Spontaneous-Regeneration of the Reconstructed Mandible in a Segmental Mandibulectomized Young Girl

Spontaneous bone regeneration of the reconstructed mandible in children is rarely reported. Most of previous reports discussed the role of periosteum in regeneration of bone. Alternatively, other factors such as mechanical stress and muscle attachment have also been implicated in spontaneous bone regeneration. This paper presents spontaneous-regeneration of the reconstructed mandible in a young girl, undergone a segmental mandibulectomy, and discusses the factors associated with regeneration based on the results of image examinations and Finite Element Analysis (FEA). The patient was an 11 year-old girl diagnosed as ossifying fibroma in the mandible. A segmental mandibulectomy and immediate mandibular reconstruction using a Ti-mesh tray and particulate cancellous bone and marrow was planned. The spontaneous-regeneration of the coronoid process was observed on the reconstructed mandible. On the CT slabs, the reattachment of the masseter and temporal muscle was confirmed. Before treatment, the transversal growth of her maxilla was asymmetrical. After the mandibular reconstruction and prosthodontic treatment, her maxilla grew back with bilateral symmetry. The occlusal loading on her mandible appeared symmetrically via an FEA. In addition, the stress was concentrated in the external oblique ridge, and the graft bone remodeled into the anatomical configuration. Through this case, it is suggested that the reattachment, the healthy growth of masticatory muscles, and the rehabilitation of oral function contributed to spontaneous bone regeneration and remodeling in the mandible, as well as the preservation of periosteum.