Twenty-five cases of mandibular fractures with triangular fragments in the lower border were analyzed with respect to mode of treatment and rate of complication by infection. Fragments that remained unexposed and unreduced during treatment of the mandibular fractures were not complicated by infection, whereas about 50% of the fragments that were repositioned and fixed became infected. The study discusses the complexity of the physiopathology and management of these fragments. It appears that triangular fragments should be left unexposed.