatally displaced and in crossbite Class III MALOCCLUSION

35. Class IIdivision 2 WITH DISPLACED UPPER RIGHT LATERAL INCISOR PALATALLY AND IN CROSS BITE .

36. Where the maxillary lateral incisors have erupted palatally , often the most challenging and time-consuming treatment objective is labial movement of the roots of these teeth.

37. Class II Division 1 malocclusion maxillary lateral incisors have erupted palatally ,

38. Root bulge of the upper lateral incisors

39. Class II division 1 malocclusion . Root bulge of the upper lateral incisors Root bulge of the upper lateral incisor

40. Class 1 malocclusion with cross bite of upper lateral incisors

41. In some Class II division 1 malocclusions, the upper lateral incisors may be palatally displaced. Orthodontic treatment aims to align both crown and root;

42. This is complicated further by the fact that the torque prescription of the upper lateral incisor favours palatal root torque. To address this, the lateral incisor bracket can be inverted. Upper Laterals Torque Values

43. Torque or root movement is achieved by keeping the crowns stationary and applying a moment to force only to the root. The center of rotation of a tooth is at the incisal edge in case of root movement

44. The effect of this is to change the torque prescription of the bracket to promote labial movement of the root. Using upside down Roth brackets in the upper lateral incisor is a simple way to get more labial root torque with classic Roth brackets .

45. however, a standard lateral incisor bracket may provide insufficient labial root torque to position the lateral incisor root correctly. . standard lateral incisor bracket

46. There is a risk of moving the crown labially , while leaving the root palatally placed. In this situation, there will be a need for additional wire bending, and treatment time will be extended.

47. Labial root torque may be introduced into the archwire with torquing pliers (e.g. Rose torquing pliers) or by a single tooth torquing auxiliary . Bracket variations

48. A simpler solution, however, is to invert the lateral bracket. At the start of treatment bracket inversion maintains the crown angulation, but boosts( facilitates ) labial torque by reversing slot inclination. This approach may also increase patient comfort by gradual introduction of labiolingual torque .. Inverted upper lateral incisor brackets give -10° torque and +8° angulation in cases with in-standing laterals.

49. In cases with palatally displaced upper lateral incisors, it is beneficial to invert the upper lateral incisor brackets to create -10° torque instead of +10° of torque .This creates the necessary labial root torque to aid in moving the lateral root forward

50. Inverted upper lateral incisor bracket applying additional root torque to an instanding left lateral incisor. The right-side bracket is placed in the normal position. Note the more labial position of the root apex when the bracket is inverted, reversing the torque .

51. Inverted upper lateral incisor brackets give -10° torque and +8° angulation in cases with in-standing laterals. ... It shows the slightly increased prominence of the upper lateral incisors, resulting from the reduced in-out on the brackets. in-out

52. Effective torque however, depends on the bracket prescription. Before bracket positions are modified the prescription of the brackets must be known. MBT™ Versatile+ Appliance System

53. It is not correct to switch sides. The left bracket goes on to the left incisor and the right bracket on to the right incisor. Inverting the bracket in this way applies effective labial root torque at the rectangular wire stage, for easy root correction.

54. The palatally displaced lateral incisor is bracketed with the normal bracket, but it is rotated 180° , which changes the torque from +10° to-10°. This assists in labial root torque at the rectangular wire stage. The tip stays the same at 8°. Conventional placement of an upper lateral incisor Rotation of the lateral incisor bracket by 180° bracket gives +10° of torque. changes the torque from +10° to -10°

55. The left side bracket is placed on the left incisor and the right side bracket is placed on the right incisor. This is mentioned because it is a frequently asked question! It is not correct to place the left incisor bracket on the right incisor or vice versa Conventional placement of an upper lateral incisor Rotation of the lateral incisor bracket by 180° bracket gives +10° of torque. changes the torque from +10° to -10°

56. A convenient way to manage INSTANDING UPPER LATERAL INCISORS cases involve the following procedures: • During the alignment stage, it is necessary to create enough space for the palatally displaced tooth.

57. This is achieved using coil spring. The brackets on the adjacent teeth are tied with wire ligatures, to prevent rotations .

58. It is necessary to create sufficient space for palatally displaced incisors before attempting to move them labially . Bendbacks are placed 2 mm distal to molar tubes, to allow an increase in arch length.

