MAXILLRY OSTEOTOMY.pptx

MAXILLARY OSTEOTOMY BY DR. SHIVARAJ W

1. Dr.shivaraj.s.wagdargi ORAL AND MAXILLOFACIAL SURGERY MAXILLARY ORTHOGNATHIC PROCEDURES

2. CONTENTS: Common dento -facial deformities Diagnosis and treatment planning for orthognathic cases Surgical anatomy of mid-face Timing of surgery Surgical approaches to mid-face Types of mid-face osteotomy Complications Conclusion References.

3. COMMON DENTOFACIAL DEFORMITIES: MAXILLARY DEFORMITIES 1) Maxillary anteroposterior excess (AP) Protrustive maxilla where there is an overgrowth in an anterior horizontal direction. There is often a Class II molar relationship, sometimes combined with mandibular protrusion ( Bimaxillary protrusion )

4. Diagnosis and treatment planning for orthognathic surgery

5. Definition: Orthognathic surgery - is the art and science of diagnosis, treatment planning and execution of treatment by combining orthodontics and oral and maxillofacial surgery to correct musculoskeletal, dento -osseous and soft tissue deformities of the jaws and associated structures.

6. Specific Therapeutic Goals: 1. Correct masticatory and/or swallowing abnormalities. 2. Establish a functional occlusion overbite, overjet, occlusal plane angulation and transverse dimension. 3. Correct inability to open or close the jaws. 4. Correct associated TMJ dysfunction, pathosis or pain . 5. Correct structural abnormalities resulting from over or under development. 6. Decrease or eliminate Myofascial pain and or head aches .

7. Patient evaluation and Diagnosis : Gathering diagnostic information involves : Patient concerns – to determine the patient’s feelings about the existing problems and their expectations for treatment results Clinical evaluation Radiological analysis – cephalometric anaylsis , OPG Dental Model Analysis Others – speech, audiometry, psychological , medical

8. Treatment planning Dental and periodontal treatment : The main objective is to maintain as many of the teeth as possible and to stabilise the periodontium prior to orthodontic and surgical intervention. Extractions: To facilitate orthodontics ie . Bicuspids To facilitate subsequent surgery- lower third molars extracted 9-12 months prior to sagittal split osteotomy otherwise there will be weakened lingual cortex. Pre-surgical orthodontics Position the teeth over their respective basal bone Align and level the teeth Adjust for tooth size discrepancies Correct rotated teeth Divergence of roots adjacent to surgical sites.

9. Timing of surgery As a rule of thumb it is better to wait till the skeletal growth is completed before doing orthognathic surgery. Maxillary growth usually ceases 2 years before mandibular growth completion but there is a difference of 6 years in late maturers . Post menarche growth of maxilla is negligible. Radius epiphyseal fusion is a definite indicator of completion of maxillary growth. Surgical correction for maxillary excess is not contraindicated during growth period as reduction in growth of maxilla helps in the surgical measure for the patient.

10. Surgical approach to Midface: Wasmund 1935,Axhausen 1937 & 1939 and Schuchardt 1942 developed approaches initially to anterior maxilla and later to posterior and whole maxilla Extra Oral Approaches To Midface

11. Types of mid-face osteotomies : Single tooth osteotomy Corticotomy Anterior segmental osteotomy Wassmund (1935) Wunderer (1963) Epker and Wolford(1980) Cupar Posterior segmental osteotomy Schuchardt (1959) Kufner (1971) Horseshoe osteotomy Wolford and Epker (1975) SEGMENTAL MAXILLARY SURGERY :

12. Total maxillary surgery Le-Fort I osteotomy Classic down-fracture(Bell 1969-75) Surgically assisted maxillary expansion(buttress release) Quadrangular (Keller and Sather 1990) Le-Fort II osteotomy Anterior Le-Fort II osteotomy (Converse et al 1970) Pyramidal Le-Fort II osteotomy(Henderson and Jackson 1973) Quadrangular Le-Fort II osteotomy( Kufner 1971) Le-Fort III osteotomy Gillies (1940s) Tessier(1950s and 60s) Other mid-face osteotomies Zygomatic osteotomies Malar-maxillary osteotomy( Obwegeser 1969) malars attached as wings to maxilla.

13. Anterior segmental maxillary osteotomy: Where alteration of premaxilla in the vertical plane is required as in anterior open bite or deep overbite . Three techniques are described but the downfracture technique is preferable when vertical movement is needed. Frontal view of set back procedure Lateral view – extraction of premolars Palatal view- shaded area shows ostevtomy to set-back the anterior segment.

14. Wassmund technique (1935) Preserves both buccal and palatal soft tissue pedicles. Vertical mucosal incision b/w Canine & PM (gingival margin to level of anterior nasal floor. superior to the root apex of maxillary canine.) Mucoperiosteum reflected to apical 3 rd of max canine Tunnel subperiostelly expose nasal piriform aperture Extraction or presurgical space of 3 – 5 mm.

