Embryologically Based Classification Specifies Gender Differences in the Prevalence of Orofacial Cleft Subphenotypes

Background: A recently published validated classification system divides all orofacial cleft (OFC) subphenotypes into groups based on underlying developmental mechanisms, that is, fusion and differentiation, and their timing, that is, early and late periods, in embryogenesis of the primary and secondary palates. Aims: The aim of our study was to define gender differences in prevalence for all subphenotypes in newborns with OFC in the Netherlands. Methods: This was a retrospective cross-sectional study on children with OFC born from 2006 to 2016. Clefts were classified in early (E-), late (L-), and early/late (EL-) embryonic periods, in primary (P-), secondary (S-), and primary/secondary (PS-) palates, and further divided into fusion (F-), differentiation (D-), and fusion/differentiation (FD-) defects, respectively. Results: A total of 2089 OFC children were analyzed (1311 males and 778 females). Orofacial cleft subphenotypes in females occurred significantly more frequent in the L-period compared to males (66% vs 55%, P = .000), whereas clefts in males occurred significantly more in the EL-periods (40% vs 27%, P = .000). Females had significantly more S-palatal clefts (42% vs 23%, P = .000), while males had significantly more PS-palatal clefts (44% vs 30%, P = .000). Furthermore, the clefts in females were significantly more frequent the result of an F-defect (60% vs 52%, P = .000). Conclusions: Orofacial cleft in females mainly occur in the L-period are mostly S-palatal clefts, and are usually the result of an F-defect. Orofacial cleft in males more commonly occur in the EL-periods, are therefore more often combined PS-palatal clefts, and are more frequent D- and FD-defects

Ten Years Recording Common Oral Clefts With a New Descriptive System

Objective: After introducing a new descriptive recording system for congenital craniofacial abnormalities in The Netherlands, common oral clefts are highlighted. Design: Prospective observational study. Setting: Fifteen cleft palate teams, united in the Dutch Association for Cleft Palate and Craniofacial Anomalies, registered patients from 1997 to 2006. Patients: All unoperated patients with a common oral cleft were included. Main Outcome Measures: Detailed information and birth prevalence rates of cleft lip/alveolus, cleft lip/alveolus and palate, and cleft palate were provided, relating referral age, gender, family history, additional congenital abnormalities, and syndrome diagnoses to these three categories. Results: This study included 3512 patients, resulting in an overall prevalence of 16.6 per 10,000 live births. Patients showed a cleft lip/alveolus (28%), a cleft lip/alveolus and palate (39%), or a cleft palate (33%). The three categories exhibited very heterogeneous cleft types. Mean referral age was 5.8 months (median 3 weeks). Birth weight was the lowest in cleft palate patients (3238 g; p < .001 to .009). Cleft palate patients showed less positive family history concerning congenital anomalies (23%, p < .001 to .013), but more syndrome diagnoses were established in this category (24%, p < .001). Ten percent of all cleft patients showed additional abnormalities of the head and neck area, and 13% displayed congenital anomalies of other systems. Conclusions: This new recording method allows adequate description of common oral clefts. Many cleft types exist within these three categories and should be differentiated, because they originate from different time frames and/or cell biological mechanisms during embryogenesis

Classifying Common Oral Clefts: A New Approach After Descriptive Registration

Objective: Using the Dutch Oral Cleft Registration, which records the morphology and topography of common oral clefts, a new classification based on the (patho) embryology of the primary and secondary palates was tested. Design: Prospective observational study. Setting: The fifteen cleft palate teams in the Netherlands register patients to the national registry. Patients: All unoperated patients with common oral clefts reported between 1997 and 2006 inclusive were included. Main Outcome Measures: The classification is based on the pathoembryological events that ultimately result in various subphenotypes of common oral clefts. Patients within the three categories cleft lip/alveolus (CL/A), cleft lip/alveolus and palate (CL/AP), and cleft palate (CP) were divided into three subgroups: fusion defects, differentiation defects, and fusion and differentiation defects. A timetable was constructed to relate the type of clefting to the time of derailment during embryonic development. Results: 3512 patients were included. Patients with CL/A showed 22% fusion defects, 75% differentiation defects, and 3% fusion and differentiation defects. CL/AP patients and CP patients mostly showed fusion defects (70% and 89%, respectively). We were able to relate almost all (over 90%) cleft subphenotypes to specific weeks in embryonic development. Conclusions: This classification provides new cleft subgroups that may be used for clinical and fundamental research. The subphenotypes of these subgroups originate from different time frames during embryonic development and different cell biological mechanisms, thereby enabling more accurate data for, e. g., gene identification and/or environmental factors