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Extraction teeth for gaining space in orthodontics

  1. Extraction teeth for gaining space in orthodontics Prepared by :Ameen Mohammed Supervisor : Prof: Maher Fouda
  2.  Introduction  The need for extraction in orthodontics  Choice of teeth for extraction  Maxillary Incisors . indication , contraindication , case report  mandibular incisors . Indication , contraindication , case report + vid  Canines. indication , contraindication , case report  First premolars . indication , contraindication , case report +vid  Second premolars . indication , contraindication , case report +vid  Maxillary First molar . indication , contraindication , case report  Maxillary second molar. indication , contraindication , case report  mandibular First molar. indication , contraindication , case report  mandibular second molar. indication, contraindication , case report +vid  mandibular third molar. indication , contraindication , case report
  3. Extraction teeth for gaining space in orthodontics Painless removal of teeth from its socket is termed as extraction. Extraction in orthodontics is a therapeutic method to gain space for relieving crowding. Extractions in orthodontics remains a relatively controversial area. It is not possible to treat all malocclusions without taking out any teeth.
  4. Extractions in orthodontics may be carried out as an -interceptive procedure during the mixed dentition as serial extraction And as therapeutic extractions carried out as treatment procedure for gaining space.
  5. THE NEED FOR EXTRACTION Extraction of teeth may be required in the following circumstances.  Arch Length-Tooth Material Discrepancy .  Correction of Sagittal Inter arch Relationship .  Extraction for the Relief of crowding : must be observance A-Condition of the teeth B-Position of the crowding C-Position of the teeth
  6. Arch Length-Tooth Material Discrepancy Ideally the arch length and tooth material should be in harmony with each other. If the dentition is too large to fit in the dental arch without irregularity, it may be necessary to reduce the dentition size by the extraction of teeth. It is not normally acceptable to increase the dental arch size, because the increased dental arch dimension would not be tolerated by the oral musculature.
  7. Arch Length-Tooth Material Discrepancy Angle believed that all 32 teeth could be accommodated in the jaws, in an ideal occlusion with the first molars in a Class I occlusion, with the mesiobuccal cusp of the upper first molar occluding in the buccal groove of the lower first molar.  .
  8. Correction of Sagittal Interarch Relationship Abnormal sagittal malrelationship such as Class II /Ill malocclusion may require extraction to achieve a normal interarch relationship . Class II Class III
  9. Correction of Sagittal Interarch Relationship  In a Class I malocclusion it is preferable to extract in both the arches because it is not advisable to discourage the development of only one arch more than the other.  In most Class II cases with abnormal of the lower teeth and where a point is upper proclination, normal alignment abnormally forward relative to the B point,  Class III cases are usually treated by extracting teeth only in the lower arch
  10. Extraction for the Relief of Crowding Extraction for the relief of crowding will be governed by: Condition of the teeth Grossly carious teeth, root canal treated teeth and teeth with large restorations are preferred for extraction over healthy teeth. Position of the crowding Crowding in one part of the arch is more readily corrected if extractions are done in that part rather than a remote area of the arch. However, incisor crowding is usually relieved by premolar extraction as it gives a more pleasing appearance and occlusal balance than with incisor extraction.The first premolar, positioned in the center of each quadrant, is usually near the area of crowding whether in the anterior or buccal
  11. CHOICE OF TEETH FOR EXTRACTION Choice of teeth to be extracted depends un local conditions which include:  Direction and amount of jaw growth  Discrepancy between size of dental arches and basal arches  State of soundness, position and eruption of teeth facial profile  Degree of dentoalveolar prognathism  Age of patient  State of dentition as a whole
  12. INCISORS Maxillary Incisors The maxillary central incisors, are rarely extracted as a part of orthodontic therapy. Indications for maxillary incisor extraction  Unfavorably impacted maxillary incisors.  Buccally or Lingually blocked out lateral incisor with good contact between central incisor and canines.  If a lateral incisor is crowded in linguo-occlusion with its apex palatally displaced and if the canine is erupting in a forward position and is upright or distally inclined, lateral incisor extraction is indicated (Fig. 21,9A).  Grossly carious incisor that cannot be restored.  Trauma/irreparable damage to incisors by fracture.