59. After creation of space, a .015 multistrand wire or a .016 HANT wire may be used to gently move the lateral incisors labially

60. Piggy back technique to align the in-standing upper left lateral incisor

61. The alternative is wire bending, but it is difficult and time consuming to introduce the exact amount of torque needed into rectangular wire. Inverting the bracket is more precise and easier . In cases with instanding upper lateral incisors it is often helpful if the bracket is inverted. An occlusal view of a case, close to completion. It shows the slightly increased prominence of the upper lateral incisors, resulting from the reduced in-out on the brackets. This gives better smile aesthetics, which is much appreciated by patients

62. In the Andrews prescription a lateral incisor bracket with a 3 degrees of torque when inverted delivers an inclination, which was increased by 6 degrees (from –3 to 3 degrees with the standard bracket prescription). Andrews/Roth/MBT torque values

63. I nverted Roth lateral incisor brackets produce a difference of 16 degrees compared with 6 degrees with Andrews prescription as normally positioned .Roth lateral brackets have 8 degrees of palatal root torque incorporated into their design. Andrews/Roth/MBT torque values

64. An MBT bracket inverted on a lateral incisor changes torque by 20 degrees as 10 degrees changes to - 10 degrees . Full bracket expression is unlikely with the archwire dimensions used in clinical practice. Andrews/Roth/MBT torque values

65. This may be further compounded by the slot size being larger than manufacturers’ state.

66. Inverted upper lateral incisor bracket applying additional root torque to an instanding left lateral incisor. The right-side bracket is placed in the normal position. (a) Apical view .

67. (c) Incisal view. Note the more labial position of the root apex when the bracket is inverted, reversing the torque.

68. 2-Absent lateral incisors: space closure When maxillary lateral incisors are absent and space closure is planned, which bracket is best placed on the canine?

69. Absent lateral incisors: space closure The standard MBT canine bracket has 7 degrees of labial root torque, which is appropriate for a canine in its usual position in the line of the arch. Torque Values

70. Absent lateral incisors: space closure This is inappropriate, however, if this tooth is to replace a lateral incisor where palatal root torque is indicated, rather than labial torque . the canines receive the lateral incisor brackets . canines extrusion and premolars intrusion to adjust the gingival level . the canines should receive, lingual root torque . The first premolars receive canine brackets A multidisciplinary treatment of congenitally missing maxillary lateral incisors: a 14-year follow-up case report J Appl Oral Sci . 2014;22(5):465-71

71. Absent lateral incisors: space closure One suggestion is to place a lateral incisor bracket on the canine crown. However, the height of the bracket stem and the labiolingual thickness may be too great, and may position the tooth palatally in the line of the arch unless first order bends are also incorporated. Prescription in Roth technique Torque Values Tip Values

72. Absent lateral incisors: space closure Also there may be insufficient torque in view of the greater crown-root angle found in canines. Torque Values The collum angle and the crown to root angulation

73. Absent lateral incisors: space closure Bracket fit creates a further problem as canine crown labial convexity is greater than that of the lateral incisor . Torque Values Upper lateral incisor bracket .

74. Lateral incisor brackets were placed on the upper canines to allow a more palatal root torque and reduce the canine eminence. The upper first premolar brackets were bonded in a slightly distal position which will rotate the premolars mesially for better esthetics.

75. Lateral brackets may be placed on canines when treating patients with canine substitution , positioned according to gingival margin height rather than on the cusp tip of the substituted canines . The brackets on the substituted canines should be placed at a distance from the gingival margin such that they will erupt these teeth to the appropriate lateral incisor vertical height .

76. To substitute canines in the position of missing laterals, special bracket placement was necessary for both maxillary canines and the first premolars . The lateral incisor brackets were bonded to the canines and the canine brackets were placed on the first premolars.

77. Before bonding the lateral incisor bracket on the canine, the labial surface was reshaped for the bracket adaptation. It is necessary to position these brackets gingivally to permit the recontouring of the canines required for esthetics and function. Recontouring (red color) of the maxillary canine to resemble like a lateral incisor .

78. To make the canine appear less curved and more like a lateral incisor, the bracket was placed more distally in the center of the canine rather than at the height of contour

79. In addition, a canine bracket was placed on the first premolar in the same mesiodistal position (more distally) in which it is placed on the canine.

80. However , to improve the interproximal contact points, offset bonds (in-out) was needed between the central incisor and canine . In the archwire design, to improve the interproximal contact points, the 1st order (in-out) bends was performed on the maxillary canines.

