CRANIOFACIAL AND DENTAL TISSUE - 3D Bioprinting and Nanotechnology in Tissue Engineering and Regenerative Medicine - page 190

the bone segments apart 1 mm/day. This rate is slow enough to allow bone to form in the intervening
gap. This is continued until the desired bone lengthening is achieved.
The cranial bones of craniosynostosis patients are cut apart, repositioned, and then fixated accord-
ing to the principles mentioned (usually with plates and screws with or without bone graft).
Ear deformities (e.g., microtia, atresia) can be reconstructed by harvesting autogenous rib cartilage,
carving it into the shape of an ear, and implanting it under the skin. However, the reconstructed ear
often lacks symmetry with, and the aesthetic definition of, the contralateral ear. Thus, recent data re-
ported by Reinisch et al . showing optimal aesthetic outcomes and minimal complications with a med-
por (high-density porous polyethylene) ear implant could lead to medpor becoming the gold standard
treatment for this deformity ( Reinisch and Li, 2014 ).
9.2.2.3 Soft Tissue
The treatment paradigm for soft tissue defects has traditionally adhered to the reconstructive ladder,
where simple and more local solutions are used if possible; but when these options are nonviable, the
surgeon steps up to a feasible but more complex solution ( Figure 9.2 ). Many surgeons have also begun
expanding their personal reconstructive ladder to include skin substitutes, such as Integra (Integra Neu-
roSciences, Plainsboro, NJ), which is a bilayered construct that contains an inner layer consisting of a
collagen/glycosaminoglycan matrix that acts as a scaffold for cellular ingrowth and dermal regeneration.
Some early products for facial augmentation were made of expanded polytetrafluoroethlene
(ePTFE, W.L. Gore & Associates Inc., Newark, DE; PTFE is best known as Teflon®, ® , Dupont Co.,
Wilmington, DE). These products were largely abandoned because of extremely high complication
FIGURE 9.2
The reconstructive ladder.