Idiopathic hypoplasia of the masseter muscle: A case report.

Objective and importance: Hypoplasia of the masseter muscle is a rare condition, described as partial or total, associated with congenital malformations or pathologies. Rare cases are those with no genetic alterations in their familiar picture. The authors present a case of an idiopathic masseter muscle hypoplasia in the absence of other pathologies.Clinical presentation: The case report involved a patient who presented to the consultant clinic complaining of facial asymmetry. The patient underwent several exams to confirm the diagnosis of masseter muscle hypoplasia, which included an X-ray, magnetic resonance of the temporomandibular articulation, and electromyography.Intervention: The patient was treated with a customized functional appliance and fixed orthodontic treatment with satisfactory functional and esthetic results.Conclusion: The case presented highlights the possibility of finding a hypoplasia of the masseter muscle even in the absence of other pathologies and without specific clinical symptom...