Purpose: To simultaneously address all of the deformities in severe hypertelorism with a hybrid distraction protocol.

Introduction: Since Tessier first described the facial bipartition procedure, it has been the de facto standard of care for the treatment of severe hypertelorism. This osteotomy, like the monobloc, may be combined with distraction osteogenesis to improve stability, decrease relapse, minimize infection rates and gradually lengthen soft tissues to achieve more harmonious results. In severe cases, however, there is a multi-level deformity that is impossible to correct with a strictly monobloc approach. A novel approach to this problem was devised that integrates a facial bipartition with a LeFort III distraction and prn lower facial osteotomies to address the three dimensional nature of the deformity.

Methods/Materials: A total of 5 patients with severe hypertelorism (medial canthal distance > 60 mm) were treated with this regimen over 18 months. All patients underwent pre- and postoperative CT scanning, cephalometric analysis, and complete dental records were obtained.

Initial surgery consisted of facial bipartition. In two cases, this was combined with immediate monobloc distraction. This was followed by a later LeFort I or III distraction. The segments were stabilized with a transfacial Steinman pin as described by Arnaud, et al. In the remaining three, the patient was allowed to heal, and a subsequent LeFort III distraction was performed. The upper facial correction was based upon ethnic normative values for the patient population. Secondary osteotomy design was based upon midfacial morphology and residual deformity.

In two cases, total nasal reconstruction was performed simultaneously with midfacial distraction. This consisted of carved rib cartilage scaffold assembled with cyanoacrylate adhesive, followed by local flap elevation to permit midline closure. Neither patient had reestablishment of patent nasal passages. In these patients, the LeFort III osteotomy was performed from the midline nasal exposure and the pterygomaxillary dysjunction was performed intraorally.

Ancillary procedures consisted of canthopexies, onlay/inlay bone grafting to cranium or maxilla, mandibular osteotomy (n=2), and genioplasty (n=1).

Results: Two of 5 patients had a combination of hypertelorism with facial clefting and microtia (Bixler syndrome). The remainder were isolated hypertelorism patients. Mean age was 4.2 years. Mean preoperative medial canthal distance was 71 mm. (Maximum MCD was 124 mm.) Mean postoperative MCD was 31 mm. Mean AP distraction at infraorbitale was 27 mm. Mean advancement at ANS was 41 mm. Mean follow-up is 16 months. Relapse at both the orbital and occlusal levels is not statistically significant .

There were no distraction failures. There was one infection which resolved with IV antibiotics. There were no postoperative changes in visual acuity. Obstructive sleep apnea was corrected in 4/4 patients with preoperative positive sleep studies. Postoperative major cephalometric landmarks were corrected to within 0.2 standard deviations of ethnic norms. Interestingly, a pair of morphologically normal central incisors were found near the optic chiasm during encephalocele repair in one of the two Bixler syndrome patients.

Conclusions: The introduction of distraction osteogenesis and multiple, cantilevered osteotomies to the facial bipartition permits correction of even the most severe hypertelorism. This multi-level “stairstep” approach enhances aesthetic correction, improves stability, and permits planning these cases without the constraints imposed by occlusal discrepancies or fear of relapse.