81. A. Recontouring (red color) of the maxillary canine to resemble like a lateral incisor . B. Recontouring (red color) of the prominent labial ridge of canine before bonding a bracket. The lingual surface was reduced (blue color) to establish a balanced occlusion. B. The lingual cusp of the maxillary first premolar for canine substitution was recontoured (blue color).

82. Absent lateral incisors: space closure Regarding the solution of placing a lateral incisor bracket after recontouring of the canine to mimic the lateral incisor, p otential obstacles are the wide range of canine crown anatomies and unfavourable crown-root angulations.

83. Maxillary canine, labial aspect. Maxillary canine, mesial aspect. the wide range of canine crown anatomies

84. Maxillary canine, incisal aspect . the wide range of canine crown anatomies

85. Maxillary canine. Ten specimens with uncommon variations are shown. 1, Crown very long, with extreme curvature at apical third of the root. 2, Entire tooth unusually long. Note hypercementosis at root end. 3, Very short crown; root small and malformed. 4, Mesiodistal dimension of crown at contact are extreme; calibration at cervix narrow in comparison; root short for crown of this size. 5, Extreme labiolingual calibration; root with unusual curvature. 6, Tooth malformed generally. 7, Large crown; short root. 8, Root overdeveloped and very blunt at apex. 9, Odd curvature of root; extra length. 10, Crown poorly formed; root extra long.

86. Absent lateral incisors: space closure An alternative is to invert the canine bracket on the canine tooth. This achieves a crown angulation of 11 degrees , but 7 degrees labial root torque becomes 7 degrees of palatal root torque for both MBT and Andrews prescription, but slightly less for Roth brackets due to the prescription . Torque values for the three bracket prescriptions (degrees). Angulation prescription (in degrees) with popular pre-adjusted edgewise prescriptions. Positive values indicate mesial crown tip

87. Absent lateral incisors: space closure The canine bracket is compound contoured to fit the crown surface; the bracket stem height is unchanged . Tip may be excessive where a canine is replacing a lateral incisor. Canine tip varies between different prescriptions . Torque values for the three bracket prescriptions (degrees). Andrews/Roth/MBT tip values

88. Absent lateral incisors: space closure In the MBT prescription, the tip value is identical for both the lateral incisor and the canine. In the Roth prescription there is a 5 degrees difference and with the Andrews there is a difference of 3 degrees . Andrews/Roth/MBT tip values

89. Absent lateral incisors: space closure Therefore, a Roth bracket (with 13 degrees of tip when inverted onto a canine replacing a lateral incisor) delivers 4 degrees of additional tip beyond the norm for a lateral incisor. Andrews/Roth/MBT tip values

90. Case Report Orthodontic Space Closure of a Missing Maxillary Lateral Incisor Followed by Canine Lateralization Hindawi Case Reports in Dentistry Volume 2020, Article ID 8820711, 7 pages https://doi.org/10.1155/2020/8820711 class I molar relationship bilaterally, missing left maxillary lateral incisor, upper right peg lateral incisor, and gap between the teeth in the upper front region

91. Case Report Orthodontic Space Closure of a Missing Maxillary Lateral Incisor Followed by Canine Lateralization Hindawi Case Reports in Dentistry Volume 2020, Article ID 8820711, 7 pages https://doi.org/10.1155/2020/8820711 The canine brackets on the upper left side are inversed to have +7° torque on the left upper canine which matches nearly with the torque of the upper lateral incisor tooth. Torque values for the three bracket prescriptions (degrees).

92. Case Report Orthodontic Space Closure of a Missing Maxillary Lateral Incisor Followed by Canine Lateralization Hindawi Case Reports in Dentistry Volume 2020, Article ID 8820711, 7 pages https://doi.org/10.1155/2020/8820711 Apart from this, the bracket on the upper left canine is positioned slightly gingivally to match with the gingival zenith of the contralateral lateral incisor. The first premolar bracket is positioned slightly distal to hide the palatal cusp of the first premolars on the left side and to give the cervical prominence as that of the canine.

93. 3-Canine WITH gingival recession In cases where the gingivae has receded or the canine is very prominent , inverting the bracket gives palatal root torque, which can help reduce further recession Torque Values Torque values for the three bracket prescriptions (degrees).

