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. 2010 Dec;39(8):486-93.
doi: 10.1259/dmfr/92017549.

Temporomandibular joint and 3.0 T pseudodynamic magnetic resonance imaging. Part 2: evaluation of articular disc obscurity

H Iwasaki  1 , H Kubo, M Harada, H Nishitani, Y Ohashi
Affiliations

Temporomandibular joint and 3.0 T pseudodynamic magnetic resonance imaging. Part 2: evaluation of articular disc obscurity

H Iwasaki et al. Dentomaxillofac Radiol. 2010 Dec.

Abstract

Objectives: This study examined the relationship between temporomandibular joint (TMJ) dysfunctions and obscurity grades of interpreted anterior and posterior borders of the articular disc (Da and Dp, respectively) by 3.0 T pseudodynamic MRI.

Methods: Da and Dp were classified into seven obscurity grades, and the Dp contour was classified into three types. The grades, types and TMJ function were compared by 3.0 T pseudodynamic MRI.

Results: Unobscured Da images at condylar positions posterior to the articular eminence were associated with normal TMJ function (P = 0.046 < 0.05). Unobscured Dp images at condylar positions anterior to the articular eminence were associated with normal TMJ function (P = 0.033 < 0.05). In addition, unobscured Dp images following flap insertion were associated with normal TMJ function (P = 0.043 < 0.05). There was no statistical relationship between Dp contour types and TMJ movement, but any change observed in the Dp contour during mouth opening was associated with abnormal TMJ function (P = 0.040 < 0.05).

Conclusions: Grading of Da and Dp obscurity based on how well the areas were defined in the images, identifying the condylar positions in relation to the glenoid fossa and articular eminences, and observing the changes in Dp contour types were useful for diagnosing TMJ abnormalities.

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Figures

Figure 1
Figure 1
Condylar positions. Cd, condylar head; Em, lowest articular eminence; TMJ, temporomandibular joint; position 0, posterior to fossa; position 1, between fossa and 1/2 of posterior slope of Em; position 2, between 1/2 of posterior slope of Em and Em; position 3, between Em and 1/3 of anterior slope of Em; position 4, anterior to 1/3 of anterior slope of Em
Figure 2
Figure 2
Anterior border (Da) contour grades
Figure 3
Figure 3
Posterior border (Dp) contour grades
Figure 4
Figure 4
Posterior border (Dp) contour types. (a) Concave (C-type); (b) Flat (F-type); (c) Convex (V-type)
Figure 5
Figure 5
The relationship between condylar (Cd) positions (0–4) and flap steps (0–5) of nine volunteers
See this image and copyright information in PMC

References

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