Rigid External Distraction with Intranasal Bone-borne Traction Hooks for Midfacial Hypoplasia

Ningbei Yin,Yilue Zheng,Zhenmin Zhao,Tao Song,Feng Niu,Haizhou Tong

doi:10.1038/s41598-018-28068-8

Abstract

Rigid external distraction is currently performed to correct cases of severe maxillary hypoplasia. As an improvement of this technique, we propose the use of an intranasal bone-borne traction hook. This study is a retrospective chart review of the intranasal bone-borne traction hooks used in the treatment of severe maxillary hypoplasia. There were 110 patients treated with the hooks from 2005 to 2017. The maximum traction force was 7.75 kg, and there were few complications encountered during distraction. There were 76 patients who had the hooks removed under local anaesthesia. A cephalometric analysis was conducted in 56 patients. The average advancement of A-point was 9.9 ± 4.2 mm, 8.4 ± 2.5 mm, 11.0 ± 3.7 mm, 17.9 ± 4.4 mm for the trans-sutural distraction osteogenesis (DO), maxillary anterior segment DO, Le Fort I osteotomy DO and Le Fort III/II osteotomy DO, respectively. The average changes of sella-nasion-point A (SNA) were 8.89 ± 4.30 degrees, 8.21 ± 3.17 degrees, 10.49 ± 3.26 degrees, and 15.10 ± 4.00 degrees, respectively. The A point-nasion-B point (ANB) also showed increases in all procedures with P < 0.001. In conclusion, this technique sufficiently advances the midface and ensures the scars are concealed in the nasal base. The traction hook can bear a large traction force, causes minimal complications and is easily removed.

Highlights

In 1997 Polley and Figueroa[2] first introduced the use of a rigid external distraction (RED) device to treat severe maxillary hypoplasia using distraction osteogenesis (DO)
External DO is a well-established treatment for midfacial hypoplasia[7,8]
DO gradually advances the bony structures of the midface, which allows for progressive osteogenesis and adaptation of the surrounding soft tissues

Summary

Introduction

In 1997 Polley and Figueroa[2] first introduced the use of a rigid external distraction (RED) device to treat severe maxillary hypoplasia using distraction osteogenesis (DO). This approach was shown to be an effective technique. RED involves an external bow fixed to the cranium by screws and an intraoral splint cemented to the maxillary first molars. We propose an intranasal bone-borne traction hook to replace the fixation plate. This technique sufficiently advances the midface while ensuring that scars are concealed in the nasal base; this technique eliminates the need for an intraoral splint

Methods

Results

Conclusion