Table I.

Categorization of TFJ and PFJ OA

	Presence of OA*	Severity of OA†
TF-OA (K/L grade)	No: 0 = no OA; 1 = questionable OA	2, 3, 4
	Yes: 2 = mild OA; 3 = moderate OA; 4 = severe OA
TFJ and PFJ osteophytes	No: 0 = absent	1, 2, 3
	Yes: 1 = mild; 2 = moderate; 3 = severe
TFJ and PFJ JSN	No: 0 = normal	1, 2, 3
	Yes: 1 = 33% abnormal; 2 = up to 66% abnormal; 3 = up to 100% abnormal
TFJ and PFJ sclerosis	No: 0 = absent	N/A
	Yes: 1 = present
TFJ cysts	No: 0 = absent	N/A

^*Odds ratios to assess the magnitude of association between race and radiographic features.

^†Proportional odds ratios for multiple categories to assess higher levels of severity.