Temporomandibular disorders and psychological status in adult patients with a deep bite

Temporomandibular disorders (TMDs) and psychological status were examined in adult patients with a deep bite and compared with an adult age- and gender-matched control group with neutral occlusion. The deep bite group consisted of 20 females (mean age 30.3 years) and 10 males (mean age 33.1 years). The control group comprised 20 females (mean age 29.4 years) and 10 males (mean age 34.2 years). TMD examination, according to the Research Diagnostic Criteria for TMD (RDC/TMD), cephalometric lateral radiographs, registration of occlusion, and bite force were performed. To test the mean differences between craniofacial morphology, bite force, the occurrence of RDC/TMD diagnostic groups, and headache between the two groups, unpaired t-test, Fisher's exact test, Mann-Whitney U test, and multiple logistic regression analyses were performed. Deep bite patients more frequently reported nocturnal and diurnal clenching (P < 0.01), an uncomfortable bite (P < 0.001), jaw stiffness (P < 0.05), and 'ringing' in the ears (P < 0.001) than the controls. Headache (P < 0.001), muscle disorders (P < 0.001), disc displacement (P < 0.05), and other joint disorders (P < 0.05) occurred significantly more often in the deep bite group compared with the controls. Somatization scores were significantly higher in the deep bite group compared with the controls (P < 0.001). Headache, muscle disorders, disc displacement, and other joint disorders were significantly associated with a number of craniofacial dimensions and psychological factors [R between 0.32 and 0.72; P < 0.05 and odds ratio (OR) from 0.45 to 7.46; P < 0.05]. These findings suggest that a deep bite, in particular with retroclined upper incisors, can represent a risk factor for TMD.