Cleft palate morphology, genetic etiology, and risk of mortality in infants with Robin sequence.

Robin sequence (RS) has many genetic and nongenetic causes, including isolated Robin sequence (iRS), Stickler syndrome (SS), and other syndromes (SyndRS). The purpose of this study was to determine if the presence and type of cleft palate varies between etiologic groups. A secondary endpoint was to determine the relationship of etiologic group, cleft type, and mortality. Retrospective chart review of patients with RS at two high-volume craniofacial centers. 295 patients with RS identified. CP was identified in 97% with iRS, 95% with SS, and 70% of those with SyndRS (p < .0001). U-shaped CP was seen in 86% of iRS, 82% with SS, but only 27% with SyndRS (p < .0001). At one institution, 12 children (6%) with RS died, all from the SyndRS group (p < .0001). All died due to medical comorbidities related to their syndrome. Only 25% of children who died had a U-shaped CP. The most common palatal morphology among those who died was an intact palate. U-shaped CP was most strongly associated with iRS and SS, and with a lower risk of mortality. RS with submucous CP, cleft lip and palate or intact palate was strongly suggestive of an underlying genetic syndrome and higher risk of mortality.

Maternal periconceptional folic acid supplementation reduced risks of non-syndromic oral clefts in offspring.

Maternal periconceptional folic acid supplementation (FAS) has been documented to be associated with decreased risk of nonsyndromic oral clefts (NsOC). However, the results remain inconclusive. In this population-based case-control study of 807 singletons affected by NsOC and 8070 healthy neonates who were born between October 2010 and September 2015 in Chengdu, China, we examined the association of maternal FAS with the risk of nonsyndromic cleft lip with or without cleft palate (NsCL/P), and cleft palate (NsCP). Unconditional logistic regression analysis was used to estimate the crude and adjusted odds ratios (ORs) and 95% confidential intervals (CI). Significant associations were found between maternal periconceptional FAS and decreased risk of NsCL/P (aOR = 0.41, 95% CI 0.33-0.51). This protective effect was also detected for NsCL (aOR = 0.42, 95% CI 0.30-0.58) and NsCLP (aOR = 0.41, 95% CI 0.31-0.54). Both maternal FAS started before and after the last menstrual period (LMP) were inversely associated with NsCL/P (before LMP, aOR = 0.43, 95% CI 0.33-0.56; after LMP, aOR = 0.41, 95% CI 0.33-0.51). The association between NsCP and maternal FAS initiating before LMP was also found (aOR = 0.52, 95% CI 0.30-0.90). The findings suggest that maternal periconceptional FAS can reduce the risk of each subtype of NsCL/P in offspring, while the potential effect on NsCP needs further investigations.

Folate intake, markers of folate status and oral clefts: An updated set of systematic reviews and meta-analyses.

BACKGROUND: There has been a longstanding debate about the role of folate in the etiology of orofacial clefts (OFCs). Studies of different measures of nutritional intake or folate status have been done to investigate the possible role of folate in the prevention of OFC. Only one knowledge synthesis has attempted to bring together different types of evidence. The aim of the present work was to update it. METHODS: Evidence for associations between OFC and dietary folate, supplement use, folic acid fortification, biomarkers of folate status, and variants of MTHFR (C677T and A1298C) were included. Potentially eligible articles were systematically identified from PubMed, Medline, Embase, and Web of Science (2007-2020) and combined using random-effects meta-analysis when appropriate. Quality assessments were conducted using the Newcastle-Ottawa scale and Cochrane's risk of bias tool. RESULTS: Sixty-four studies published since the previous knowledge synthesis were identified, with eight of these identified through a supplementary search from October, 2018 to August, 2020. There was an inverse association between folic acid-containing supplement use before or during pregnancy and cleft lip with or without cleft palate (CL/P) (OR 0.60, 95% CI 0.51-0.69), with considerable between-study heterogeneity. The prevalence of CL/P showed a small decline post-folic acid fortification in seven studies (OR 0.94, 95% CI 0.86-1.02). No association was found between OFC and genetic markers of folate status. The coronavirus-19 pandemic has threatened food availability globally and therefore there is a need to maintain and even enhance surveillance concerning maternal intake of folate and related vitamins. CONCLUSIONS: The risk of non-syndromic OFC was reduced among pregnant women with folic acid-containing supplements during the etiologically relevant period. However, high heterogeneity between included studies, incomplete reporting of population characteristics and variation in timing of exposure and supplement types mean that conclusions should be drawn with caution.