  13. Case report central incisors  Extraction of upper central incisors is not common in orthodontics. However, malformed central incisors with poor prognosis could be candidates for extraction
  14. pretreatment
  15. Treatment plane Based on clinical and radiographic findings, together with poor prognosis of upper central incisors and the appropriate size of lateral incisors with long roots, extraction of the upper central incisors plus substitution of the lateral incisors was determined as a suitable treatment
  16. Treatment plane Once the maxillary lateral incisors had been situated in the central incisor and the maxillary canines in the lateral incisor positions, rectangular stainless steel arch wires were ligated in place to correct the torque in both arches and uprighting of the incisors roots. The active orthodontic treatment was completed in 16 visits over the course of 19 months. At the completion of orthodontic treatment, the smile was consonant and the palatally lateral incisors were corrected. Further aims of treatment including preservation of class I molar relationships and creation of normal overjet and overbite were also achieved (Figures 4 and 5). By the completion of orthodontic treatment brackets were removed and the patient was referred for prosthodontic alteration of the shape of teeth. The maxillary lateral incisors were built up with Z100-3M resin composite to resemble central incisors.
  17. Before After
  18. After
  19. BeforeAfter The cusps of canines were grinded. The distal and labial surfaces were flattened and reshaped to mimic lateral incisors and also meet the patient’s esthetic requirements
  20. Indications lower incisor extraction  Angle Class I malocclusion with severe anterior tooth size discrepancy (greater than 4.5 mm  lower anterior crowding with lack of space for approximately one mandibular incisor  Dental Class I malocclusions with anterior cross bite due to crowding and protrusion of the lower incisors.  Malocclusions that tend towards a Class III malocclusion  Moderate Class III malocclusions with anterior cross bite, or incisors with edge-to-edge relationship, showing a tendency towards anterior open bite.
  21. Video lower extraction
  22. Indications lower incisor extraction  Class II Division 1 skeletal and dental malocclusions with maxillary protrusion and crowding or protrusion of the lower incisors  Cases in which one wishes to avoid increasing intercanine width in certain malocclusions  As a non-surgical alternative in Class III treatments.  Extraction of lower incisors may be appropriate:  When one incisor is completely excluded from the arch and there are satisfactory approximal contacts between other incisors (Figs 21,9B and 21,9C).  Poor prognosis as in case of trauma, caries, bone loss, etc.  Severely malpositioned incisor.  Lower canines are severely inclined distally and lower incisors are fanned-it is very difficult to correct this condition by extractions further back
  23. contraindications  All cases requiring extractions in both arches with severe overbite and horizontal growth pattern, bimaxillary crowding, no tooth size discrepancy in the anterior teeth  Deep bite cases with horizontal growth pattern.  All cases which require upper first premolar extraction while canines arc in a Class I relationship.  Bimaxillary crowding cases with no tooth size discrepancy in the incisor area.  Cases having anterior discrepancy due to either sma11 lower incisors or large upper incisors.
  24. Case Report: A female patient 16 years old reported with a chief complaint of crowding in lower anterior teeth and forwardly placed upper anterior teeth. She had a mild convex pleasing facial profile with competent lips
  25. intra-oral clinical examination showed severe crowding with mandibular anteriors and mild crowding with maxillary anteriors and angles Class I molar relation bilaterally. Due to lower anterior crowding, mandibular left canine was displaced buccally [Figure 2] Model analysis showed Boltons ratio, mandibular anterior and overall excess of 5.6 mm and 1.4 mm respectively
  26. The main objective of treatment plan was aimed at relieving lower and upper anterior crowding without much disturbing her facial profile. Extraction of mandibular left lateral incisor, to facilitate proper aligning of 33 was planned which would gain space enough to relieve lower anterior crowding
  27. The orthodontic treatment was started using PAE 0.022 slot brackets. 0.014 inch NiTi preformed arch wire was used as initial wire as to exert very light forces.4 Alignment and levelling was achieved with subsequent wire sequence (Table 1). After levelling, using 0.019 x 0.025 SS arch wire space closure was started with very light forces using tie backs. Extraction of one incisor in cases of moderate to severe crowding may even satisfy the requirement of maintaining the arch form and width without expansion of the inter-canine width
  28. Post treatment
  29. Conclusion Selecting the best treatment option is often difficult and not all factors can be achieved, but a proper case selection and proper decision on which tooth to extract can prove extraction of mandibular incisor a therapeutic extraction option in severe lower anterior crowded cases. A systematic treatment approach with simple mechanics and torque control can aid in achieving a stable occlusion that is esthetic and in functional harmony
  30. CANINES The permanent canines are important teeth and are not frequently extracted as a part of orthodontic treatment . Their extraction causes flattening of the face, altered facial balance and change in facial expression . When the lower canine is crowded, it is sometimes tempting to extract this tooth . However, this is avoided because the approximal contact between the lateral incisor and first premolars rarely satisfactory.
