Influence of the Temporomandibular Joint in the Estimation of Bone Density in the Mandible through a Bone Remodelling Model

Table 1

Forces exerted by masticatory muscles. Only the orientation of the forces of the right side are given (symmetry with respect to the sagittal plane was assumed). The magnitude of the muscle force peak in CO for the ipsilateral (I) and contralateral (C) sides are also provided. The +x-axis is directed anteriorly, the +y-axis rightward, and the +z-axis downward. CP: closing phase, OP: opening phase. 1: length with the mouth closed [27]. 2: Korioth et al. [28] for the jaw closing muscles. 3: van Eijden et al. [27] for the jaw opening muscles. 4: Nelson [29] for the jaw closing muscles. 5: proportional to the values adopted by Hannam et al. [12] for the jaw opening muscles.

Muscle	Portion	Length		cos-y^2,3	cos-z^2,3	Activity peak
						I	C
Masseter	Superficial	48.0	0.419	0.207	-0.885	0.56	0.20	190.4
	Deep	25.7	-0.358	0.546	-0.758	0.56	0.20	81.6
Temporalis	Anterior	51.9	0.044	0.149	-0.988	0.65	0.51	158.0
	Middle	52.7	-0.5	0.221	-0.837	0.60	0.53	95.6
	Posterior	52.9	-0.855	0.208	-0.474	0.54	0.54	75.6
Medial pterygoid		42.7	0.372	-0.486	-0.791	0.97	0.47	174.8
Lateral pterygoid (CP)	Inferior	32.6	0.757	-0.63	0.174	0.50	0.36	66.9
Lateral pterygoid (OP)	Inferior	32.6	0.757	-0.63	0.174	0.10	0.10	66.9
	Superior	31.3	0.645	-0.761	-0.074	0.039	0.026	28.8
Anterior belly digastric		43.2	0.053	0.815	-0.576			40.0
Geniohyoid		40.0	-0.995	0.103	0.018			38.8
Mylohyoid	Anterior	23.0	-0.176	-0.831	0.528			63.6
	Posterior	42.6	-0.223	-0.616	0.756			21.2