›› 2018, Vol. 38 ›› Issue (3): 211-216.

• Basic Research • Previous Articles     Next Articles

The role of lateral pterygoid muscle in traumatic temporomandibular joint ankylosis

  

  • Received:2017-10-06 Revised:2017-11-06 Online:2018-03-28 Published:2018-03-16

Abstract: Objective To reveal the role of lateral pterygoid muscle in traumatic temporomandibular joint (TMJ) ankylosis. Methods Bilateral TMJ complex trauma was performed in eight 6-month-old male sheep. Then, function of the right and left lateral pterygoid muscles was maintained (control group) or blocked (test group), respectively. At the end of the 12th week after operation, all the animals were sacrificed and TMJ complex samples were evaluated by gross observation, spiral computed tomography (CT) scanning, Micro-CT scanning and histological examinations. Results Gross observation revealed bony ankylosis in the control group while fibrous adhesions in the test group. Results of spiral CT and Micro-CT demonstrated that the control group showed calcified callus formation in the joint space and roughened articular surfaces after new bone formation, which protruded into the joint space. The maximum anteroposterior and mediolateral condylar diameters were significantly larger in the control group than those in the test group. Micro-CT also showed that the primary growth orientation of new trabeculae was consistent with the direction of lateral pterygoid traction in the control group. Furthermore, histological examination showed fibro-osseous ankylosis in the control group. However, these characteristics were not found in the test group. Conclusion The lateral pterygoid muscle plays an important role, which is similar to distraction osteogenesis, in traumatic TMJ ankylosis.

Key words: Lateral pterygoid muscle, model animal, Distraction osteogenesis, condyle sagittal fracture, Ankylosis of temporomandibular joint

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