  31. Indications  Mandibular canine may be extracted when it is likely to be very difficult to align, e.g. when it is excluded from the arch and the apex is severely malpositioned or when it is unfavorably impacted.  Maxillary canines develop far away from their final location and have a long path of eruption from their development site to their final position in the oral cavity. Therefore, they are not uncommonly impacted or ectopic and their alignment is difficult, even impossible. Extraction may be required in such cases.  When maxillary canine is completely excluded from the arch and approximal contact between lateral incisor and first premolar is good, extraction of the canine may be considered .
  32. 37-year-old female patient with Class II malocclusion and severe maxillary crowding, including palatally displaced upper left lateral incisor and buccally displaced upper left canine (which was completely blocked out of the arch), The upper left canine showed severe gingival recession and bone loss. The upper and lower midlines were shifted to the left by 4mm and 2mm, respectively., Case report (1) canine
  33. After extraction of both upper canines, a passive self-ligating appliance (Damon 3*) was bonded in the upper arch from second molar to second molar, and an .014" superelastic nickel titanium archwire was placed for initial alignment and correction of the lateral incisor crossbite (Fig. 2A).
  34. Two months later, the mandibular arch was bonded from second premolar to second premolar. After initial lower alignment, an .017" × .025" superelastic nickel titanium wire was placed in the upper arch and an .018" superelastic nickel titanium wire in the lower, and Class III elastics were prescribed to improve the overjet (Fig. 2B)
  35. Upper .019" × .025" stainless steel posted and lower .018" stainless steel archwires were placed for finishing, with bilateral maxillary tiebacks and interarch elastics used to resolve the remaining lateral open bite (Fig. 2C
  36. After 12 months of treatment, the patient had a bilateral Class II molar relationship with the upper first premolars in the canine positions (Fig. 3). The treatment achieved the objectives of crossbite correction and improvement of the patient’s smile and facial esthetics
  37. Case report (2) canine  This 1 3 -year-old female presented to my office with the chief complaint of crooked teeth (Fig. 1 ) . Her health history was unremarkable.  Analysis of the case showed a Class I dental pattern, moderate maxillary and mandibular crowding, ectopic maxillary canines, which were erupting into the mouth from the buccal side, and a retained primary canine tooth.  The panoramic radiograph ( Fig. 2 ) shows a transmigrated mandibular canine with its incisal tip resting at the apex of # 2 2 in the mandibular symphysis
  38. Pretreatment photo Figure 1
  39. Figure 2
  40. Treatment option  Remove the severely impacted tooth and retained primary canine. Substitute for the missing canine with the first premolar.  After the five treatment options were presented, the decision was made to remove the transmigrated canine and to substitute for the loss of the canines with lower first premolars.
  41. With a plan for substitution, after removing the impacted canine and retained primary this case can now be seen as a straight forward Class II subdivision case. The PowerScope Class II Corrector (Fig. 3) was planned to provide the force to the lower anterior for protracting the right premolars and molars into the substituted position. This is a wire to wire attached Class II cor- rector. When fully activated, it will consistently provide 260g of force for the protraction of the right buccal segment. The Power Scope Class II Corrector
  42. The Power-Scope has several advantages over Class II elastics for this situation. The compressed NiTi spring will provide a predominantly horizontal and only slightly intrusive push-type force mesial to the maxillary molar and distal to the lower canine position.
