Effects of unilateral clefts on brain structure

Should left- and right-sided unilateral cleft lip and palate patients be grouped together when reporting the outcomes?

OBJECTIVES

Investigate associations between cleft laterality in patients with non-syndromic unilateral cleft lip and palate (UCLP) and oral-health, dental-arch, speech, audiological, psychological and nasolabial-aesthetic outcomes.

METHODS

Secondary data analysis of the outcomes of 5-year-old children with non-syndromic complete UCLP identified from three studies: Cleft Collective (n = 155), Cleft Care UK (CCUK) (n = 266) and Clinical Standards Advisory Group (CSAG) study (n = 238). Outcome measures included occlusal assessment using the 5-year-old's index score, speech intelligibility rating using the CAPS-A Audit tool, audiological assessment using pure tone audiometry, nasolabial aesthetic assessment using the Asher-McDade tool, oral-health assessment using decayed, missing, filled teeth scores and parent-reported outcomes. Logistic regression with adjustment for age, sex and index-of-multiple-deprivation scores were performed.

RESULTS

No differences were found in patient-reported outcomes between the left and right clefts in the Cleft Collective study. From the CCUK study, right clefts had poorer speech (n = 236; 95% CI 1.09, 3.42; and P = .03) and hearing outcomes (n = 211; 95% CI 1.03, 3.43; P = .04). In the CSAG study, patients with left clefts were more likely to be teased (n = 213; 95% CI 0.26, 0.85; and P = .01).

CONCLUSION

Weak associations between cleft laterality, speech, hearing and psychological outcomes were found, however the findings were inconsistent across the studies. This study contributes to evidence of associations between laterality and outcomes in children born with UCLP.

Cleft Laterality Dental Arch Relationship Outcomes for Children with Unilateral Cleft Lip and Palate in New Zealand

OBJECTIVES

To investigate cleft laterality dental arch relationship outcomes of children with non-syndromic complete unilateral cleft lip and palate (UCLP) in New Zealand.

DESIGN

A retrospective nationwide study.

SETTINGS

Virtual 3D orthodontic study models collected prior to undertaking secondary alveolar bone grafting.

PARTICIPANTS

A total of 104 patients with UCLP (L = 80: R = 24).

OUTCOME MEASURES

Four calibrated assessors used the GOSLON Yardstick and 100 mm Visual Analogue Scale (VAS) to score the randomised models on 2 separate assessment sessions. Weighted Kappa were used to determine the intra/inter-rater reliability for the GOSLON and correlations for the VAS.

RESULTS

Intra-rater reliability ranged from 0.57-0.88 (GOSLON) and 0.45-0.93 (VAS). Inter-rater reliability ranged from 0.62-0.86 (GOSLON) and 0.64-0.93 (VAS).GOSLON scores for the left UCLP were 31.2% for good/very good; 26.3% for fair; 42.5% for poor/very poor while the right UCLP scored 8.3% for good/very good; 37.5% for fair; 54.2% for poor/very poor. The mean VAS for left and right UCLP were 53.4 (sd 22.5) and 44.6 (sd 17.1) respectively. Neither the GOSLON nor VAS differences reached statistical significance (both P = .08).

CONCLUSIONS

From a clinical perspective right UCLP had worse dental arch relationship outcomes, however, these differences failed to reach statistical significance. Further studies using larger sample sizes are required to determine if cleft laterality is an important consideration when investigating UCLP dental arch outcomes.

Sidedness in Unilateral Orofacial Clefts: A Systematic Scoping Review

OBJECTIVE

An overview of the literature relating to the sidedness of unilateral cleft lip with or without cleft palate to map current knowledge on the cause and impact of directional asymmetry.

DESIGN

Scoping review with a systematic search of Medline and Embase from inception to May 2023.

PATIENTS, PARTICIPANTS

Humans born with a left or right unilateral cleft lip with or without a cleft palate.

MAIN OUTCOME MEASURES

Cleft sidedness as a co-occurrence, an outcome or an exposure.

RESULTS

Forty studies were eligible for inclusion and confirmed the predilection for the occurrence of left sided cleft lips; 12 studies reported cleft sidedness co-occurring with another phenotype, 11 studies report sidedness as an outcome and 17 studies as an exposure. Phenotypes which were reported to co-occur with either left or right sided clefts included congenital dental anomalies, handedness and additional congenital anomalies. Variables investigated as a potential cause of left or right sided clefts as an outcome included chromosomal anomalies, genetic variants and environmental factors. Outcomes investigated in relation to cleft sidedness as an exposure included facial anatomical features, facial growth, educational attainment, functional and psychological characteristics. More studies showed worse outcomes in right sided clefts versus left sided clefts than vice versa, although studies were inconsistent, and a quality assessment was not performed.

CONCLUSIONS

The field of cleft sidedness research is expanding and there are promising early findings to differentiate cause and outcome by sidedness of the cleft.

The Brain in Oral Clefting: A Systematic Review With Meta-Analyses

Background

Neuroimaging of individuals with non-syndromic oral clefts have revealed subtle brain structural differences compared to matched controls. Previous studies strongly suggest a unified primary dysfunction of normal brain and face development which could explain these neuroanatomical differences and the neuropsychiatric issues frequently observed in these individuals. Currently there are no studies that have assessed the overall empirical evidence of the association between oral clefts and brain structure. Our aim was to summarize the available evidence on potential brain structural differences in individuals with non-syndromic oral clefts and their matched controls.

