Three-dimensional analysis of craniofacial asymmetry and integrated, modular organization of human head

To achieve craniofacial symmetry is one of the important goals of orthodontic and orthognathic treatment planning. With the increasing popularity of cone beam computed tomography (CBCT) in recent years, it is frequently considered for three-dimensional evaluation of craniofacial asymmetry. Currently, there are no published reviews reporting craniofacial modularization to explain the aggravated asymmetry from the upper to lower face. This review highlights the characteristics of craniofacial asymmetry; the covariance and integration of the brain, cranium, and face; and the evolutionary development pattern of craniofacial modularization. In addition, the relationship between the brain and the facial midline is discussed in this context. We have proposed a new method to determine the midsagittal plane and three-dimensional analysis of craniofacial asymmetry using the bilateral hemisphere midline structure (cerebral falx) as a reference plane. The cerebral falx is a dura mater separating the cerebral hemispheres and a potential gold standard midline reference for assessing the brain midline shift during computed tomography (CT).