INTRODUCTION
Many physicians investigate temporomandibular disorders (TMDs) such as artbromyalgia, disk condyle incoordination, and osteoarthritis. For example, 126 temporomandibular joints (TMJs) of 63 patients with temporomandibular disorders have been investigated in [1] by using clinical examination and magnetic resonance imaging (MRI). The value of maximum jaw motion has been measured for 41 patients in [2]. A reconstruction and animation of the temporomandibular joint during chewing with real anatomic and kinematic data has been performed in [3]. In [3] a temporomandibular joint and jaw tracking device has been used as shown in Fig. 1a). The targets in Fig. 1a) locate the position of the temporomandibular joint that is also shown in the scheme of Fig. 1b).