TABLE 2

Demographic characteristics of the study population.

DIAGNOSTIC GROUP	SAMPLE SIZE	MEAN (SD) AGE, IN YEARS	FEMALE SEX (%)
Healthy Control	96	36.2 (13.2)	62.5
Nonpainful Temporomandibular Joint (TMJ) Disorder	116	39.9 (13.1)	76.7
Pain-Related Temporomandibular Disorder (TMD)	212	36.9 (12.6)	91.0
Headache Without TMD Pain^†	45	37.7 (11.7)	80.0
Odontalgia	80	37.4 (18.3)	53.8

^*Across the primary groups, age did not differ; significant Bartlett’s test for equal variances (χ²₃ = 18.6, P = .000) was followed by a W test with robust errors (W = 1.81 [3, 213.9], P = .15). Female sex was predominant overall (P = .000) and was allocated unequally across groups (χ²₃ = 58.2, P = .000). Across the two subsets, age did not differ (F = 0.08 [1, 195], P = .78); female sex was predominant (P = .000) but the proportion was different across the two groups (χ²₁ = 3.3, P = .07).

^†This group is a subset of the group with nonpainful TMJ disorder and the healthy control group.