The traction device is mainly composed of two parts: Martin’s external fixation device and our self-designed bone traction hook. The external fixation device consists of three parts: cranial fixation bracket, mid-facial bar and screw adjuster. The cranial fixation device is made of titanium alloy, which can be adjusted in width and length according to the patient’s craniomandibular morphology, and is fixed to the temporal bone plate on both sides by screws, providing a very stable support force for traction. The midface bar is made of carbon, which allows the position of the screw adjuster to slide up and down according to the traction requirements. The screw adjuster is connected to our self-designed bone traction hook, which allows traction on the truncated midface bone by means of an adjustment knob. The bone retraction hook consists of two small parts, one screwed into the lateral edge of the pear-shaped foramen on both sides, and the other connected to the screw adjuster through the nostril. The Le Fort III osteotomy is performed under general anesthesia with a transoral cannula. The surgical approach was a small facial incision, a lower lid margin incision and an intraoral maxillary vestibular groove incision. Subperiosteal separation was performed to reveal the bony surfaces of each part. The bony joints are cut in sequence: (1) transverse cut of the zygomatic frontal process at the zygomatic-frontal suture with a fissure drill or rifling saw; (2) vertical downward cut of the lateral zygomatic bone with a fissure drill or rifling saw; (3) cut of the lateral part of the lateral and infraorbital walls to the infraorbital fissure with a fissure drill or oscillating saw; (4) incision of the lower lid margin. A small narrow, sharp bone cutter is used. (5) From the lateral orbital wall osteotomy line downward, use a bone knife to cut the posterior lateral wall of the maxillary sinus to the plane of the zygomatic alveolar ridge; (6) Make the contralateral zygomatic orbital osteotomy in the above sequence; (7) Use a fissure drill to cut the nasofrontal suture and the frontal maxillary suture; (8) Use a small bone knife to cut the inferior wall along the medial canthal incision zone and posterior to the nasolacrimal sulcus, and use a bone knife to cut the sieve bone and plow bone from the nasofrontal suture toward the posterior nasal spine (hard and soft palate junction) (9) Turning to the intraoral osteotomy, the lower end of the osteotomy line of the posterior lateral wall of the maxillary sinus is cut horizontally and posteriorly, and a small section of the posterior lateral wall of the maxillary sinus is cut horizontally with the osteotome to reach the pterygomaxillary union; (10) The pterygomaxillary union is cut with the curved osteotome. At this point, all Le Fort III osteotomies were completed. The maxillary gripper is used to pull the truncated maxilla anteriorly and inferiorly to loosen the tissue connection of the pterygomandibular union. Placement of the retraction device A vestibular sulcus incision is made to expose the pear-shaped foramen margin on both sides. The first part of the bone retraction hook is led out of the nostril with a coarse fissure drill at the lateral edge of the pear-shaped foramen on both sides, about 8 mm from the edge of the pear-shaped foramen, and the other end is fixed to the edge of the pear-shaped foramen with a bolt under the guidance of a thin silicone tube. The cranial fixation bracket was adjusted to the appropriate position according to the patient’s skull width, and the screws on both sides were slowly screwed simultaneously to fix the cranial fixation bracket to the temporal bone plate on both sides. Traction As the surgery is traumatic, there will be blood oozing from the osteotomy and nasal cavity, so traction is appropriate after the blood crust is formed and stabilized. We usually start traction on the 3rd day after surgery, using a thin wire to connect the bone traction hook to the spiral adjuster, and the direction of traction is horizontal and downward. Traction is applied twice a day, 0.5 mm each time, and is maintained in the intended position for 1 month. Remove the external fixation device and replace the frontal chin-supported facial arch traction with an orthodontic rubber band connecting the cross-beam of the facial arch to the bone traction hook, and replace the rubber band daily. Traction was maintained for 3 months. The effect of traction was analyzed through clinical observation by taking frontal and lateral photographs of the face and lateral cephalometric films. At 20 d postoperative traction, the nasal maxillary complex reached its predetermined position with ideal contour, and was continued in situ for 1 month to prevent maxillary recession. After removal of the Martin external fixation device, the bone at the osteotomy had not yet healed bony, so traction was still needed to maintain it, but with less force, and the frontal chin-supported resisted facial arch traction was replaced, and traction was maintained for 3 months, with no change in facial shape at this stage. After completion of traction treatment, the bone retractor was removed under local anesthesia. The patient’s maxilla reached its intended position and remained stable. The relationship between the upper, middle and lower parts of the patient’s face was coordinated. The mouth opening and closing movements were normal and there was no temporomandibular joint popping discomfort. In severe midface hypoplasia, orthognathic surgery was difficult to move the upper bones into the desired position, so a compromise option of mandibular recession had to be made. We treated this patient with a Le Fort III osteotomy with strong external traction to bring the midface bones into their intended position without the need for mandibular recession. To date, there are three types of maxillary and midfacial traction techniques used clinically: built-in retractor traction, arch-supported DD facial arch traction, and arch-supported external fixed traction. The built-in traction does not require arch bearing and does not leave external marks. However, the surgical operation is more complicated in direction, and the extension axes on both sides are not in a parallel line, so there may be force interference or antagonism, and there are clinical reports of abnormal skeletal rotation with built-in retraction. Hata et al. found that under the same conditions where the traction direction was parallel to the occlusal plane, the traction force applied to different planes moved the upper and lower portions of the facial middle portion of the skeleton by different distances and there was rotation. When applied 5 mm above the palatal plane, the upper jaw showed parallel forward movement. In this patient, the force-bearing point was located at the lower outer edge of the pyriform foramen, which roughly coincided with this plane. The results of the actual traction showed that the bone movement was balanced in the upper, lower, left and right parts, which achieved the purpose of correcting the facial shape and adjusting the position of the upper and lower jaws in relation to each other. We believe that the orthodontic treatment of this patient was successful. After thorough preoperative preparation and careful intraoperative manipulation, the Le Fort III osteotomy was safe and feasible, and the sturdy external fixation traction technique was able to parallelize the anterior displacement of the mid-facial skeletal complex and effectively correct the mid-facial hypoplasia associated with patients with congenital ectodermal hypoplasia.