Morphological integration of the skull in craniofacial anomalies

Abstract

Objectives To understand how surgical interventions impact the organization and internal integration of the major components of the skull, we address the functional and developmental relationships during perinatal development. Methods A number of methods for quantifying modularity and integration of morphological data are available. Here, measures derived from three-dimensional computed tomographic (CT) images are used to investigate the statistical relationships among measures of the cranial vault, face and cranial base. First, we establish the pattern of associations among quantitative measures in a sample of children unaffected by a craniofacial anomaly. We statistically compare these normative patterns of cranial integration to those of a sample of children with a facial anomaly (complete unilateral complete cleft lip and palate), and to children with a neurocranial anomaly (isolated sagittal synostosis). Finally, we test whether surgery affects the strength and pattern of associations among measures within the cranial base in the affected children. Results Our analyses reveal strong internal integration of the cranial base in unaffected children and in our samples of unoperated cleft lip and palate, and sagittal synostosis. Post-operatively, the magnitude of integration of the cranial base is reduced relative to the pre-operative condition in both samples of children with craniofacial anomalies. Conclusion Our results show how the cranial base adjusts to its broader structural context, and provides added support for the developmental and structural integration of cranial base with both cranial vault and face.

Morphological integration in human skull and its possible role in etiogenesis of neuropsychiatric disorders: Deciphering the link between evolution, development and disease

“…Morphological integration enjoys good support from various studies in literature which associate developmental dysmorphogenesis of skull (and consequently of brain) with genesis of certain neuropsychiatric disorders, which include various craniofacial anomalies (ending in neurocognitive dysfunction) (8), syndromes featuring mental retardation (7,21), and distinct psychiatric diseases (17,18). Associated studies assert that it may be one of the etiomechanisms involved in causation of such diseases (8,17,18).…”

“…Even a small change in the dimensionality of a single landmark, in the course of evolution, has capacity to redirect the dimensionality of all the skull landmarks, and hence to create a different data set of measurements for inter-landmark distances (3). Although, such a re-modeling of the human skull may not always result in a functional gain and may predispose individuals to certain neuropsychiatric disorders (8,20,21), as a cost to the evolutionary benefits of the survival (22)(23)(24).…”

“…Associated studies assert that it may be one of the etiomechanisms involved in causation of such diseases (8,17,18). A study established links between posterior cranial fossa dysmorphogenesis and major depression (20).…”

“…A structural basis has, however, been speculated; as in the case of epilepsy (8,9), schizophrenia (10,11), bipolar disorder (12), and certain types of migraines (8,9). This also presents a missing link connecting evolution, embryonic development and multi-factorial etiogenesis of such disorders.…”

“…Now as the skull contains brain in closed and filling proximity, certainly a deformed skull has to harbor a correspondingly deformed brain. The development of skull and brain go in tandem (16) and a cranial deformity may present as a craniofacial anomaly, the associated dysmorphogenesis of brain may result in compromised neural functions at birth or may manifest as a neuropsychiatric disorder later in life (8,10,12) depending upon the degree of disruption and consequent remodeling of molecular regulation in developing brain (39,21).…”