94. Orthodontic camouflage is carried out when a Class III malocclusion is treated by accepting the skeletal pattern; orthodontic appliances tilt the upper and lower incisors to compensate for the skeletal discrepancy. 4-Canine angulation in Class III cases

95. Camouflage effectively retroclines the lower labial segment. Canine angulation in Class III cases

96. It has been suggested that contra-lateral canine brackets on the lower canines encourage the crowns to tip distally. (a) Contra-lateral brackets placed upon the lower canines. The crowns are tipped distally. (b) Clinical photograph with lower canine brackets transposed to achieve dental camouflage in a Class III malocclusion Canine angulation in Class III cases Torque values for the three bracket prescriptions (degrees). Andrews/Roth/MBT tip values

97. In some Class III treatments it is helpful to switch left and right lower canine brackets. This changes the tip from +3° to -3° and can make the mechanics easier. Tip Values

98. Canine angulation in Class III cases Dentoalveolar compensation is facilitated and anchorage requirements are reduced. Transposed MBT brackets attached to mandibular canines

99. Canine angulation in Class III cases The outcome of bracket transposition will depend on the bracket prescription. In the Andrews prescription 5 degrees tip becomes a 10 degrees difference; with MBT 3 degrees becomes a 6 degrees difference. Andrews/Roth/MBT tip values

100. 5-Labial movement of palatal canine Palatal canine movement results in crown movement without the root, causing unattractive tip. In order to increase labial root torque, the lower contra-lateral canine bracket can be inverted to the upper. This is relevant in Roth where there is 9° change; in MBT there are similar torque values. Torque values for the three bracket prescriptions (degrees).

101. 5-Labial movement of a palatal canine When a palatally displaced canine is moved labially , movement of the crown may occur in advance of the root leaving it unattractively tipped. Increased labial root torque overcomes this. Inclination/torque prescription (in degrees) with popular pre-adjusted edgewise prescriptions. Positive values indicate palatal root torque

102. 5-Labial movement of a palatal canine One option is to invert the lower contra-lateral canine bracket onto the upper canine. Inclination/torque prescription (in degrees) with popular pre-adjusted edgewise prescriptions. Positive values indicate palatal root torque

103. 5-Labial movement of a palatal canine The MBT prescription in this case would provide no benefit as the torque values are similar for the upper and lower canines. Canine bracket inverted on the upper right canine

104. 5-Labial movement of a palatal canine Roth and Andrews prescriptions, however, would provide a small benefit, as there is a difference of 9 and 4 degrees , respectively. The additional labial root torque may, therefore, help to correct tooth position . Inclination/torque prescription (in degrees) with popular pre-adjusted edgewise prescriptions. Positive values indicate palatal root torque

105. 6-Absent upper central incisor In order to facilitate restorative treatment, the preferential mesial root movement over the crown should occur. Inclination/torque prescription (in degrees)

106. A central incisor bracket should be placed on a mesially substituted lateral incisor to achieve an appropriate angulation ( tip) for the labial surface of the incisor, as well as to better control its rotation, and correct the second order axial inclination. Tip Values Torque Values

107. The emergence profile of a maxillary central incisor is generally flat on the mesial surface, but the adjacent lateral incisor is more angulated . When substituting a lateral for a central incisor, it is necessary to move it close to the midline to provide a more natural midline papillae.

108. Angulation/ Inclination/ Crown Size Compared to normal tooth form (right), angulation (2 degrees ) and mesiodistal positioning of the substituted lateral incisor is essential for simulating the midline papilla and central incisor crown form (left).

109. Angulation/ Inclination/ Crown Size The mesially substituted teeth were altered restoratively to simulate upper left incisors and canine. Note that the primary consideration is aligning the gingiva and papillae. Once there axial inclinations were corrected, restorative procedures were performed. Because of the size difference between the incisors , the lateral incisor must be extensively recontoured on the distal surface which may or may not be consistent with periodontal health. Missing Maxillary Central Incisor Treated with Mesial Substitution of the Lateral Incisor, Canine and First Premolar iAOI CASE REPORT

110. lateral incisor in the space for restorative purposes claiming this improves force transmission through the root Bonding the contralateral central incisor bracket to tilt the tooth allows this ; however, some clinicians prefer centring the Tip Values

111. 6-Absent upper central incisor: space closure Following loss of an upper central incisor, space closure may involve moving the lateral incisor mesially . The lateral then abuts the adjacent central incisor . .

112. 6-Absent upper central incisor: space closure As the lateral moves mesially , its root should move further mesially than its crown; the mesial surface is then vertical. The mesially substituted teeth were altered restoratively to simulate upper left incisors and canine. Note that the primary consideration is aligning the gingiva and papillae. Once there axial inclinations were corrected, restorative procedures were performed.

