The recovery of the masticatory function and good esthetic results of orthopedic treatment in patients with Kennedy IV mandibular defects is still a topical problem. The aim of the work was to study biochemical aspects of interactions between bony structures of the front part of the mandible and different endosteal implants, especially under functional load, to develop the most rational method of orthopedic treatment of patients with Kennedy IV mandibular defects. In total, 14 variants of elimination of defects in the front part of the mandible with different supports (natural teeth, standard implants, and miniimplants) for a non-removable orthopedic construction were studied. For each variant, maximal compression and stretch tensions, maximal shift tensions, and the probability of biochemical system destruction were calculated. These variables were compared, and conclusions on the most rational method of orthopedic treatment of patients with Kennedy IV mandibular defects were made; practical recommendations were given.