24: Maxillary Distraction Using Le Fort I Osteotomy and a RED 2 External Fixator

CHAPTER 24
Maxillary Distraction Using Le Fort I Osteotomy and a RED 2 External Fixator

Lester Machado

Division of Oral and Maxillofacial Surgery, Rady Children’s Hospital of San Diego, San Diego, California, USA

 

A method of obtaining significant advancement of the maxilla and midface with the use of distractors.

Indications

  1. Maxillary advancement in noncleft patients of greater than 8 mm
  2. Maxillary advancement in cleft patients of greater than 5 mm
  3. Maxillary downgrafting where stability is in question
  4. Maxillary advancement and/or downgrafting movements where stability using rigid fixation would be impossible to achieve

Contraindications

  1. Incomplete development of the skull
  2. Developmental delay that compromises comprehension and cooperation
  3. Seizure history
  4. Psychological instability: severe depression, anxiety, or schizophrenia
  5. Uncooperative patient

Technique

  1. After oral endotracheal intubation, the tube is secured and corneal shields with ophthalmic ointment are placed bilaterally (Figure 24.1 [all figures cited in this chapter appear in Case Report 24.1]). The face, scalp, and oral cavity are prepped in a sterile fashion. A half sheet with two towels is placed under the patient’s head, and the inner towel is clamped to expose the frontal and temporal areas bilaterally down to the upper neck. A split sheet is then applied to cover the rest of the body. The area where the halo will be attached must be in the field.
  2. Local anesthesia is injected within the maxillary vestibule and into the greater palatine canals. The fixation device is assembled on the back table of the sterile field. The vertical bars are joined to the halo.
  3. Eight fixation screws are lightly lubricated with ointment and inserted partially into the desired positions within the anterior cortex of the skull. It should be noted that the manufacturer recommends six screws in the halo, but eight screws enhance stability.
  4. Two horizontal bars are attached to the vertical bar for four-point fixation of the maxilla. Four-point fixation allows for complete control of the movement of the maxilla in all dimensions.
  5. A maxillary vestibular incision is utilized to expose the anterior and lateral walls of the maxilla as in the Le Fort 1 osteotomy procedure. The mucosa is elevated from the anterior nasal spine extending posterior to the nasal tuberosity area in a tunnel fashion. The nasal mucosa is elevated from the floor of the nose, the lateral nasal walls, and the nasal septum. Care is taken to minimize tears within the nasal mucosa.
  6. A reciprocating saw is used to create the osteotomy at the Le Fort I level. The horizontal osteotomy is placed 5–6 mm above the roots of the longest maxillary teeth and superior to the junction of the nasal floor and the pyriform rim. Sufficient space is required on the maxilla for placement of the fixation plates without compromising the teeth roots.
  7. The bone attachments are released similarly to a standard Le Fort I osteotomy. The nasal crest of the maxilla is released from the septum–vomer with a guarded vomer osteotome. A single guarded osteotome is used to separate the lateral nasal walls. A curved osteotome is used to separate the posterior maxilla from the pterygoid plates just anterior to the pterygomaxillary junction or within the posterior part of the tuberosity bilaterally. The maxilla is gently downfractured. Any tethering of the nasal mucosa to the palatal mucosa in the cleft case is identified and carefully divided. Holding the maxilla down, the nasal mucosa is checked for full release from the maxilla.
  8. Ronguers are used to remove any remaining posterior attachments of the lateral nasal walls. The maxilla is mobilized without tearing the mucosal attachments. Full mobility of the maxilla is essential, yet care must be taken to retain all of the soft tissue attachments for blood supply. You may not start placement of the distractor unless full mobility of the maxilla is achieved.
  9. Two L-shaped plates are secured to the anterior superior edge on each side of the maxilla. Four or five screws are used to attach each plate, and one screw hole is left empty in the short arm of the L for a full-length 25-gauge stainless steel wire (Figure 24.2). The long wire is passed through the most anterior hole on the plate and then bent away from the field and tagged with a hemostat.
  10. A long 25-gauge wire is passed through the orthodontic tube on the upper first molar on each side. The wire is bent on itself when passed halfway. The two free ends are tagged to each other with a hemostat on each side. Four points of fixation are established on the maxilla to control maxillary movement in all directions.
  11. A 15# blade is used to create a tiny nick in the nasolabial fold at the very base of the nose a few millimeters lateral to the philtrum bilaterally. Each pair of the two pairs of wires attached to the maxillary plates are passed through the ipsilateral skin openings using a fine-tipped hemostat, externalizing the maxillary wires (Figure 24.2). Alternatively, the wire may be passed with a Keith needle. The dental wires are passed through the oral cavity (
Jan 18, 2015 | Posted by in Oral and Maxillofacial Surgery | Comments Off on 24: Maxillary Distraction Using Le Fort I Osteotomy and a RED 2 External Fixator
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