Table 1.

Definition for the osseous degenerative features observed in the TMJ condyle.

Nomenclature	Definition Criteria
Deviation in form	A departure from normal shape, such as concavity in the cortical outline, attributable to surface erosion, osteophytes, hyper or hypoplasia.
Surface erosion	Reduced density or a loss of continuity of the articular cortical outline.
Subcortical cyst	A radiolucent cavity beneath the articular surface that looked different from normal bone marrow patterns.
Subcortical sclerosis	An increased calcification density relative to adjacent bone marrow.
Osteophyte	A sclerotic border with marginal hypertrophy and beak-like angular formation of osseous tissue arising from the articular surface.

Note. Adapted from Ahmad M, Hollender L, Anderson Q, Kartha K, Ohrbach R, Truelove EL, et al. Research diagnostic criteria for temporomandibular disorders (RDC/TMD): development of image analysis criteria and examiner reliability for images. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107: 844–60.