A pilot study of four-dimensional visualization of mandibular and temporomandibular joint movement

Background: Mandibular movements are reliable indicators of mandibular system disease and changes in movements can be useful to estimate treatment effect. Detection of mandibular movement is important.

Objectives: We evaluated four-dimensional (4D) visualization of mandibular and temporomandibular joint movement using 320-row computed tomography (CT).

Methods: A stepwise mouth gag was placed between mandibular and maxillary incisors to control mouth opening (0.5-cm increments) in healthy volunteers and one temporomandibular disorder (TMD) patient. A 320-row CT Joint-Move and Shot sequence was used for scanning with an image taken after each increment. 4D reconstruction was used to establish volume data.

Results: 4D visualization of joint and dentition in a rest state and in a state of mandibular movement from multiple angles and in different planes demonstrated differences between healthy subjects and the subject with TMD. The effective dose per scan was approximately 17% of the 16-slice spiral CT.

Conclusion: 4D visualization of mandibular movement can be achieved through 320-row volume CT, which may provide a diagnosis of temporomandibular joint disorder and assessment of treatment effects.