  43. Post treatment photo
  44. FIRST PREMOLARS lt is the tooth most commonly extracted as part of orthodontic therapy especially for the relief of crowding because: • It is positioned near the center of each quadrant of the arch and is therefore near the site of crowding, i.e. the space gained by their extraction can be utilized for correction both in the anterior and posterior region. • First premolar extraction is the least likely to upset molar occlusion and is the best alternative to maintain vertical dimension. • The contact between the canine and second premolar is satisfactory. • First premolar extraction leaves behind a posterior segment that offers adequate anchorage for retraction of the 6 anterior teeth.
  45. Extraction first premolars
  46. Indications 1. Tooth of choice for extraction to relieve moderate to severe anterior crowding in both the arches. In lower arch crowding, where canines are mesially inclined, spontaneous improvement in incisor alignment will follow. 2. Correction of moderate to severe anterior proclination as in Class lJ div 1 or Class I bimaxillary protrusion. 3. In high anchorage cases, first premolar takes precedence over second premolar as the teeth to be extracted. 4. As a part of serial extraction
  47. Timing of Extraction  The first premolars should not be extracted until all premolars, permanent incisors and canines have erupted sufficiently for brackets to be placed on them .  The only exception to this rule is when second premolars cannot erupt because they are impacted.  The four first premolars shouId not be extracted more than three weeks before starting active treatment to avoid mesial migration of posterior teeth and therefore leaving insufficient space for retraction
  48. Case reports  A 28-year-old male presented with a severe arch-length discrepancy that had produced severe upper and lower crowding and labially blocked-out canines .  He had a Class I molar relationship, with the upper and lower left first molars in crossbite. Cephalometric analysis showed a Class I, straight skeletal profile and normal incisor relationships.  A diagnostic cast setup was performed with the four first premolars removed to evaluate the projected alignment of the treated case, assuming that the teeth distal to the extraction sites would not move forward
  49. Pretreatment photo
  50. Treteatment plane The computer-generated Clin Check setup, showing the type and placement of attachments, was reviewed, modified, and accepted (3). Because the canines were mesially angulated, the Clin Check technician was instructed to maintain their root angles throughout the retraction phase and not to upright the virtual images as the extraction spaces were closed. The case required 50 upper and 49 lower aligners; interproximal reduction was not indicated until the middle and later stages (21 and 48).
  51. Figure 3 Figure 4
  52. Post treatment photo
  53. SECOND PREMOLARS Indications for Extraction 1. When second premolar is completely excluded from the arch following forwards drift of first molar after early loss of deciduous second molar. 2. Second premolar extraction is preferred in mild anterior crowding cases as space closure and vertical control is easier after anterior alignment. The presence of first premolar anterior to extraction site strengthens the anterior anchorage, thereby facilitating closure from behind. 3. Second premolar extraction is preferred when one wishes to maintain soft tissue profile and esthetics. 4. Unfavorably impacted second premolars. 5. Grossly carious or periodontally compromised second premolar (Fig. 21.90). 6. In open bite cases second premolar is preferred for extraction as it encourages deepening of the bite.
  54. Case reports  This case report describes the management of 18-year old female patient with moderate crowding which was treated with second bicuspid extraction. At the end of treatment, patient had pleasing profile, good intercuspation, ideal overjet, and overbite.  The patient had a mild convex profile and symmetric face.  chief complaint of unesthetic appearance of her smile
  55. Pretreatment extra oral and intraoral photo
  56. Pretreatment  Intra orally the patient had a Super Class I molar (SI 11) relationship and Class I canine on both sides with an overjet of 3 mm and an overbite of 2 mm with mild anterior crowding and proclination. Her lower right canine and upper right lateral incisor were in cross bite.  Cephalometric analysis indicated a skeletal Class I relationship with average growth pattern. The maxillary and mandibular incisors were mildly proclined with the normal nasolabial angle
  57. Pretreatment cephalometrics
  58. The treatment objectives were:  To correct proclination in both the arches  To correct canine cross bite on the right side  To relieve the crowding  To correct the dental midline  To establish a Class I molar relationship and to maintain a Class I canine relationship  To obtain ideal overjet and overbite
  59. Treatment Progress  Orthodontic tooth movement is initiated with 0.022 slot MBT bracket system in both the arches. 0.016 NiTi was the initial wire, followed 0.017 × 0.025 NiTi, 0.019 × 0.025 NiTi, 0.019 × 0.025 SS. In the maxillary arch premolars and canines retracted separate followed by upper anterior retraction. In the mandibular arch, en masse retraction was carried out.
