Distraction osteogenesis part 2: technical aspects

Distraction osteogenesis is undertaken in a number of key stages (Figure 1). The success of DO relies on meticulous planning and provision of care with input from a multidisciplinary team specialized in the craniofacial region.

The first stage in DO focuses on planning and preparation. Identifying which structure is abnormal and the likely aetiology is essential to successful management. DO is used to correct the underdevelopment associated with hypoplastic or absent structures, to compensate for overdevelopment of contralateral structures. Diagnosing which structures require intervention is fundamental to planning the type, direction and magnitude of distraction.

A combination of photographs, conventional radiographs, such as orthopantomographs and lateral cephalograms, and 3D images are used for diagnosis and treatment planning (Figure 2). Advances in 3D printing from CBCT images has enabled the production of highly accurate 3D models of the craniofacial hard tissues, known as stereolithographic models, which are built up in layers from a polymer (Figure 3). Stereolithographic models can be used to aid visualization for diagnosis and for counselling patients. Detailed surgical planning and mock-distractor placement can be undertaken on models and used to produce a surgical stent that then accurately transfers the planning to the patient.¹ The mock-up can also guide preparatory bending of distractors, reducing surgery time.²