Orthognathic surgery

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1. Orthognathic surgery Supervised by Dr.Ahmad Altarawneh Prepared by Dr.Ali Mohammed alsayani

2. Outlines Introduction Diagnosis and assessment Initial Planning The Borderline Patient Camouflage Versus Surgery Indications and contraindications Special Considerations in Planning Surgical Treatment Presurgical orthodontics Orthodontic appliance Stabilizing arch wire Procedure of cast prediction (Model Surgery) Splints and Stabilization Surgical techniques Post surgery Care Retention Stability Adjunctive facial procedure Problems Distraction Osteogenesis References

3. Introduction Orthognathic surgery is surgery aimed to correction of functional and aesthetic of severe dentofacial deformity through combination of orthodontic , surgical and possibly restorative dentistry.

4. However, the most common reason for patients seeking combined orthodontic and surgical treatment is dental and/or facial aesthetic problems.

5. Diagnosis and assessment History : Patient age. Patient concern. Patient motivation& expectation. Psychological status. Medical and dental history.

6. 2) Clinical Examination: Assess skeletal , soft tissue and dental features. 1. Extra oral features:- A) Frontal analysis Symmetry

7. Vertical proportions In normal proportions the face can be divided into three equal thirds. The lower third can be divided so that the commisures of the lips is one third of the way from the base of nose to chin.

8. Lip line At rest 2-4 mm of incisor show. During smiling, whole length of incisor is showing. If there is excess of gingiva is showing, it may referred as a gummy smile.

9. B) Profile analysis The patient should be assessed in the natural head position. The middle and lower thirds are assessed in relation to the forehead. In normal profile, the base of the nose lies approximately vertically below the anterior part of the forehead .

10. It is a line joining the soft tissue chin and tip of nose. Normal value; 0- 2mm(+/-2mm). In normal face, lower lip lie on or anterior to this line and upper lip little further posterior. Rickett’s E-line

11. zero meridian line It is a line perpendicular to FH –line passing through the soft tissue nasion to measure the position of the chin. Ideally passes through the soft tissue Pogonion ( 0 +/-2mm).

12. Harmony line & angle It is a line from soft tissue pogonion through upper lip bisecting the nose. H-line angle formed between H-line and line joining N to Pog. The Average value 7-15 degree. Measures upper lip prominence and/or retrognathic soft tissue chin.

13. Nasolabial angle Angle formed by joining tip of nose, sub nasal and labrial Superioris. The normal value 90-99 degree. The Nasolabial angle should be noted, as it can be affected by excessive retraction or proclination of the upper incisors.

14. 2. Intra oral features A full assessment of the dentition and occlusion needs to be undertaken. Any dental disease needs to be identified , treated and stabilized before combined orthodontics and orthognathic surgery can begin.

15. 3) Temporomandibular Joint ( TMJ ) The presence of any signs or symptoms of TMJ dysfunction such as limitation of opening , noises , pain should be noted. Any symptoms should be treated conservatively prior to treatment.

16. 4) Radiographic Examination This usually includes radiographs taken as part of the routine orthodontic assessment of a patient with a skeletal discrepancy. A panoramic dental view (OPT) , a lateral cephalometric radiograph. Additional views may be needed depending on the case. For example; PA skull radiograph may be taken to assess asymmetry.

17. Planning for orthodontic/orthognathic surgary A team approach composed of an orthodontist , surgeon , restorative dentist and psychologist if needed. Using the information taken from the history , clinical examination and diagnostic records, it should be possible to create a problem list. Establish where the problem maxilla , mandible or both.

18. The Borderline Patient Camouflage Versus Surgery The envelope of discrepancy shows the amount of change that could be produced by orthodontic tooth movement alone (the inner envelope ), orthodontic tooth movement combined with growth modification (the middle envelope) and orthognathic surgery (the outer envelope). Soft tissue limitations not reflected in the envelope of discrepancy often are a major factor in the decision for orthodontic or surgical–orthodontic treatment.

