Le fort i maxillary osteotomy

EXCELLENT PPT ON LEFORT I

1. Le Fort I Maxillary Osteotomy Dr J ameel Kifayatullah Oral and maxillofacial surgeon Khyber college of dentistry [email protected]

2. Treatment /Reconstructive Goals To establish proper function and esthetics through establishment of the appropriate form and position of the jaws, a Class I occlusion with appropriate bucco -lingual relationship and appropriate overlap and overjet with aesthetic vertical and soft tissue relationships

3. Indications Correction of maxillary Hypoplasia and Hyperplasia Vertical excess and deficiency Asymmetry Transverse anomalies Occlusal plane abnormalities Obstructive sleep Apnoea Access to pharynx and base of skull for tumor resection

4. Contraindications Major medical comorbidities with poor operative tolerance Cardiac disease with inability to tolerate hypotensive anesthesia Presence of active dentoalveolar infection Maxillary posterior repositioning in the presence of constricted airway anatomy or obstructive sleep apnea A patient in active growth phase Possible need for postoperative maxillomandibular fixation in the presence of underlying substance abuse, psychiatric illness, or uncontrolled seizure disorders Need for presurgical orthodontic treatment Major discordance between patient’s and surgeon’s goals and expectations Poorly compliant patient with toxic habits including, but not limited to, incessant smoking, substance abuse, or poor personal and oral hygiene Questionable blood supply to the maxilla as seen in multiply operated patients (e.g. cleft palate) or patients with a history of radiation therapy to the region

5. The important surgical bony landmarks piriform nasal apertures the lateral nasal walls/medial sinus walls the nasal septum and vomer , the anterior nasal spine, the infraorbital foramen and neurovascular bundle the lateral maxillary wall , the maxillary tooth apices, the zygomaticomaxillary buttresses , the pterygomaxillary fissure and pterygoid plates.

6. Vascular landmarks  The internal maxillary artery enters the pterygopalatine fossa approximately 16.6 mm above the nasal floor and gives off the descending palatine artery. The descending palatine artery travels a short distance within the pterygopalatine fossa and then enters the greater palatine canal. It travels approximately 10 mm within the canal in an inferior, anterior, and slightly medial direction to exit the greater palatine foramen in the region of the second and third molars . The osteotomized maxilla depends on the rich collateral circulation provided by the ascending pharyngeal artery and the ascending palatine branch of the facial artery.

7. VASCULAR LANDMARKS

8. Patient positioning and draping The patient is positioned on the operating table supine with the head in a head holder. For corrective bone surgery, the whole face including the lower part of the forehead and eye brows, the auricles and the superior part of the neck need to be visible, and not covered with drapes. The nasal anaesthetic tube is covered with sterile adhesive tape and the cranium covered with two sterile drapes as illustrated. The eyes are protected with a bland eye ointment and the lips are lubricated.

9. Anaesthesia considerations Execution of the surgical procedure is best done with controlled hypotension, the use of local anesthesia with vasoconstrictor and nasotracheal intubation

10. Vertical reference Point  A screw inserted into the glabella (the root of the bridge of the nose) provides a good vertical reference point. The procedure starts with the insertion of a 12-14 mm long screw with a cruciform head into a 6-8 mm hole drilled into the glabella . The distance between the middle of the cruciform head and the arch wire is measured with a caliper and recorded. All vertical changes are then measured against this reference distance.

11. Reference point in posterior region Place reference hole in buttress region to allow for accurate posterior/superior positioning

12. Incision

13. Circumvestibular Incision Incisions are made in the vestibule above the apices of the teeth from the upper right to the upper left first molar(parotid papilla identified and protected). The incision is made through the mucosa, submucosa , underlying facial muscles and periosteum

14. Exposure of surgical site The maxilla is exposed from the anterior nasal spine to the tuberosity and pterygoid plates Subperiosteal dissection carried out superiorly and posteriorly to expose piriform rim,infraorbital foramen,zygomatic buttress and posterior maxilla Sharp periosteal elevators are used to strip the soft tissues in the subperiosteal plane to expose the anterior maxillary wall, pyriform rims and nasal apertures, and zygomatico -maxillary buttresses. The periosteal dissection is performed in a systematic fashion.

15. Subperiosteal Dissection

16. Dissection

17. Exposure gained

18. OSTEOTOMY CUTS Roots of the canine and upper first molar is marked for guidance Bone cut 5 mm above canine root is marked Cuts are made with a thin reciprocating saw blade or piezo ‐surgical saw from the lateral nasal aperture to the junction of the posterior maxilla and the pterygoid plates .

19. Nasal septal separation The nasal septum and vomer is separated with a nasal septal osteotome (guarded nasal osteotome )

20. Release of Lateral nasal walls the bone attachments of the lateral nasal walls are also released with an osteotome . Osteotomy is performed on the other side using the same steps

21. RELEASE OF LATERAL NASAL WALLS

22. Pterygomaxillary dysjunction The attachment of the maxilla to the pterygoid plates are then osteotomised and this allows the maxilla to be ‘down‐fractured’ Content of pterygomaxillary fissure and soft palate is protected by keeping index finger at hamulus to feel osteotome during pterygoid osteotomy

23. Pterygomaxillary dysjunction A curved pterygoid chisel is placed with the curvature pointing medially and inferiorly between the tuberosity and the pterygoid plates. A mallet is used to drive the osteotome medially to complete the pterygomaxillary dysjunction . The position of the tip of the osteotome can be checked with a palpating finger.

