Abstract
Unilateral condylar hyperplasia (UCH) is a growth disorder that commonly presents with facial asymmetry and may manifest as hemimandibular elongation, hemimandibular hyperplasia (HH), or hybrid forms. HH is characterized by a predominantly vertical growth pattern and is frequently associated with condylar osteochondroma, a benign neoplasm with autonomous and unpredictable growth. Accurate differentiation between active and inactive disease using three-dimensional imaging and metabolic assessment is essential for appropriate treatment planning and long-term stability.
This article reports two clinical cases of severe active HH associated with condylar osteochondroma in patients with a skeletal Class I sagittal relationship. Diagnosis was established through comprehensive clinical examination, computed tomography (CT) imaging, and single photon emission computed tomography (SPECT), which demonstrated markedly increased radiopharmaceutical uptake in the affected condyles, consistent with neoplastic activity. Management consisted of low-level condylectomy to ensure complete tumor removal, combined with asymmetric mandibular osteotomies (AMO) to correct vertical and transverse discrepancies while preserving sagittal mandibular position. Maxillary repositioning with Le Fort I osteotomy was performed to correct occlusal canting and facial asymmetry.
This combined surgical approach allowed effective arrest of pathological growth, restoration of facial symmetry, preservation of muscular balance, and maintenance of a stable Class I occlusal relationship, resulting in minimal postoperative orthodontic requirements. These cases support the use of low condylectomy combined with AMO as a predictable and biologically sound strategy for managing HH associated with osteochondroma in patients without sagittal mandibular discrepancy, emphasizing the importance of precise diagnosis and individualized, multidisciplinary treatment planning.