113. 6-Absent upper central incisor: space closure This permits the restorative phase to build up the distal surface with an optimal emergence profile. This avoids the problem of retention from a mesiogingival margin on the restoration.

114. 6-Absent upper central incisor: space closure It has been suggested that it is useful to bond the contra-lateral central incisor bracket to tilt the tooth so its distal crown aspect approaches vertical .

115. 6-Absent upper central incisor: space closure Contra-lateral central incisor bracket placed on the upper left lateral incisor. Note the exaggerated tip, which brings the mesial surfaces together and allows build up of the distal emergence profile Upper canine brackets are inverted to provide additional palatal root torque. The lateral incisor brackets are transposed to achieve improved root paralleling prior to mesial movement and restorative build-up Inclination/torque prescription (in degrees)

116. • For good root control with buccally ectopic upper canines, the -7° torque bracket is not really suitable, and works better when inverted to give the +7° option, which guides the root into cancellous bone. Torque Values 7-Buccally ectopic canine

117. In class 3 cases, there is a need for upper incisor proclination . It is possible to invert incisor brackets for labial root torque, MBT giving the greatest change at 34 ° although there are concerns that this amount of torque risks root resorption . 8-Incisor inclination In class III

118. 8-Incisor inclination in Class III malocclusions When Class III malocclusions are treated orthodontically the upper incisors tend to be proclined as the malocclusion is camouflaged .

119. 8-Incisor inclination in Class III malocclusions Subtelny and Catania advocated the use of labial root torque and tying the archwire forward to advance ‘A’ point and boost anteroposterior arch length . The forward arch must be separated 2 mm from the slots of the anterior braces. Lateral view of the stop and the separation of the wire from the slot of the braces.

120. It can be helpful to invert lower incisor brackets (to give +6° torque) in some Class III cases to prevent unwanted retroclination of lower incisors. Torque Values It is helpful to invert the lower incisor brackets in some cases .

121. This can also be useful in cases where molar anchorage loss is needed or where a single lower incisor is proclined . Torque Values It is helpful to invert the lower incisor brackets in some cases .

122. IN THIS CLASS III IT IS NOT ADVOCATED TO PROCLINE THE UPPER INCISORS DURING ORTHODONTIC CORRECTION

123. DO NOT PROCLINE THE UPPER INCISORS DURING ORTHODONTIC CORRECTION

124. 8-Incisor inclination in Class III malocclusions The possibility exists to invert incisor brackets and use these to provide labial root torque, which may be useful in some selected cases .

125. 8-Incisor inclination in Class III malocclusions For the central incisors this would effectively change the torque values: Andrews (a 14 degrees change), Roth (a change of 24 degrees), and MBT (a change of 34 degrees ).

126. 9-Upper premolar substituting canine In cases where the canine is absent or replacing the lateral incisor, placement of the bracket more distally on the premolar moves the palatal cusp out of the way . Smoothing the palatal cusp of the first premolar may be required to further hide it or improve occlusal interference . Two supernumerary teeth were observed between the lateral incisors and first premolars. The maxillary permanent canines were impacted over the roots of the upper central incisors . Substitution of retained canines with first maxillary premolars. Case report Revista Mexicana de Ortodoncia Vol. 4, No. 4 October-December 2016

127. Treatment plan • Removal of the maxillary canines and replace them with the first premolars because these had the necessary size and root shape to achieve lingual crown torque . • Substitute canine guidance with premolar guidance or group function . • Placement of 0.022” x 0.025” slot Roth fixed appliances. • Final articulation mounting in order to perform the occlusal adjustment and for the premolars to better withstand the occlusal loads. • Rehabilitation with interproximal resins in the lateral incisors and premolars to achieve an adequate periodontal health

128. 10-Case finishing In order to achieve good finishing and occlusion in MBT prescription, lower second molar tubes can be used on the contralateral upper first and second molars to result in zero tip and zero rotation, resulting in mesio -palatal rotation of upper molars.

