A unified reference that covers the face and many other structures in the ArtiSynth Models package is:

I. Stavness, M. Nazari, C. Flynn, P. Perrier, Y. Payan, J. E. Lloyd and S. Fels (2014). Coupled Biomechanical Modeling of the Face, Jaw, Skull, Tongue, and Hyoid Bone. In 3D Multiscale Physiological Human, Nadia Magnenat-Thalmann, Osman Ratib & Hon Fai Choi editors, Chapter 11, Springer Verlag London, pp. 253-274.

Otherwise, for more specific models, please cite, where appropriate, the following:

Unified Jaw and tongue model

Stavness I., Lloyd J., Payan Y. & Fels S. (2011). Coupled Hard-Soft Tissue Simulation with Contact and Constraints Applied to Jaw-Tongue-Hyoid Dynamics. International Journal for Numerical Methods in Biomedical Engineering, Vol. 27, pp. 367–390.

Jaw and hyoid model

Hannam, A. G., Stavness, I., Lloyd, J. E., & Fels, S. (2008 ). A dynamic model of jaw and hyoid biomechanics during chewing. Journal of Biomechanics, 41(5), 1069–1076

Tongue Models

Gerard J.M., Wilhelms-Tricarico R., Payan Y. & Perrier P. (2003). A 3D biomechanical tongue model to simulate speech movements. Archives of Physiology and Biochemistry vol. 111, pp. 7.