15. 6 ) ) Osteotomy – bony cuts done leaving 2mm over the adjacent teeth 7)Bone in midpalatine region is thick, sometimes a midpalatal incision may be required. 5) Palatal mucosa reflected to just past the midline

16. Repeated on opposite side Dentoalveolar segment disarticulated from nasal septum Anterior midline mucoperiosteal incision reflected nasal septum osteotome malleted above nasal spine to free the segment from the septum. After mobilising – segment is placed in the occlusal splint. Palatal soft tissue pedicle checked for any folds, compromising the blood supply

17. Wunderer technique: Similar to Wassmund , except the palate is exposed by a transverse palatal incision with the margins away from the osteotomy line. This incision is combined with buccal vertical incisions in the region of planned extraction or interdental osteotomies. A. Reflection of tissue in preparation for palatal osteotomy in Wunderer technique B. Gentle outfracturing of the anterior maxillary segment after completion of Wunderer technique

18. Advantage : Direct palatal access which allows the ability to create transverse osteotomy through a molar site  this osteotomy technique relies on the intact buccal pedicle for its blood supply. Modification: Include a mid-line vertical incision to achieve access to complete the horizontal osteotomy through a subperiosteal tunnel connected with the vertical incisions at the extraction sites.

19. Cupar method : Is a surgical procedure most commonly used for AMO. It is a minor version of downfracture technique . Technique : A buccal vestibular incisions is created, allowing direct access to the anterior lateral maxillary walls, piriform aperture and nasal floor and septum. Horizontal osteotomy nasal mucosa is elevated from the superior surface of the maxilla Followed by vertical osteotomy bilaterally between the teeth

20. 4. Through this vertical cut, transpalatal osteotomy is completed with an osteotome . 5. A finger is placed on the palatal mucosa to palpate the osteotome and transpalatal ostectomy is completed 6. Fixation is compelted by occlusal stent stabilisation , osseous wiring or rigid internal fixation Rigid fixation  use of stent can be reduced to 6weeks duration Only occlusal stent 3months.

21. Posterior segmental maxillary osteotomy:

22. Surgical technique: Most commonly performed as a single-stage procedure through a buccal vestibular incision extending from the canine region to that of the second molar below the zygomatic buttress. Followed by vertical incisions in the region of anterior and posterior osteotomies can be created and combined with a parasagittal palatal incisions.

23. Horse-shoe osteotomy :

24. Le-Fort I osteotomy: 1) CLASSIC LE-FORT I DOWN-FRACTURE: Bell et al.(1969-1975) – laid the biological foundations for the safety of the Le Fort I downfracture osteotomy. Using 14 adults rhesus monkeys , they undertook microangiographic and histological studies of total maxillary ostoemtomies undergoing healing at various time intervals . They found : Only transient vascular ischaemia Minimal osteonecrosis Early osseous union.

25. Hence their results demonstrated : As long as the maxilla is pedicled to palatal mucosa and labio-buccal gingivae and mucosa , there was adequate nutrient pedicles required for Le-Fort I down-fracture and maxillary viability. Segmentalization , stretching of vascular pedicles and transection of the descending palatine vessels had no discernible effect on revascularisation or bone healing associated with Le Fort I osteotomies. Bell’s work permitted technical advances in total maxillary surgery such as: Allowing full mobilisation of maxilla hence reducing risk of relapse Permitting bone surgery under direct vision.

26. Quadrangular LeFort -I osteotomy: First reported by Keller and Sather (1990) , who reviewed 54 patients . This is similar to the Quadrangular LF II osteotomy with the exception that the inferior orbital rims are not mobilised . Indications: Significant maxillary midline shifts (> 2mm) and maxillary vertical (>5mm) and transverse discrepancies which cannot be normally corrected with LF-II procedure. It is basically a high LF-I osteotomy that incorporates almost all anterolateral aspects of maxilla below infraorbital nerve and parts of body of malar.

27. LE- FORT II OSTEOTOMY

28. Le-Fort II osteotomy: Steinhauser (1980) provided an excellent review of LF-II osteotomies and classified them into 3 types : Anterior LF-II osteotomy (Converse et al 1970) Pyramidal LF-II osteotomy (Henderson and Jackson 1973) Quadrangular LF-II osteotomy (Keller and Sather 1987)

29. LE-FORT III OSTEOTOMY

30. High level midface osteotomy surgery LF-III osteotomies was first reported by Gillies and Harrison in 1950. However, extensive pioneering work by Tessier in the 1960s established the feasibility of routinely performing the LF-III osteotomy to correct severe midfacial congenital deformities as commonly found in craniofacial dysostoses such as Aperts , Crouzon and Pfieffer syndromes.