19. Indications of orthognathic surgery Severe CI 3 Severe CI 2 Long face syndrome/AOB Facial asymmetries Chin abnormalities Craniofacial anomalies e.g. CLP

20. For class II according to Proffit 1992 OJ > 10mm ANB > 9° Pog posterior to N perpendicular > 18mm Mandibular length > 70 mm Anterior facial height > 125mm

21. For class III according to Kerr et al 1992 ANB = - 4°. maxillary mandibular ratio = 0.84. lower incisor inclination (LI/MP = 83°). Soft tissue profile (Holdaway angle = 3.5°). *vertical dimension had little effect on treatment decision.

22. Contraindications &/or limitations Growing patient Minor cases Medical condition Psychologically unstable patient

23. Special Considerations in Planning Surgical Treatmen Orthognathic surgery should be delayed until growth is completed in patients who have problems of excessive growth (mandibular prognathism ) patients who have problems of growth deficiencies, surgery can be considered earlier but rarely before the adolescent growth spurt.

24. The major indication for orthognathic surgery before puberty is:- a progressive deformity. severe psychosocial problems caused by restriction of growth due to ankylosis of the mandible after a condylar injury or severe infection.

25. Other Considerations Special Points in Planning Orthognathic Surgery If the attached gingiva is inadequate, gingival grafting should be completed before genioplasty to prevent recession of the gingiva in the lower incisors. Remove the lower third molars at least 6 months before orthognathic procedure.

26. Correction of combined vertical and anteroposterior Problems Short face Class II patients ( Increasing AFH ) : Mandibular ramus surgery is preferred to increase face height with downward movement of the posterior maxilla, so that the mandible is forced to rotate down and back .

27. Long face Class II patients ( Decreasing AFH ): A LeFort I osteotomy to elevate the posterior maxilla is preferred to reduce face height but If the mandible is still deficient after it rotates up and forward , mandibular advancement should be done. For Class III patients, the same guidelines for vertical change are applicable.

28. Presurgical orthodontics Alignment and leveling Decompensation. Arch coordination Presurgical orthodontics objectives in the transverse plane Presurgical orthodontics objectives in the vertical plane

29. Alignment and leveling Dental crowding, spacing, and rotations should be corrected before orthognathic surgery. If segmental osteotomy is planned we should provide spaces between the roots, so we can tip the bracket

30. Curve of spee should be flat (according to ideal occlusion) A better result may be achieved by completing leveling post surgically .

31. In short face , when an increase in face height is desired, lower incisors should not be depressed before surgery. Maintenance of curve of spee is needed(3- point landing). In normal or excessive face height , leveling by intruding the incisors should be done before surgery.

32. Decompensation Compensations can be dental or skeletal, vertical, transverse and/or sagittal. Presurgical orthodontic decompensation is essential to enable the surgeon to make a considerable amount of surgical correction

33. Decompensation

34. Decompensation in class II Procline upper incisors. Retrocline lower incisors. Use class III elastic. Decompensation in class III Retrocline upper incisors. Procline lower incisors. Use class II elastic.

35. Decompensation in deep bite Extrusion mechanics to molars. Incisors also need to be extruded. clockwise rotation of mandible occurs. L.F.H increases & chin prominence reduces.

36. Decompensation in open bite The presurgical orthodontics should accentuate the open bite through intrusion of the labial segments and extrusion of the buccal segments .

37. Dental extrusion of skeletal open bite will be unstable in the long run. It may also create an excessive display of gingiva. Reversed curve of spee should be levelled.

38. Arch coordination Arch coordination refers to coordinating the widths of the dental arches. Coordination involves:- Arch expansion. Arch contraction. Occlusal plane leveling and alignment.

39. Presurgical orthodontics objectives in the transverse plane The problem is the skeletal or dental Dental discrepancies are usually treated by means of buccal tipping of the posterior teeth while skeletal discrepancies are corrected by bodily movement of the posterior teeth. the tipping should not exceed 4 to 6 mm total. Bodily movement of the posterior teeth should be done by means of segmental osteotomy.

