Laterality and Completeness Patterns of Nonsyndromic Clefts in a Multiethnic Cohort

Area of Science:

• Craniofacial anomalies
• Genetics and developmental biology
• Public health

Background:

• Orofacial clefts, including cleft lip with or without cleft palate (NSCL/P), vary in severity from partial to complete thickness.
• Understanding patterns of cleft completeness is crucial for diagnosis and treatment planning.

Purpose of the Study:

• To evaluate side preference for cleft completeness in nonsyndromic asymmetric bilateral and unilateral cleft lip with or without cleft palate (NSCL/P).
• To analyze associations between cleft completeness, sex, ethnicity, and race across diverse populations.

Main Methods:

• Analysis of 3,561 individuals with NSCL/P from four multiethnic cohorts (North/South America, Asia, Africa).
• Utilized Chi-square or Fisher's exact test to assess associations between cleft completeness, sex, ethnicity, and race.
• Included patients with complete information on cleft type and completeness.

Main Results:

• Left-sided cleft completeness was significantly more frequent than right-sided in asymmetric bilateral cases (73.7% vs. 26.3%; p<0.001).
• Hispanics showed higher completeness rates than non-Hispanics in symmetric bilateral and unilateral cases.
• Caucasians had lower completeness rates compared to Asians, Blacks, or other racial groups (p<0.001), and females presented with more complete clefts than males (p=0.003).

Conclusions:

• The left side is more frequently complete in NSCL/P with bilateral asymmetry.
• Completeness in unilateral clefts shows no side preference, contrary to the overall higher incidence of left-sided clefts.
• Significant associations exist between race, ethnicity, and patterns of cleft severity.