The authors describe a new technique for reconstruction of mandibular body defects. The feasibility of distraction osteogenesis with submerged (internal) devices for reconstruction of segmental mandibular defects is investigated in an experiment with five adult dogs. A segmental mandibulectomy was performed on the horizontal ramus. The bony defect was regenerated using distraction osteogenesis (bone transport) at a rate of 1 mm daily. The animals were killed after the consolidation period. Complete bone regeneration of the surgically created gap was successful in three of five dogs. Two animals failed to create new bone. In these two cases, the screws did not offer proper stability to the bony fragments, and this caused a lack of ossification. This experimental study demonstrates the possibility to use internal distraction devices to reconstruct segmental mandibular defects in a canine model. Internal devices show enormous advantages in comparison with the external ones. This method with no donor-site morbidity may become a very useful option in human mandibular reconstruction.

a b s t r a c tThe market potential indicator is a commonly used tool in transport planning for evaluating the potential economic effects derived from improvements in transport infrastructures. The general assumption is that exports from a given region will rise with increased accessibility, thus benefiting economic activities. However, the specification of the market potential model is typically very simple and ignores both the impact of competing rivals and the role of international borders, which leads to unrealistic results. Spatial interaction models on bilateral trade have already proved that international trade is affected by multilateral resistance, borders, adjacency, language or currency. Nevertheless, apart from some recent analyses that simply calibrate the distance decay parameter from trade datasets, these variables have hardly been integrated into research on market potential. This paper sets out to demonstrate that more realistic results are obtained by calibrating the distance-decay parameter and introducing the impact of competing rivals and border effects into the market potential formulation. The proposed model is then applied to the assessment of the accessibility impacts of new road transport infrastructure in the European Union between 2001 and 2012, which shows that the greatest improvements in accessibility were experienced by peripheral countries with high road infrastructure investment.

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