40. Is the problem relative or absolute Articulation of the casts into a class I occlusion allows the clinician to easily distinguish between relative and absolute maxillary constriction. If the occlusion is proper when the casts are brought into class I canine relationship the discrepancy is relative; otherwise, if a crossbite still exists, then the discrepancy is absolute.

41. Absolute skeletal transverse discrepancy requires planning for segmental osteotomy or surgically assisted rapid palatal expansion (SARPE). SARPE technique is used in cases with a severe discrepancy or when the transverse defect of the maxillary bone is an isolated skeletal anomaly. Segmental maxillary osteotomy is used for more modest defects (up to 7 mm).

42. Orthodontic appliance Use metal bracket is the best. Use 0.022 slot to allow use rigid wire for more stability. Second molar should be banded.

43. Stabilizing arch wire As the patient is approaching the end of orthodontic preparation for surgery. The stabilizing wires are full-dimension edgewise wires (i.e., 17 × 25 steel in the 18-slot appliance, 21 × 25 TMA or steel in the 22-slot appliance). Hooks as attachments to tie the jaws together while rigid fixation is placed.

44. Stabilizing archwires should be placed at least 4 weeks before surgery so that they are passive when the impressions are taken for the surgical splint (usually 1 to 2 weeks before surgery). Minor interferences that can be corrected easily with archwire adjustments can significantly limit surgical movement.

45. Procedure of cast prediction (Model Surgery) The selection of articulator is the first step in preparation for effective model surgery. Face Bow Selection.

46. The maxillary dental cast is mounted on a semi adjustable articulator with the aid of a facebow transfer from the patient. The mandibular dental cast is mounted with the aid of a bite registration taken with the patient's jaws in centric relation.

47. Model simulation for surgical movement . The sequence of movements are: The maxillary cast is repositioned and fixed in the new position on the articulator. intermediate occlusal wafer splint is generated. The mandibular cast then is repositioned to oppose the maxillary cast, simulating the final position of the jaws at surgery. This final position generates the final occlusal wafer splint for use at surgery and during the period of jaw rehabilitation following surgery.

48. Splints and Stabilization The splint should be thin 2mm thickness with adequate strength. Splint stays in place during initial healing ( 3 to 4 weeks). It should be trimmed to allow good access to the teeth for hygiene and permit lateral movements during jaw function. It should remain in place until the stabilizing wires also are replaced with lighter and more flexible archwires

49. Surgical techniques

50. in general can achieve+ 1cm movement, mainly used to correct maxillary excesses and AOB. Procedures Segmental ;- Wassmund/ Wunderer (anterior). Schuchardt (posterior). Le Fort I osteotomy Le Fort II osteotomy Le Fort Ill osteotomy ± Kufner modification, does not alter position of nose Maxillary Surgical procedures

51. Maxillary Surgery

52. Total maxillary osteotomy Le Fort I. Osteotomy The surgical cut goes through the wall of the maxillary sinuses , lateral nasal walls and the nasal septum at the level just superior to the apices of the maxillary teeth. Le Fort II osteotomy It is a pyramidal osteotomy, it differs from Le Fort I that it passes anteriorly toward the orbit. It is used mainly with CLP. Le Fort III osteotomy It is used for the correction of symmetrical mid-face recession affecting zygomatico-maxillary and orbital regions.

53. Le Fort III modified Kufner (does not alter position of nose) Used when the nasal bridge and projection are both good, but the infra orbital region and the dentoalveolus are retruded, with mild zygomatic flattening.

54. Segmental alveolar maxillary osteotomy: Anterior segmental osteotomy: Mobilize the anterior segment of the maxilla and allows the reposition in an upward, downward and a rotational manner. Posterior segmental osteotomy. Anterior and posterior segmental osteotomy.

55. Anterior segmental osteotomy: Typical sites for interdental osteotomies are between laterals and canines, premolars and canines, or between incisors.

