Asymmetry of the parental craniofacial skeleton in orofacial clefting.

OBJECTIVE

To evaluate size-related and shape-related craniofacial skeletal asymmetries in the parents of children with orofacial clefting (OFC).

DESIGN

Retrospective PA cephalometric study.

SETTING

Glasgow/Dundee, Scotland.

SUBJECTS: Ninety-two parental volunteers from a completely ascertained sample of 286 children born with OFC between 1980-1984 in the West of Scotland.

INTERVENTIONS: None.

MAIN OUTCOME MEASURES: A conventional cephalometric asymmetry analysis (CCAA) evaluated size-related right:left asymmetry comprising eight linear distance, nine angular, and three mid-facial area measurements. The right and left landmark configurations were uniformly scaled using Procrustes superimposition and Euclidean Distance Matrix Analysis (EDMA) evaluated shape-related right-left asymmetry.

RESULTS

The three linear distances, nine angles and two areas differed between the right and left sides of the craniofacial complex (P <0.05) indicate size asymmetry characterized by a wider left side of the face and a shorter vertical dimension on the right side (directional asymmetry). EDMA detected shape asymmetry [T statistic = 2.671 (P = 0.10)]. Forty per cent of the EDMA ratios were clinically importantly larger or smaller on the left and right sides respectively, involving landmarks anatomically and morphogenetically important in OFC.

CONCLUSION

Size and shape directional asymmetries characterize the parental craniofacial skeleton in OFC. This heritable directional craniofacial skeletal asymmetry could be of relevance in the left-sided predilection of OFC.