Temporomandibular joint disorders (TMJD) involve orofacial pain and functional limitations that may limit important daily activities such as chewing and speaking. This observational case-control study attempted to identify factors associated with TMJD development, particularly inflammation. The study participants were patients treated at Karolinska University Hospital, Stockholm, Sweden. The cases were patients who received a diagnosis of TMJD, chronic closed lock, or painful clicking and were treated surgically during the period from 2007 through 2011. The control group was randomly selected from among patients who had undergone tooth extraction and was matched by age and sex. A total of 146 cases and 151 controls were included in the analyses. The response rate was 55.3% for the case group and 21.8% for the control group. The male:female ratio for patients with TMJD was 1:4.4. TMJD was significantly associated with pneumonia (odds ratio [OR], 2.1), asthma (OR, 2.1), allergies (OR, 1.8), headache (OR, 3.1), general joint hypermobility (OR, 3.8), orofacial trauma (OR, 3.9), rheumatism (OR, 2.5), and orthodontic treatment (OR, 2.4) (P < 0.05 for all outcomes). In conclusion, autoimmune diseases and inflammatory conditions are associated with increased risk of TMJD. Moreover, certain lung disorders may predict subsequent development of TMJD.