56. Segmental osteotomy between maxillary laterals and canines.

57. Indications:- Poor transverse relationship of the maxilla and control of intercanine width. Correcting Bolton discrepancy. Controlling incisor buccolingual angulation. An easier technique.

58. Advantages:- Single-stage surgery. Intraarch asymmetry correction. Controlling the Curve of Spee. Controlling the Curve of Wilson.

59. Disadvantages :- When there are already 2 occlusion planes between canines and premolars. When there is maxillary anteroposterior skeletal excess and premolar extractions are planned.

60. Maxillary osteotomies for transverse problems LeFort I down fracture surgery with parasagittal osteotomies It consist of parasagittal osteotomies in the floor of the nose or floor of the sinus that are connected by a transverse cut anteriorly. LeFort I down fracture surgery with mid sagittal osteotomies . Surgically-assisted palatal expansion : U sing bone cuts to reduce the resistance without totally freeing the maxillary segments, followed by rapid expansion of the jackscrew .

61. Soft tissue effects of Le Fort I advancement Nasal tip is advanced by one sixth of the maxillary advancement (Henderson et al 1984). AP advancement of the lip 60-80% and the tip of nose 20%. NLA decreased. Upper lip flattens. Vermilion exposure increased. Increase in the width of the alar base. Tip of nose move superiorly. Lower lip rolled and advanced.

62. in general can achieve± 1cm movement, mainly used to correct Cl 2/3 problems. Procedures Condyle. Segmental - Kole osteotomy. Body osteotomy (rarely used). Ramus - bilateral sagittal split osteotomy (BSSO). Vertical subsigmoid osteotomy (VSS). C-shaped and inverted L osteotomy (rarely used) ± grafts. Genioplasty -augmentation, reduction, asymmetries. Mandibular Surg ical procedures

63. Bilateral Sagittal Split Osteotomy (BSSO) Mandibular Surgery

64. Bilateral Sagittal Split Osteotomy (BSSO) Indication:- Mandibular advancement(less than 10 -12 mm). Mandibular set back (less than 7-8 mm). Correction of asymmetry (Minor). Anterior open bite patient with maxillary operation to reduce the posterior facial height.

65. Vertical Subsegmoid Osteotomy (VSO) Indication: Large mandibular set back. Restricted mouth opening. Thin ramus.

66. Inverted L osteotomy Indications:- Big advancement where the mandibular rami are deficient both vertically and horizontally. Big set back. Big asymmetry.

67. Body osteotomy (rarely used) The objective is to remove a pre-planned segment of mandibular body allowing the anterior segment of the jaw to be set back.

68. Lower labial segmental osteotomy (Subapical osteotomy) Indications: 1- An exaggerated curve of Spee. 2- Correction of bimaxillary protrusion. Anterior mandibuloplasty It combines lower labial segment surgery with simultaneous genioplasty , all the cuts being continuous.

69. Genioplasty in Orthognathic Treatment A. Reduction genioplasty: 1- Vertical reduction genioplaty. 2- Horizontal reduction genioplasty. B. Augmentation genioplasty: 1- Vertical augmentation. 2- Horizontal augmentation. (sliding or double sliding genioplasty)

70. Post surgery Care Mandibular osteotomies almost never requires an overnight stay , maxillary osteotomies typically require overnight hospitalization and two-jaw surgery almost always requires 1 to 2 days hospital stay. Patients require surprisingly little pain medication, particularly following maxillary surgery.

71. The first week after surgery, Patients are advised to maintain a soft diet and advised to open and close gently within comfortable limits. The next 2 weeks, patients advice to progress to foods that require some chewing and three (10-15minute) sessions of opening and closing exercises as well as lateral movements are indicated, with the patient closing into the splint.

72. From the third to the eighth week , the range of motion is increased. By 6 to 8 weeks after surgery , they should be back on a normal diet. This c oincides with the time when the orthodontist can allow the patient to eat without the use of elastics.