  60. Post treatment extra oral and intraoral photo
  61. Three years after retention
  62. FIRST MOLAR Extraction of First molars are regarded as the cornerstones of dental arches and are considered to play a key role in the establishment of occlusion by Angle. They are usually not extracted unless otherwise indicated Extraction of first molars is avoided because: • It does not give adequate space to relieve anterior crowding. • Deepening of bite • Poor a proximal contact between second premolar and second molar • Second premolar and second molar may tip into extraction space • Mastication is affected
  63. Indications 1. Minimum space requirement for correction of anterior crowding or mild proclination 2. Grossly decayed/periodontally compromised molar with poor prognosis 3. Impacted molar-rarely seen. 4. First molars are extracted when they are grossly decayed or heavily filled. First permanent molars are highly susceptible to dental caries, especially during childhood, immediately after their eruption. 5. Extraction of first molars may be advantageous in open bite cases as this may lead to deepening of the bite.
  64. Case report :first molar extraction in four quadrents A 12-year-old female who presented with a Class I malocclusion on a Skeletal I base, having an average maxillary–mandibular planes angle and slightly increased lower facial height. She had moderate upper and lower crowding, and her first molars had suffered previous caries. Treatment was carried out using fixed appliances with reinforced anchorage and first molars were extracted in all four quadrants.
  65. Pretreatment photo
  66. Treatment plan  Oral hygiene and dietary advice. Upper palatal arch to upper second molars with anterior Nance button.  Extraction of the upper and lower first molars left and right . Upper and lower fixed appliances using pre-adjusted Edgewise system. Upper removable wrap around retainer. Lower bonded retainer .  The 4 first molars were extracted to relieve the upper and lower crowding.  Three of these teeth were heavily restored and had a poor long-term prognosis.  Because of this the first molars were chosen instead of first premolars, which would normally have been the extraction choice, being nearer to the site of crowding.
  67. Treatment plan  Nance button was fitted to bands on the fully erupted second molars.  This would maintain sufficient upper first molar space for correction of the malocclusion.  The 4 first molars were extracted, the lower second molars banded and all the remaining teeth were bonded with brackets of 0.022x0.028-inch slot size, Andrew’s prescription  Initial alignment was carried out with upper and lower 0.016-inch nickel- titanium wires, using stainless Steel tubing to protect the wires in the extraction sites and lace-backs in all 4 quadrants.  Space was created for the lower lateral incisors by the use of a NiTi coil spring on a lower 0.018-inch stainless steel round wire.  Subsequently, a 0.012-inch nickel-titanium piggy-back arch wire was used to align the lateral incisors to the base arch wire.
  68. After full expression of the round nickel titanium wires, 0.018x0.025-inch rectangular nickel titanium wires were placed, and followed by upper and lower 0.019x0.025-inch stainless steel working wires to allow final space closure. Intra-arch nickel-titanium closed-coil springs in all four quadrants were used for space closure after removal of the upper palatal arch dead ligatures were used to maintain space closure, whilst upper and lower 0.014-inch stainless steel wires were placed with minor bends to allow final tooth positioning. .
  69. No inter-arch elastics were used as this might have reduced the overbite.nickel- titanium closed-coil springs in all four Following debond, an upper removable wraparound retainer was provided for 3 months full-time wear, 6 months night time wear and a lower 0.0175- inch annealed twistflex retainer was bonded lingually to the lower incisors and canines.