129. Upper second molars: Usually, a step between first and second molar occurs . To avoid this step, it is important to understand how these teeth are in a normal situation. 10-Case finishing (a and b) An undesirable step between the first and second upper molar

130. Upper second molars : 10-Case finishing By analyzing the position and inclination of the second molars in a collection of skulls with normal occlusion, it is found that these teeth are in a more distocervical direction to the occlusal plane and at a slight angle to distal . Observe the position of the second molars in a collection of skulls with normal occlusion. These teeth are in a more superior position to the occlusal plane and at a slight angle to the distal

131. It seems that the position of these teeth is a little different from what is common to mount orthodontic appliances. Therefore, the clinical crowns of the second molars are always angulated in distocervical direction [ Observe the position of the second molars in a collection of skulls with normal occlusion. These teeth are in a more superior position to the occlusal plane and at a slight angle to the distal 10-Case finishing

132. One can observe the same situation illustrated in Angle’s book, as a normal occlusion . Normal occlusion illustrations from the Angle’s book (1907). The same characteristic position of second molars can be observed 10-Case finishing

133. Klontz also emphasizes this condition in a very clear way in his article– “Readout.” Thus, to have no problems in positioning the brackets and tubes on upper second molars, it is necessary to follow the precepts: (1) hold tooth in its normal position, (2) position the bracket as occlusal as possible, and (3) control torque 10-Case finishing

134. A 25-year-old female patient presented at the office for a second opinion as she had been advised to undergo orthognathic surgery in order to resolve her complaint. Patient’s smile at initial appointment. Notice the canted occlusal plane from the right to the left side. 11-Canting of the occlusal plane

135. She had a mild frontal asymmetric face, but her only complaint was the asymmetric superior occlusal plane, notably on smiling, and consequently the lower arch followed these upper disharmonies, but to a lesser extent . Patient’s smile at initial appointment. Notice the canted occlusal plane from the right to the left side . 11-Canting of the occlusal plane

136. Initial intraoral photograph. Notice the canted occlusal plane from the right to the left side . She presented with a Class I relationship and mild lower teeth crowding that could be solved by stripping 11-Canting of the occlusal plane

137. Ceramic standard edgewise 0.022” x 0.028” orthodontic brackets were placed on all teeth. Individualized vertical bonding of maxillary brackets: the brackets on the right side were bonded at a higher position from the incisal /occlusal edge and at a lower position on the left side 11-Canting of the occlusal plane

138. The brackets on the upper right side were bonded at a higher position from the incisal / occlusal edge and at a lower position on the left side following a correct height relationship between them (i.e.: the lateral incisors placed 0.5mm more incisally than the central incisors) ndividualized vertical bonding of maxillary brackets: the brackets on the right side were bonded at a higher position from the incisal /occlusal edge and at a lower position on the left side 11-Canting of the occlusal plane

139. Orthodontic leveling of the maxillary and mandibular arches were performed with nickel-titanium 0.014” and heat-activated 0.019” x 0.025” wires. Individualized stainless steel 0.019” x archwires were placed. The maxillary archwire received a substantial lingual crown torque in the left posterior side to counter the effects of intrusion, while force was applied outside the center of resistance of these teeth. 0.026 ” 11-Canting of the occlusal plane The appliance was mounted according to the malocclusion. The height of the canine bracket from one side is different to other side with the leveling resulting in a significant improvement

140. individualized vertical bonding of maxillary brackets: the brackets on the right side were bonded at a higher position from the incisal /occlusal edge and at a lower position on the left side One millimeter difference in vertical positioning could alter torque values up to 10 degrees. Intense posterior torque was applied to the left side of the maxillary archwire in order to oppose asymmetric torque in maxillary teeth. 11-Canting of the occlusal plane

141. The patient was very pleased with the results . A symmetrical occlusal plane was obtained and incisor angulation corrected. Therefore, the proposed objectives were achieved Patient at debonding appointment. Patient’s smile at the end of treatment. 11-Canting of the occlusal plane

142. 12-Class II cases where anchorage at a premium in maxillary arch Maxillary premolar bracket on maxillary canine (or intentional mesial angulation of canine bracket) This limit mesial crown tipping and associated anchorage demand to move root distally Tip Values Torque Values Angle Class II division 1 malocclusion (a) with proclined maxillary incisors (red line in a), and Angle Class II division 2 malocclusion (b) with retroclined maxillary central incisors (purple line in b).

143. Thin gingival biotype with lower labial recession where lingual root positioning may be beneficial Inversion of MBT™ mandibular incisor bracket ™ will give Additional lingual root torque Torque Values Tip Values 13 -Gingival recession on the lower incisors

144. 14-Scissors bite where mandibular arch expansion may improve transverse co-ordination Inversion of mandibular premolar brackets gives a dditional lingual root torque Tip Values Torque Values

145. 15-Posterior crossbite where maxillary arch expansion may improve transverse co-ordination Inversion of maxillary premolar brackets will give Additional palatal root torque Torque Values Tip Values