73. Postsurgical Orthodontics (6 - 8 weeks) Once a range of motion is achieved and the surgeon is satisfied with the initial healing, the finishing stage of orthodontics can be started. With rigid fixation, this now is at 2 to 4 weeks post surgery. The splint is removed, the stabilizing arch wires are also removed and replaced by working wires to bring the teeth to their final position.

74. Light vertical elastics are needed initially with these working arch wires . The typical settling of teeth into full occlusion can be achieved rapidly using light round wires (16 mil steel) and posterior box elastics with an anterior vector.

75. A flexible rectangular wire in the upper arch to maintain torque control of the maxillary incisors (in 18-slot, 17 × 25 TMA & in 22-slot, 21 × 25 M- Niti often is a good choice, with a round wire in the lower arch. Patients wear the light elastics full time, including while they are eating for 4 weeks , then for the first 4 weeks full time except for eating followed by another 4 third weeks night time wearing.

76. Retention Retention after surgical orthodontics is no different than for other adult patients. One important exception; if the maxilla was expanded transversely, it is important to maintain the expansion during the finishing orthodontics with full-time retainer wearing in the maxilla for at least 6 months. If a transpalatal lingual arch was placed following surgery, it should not be removed during the first postsurgical year.

77. Stability Profitt produce a hierarchy of stability:- Maxillary superior movement – very stable. Mandibular Advancement – stable. Two jaws surgery – stable with rigid fixation. Mandibular Setback – unstable. Maxillary inferior movement – unstable. Maxillary transverse expansion – very unstable.

78. Adjunctive facial procedure A variety of adjunctive facial procedures can be used as adjuncts to orthognathic surgery to improve the soft tissue contours beyond what is available from repositioning the jaws.

79. Adjunctive facial procedure Chin procedure (Augmentation or Reduction) Rhinoplasty Lip Procedures (Augmentation or Reduction) Sub mental Procedures

80. Rhinoplasty

81. Lip Procedures

82. Submental Procedures

83. Problems Surgical:- Morbidity of surgical procedure. 20-25% Risk of permanent altered sensation with BSSO. Increase alae width with fullness of upper lip with maxillary impaction. Double chin with mandibular set back. Lip sag following augmentation genioplasty.

84. Orthodontic:- All associated risks of orthodontic treatment. Problems with closure of old Xtn spaces, root resorption, inadequate expansion. Risk of periodontal recession especially around lower incisors in Class III cases.

85. Relapse:- Variable depending on procedure. Increase risk when mandibular procedures are used to close AOB due to stretching of pterygo-massetric sling.

86. Distraction Osteogenesis It is an inducing a callus of bone by osteotomy or corticotomy followed by distraction of proximal and distal ends resulting in increase of bone length. llizarov first to define practical use in limb lengthening by corticotomy.

87. Indications :- Correction of severe congenital craniofacial defects ; (Micrognathia, Midface retrusion, Craniofacial anomalies). Maxillary hypoplasia due to previous cleft palate surgery . Palatal and mandibular expansion . Dentoalveolar hypoplasia for implant insertion . Tumour/trauma reconstruction . TMJ ankylosis.

88. Technique :- Corticotomy or osteotomy. 7 day latency period , until intact vascular supply established. Prolonged, progressive and gradual distraction , correct rate and rhythm of distraction which should be 1mm/day: below 0.5mm / day ---- premature union above 1.5mm / day ---- non-union Consolidation period of 8-10 weeks.

89. References Contemporary Orthodontic 5 th edition – William R. Proffit . Postgraduate Notes in Orthodontics 7 th edition Excellence in orthodontic 2010 – David Birnie , Nigel Harradine. Why segment the maxilla between laterals and canines? Lucas Senhorinho Esteves1, Jean Nunes dos Santos2, Steven M. Sullivan3, Orthodontic Preparation for Orthognathic Surgery Abdolreza Jamilian, Alireza Darnahal and Letizia Perillo

90. Thank you