  70. Extraction molars
  71. Case reports extraction first lower molar  The patient, male, 13 years and four months old, presented for initial examination with the chief complaint of maxillary incisor protrusion .  He had no sucking or postural habits and had normal swallowing and speech. Regarding oral health,  His mandibular first molar crowns were significantly destroyed.  The mandibular second molars and maxillary first molars showed carious lesions on the occlusal surface and the presence of dental calculi and gingivitis was observed
  72. Pretreatment photo
  73. TREATMENT PLAN  The treatment plan provided for extraction of the mandibular first molars given their crown destruction, and need of endodontic treatment and prosthetic rehabilitation, which would be convenient to avoid in such a young patient.  In order to maintain mechanics symmetry while not depending heavily on patient compliance, maxillary first molar extractions were also planned.  The planned retention consisted of a removable maxillary retainer and an canine to canine bonded lingual retainer in the mandibular arch.
  74. Post treatment photo
  75. Extraction Mandibular second molars  Mandibular second molar is positioned at the end of the dental arch and therefore is away from the site of crowding. Its extraction does not help in relieving the crowding, however, extraction may be indicated in the following cases:  second molar extraction allows distal movement of the first permanent molar. This provides enough space for premolar eruption.  To relieve impaction of mandibular third molar: Since the position of eruption of third molar is variable, extraction of second molar is not usually indicated to relieve third molar impaction.  To prevent lower incisor crowding: evidence shows that patients with lower second molar extraction suffered less lower arch shortening.
  76.  To correct mild to moderate arch length deficiencies existing with good facial profiles .  Severely carious, ectopically erupted or severely rotated second molar .  Open bite cases, extraction may help in correcting the anterior open bite .
  77. Mechanism of extraction of lower second molars in correction of skeletal Class III malocclusion To correct anterior crossbites and normalize molar relationship, the upper arch should move forward and the lower arch backward. Therefore, extractions in the upper arch may be undesirable. Extraction of lower teeth mesial to the first molars might aid correction of the anterior crossbite, but it might also be unfavorable to the correction of molar relationship. Furthermore, occlusal interlocking of all eight premolars might increase stability after orthodontic therapy, which is crucial to treatment of Class III malocclusion
  78.  Extraction of the lower second molars may be a useful treatment option in the management of severe Class III malocclusion. However, such treatment should be carried out after detailed evaluation of third molar position, etc. Although extraction of lower second molars provides enough space to move the lower arch backward compared with the extraction of lower third molars, it has little advantage on relieving crowding in the lower anterior segments. Therefore, to identify the indication of extraction of lower second molars in correction of severe Class III malocclusion is the key for the success of the treatment.
  79. Case Report Lower Second Molar Extraction A 12-year-old girl presented with an anterior crossbite and a concave profile . A concave facial profile was present, in combination with a retrusive maxilla and a protrusive mandible with no mandibular displacement. Surgical correction of the skeletal deformity and facial profile was recommended, but the patient refused the procedure and insisted on an orthodontic correction.
  80. The intraoral examination showed a complete Class III molar relationship on the right side and a super Class III molar relationship on the left side. A crossbite of left maxillary second premolar to right maxillary second premolar was noted .
  81. A Tip-Edge straight-wire appliance was initiated after extraction of the lower second molars. After 4 months of Class III elastics, the anterior crossbite was corrected. Ten months later, a Class I molar relationship was established. At the end of treatment, the patient showed a straight profile, normal overbite, and overjet
  82. The superimposition of pretreatment and posttreatment cephalogram tracings revealed that the retroclination of the lower anterior teeth had changed to a mean of 11.8 degree. A skeletal Class III tendency remained after the treatment with an ANB of 0.68 degree , but the facial profile showed a significant improvement. A follow-up panoramic radiograph showed complete eruption of the lower third molars.
  83. • Success in treatment of the some severe Class III deformity in permanent dentition could be achieved with fixed appliance and extraction of lower second molars. • Fixed appliance in combination with extraction of lower second molars allowed tipping movement of teeth in a larger range and definite and limited skeletal change. • Remarkable soft-tissue change was noted after extraction of lower second molars, and concave facial profile changed to straight profile. • Eruption of lower third molar should be the follow-up after extraction of lower second molar
  84. Extraction mandibular second molar
  85. pretreatment posttreatment
  86. MAXILLARY SECOND MOLARS Indications: 1. In mildly crowded cases, where less than 3-4 mm space is required for the labial segments . 2 . To make space for crowded second premolar by distalization of first molar . 3. When second molar is impacted against first molar second molar extraction is preferred over extraction of severely impacted third molar for which there is no space in the line of occlusion.