24. Pterygomaxillary dysjunction An upward and posteriorly oriented osteotome will not reliably separate the maxilla from the pterygoid plates. It is also associated with increased risk of bleeding from the pterygoid plexus and internal maxillary artery.

25. DOWNFRACTURING The maxilla is downfractured anteriorly , with the help of a bone hook or manually

26. Removal of bone The downfracture maneuver allows for a complete visualization of the osteotomy lines. Remaining bony bridges at the posterior aspect of the maxilla can be transected under direct vision. To minimize bleeding when trimming bone close to the posterior maxilla, meticulous soft tissue protection should be employed. The downfracture technique allows good access to the nasal septum for septal corrections when indicated

27. Maxilla repositioning . The upper jaw can then be separated and mobilized and moved to the new planned position. Maxillary repositioning may involve movements in superior, inferior, differential, asymmetric, anterior, and posterior directions

28. Mobilisation of maxilla It may be useful to use Tessier mobilizers or curved osteotomes which are inserted behind the maxilla on each side in order to pull the maxilla forwards. Rowe disimpaction forceps can also be used for this purpose. At this point the mobilized maxilla should be free and able to be moved by the surgeon's hand more than is actually required.

29. Anterior movements Anterior movements can be facilitated with traction using a wire directly attached to the maxilla or to a bone screw in the maxilla.

30. Positioning of the maxilla Mandibulo -maxillary fixation Once the desired mobility is accomplished, the maxillary and mandibular teeth are wired together with or without a wafer splint. With the maxilla and mandible attached together and the condyles properly seated in the glenoid fossas,the complex is passively closed in the desired vertical dimension using the external reference point

31. Control of vertical height The preplanned vertical position of the maxilla is then established against the fixed reference marker in the nasofrontal junction. When necessary, maxillary bone is removed with a drill until that vertical relationship is achieved passively. If the nasal septum or the inferior turbinates are preventing upward movement of the maxilla, they are reduced at this stage.

32. Internal fixation Internal fixation is performed with four miniplates , usually L- or reversed L-shaped, along the pyriform aperture and the zygomaticomaxillary buttress. Care must be taken to passively adapt the plates to the bone surfaces. The screws in the mobilized maxillary segment must avoid the tooth roots.

33. ALAR CINCH SUTURE Extensive anterior movements of the maxilla will stretch the soft tissue envelope of the face and will lead to bilateral widening of the alar base and the nasal vestibules. This can be prevented by performing an alar cinch suture, which engages both alar bases in an attempt to approximate them towards the midline immediately before wound closure.

34. Posterior movement (backward) Posterior movements are rarely indicated. If needed, a segment of bone must be removed usually from the posterior aspect of the maxilla. This is usually performed under direct vision from a downfracture approach.

35. Superior (upward) movement Superior movement (shortening) of the maxilla requires an ostectomy of a bone segment. In an upward movement of the maxilla the septum needs to be vertically trimmed to avoid septal buckling deviation, which may lead to impaired airway flow and nasal deformation. In large impactions, the inferior turbinates should be trimmed to avoid airway obstruction

36. Inferior (downward) movement Inferior movement (lengthening) of the maxilla is possible, but results in a gap and a non-contact situation between the upper and lower part of the maxilla.

37. Downgrafting The gaps need to be bone grafted, usually with free bone grafts from the iliac crest or the outer table of the skull, or allogeneic bone. The amount of lengthening is checked against the vertical reference mark at the naso -frontal junction.

38. Asymmetric movement/rotations Asymmetric movements and rotations are also possible. In this case a bone gap may occur on one side and bone may need to be trimmed on the contralateral side.

39. Need for bone grafts After osteosynthesis , the need for bone grafts ( eg . by rotational movements) should be evaluated and if required, they should be placed at this time

40. Control of position After completion of osteosynthesis on both sides, the MMF is released and the resulting occlusion is checked against the pre-planned position. The splint may be fixed to the maxillary teeth with a few thin wires (especially when the maxilla is segmented) and left in place during the healing phase to allow for neuromuscular adaption and position control.

41. SEGMENTAL LEFORT I OSTEOTOMY 2 piece maxillary surgery required for surgically assisted maxillary expansion procedure 3 piece maxillary osteotomy most commonly used procedure

42. Two piece segmental maxillary osteotomy In the two pieces maxillary segmentation interdental osteotomy performed between the central incisors roots, under finger control by the palatal side

43. Two piece segmental maxillary osteotomy

44. Advantages of segmentalisation For gaining width Allows for vertical changes Adjustment of angulations of posterior maxillary segments

45. Most common sites of segmentalisation Between Central incisors Between the canine and lateral incisors Between the canine and premolar teeth

46. TECHNIQUE Conservative tunneling from the standard circumvestibular incision can be made inferiorly to alveolar crest on buccal surface of maxilla with a woodsen elevator Interdental osteotomy made with a thin cement spatula osteotome prior to performing horizontal osteotomy The osteotomy can be carried superiorly to the level of planned horizontal maxillary osteotomy

47. Technique Following horizontal osteotomy and down fracture the maxilla is segmentalized by making two parasagittal cuts that join across the midline and connect with interdental osteotomies using round end cutting bur( Steiger Bur)

48. Segmetal maxillary osteotomy

49. Segmental Lefort I maxillary osteotomy