31. Technique :

32. COMPLICATIONS OF MAXILLARY OSTEOTOMY

33. 1. Vascular Compromise: Cyanosis or ischemia in the flaps warrants immediate attention. Loss of arterial supply to an osteotomised segment can result in complete or partial loss of that segment, leaving a significant functional and aesthetic defect. Venous congestion can also result in loss of tissue , but usually not as complete. Management of flap ischemia : Remove MMF and splints Angiographic definition of occluded or spastic vessels Anticoagulation Directing vasodilating agents Transfusion and /or Hyberbaric O2 treatment

34. 2. Hemorrhage : Excessive bleeding encountered during maxillofacial osteotomies is usually controlled by conventional method. Regional vascular structure is identified  it is ligated , clipped or cauterised. Involved vessels cannot be identified packing the wound False impression that bleeding is controlled due to hypotensive anaesthesia  especially true when the patient becomes normotensive or experiences a transient increase in blood pressure in the early postoperative period. Failure to treat the haemorrhage can result in significant soft tissue swelling, airway compromise, flap compromise and significant blood loss

35. 3. Infection:

36. 4.Oedema Excessive oedema is common in midface surgeries. Cause : due to laxity of subcutaneous tissue of midface. Management : Shelton and Irby (1980) recommended use of steroids in initial post operative period. They used dexamethasone sodium 8-10 mg, 6th hourly, first dose being started at operating room. This is continued for 48 hourly and following this methyl prednisolone acetate 80 mg. is given for next 2 days

37. 5. Incorrect line of fracture

38. 6. Loss of Segment: Decreased blood flow may lead to loss of segment and delayed union. This can occur in segmental surgeries. Cause : Improper vascular pedicle and subsequent ischemic necrosis. Rare in  retained buccal mucosal pedicle Common  total sulcus incision. The damage to palatal mucosa during palatal bony cut is common cause of this. Use of ill fitting splints which causes excessive pressure can cause ischaemia. Avascular necrosis will lead to gingival infection, gingival recession, loss of alveolar bone, loss of teeth and total loss of segment.

39. Ischemic Necrosis If ischemic necrosis occurs- Keep good oral hygiene. Prophylactic antibiotics to be given. Retain teeth as much as possible. Some bone may revascularise later. Epker 1984 recommended the following steps to avoid ischaemic necrosis Avoid transection of greater palatine vessels . Stretch (as opposed to tear) the soft tissue during mobilisation of maxilla. Make appropriate palatal soft tissue relaxing incisions for simultaneous expansion. Consider a vertical vestibular incision in potentially troublesome cases.

40. 7. Donor site morbidity: Ilium : Most common site for harvesting donor bone but less commomly used in orthognathic cases. Keller and Triplett and Arrington and coworkers cited complications that occur at the ilium donor site: Wound breakdown due to improper wound closure and the occurrence of hematoma or seroma Abdominal and urologic complications due to failure to limit the surgical dissection of ilium Detachment of the lateral thigh musculature , producing pain at the donor site.

41. 8. Fever : Post-operative fever is seen in almost all patients undergoing orthognathic surgery. It is usually low grade, app. 38°(100.4°F)  when the temperature rises above this level, patient evaluation is necessary History and physical examination usually identify the source of the fever.

42. 9. Metabolic disturbances: If oral intake is severely limited for 48 hours, fluid and electrolyte abnormalities can occur. Cause: The most common post-operative fluid disorder is volume overload characterised by an isotonic expansion of the extra-cellular fluid compartment  usually occurs as a result of excessive infusion of isotonic sodium solution during surgery. Water retention as a result of postsurgical antidiuretic hormone secretion can further add to the volume expansion. Management – Diuretics 25mg of furosemide produces an adequate diuresis.

43. 10. Nerve injury

44. 11. Loss of tooth vitality and sensitivity.

45. 12. Oroantral and oronasal fistula This usually follows a tear in palatal mucosa and in nasal mucosa . Cause : This occurs mainly in maxillary expansion with mid palatal procedures. Management : Careful soft tissue handling will minimise the complication . If such a communication does occur, the tissue is allowed to mature for 6-9 months , during this time defect can be covered with acrylic splints. Later closure using local flap can be considered.

46. 13. Velopharyngeal incompetence

47. 15. Relapse:

48. CONCLUSION Orthognathic surgery has made it possible to reposition of either or both jaws in all possible directions. This has provided solution for the patients with severe dentofacial problems and malocclusion. The basic principles of surgery and our understanding of vascular anatomy continue to be the cornerstone while performing these osteotomies Any violations of these basic principles will frequently lead to undesirable complications Proper diagnosis and careful treatment planning will always provide efficient results to our patients

49. References : Fonseca RJ Oral and Maxillofacial Surgery: Orthognathic Surgery 2 nd Edition Volume 2 Peterson’s Principles of Oral and Maxillofacial Surgery 2 nd Edition Volume 2 Essentials of Orthognathic Surgery –Johan P.Reyneke Orthognathic surgery – A Synopsis Of Basic Principles & Surgical Techniques. Mani V Orthognathic Surgery: Esthetic Surgery of the Face 

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