Table 2 Definitions of the selected TMJ measurements

Quantitative measurements

AJS

Anterior joint space

(mm)

The vertical distance from the anterior-most mandibular condyle point (ACp) to the glenoid fossa.

SJS

Superior joint space

(mm)

The vertical distance from the most superior condyle point (SCp) to the most superior point of the glenoid fossa.

PJS

Posterior joint space

(mm)

The vertical distance from the posterior-most mandibular condyle point (PCp) to the glenoid fossa.

CMS

Coronal medial joint space

(mm)

The vertical distance from the condyle’s coronal medial point (CMp)  to the glenoid fossa.

CLS

Coronal lateral joint space

(mm)

The vertical distance from the condyle’s lateral coronal point (CLp)  to the glenoid fossa.

CL ₁

Condyle length

(mm)

The horizontal distance from the posterior-most condylar point (PCp) to the anterior-most condylar point (ACp).

CL ₂

Condyle width

(mm)

The horizontal distance from the medial condyle point (MCp) to the lateral condyle point (LCp).

CH

Condyle height

(mm)

The vertical distance from the most superior aspects of the condyle (SCp) to the reference line (L).

FH

Fossa height

(mm)

The vertical distance from the highest point of the fossa (SF) to the reference line (L).

β

The slope of the anterior condyle

( ° )

The angle formed between the line passing the tangent of the anterior slope of the condyle to point (SF) and the reference line (L).

θ

The inclination of the articular eminence

( ° )

The angle formed between the line passing through the tangent of the anterior wall of the articular eminence to point (SF) and the reference line (L).

β-θ

Condylar process - articular eminence relationship

( ° )

The difference between the slope of the anterior condyle and the tangent of the anterior wall of the articular eminence.

Qualitative measurements

AS

Anterior slope

(Hu)

Anterior cortical bone density was measured in an area of 2mm² ellipse in shape bone tissue representing the anterior slope, which was determined on the anterior-most mandibular condyle point (ACp).

SS

Superior slope

(Hu)

Superior cortical bone density was measured in an area of 2mm² ellipse in shape bone tissue representing the superior slope which was determined on the superior condyle point (SCp).

PS

Posterior slope

(Hu)

Posterior cortical bone density was measured in an area of 2mm² ellipse in shape bone tissue representing the posterior slope which was determined on the posterior-most mandibular condyle point (PCp).

MS

Medial slope

(Hu)

Medial cortical bone density was measured in an area of 2mm² ellipse in shape bone tissue representing the Medial slope, which was determined on the condyle’s coronal medial point (CMp).

LS

Lateral slope

(Hu)

Lateral cortical bone density was measured in an area of 2mm² ellipse in shape bone tissue representing the Lateral slope, which was determined on the condyle’s coronal medial point (CLp).