The Mediolateral Temporomandibular Joint Disc Position: An In Vivo Quantitative Study

Aims: Temporomandibular joint (TMJ) discs displaced simultaneously, dorsoventrally, and mediolaterally are assumed to be rotated. However, a pilot study performed with individualized oblique-axial scans on supposedly rotated discs did not show disc rotation consistently. The aim of this study was the quantitative evaluation of disc rotation on a larger sample size, assessing the mediolateral disc geometry and position by the use of a reference system determined by the condylar long axis. Methods: Eighty-five TMJs from 50 subjects were analyzed. One series of sagittal and 1 of 14 individualized oblique-axial magnetic resonance (MR) scans were taken for each joint. The dorsoventral disc position was diagnosed by means of the sagittal scans. The mediolateral disc width and position were then measured on every oblique-axial scan. The width and midline was computed for each disc and its deviation from the perpendicular to the condylar long axis was calculated. Finally, a statistical analysis was performed to study whether the disc width and the direction of the disc midline varied between discs normally positioned and anteriorly displaced. Results: The disc width varied significantly more within the anteriorly displaced discs than within the normal ones. The midline of the anteriorly displaced discs deviated more from the perpendicular to the condylar long axis than that of normally positioned discs and was mostly in a lateral direction. The disc midline also deviated more in the ventral than in the dorsal part of the disc. Conclusion: Most anteriorly displaced discs were laterally displaced and showed a larger width variation than normally positioned discs. This fact seems to indicate disc deformation.

temporomandibular joint; mandibular condyle; temporomandibular joint disc; magnetic resonance imaging; comparative study

1. Kurita K, Westesson PL, Tasaki M, Liedberg J. Temporomandibular joint: Diagnosis of medial and lateral disk displacement with anteroposterior arthrography. Correlation with cryosections. Oral Surg Oral Med Oral Pathol 1992;73:364–368.

2. Kurita K, Westesson PL, Tasaki M. Diagnosis of medial temporomandibular joint disc displacement with dual space anteroposterior arthrotomography: Correlation with cryosectional morphology. J Oral Maxillofac Surg 1992;50:618–620.

3. Liedberg J, Westesson PL, Kurita K. Sideways and rotational displacement of the temporomandibular joint disk: Diagnosis by arthrography and correlation to cryosectional morphology. Oral Surg Oral Med Oral Pathol 1990;69:757–763.

4. Pereira FJ Jr, Lundh H, Westesson PL. Morphologic changes in the temporomandibular joint in different age groups. An autopsy investigation. Oral Surg Oral Med Oral Pathol 1994;78:279–287.

5. Schwaighofer BW, Tanaka TT, Klein MV, Sartoris DJ, Resnick D. MR imaging of the temporomandibular joint: A cadaver study of the value of coronal images. AJR Am J Roentgenol 1990;154:1245–1249.

6. Katzberg RW, Westesson PL. Normal anatomy. In: Katzberg RW, Westesson PL (eds). Diagnosis of the Temporomandibular Joint. Philadelphia: WB Saunders, 1993:3–23.

7. Katzberg RW, Westesson PL, Tallents RH, Anderson R, Kurita K, Manzione JV Jr, Totterman S. Temporomandibular joint: MRassessment of rotational and sideways disk displacements. Radiology 1988;169: 741–748.

8. Katzberg RW, Westesson PL. Magnetic resonance imaging. In: Katzberg RW, Westesson PL (eds). Diagnosis of the Temporomandibular Joint. Philadelphia: WB Saunders, 1993:167–221.

9. Payne M, Nakielny RA. Temporomandibular joint imaging. Clin Radiol 1996;51:1–10.

10. Chen YJ, Gallo LM, Meier D, Palla S. Individualized oblique-axial magnetic resonance imaging for improved visualization of mediolateral TMJ disc displacement. J Orofac Pain 2000;14:128–139.

11. Matsuda S, Yoshimura Y, Lin Y. Magnetic resonance imaging assessment of the temporomandibular joint in disk displacement. Int J Oral Maxillofac Surg 1994; 23:266–270.

12. Tasaki MM, Westesson PL, Isberg AM, Ren YF, Tallents RH. Classification and prevalence of temporomandibular joint disk displacement in patients and symptom-free volunteers. Am J Orthod Dentofacial Orthop 1996;109: 249–262.

13. Foucart JM, Carpentier P, Pajoni D, Marguelles-Bonnet R, Pharaboz C. MR of 732 TMJs: anterior, rotational, partial and sideways disc displacements. Eur J Radiol 1998;28:86–94.

14. Rinck PA. Magnetic Resonance in Medicine: The Basic Textbook of the European Magnetic Resonance Forum. Oxford: Blackwell Scientific Publications; 1993: 77–98.

15. Korioth TW, Hannam AG. Mandibular forces during simulated tooth clenching. J Orofac Pain 1994;8:178–189.

16. Gallo LM, Nickel JC, Iwasaki LR, Palla S. Stress-field translation in the healthy human temporomandibular joint. J Dent Res 2000;79:1740–1746.

17. Westesson PL, Bronstein SL, Liedberg J. Internal derangement of the temporomandibular joint: Morphologic description with correlation to joint function. Oral Surg Oral Med Oral Pathol 1985;59:323–331.

18. de Bont LG, Boering G, Liem RS, Eulderink F, Westesson PL. Osteoarthritis and internal derangement of the temporomandibular joint: A light microscopic study. J Oral Maxillofac Surg 1986;44:634–643.

19. Leiker M, Nickel JC, Beatty MW, et al. Tensile preconditioning changes in impulsively loaded porcine TMJ discs [abstract]. J Dent Res 2000;79(special issue):407.