Maternal folic acid supplementation reduces the severity of cleft palate in Tgf-ß3 null mutant mice.

BACKGROUND: Cleft palate (CP) constitutes the most frequently seen orofacial cleft and is often associated with low folate status. Folate plays an essential role in the human body as a major coenzyme in one-carbon metabolism, including DNA synthesis, repair, and methylation. Whether the administration of isolated folic acid (FA) supplements prevents the CP caused by genetic mutations is unknown, as is its effect on the mechanisms leading to palate fusion. METHODS: FA was administered to females from two different strains of transforming growth factor ß3 heterozygous mice. Null mutant progeny of these mice exhibit CP in 100% of cases of varying severity. We measured cleft length, height of palatal shelf adhesion, and the number of proliferating mesenchymal cells. Immunohistochemistry was also carried for collagen IV, laminin, fibronectin, cytokeratin-17, and EGF. RESULTS: FA supplementation significantly reduced CP severity and improved palatal shelf adhesion in both strains both in vivo and in vitro. Medial edge epithelium proliferation increased, and its differentiation was normalized as indicated by the presence and disposition of collagen IV, laminin, fibronectin, and cytokeratin-17. CONCLUSIONS: A maternal FA supplementation reduces the CP appearance by improving the mechanisms leading to palatal shelf adhesion.

Involvement of RBP4 in all­trans retinoic acid induced cleft palate.

The current study was designed to elucidate the mechanism of retinol binding protein 4 (RBP4) in cleft palate induced by all­trans retinoic acid (atRA). To establish a cleft palate model in C57BL/6J mice, pregnant mice were administered atRA (100 mg/kg) by gavage at the tenth embryonic stage (E10.0). Control groups were given the equivalent volume of corn oil. Pregnant mice were dissected at E12.5, E13.5 and E14.5 to obtain the embryonic palates. The expression levels of RBP4 in the embryonic palatal mesenchyme (EPM) were determined by immunohistochemistry, reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and western blotting. Human embryonic palatal mesenchymal cells were exposed to atRA to detect the variation in RBP4 induced by atRA in vitro. Small interfering RNA was used to suppress the expression of RBP4, and a plasmid overexpressing RBP4 was used to examine upregulated expression. The cell counting kit­8 assay was used to evaluate the effect of RBP4 on cell proliferation. The expression levels of p27 and cyclin D1 were determined by RT­qPCR and western blotting, while the expression levels of extracellular signal­related kinase (ERK) 1/2 and protein kinase B (AKT) were assessed by western blotting. At E14.5, RBP4 was strongly expressed in the EPM, while it was downregulated following atRA treatment, which induced cleft palate in vivo. In vitro experiments indicated that atRA suppressed the expression of RBP4 and altered the expression of p27 and cyclin D1 to cause growth inhibition. Knockdown of RBP4 resulted in decreased expression of cyclin D1 and increased p27, and suppressed proliferation. Overexpression of RBP4 reversed the inhibitory effect of atRA and promoted proliferation via the ERK1/2 and AKT signaling pathways. These results suggested that RBP4 was involved in cleft palate induced by atRA and it can be suppressed by atRA to cause growth inhibition in the embryonic palate.

Folic acid fortification and prevalences of neural tube defects, orofacial clefts, and gastroschisis in California, 1989 to 2010.

BACKGROUND: We examined whether prevalences of neural tube defects (NTDs), orofacial clefts, and gastroschisis changed more rapidly after than before folic acid fortification in California. METHODS: This population-based study used vital statistics and birth defects registry data. The study population included all live births and stillbirths delivered in central California counties from 1989 to 2010. Cases included deliveries with NTDs, orofacial clefts, and gastroschisis. Weighted least squares regression was used to estimate slopes during prefortification (before 1997) and postfortification (after 1998), respectively. The difference of the two slopes with the 95% confidence interval (CI) was calculated. RESULTS: For all NTDs combined, slopes indicated that NTD prevalence was decreasing by 8.7 (slope: -8.7; 95% CI, -13.5--3.9) cases per 100,000 deliveries per year before fortification and by 1.7 (slope: -1.7; 95% CI, -3.7-0.3) after fortification; thus the decline had slowed by 7.0 (95% CI, 2.7-11.3) cases per 100,000 deliveries per year. For orofacial clefts, slopes for cleft lip with/without palate as well as for cleft palate alone indicated that the postfortification slope was lower than the prefortification slope suggesting a more accelerated decrease in the postfortification time period. For gastroschisis, the slope after fortification was lower compared with prefortification, indicating a less accelerated prevalence increase in the postfortification time period. Stratification by race/ethnicity did not substantially alter results. CONCLUSION: We observed a slower decline in prevalence of NTDs, an emergence of a decline in orofacial clefts, and a slower increase in gastroschisis, during the postfortification period in central California, relative to the prefortification period. Birth Defects Research (Part A), 2016. © 2016 Wiley Periodicals, Inc. Birth Defects Research (Part A) 106:1032-1041, 2016. © 2016 Wiley Periodicals, Inc.

