Bonin Stephanie J, Clayton Hilary M, Lanovaz Joel L, Johnson Thomas J
Mary Anne McPhail Equine Performance Center, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, 48824, USA.
Am J Vet Res. 2006 Mar;67(3):423-8. doi: 10.2460/ajvr.67.3.423.
To develop a method of measuring 3-dimensional kinematics of the temporomandibular joint (TMJ) in horses chewing sweet feed.
4 mature horses that had good dental health.
Markers attached to the skin over the skull and mandible were tracked by an optical tracking system. Movements of the mandible relative to the skull were described in terms of 3 rotations and 3 translations. A virtual marker was created on the midline between the rami of the mandibles at the level of the rostral end of the facial crest to facilitate observation of mandibular movements.
During the opening stroke, the virtual midline mandibular marker moved ventrally, laterally toward the chewing side, and slightly caudally. During the closing stroke, the marker moved dorsally, medially, and slightly rostrally. During the power stroke, the mandible slid medially and dorsally as the mandibular cheek teeth moved across the occlusal surface of the maxillary cheek teeth. The 4 horses had similar chewing patterns, but the amplitudes varied among horses.
The TMJ allows considerable mobility of the mandible relative to the skull during chewing. The method presented in this report can be used to compare the range of motion of the TMJ among horses with TMJ disease or dental irregularities or within an individual horse before and after dental procedures.
开发一种测量马咀嚼甜饲料时颞下颌关节（TMJ）三维运动学的方法。
4匹牙齿健康的成年马。
通过光学跟踪系统跟踪附着在颅骨和下颌骨皮肤表面的标记物。下颌骨相对于颅骨的运动通过3种旋转和3种平移来描述。在面嵴前端水平的下颌骨支之间的中线上创建一个虚拟标记物，以方便观察下颌运动。
在开口冲程期间，虚拟下颌中线标记物向下、向咀嚼侧横向移动，并略微向后移动。在闭口冲程期间，标记物向上、向内并略微向前移动。在动力冲程期间，随着下颌颊齿在上颌颊齿的咬合面上移动，下颌骨向内和向上滑动。4匹马具有相似的咀嚼模式，但幅度在不同马匹之间有所不同。
TMJ在咀嚼过程中允许下颌骨相对于颅骨有相当大的活动度。本报告中介绍的方法可用于比较患有TMJ疾病或牙齿不齐的马匹之间或个体马匹在牙科手术前后TMJ的运动范围。
