In this study - the Study of TMD Patients in General Dentistry Offices (STING) - data on the treatment of TMD patients were collected by 10 practicing dentists and evaluated retrospectively. The aim of this study was to identify risk factors that could lead to treatment failure. Treatment data from 1,041 TMD patient records were entered into an analytical database, categorized, and statistically analyzed by binary logistic regression using SPSS 23. The variables "gender," "age," "number of complaints," and "duration of symptoms" had no significant effect on the treatment outcome. Likewise, individual complaints such as pain or discomfort in the cheek, neck, and/or ear region as well as tension-type headache and functional toothache had no significant effect on the target variable, which was treatment outcome. Chief complaints of dysfunctional pain (odds ratio [OR] 6.4), multilocular pain (OR 8.2), vertigo (OR 13.2), migraine (OR 4.9), tinnitus (OR 4.1), and occlusal discomfort (OR 3.9) were identified as risk factors that influence treatment outcome. The latter association showed a significant correlation with increased Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis II levels, as was also the case for tinnitus, migraine, and vertigo. Keywords: temporomandibular disorder (TMD), risk factors, Axis II score, persistent pain, chronic pain, multilocular pain, occlusal discomfort, occlusal splint