Oral folic acid supplementation decreases palate and/or lip cleft occurrence in Pug and Chihuahua puppies and elevates folic acid blood levels in pregnant bitches.

The aim of this study was to compare the frequency of the occurrence of lip and/or palate cleft (CL/CP) in new-borns of two breeds, Pugs and Chihuahuas, and to measure the folic acid blood levels in bitches during gestations both with and without folic acid oral supplementation. Bitches of 13 Pugs and 17 Chihuahuas with CL/CP cases were used in the study. In trial 1, the animals of the experimental group (n=25) were given additional folic acid from the onset of heat till the 40th day of gestation. The females of the control group (n=12) were fed a traditional diet. From all the animals blood was collected at the onset of heat, 14 days later and on the 30th day of the gestation to estimate folic acid concentration. In trial 2, the prevalence of CP/CL cases in litters from pregnancies before and after supplementation was compared. The percentage of puppies with CL/CP after supplementation decreased in both Pugs and Chihuahua puppies (10.86% and 15.78% vs. 4.76% and 4.8% respectively). On Day 0, the concentrations of folic acid were at a low physiological level (around 8 ng/ml) in all the animals. In bitches of the experimental group the blood level of folic acid on day 14th and 30th of the treatment showed an increase in both breeds (13.65 +/- 4.27 ng/ml in Pugs, 10.79 +/- 2.84 ng/ml in Chihuahuas, and 14.94 +/- 3.22 ng/ml in Pugs, 12.95 +/- 3.58 in Chihuahuas, respectively) while in the control group, this level decreased with time of gestation both in Pugs and in Chihuahuas (around 6 ng/ml). Folic acid supplementation seems to be a simple, effective preventive method to reduce the risk of CL/CP, especially in the predisposed breeds.

Epidemiology of cleft lip and cleft palate in Pakistan.

Clinical and epidemiologic studies of defined geographic populations can serve as a means of establishing data important for the diagnosis, treatment, and counseling of patients with cleft lip and cleft palate. Several descriptive epidemiologic studies have been carried out in many countries worldwide; however, no such study has ever been performed in Pakistan. Population-based data on the incidence of cleft lip and palate were obtained from birth registry information in northern Pakistan. A total of 117 cases from 61,156 live births reported were identified. The incidence for cleft lip and/or cleft palate was 1.91 per 1000 births (one per 523 births). Cleft lip alone (42 percent) was noted more frequently than isolated cleft palate (24 percent) and combined cleft lip and palate deformities (34 percent). Boys were more commonly affected by cleft lip and cleft lip with cleft palate, whereas girls predominated in the isolated cleft palate cases. Consanguineous marriages were observed in 32 percent of parents versus 18 percent in matched controls. Only 32 percent of cleft mothers received formal prenatal counseling, monthly examinations, and regular laboratory testing during the entirety of the pregnancy. Nutritional and vitamin supplements were given to only 28 percent of mothers of cleft children versus 59 percent in matched controls. Descriptive statistics were used to assess pertinent risk factors associated with cleft lip and palate. The acquisition of incidence and associated data has generated baseline information on the magnitude of cleft lip and cleft palate in Pakistan. It is hoped that this information can be used for appropriate resource use, cleft lip and cleft palate prevention programs, and counseling programs with Pakistan-specific data.

An in vitro screening system for characterizing the cleft palate-inducing potential of chemicals and underlying mechanisms.

An in vitro organ culture system with developing mouse palates was improved to characterize the cleft palate (CP)-inducing potential of chemicals and underlying mechanisms. Palatal explants collected from gestation day 12 mouse fetuses were cultured with various concentrations of teratogens and examined for palatal development after 48 and 72 h of culture to assess effects of the chemicals on growth and/or fusion of palatal shelves. When the explants were exposed to diphenylhydantoin or 5-fluorouracil, palatal growth was inhibited in a concentration-dependent manner at 48 h. Suppression of the expression of proliferative cell nuclear antigen revealed poor cell proliferation. At 72 h, the incidence of explants with CP was significantly increased in the high-dose groups, suggesting that CP induction is mainly attributable to inhibition of palatal growth. By contrast, retinoic acid and hydrocortisone significantly lowered the rates of fused palates at 72 h in all treated groups, while they exhibited no effects on palatal growth at 48 h even at the highest concentration. Because no apoptosis was found in the epithelial cells at the tip of these palates, these chemicals are suggested to inhibit palatal fusion process by preventing apoptosis.

