Temporomandibular joint or related masticatory muscle pain represents the most common chronic orofacial pain condition.Patients frequently report this kind of pain after dental alterations in occlusion.However,lack of understanding of the mechanisms of occlusion-related temporomandibular joint and muscle pain prevents treating this roblem successfully.To explore the relationship between improper occlusion (occlusal interference) and masticatory muscle pain,we created an occlusal interference animal model by directly bonding a crown to a maxillary molar to raise the masticating surface of the tooth in rats.