  87. Criteria for maxillary second molar extraction and replacement by third molar : • The chronologic and dental age of the patient should be past the average time when second molars would erupt • Size, shape and root area of third molar should be sufficient to serve in place of second molar • Maxillary tuberosity should be insufficient to accommodate all 3 molars • If second molar is in buccal occlusion and third molar is positioned in the tuberosity • Maxillary third molar in favorable angulation for eruption • Second molar severely carious with questionable prognosis.
  88. Contraindications  1. Maxillary third molars positioned high in the tuberosity  2. Poor angulation in relation to second molar  3. Undersized crown or roots  4. Third molar bud is abseent . Timing Maxillary second molar should be extracted when thethird molar has migrated sufficiently in the alveolar bone so that the occlusal surface is approximately level with the vertical midline of the second molar root.
  89. Advantages of second molar extraction • Facilitates treatment using removable appliances • Eruption of third molar is faster • Prevention of dished-in appearance of the face • Few residual spaces at the end of treatment • Good mandibular arch form • Less chances of relapse • Increases overbite hence, in openbite cases Disadvantages • Too much tooth substance is removed in mild crowding cases. • Extraction site away from area of crowding.
  90. Case report extraction upper second molar  Female patient aged 17 years and 01 month, who sought orthodontic treatment complaining of lack of space for her canines
  91. A clinical examination showed a slightly asymmetrical face; lip asymmetry (increased muscle contraction on the left side); lip seal at rest; a low smile line and asymmetry when raising the lips; mesocephalic facial pattern; balanced facial thirds; and convex profile . Case Report extraction upper second molar
  92. Intra oral photo  An intraoral examination revealed parabolic shaped arches; Class II relationship of molars and canines; 4 mm overjet; 50% overbite; teeth 25 and 34 in crossbite; light curve of Spee; lower midline shifted 0.5 mm to the right; severe crowding in the upper arch (-11 mm discrepancy) and crowding in the lower arch (-5 mm discrepancy .
  93. Intra oral photo
  94. The radiographs confirmed the presence of intraosseous third molars with normal anatomy. The upper third molars had fully formed crowns with two-thirds of root formation. The lower third molars were impacted. Supernumerary teeth were also present (Fourth right and left lower molars, and fourth right upper molar), and visible lack of space for correct positioning of the upper canines
  95. Treatment plan  In order to establish a Class I molar relationship as soon as possible and because the patient did not exhibit any growth potential, we opted for upper second molar extraction to facilitate distalization of the upper first molar and class II correction.  Additionally, we also extracted the lower third molars that were impacted and the lower supernumerary teeth. We decided against extracting the upper supernumerary molar given the possibility of damage to the third molar when doing so. The extraction of this tooth was postponed to a future, more convenient occasion.
  96. Treatment plan  After extraction, the upper first molars were banded and a cervical traction headgear was installed (350 g - 16 h / day) for first molar distalization, which was achieved after a period of four months.  The first upper and lower premolars were extracted to address the severe crowding and the protrusion. Subsequently, brackets were bonded to the lower second premolars, canines and central incisors. Brackets were not bonded to the upper and lower lateral incisors on account of the crowding. We used 0.016-in Multi loop "Tweed" style archwires to correct canine mesiobuccal inclination.
  97. Final facial photographs
  98.  After alignment and leveling, the canines were retracted with chain elastics. Brackets were then bonded to the lateral incisors followed by realignment and releveling.  Any residual space was then closed by retraction of the upper and lower incisors using rectangular archwires with bull loops.  Twenty-two months after the extraction of the second molars, third molars were erupted and ready for banding or bonding.  After treatment completion, an upper wraparound removable appliance and a fixed lower canine-to-canine lingual arch were installed for retention.
  99. Results  The patient's extraoral aspect remained as it was initially (Fig 5), except for her profile, which had its convexity reduced.
  100. The radiographs disclosed adequate root parallelism. Moreover, upper third molars were found to be appropriately positioned. At this time the removal of the supernumerary upper molar was performed (Fig 7).