C677T variant form at the MTHFR gene and CL/P: a risk factor for mothers?

Maternal folic acid supplementation in early pregnancy has been suggested to play a role in the prevention of nonsyndromic orofacial cleft, i.e., cleft lip with or without cleft palate (CL/P). Moreover, some authors demonstrated association of the C-->T mutation (C677T), converting an alanine to a valine residue in 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, with other congenital anomalies such as neural tube defects (NTDs). Because of MTHFR's involvement in the metabolism of folate, we investigated 64 CL/P patients and their parents for C677T MTHFR mutation. No linkage disequilibrium was found using the transmission disequilibrium test (TDT). However, a significantly higher mutation frequency was detected in mothers of CL/P patients compared to controls. The odds ratios calculated for mothers having CT or TT genotype, compared to the normal CC genotype, were 2.75 (95% confidence interval 1.30-5.57) and 2.51 (1.00-6.14), respectively. These results support the involvement of the folate pathway in the etiology of CL/P, and indicate an effect of the maternal genotype, rather than influence of the embryo's genotype.

Dental anesthetic procedures for cleft lip and palate patients.

Many dentists refuse to offer dental assistance to cleft lip and palate patients because they lack understanding about this malformation and do not want to make a professional mistake with the anesthesia. The aim of this work is to guide clinical practitioners, who want to work with these patients about the anatomical features of the cleft lip and palate area and the implications in the anesthetic procedures.

Surgical correction of submucous cleft palate with Furlow palatoplasty.

Many surgeons have favored using the pharyngeal flap as the primary treatment for the velopharyngeal insufficiency associated with submucous cleft palate. However, the increasing number of reports of sleep apnea and airway compromise as a result pharyngeal flap surgery support the need to eliminate any unnecessary pharyngeal flap surgery. From 1988 to 1993, 35 Chinese submucous cleft palate patients with velopharyngeal insufficiency received surgery. A Furlow palatoplasty was used in 30 patients (3 to 26 years old). The follow-up duration was 9 months to 5 1/2 years. These patients were selected after a thorough study for velopharyngeal insufficiency including intraoral examination, perceptual speech assessment, videonasopharyngoscopy, and/or multiview videofluoroscopy. The criteria for selection included age, intraoral finding of an obviously anterior inserted levator palatine muscle, size of velopharyngeal gap, pattern of velopharyngeal closure, degree of lateral pharyngeal wall movement, and response to biofeedback speech therapy. In general, younger patients with circular or sagittal pattern closure, a velopharyngeal gap less than 5 mm, or good response to biofeedback speech therapy were considered to be the best candidates for a Furlow palatoplasty. The 5 patients who did not fulfill these criteria and whose velopharyngeal function failed to improve on preoperative biofeedback therapy were treated by pharyngeal flap operation. Twenty-nine patients (96.7 percent) achieved competent velopharyngeal function after the Furlow palatoplasty. The procedure corrected the velopharyngeal insufficiency in 3 patients older than 20 years with a velopharyngeal gap of less than 2 mm. The only patient with an unsatisfactory result was a 26-year old woman who had very prominent action of the musculus uvulae before the surgery. The results show that a Furlow palatoplasty can satisfactorily correct velopharyngeal insufficiency in carefully selected submucous cleft palate patients and thus avoid the serious complications of pharyngeal flap surgery.

Issues in speech motor control and their relation to the speech of individuals with cleft palate.

A view of speech motor control is presented that is different from conventional coarticulation models. Rather than assuming that phonetic units specify targets for peripheral events, this view is based on holistic behavioral goals. The importance of discovering strategies that organize interactions among physiologic processes of the speech motor system is stressed. The concepts of motor flexibility and plasticity are developed. These motor control issues are used as the basis for discussing the relations among speech motor processes, critical minimum velopharyngeal port size, and speech adequacy in speakers with cleft palate. Different meanings of velopharyngeal incompetency are considered, and a potential misuse of the concept is explained. Finally, the developmental character of motor plasticity is discussed, and the implications of critical periods in speech motor learning are raised for children with cleft palate.