Objective: The understanding the etiology of painful temporomandibular disorders (TMD) has evolved over the last eight decades. Evidence-based systematic research had questioned historical concepts and abandoned preconceived dogmas based purely on mechanically based etiologies, transforming TMD into a complex musculoskeletal chronic pain model. Unfortunately, many of these old ideas persist in undergraduate education and the dental community. Revisiting the historical development and the way the etiology of painful TMD has changed over the years may be helpful to understand the complexities of TMD as a group of chronic pain pathologies. Method and materials: A literature search using the MeSH terms: "temporomandibular joint disorders," "TMD," "etiology," "causality," "history," and "evolution" using Medline and Scopus databases was conducted aiming to answer the focused question: "In what ways has etiologic understanding of temporomandibular disorders evolved?" A narrative review was performed with the selected studies, highlighting significant contributions that have transformed TMD from a purely mechanical-based phenomenon into a chronic pain biopsychosocial disease model. Keywords: chronic pain, etiology, myofascial pain, occlusion, pain, temporomandibular disorders, temporomandibular joint