  101.  From a cephalometric standpoint, the skeletal pattern was maintained. The most significant changes occurred in the upper and lower incisors and lips. The upper and lower incisors were retracted. Thus, correction of the dental double protrusion was achieved by moving the incisors to their original position. Due to these dental changes, the lips were retracted, reducing the patient's profile convexity (Figs 5 and 8 and Table
  102. Third molar Extraction of third molar during orthodontic treatment does not yield space for de crowding or reduction of proclination. INDICATIONS 1. The conventional timing of extraction of a third molar is when two-thirds of its root is formed. Extraction of third molar should not be delayed because: • More difficult to remove when roots are completed. • Danger of root dilacerations which may make remova I more difficult. • Pericoronitis can develop and cause bone loss and pocket formation may occur distal to second molar.
  103. INDICATIONS  2. Erupting mandibular third molars have been implicated to be the cause of late lower anterior crowding, although the evidence is not clear cut.  However, it is difficult to detect such a force. In fact, late anterior crowding often develops in individuals whose lower third molars are congenitally missing.  3. Malformed third molars, which interfere with normal occlusion, should be extracted.
  104. Case report mandibular third extraction The 13-year-old patient, in good general health. Her main complaint was related to the presence of anterior cross bite and ectopic eruption of tooth 13. Despite protrusion of the lower lip and little exposure of the upper lip, facial esthetics did not seem to be a concern to the patient . A more detailed examination of occlusion showed the presence of premature contact of the incisors, in a centric relation, leading to a more anterior position of the mandible in centric occlusion. Her mother had reported no Class III malocclusion family history, so, the peculiarities involved in this case point to a multifactorial etiology.
  105. DIAGNOSIS The patient presented significant skeletal discrepancy with ANB angle equal to -3°, (SNA = 82° and SNB = 85°), with good vertical mandibular growth direction (SN-GoGn = 31°)
  106. With regard to the tooth aspect, the patient presented Angle's Class III malocclusions with anterior cross bite, 1 mm overjet, 50% overbite and retroinclined mandibular and maxillary incisors. When handling the mandible in centric relation, premature contact was found in the incisor region which led to functional deviation in the anterior direction that accentuated the Class III malocclusion. Furthermore, moderate anterior-superior crowding, tooth 13 in palato-version, and the mandibular and maxillary midlines coinciding with each other were also found (Figs 1 and 2). When analyzing the facial characteristics, the patient presented a mesocephalic face with a concave profile, proportional facial thirds, lip competence, and absence of significant asymmetries. The lower lip was slightly more protrusive than the upper lip  panoramic radiographs (Fig 3) did not show any significant alteration that would be contraindication to orthodontic treatment
  107. Figs 1 and 2 Fig 3
  108. OBJECTIVES OF THE TREATMENT  The modified Haas expander device was used in the maxillary arch with bands on the first pre-molars and molars that were also encapsulated in the posterior region. Standard metal brackets were then bonded without torque or angulation using the 0.022 x 0.028-in slot edgewise system. In the mandibular arch, in addition to the fixed appliance, a J-Hook high-pull headgear was used.
  109. Post treatment
  110. The Role of Mandibular Third Molars on Lower Anterior Teeth Crowding and Relapse after Orthodontic Treatment: A Systematic Review Khalid H. Zawawi and Marcello Melis ( 2014 ) They concluded that the role of the third molars in the development of anterior tooth crowding cannot be drawn. A high risk of bias was found in most of the trials, and the outcomes were not consistent. However, most of the studies do not support a cause-and-effect relationship; therefore, third molar extraction to prevent anterior tooth crowding or postorthodontic relapse is not justified.
  111. Third molars and dental crowding: different opinions of orthodontists and oral surgeons among Italian practitioners Michela Gavazzi et al (2014) . Studied role of third molars in causing of incisor crowding, especially in the lower arch, continues to be controversial The aim of this work is to compare opinions of Italian oral surgeons and orthodontists on this topic. . Italian orthodontists and oral surgeons have the same opinion on the role of the third molar in causing anterior crowding. The study concluded that majority of both groups of clinicians do not consider their preventive extraction useful in order to prevent anterior crowding.
  112. Thank you
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