Ventral frontal cortex morphology in adult males with isolated orofacial clefts: relationship to abnormalities in social function.

Objective: In a previous magnetic resonance imaging (MRI) study, men with nonsyndromic clefts of the lip and/or palate (NSCLP) were found to have abnormalities in the structure of the frontal lobe of the brain. Moreover, many subjects with nonsyndromic clefts of the lip and/or palate have been described as being socially inhibited. A subregion of the frontal lobe, the ventral frontal cortex (VFC), has been shown to be related to social function. This study was designed to evaluate the morphology of the ventral frontal cortex in men with nonsyndromic clefts of the lip and/or palate, and the morphology's relationship to social function.

Methods: Subjects were 46 men with nonsyndromic clefts of the lip and/or palate and 46 sex matched controls. Social function was assessed using a standardized scale. The morphology of the ventral frontal cortex (composed of the orbitofrontal cortex [OFC] and the straight gyrus [SG]) was obtained from magnetic resonance imaging scans using the software BRAINS.

Results: After controlling for frontal lobe gray matter, the patient group had significant reductions in orbitofrontal cortex volume and area. The straight gyrus was not morphologically abnormal. Measures of orbitofrontal cortex morphology were significantly correlated to measures of social function--the greater the structural abnormality, the greater the social dysfunction.

Conclusion: Compared with healthy controls, subjects with nonsyndromic clefts of the lip and/or palate showed morphologic abnormalities in the cortical surface anatomy of a brain region known to govern social function, the orbitofrontal cortex. Moreover, the structural abnormality in this brain region was directly correlated with social function.