Spontaneous Zygomatic Remodelling after Coronoidectomy in Coronoid Process Hyperplasia and Jacob’s Disease - A Case Report and Literature Review

Rationale: Jacob’s disease associated with true coronoid hyperplasia (CH) is a rare condition characterized by a pseudo-joint between the coronoid process and the zygomatic arch. Malar asymmetry resulting from zygomatic bone deformation has been reported, but long-term morphological outcomes are seldom documented. Patient Concerns: A 13-year-old boy presented with progressive restriction of maximal incisal opening (MIO) of 20 mm and zygomatic asymmetry. Diagnosis: Computed tomography (CT) scan and histopathological examination confirmed the diagnosis of Jacob’s disease with CH. Treatment: An intraoral coronoidectomy was performed, followed by a structured program of jaw-stretching exercises. Outcomes: The patient achieved a sustained improvement in MIO. A CT scan at 17 months showed spontaneous zygoma remodeling with resolution of facial asymmetry. Take-away Lessons: Coronoidectomy with physical therapy can restore MIO effectively. This is the first report of spontaneous correction of zygomatic asymmetry, suggesting the appropriateness of an expectant attitude in this clinical scenario.