Methods

MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Web of Science and Embase were systematically searched in September 2020 for case-control studies that reported structural brain MRI in individuals with non-syndromic oral clefts and healthy controls. Studies of syndromic oral clefts were excluded. Two review authors independently screened studies for eligibility, extracted data and assessed risk of bias with the Newcastle-Ottawa Scale. Random effects meta-analyses of mean differences (MDs) and their 95% confidence intervals (95% CI) were performed in order to compare global and regional brain MRI volumes.

Results

Ten studies from 18 records were included in the review. A total of 741 participants were analyzed. A moderate to high risk of bias was determined for the included studies. The cerebellum (MD: -12.46 cm³, 95% CI: -18.26, -6.67, n = 3 studies, 354 participants), occipital lobes (MD: -7.39, 95% CI: -12.80, -1.99, n = 2 studies, 120 participants), temporal lobes (MD: -10.53 cm³, 95% CI: -18.23, -2.82, n = 2 studies, 120 participants) and total gray matter (MD: -41.14 cm³; 95% CI: -57.36 to -24.92, n = 2 studies, 172 participants) were significantly smaller in the cleft group compared to controls.

Discussion

There may be structural brain differences between individuals with non-syndromic oral clefts and controls based on the available evidence. Improvement in study design, size, methodology and participant selection could allow a more thorough analysis and decrease study heterogeneity.

Birth Defect Co-Occurrence Patterns Among Infants With Cleft Lip and/or Palate

OBJECTIVE

To investigate 2- to 5-way patterns of defects co-occurring with orofacial clefts using data from a population-based registry.

DESIGN

We used data from the Texas Birth Defects Registry for deliveries between 1999 and 2014 to Texas residents, including 1884 cases with cleft palate (CP) and 5289 cases with cleft lip with or without cleft palate (CL±P) without a known syndrome. We identified patterns of defects co-occurring with CP and with CL±P observed more frequently than would be expected if these defects occurred independently. We calculated adjusted observed-to-expected (O/E) ratios to account for the known tendency of birth defects to cluster nonspecifically.

RESULTS

Among infants without a syndrome, 23% with CP and 21% with CL±P had at least 1 additional congenital anomaly. Several combinations of defects were observed much more often than expected. For example, the combination of CL±P, congenital hydrocephaly, anophthalmia, and other nose anomalies had an O/E ratio of 605. For both CP and CL±P, co-occurrence patterns with the highest O/E ratios involved craniofacial and brain abnormalities, and many included the skeletal, cardiovascular, and renal systems.

CONCLUSIONS

The patterns of defects we observed co-occurring with clefts more often than expected may help improve our understanding of the relationships between multiple defects. Further work to better understand some of the top defect combinations could reveal new phenotypic subgroups and increase our knowledge of the developmental mechanisms that underlie the respective defects.

Common basis for orofacial clefting and cortical interneuronopathy

Orofacial clefts (OFCs) of the lip and/or palate are among the most common human birth defects. Current treatment strategies focus on functional and cosmetic repair but even when this care is available, individuals born with OFCs are at high risk for persistent neurobehavioral problems. In addition to learning disabilities and reduced academic achievement, recent evidence associates OFCs with elevated risk for a constellation of psychiatric outcomes including anxiety disorders, autism spectrum disorder, and schizophrenia. The relationship between these outcomes and OFCs is poorly understood and controversial. Recent neuroimaging studies in humans and mice demonstrate subtle morphological brain abnormalities that co-occur with OFCs but specific molecular and cellular mechanisms have not been investigated. Here, we provide the first evidence directly linking OFC pathogenesis to abnormal development of GABAergic cortical interneurons (cINs). Lineage tracing revealed that the structures that form the upper lip and palate develop in molecular synchrony and spatiotemporal proximity to cINs, suggesting these populations may have shared sensitivity to genetic and/or teratogenic insult. Examination of cIN development in a mouse model of nonsyndromic OFCs revealed significant disruptions in cIN proliferation and migration, culminating in misspecification of the somatostatin-expressing subgroup. These findings reveal a unified developmental basis for orofacial clefting and disrupted cIN development, and may explain the significant overlap in neurobehavioral and psychiatric outcomes associated with OFCs and cIN dysfunction. This emerging mechanistic understanding for increased prevalence of adverse neurobehavioral outcomes in OFC patients is the entry-point for developing evidence-based therapies to improve patient outcomes.

Associations between laterality of orofacial clefts and medical and academic outcomes

Patients with oral clefts have an increased risk of other malformations, syndromes, and lower academic performance in school. Few studies have investigated if laterality of clefts is associated with medical and academic outcomes. Oral clefts have nonrandom laterality, with left-sided clefts occurring approximately twice as often as right-sided clefts. Using a retrospective study design, we examined potential associations of cleft attributes and outcomes in patients with cleft lip with or without cleft palate (CL/P) born in 2003-2010 who were treated at the Seattle Children's Craniofacial Center. The following variables were extracted from medical records: cleft type, medical history, maternal hyperglycemia, other malformations, and the need for academic support at school. We used logistic regression to examine risk of associations with outcomes of interest. Relative to patients with left-sided clefts, patients with bilateral CL/P were more likely to have a syndrome. Patients with nonsyndromic right-sided CL/P had a higher risk (OR and 95%CI: 3.5, 1.3-9.5, and 5.5, 1.9-16.0, respectively) of having other malformations and requiring academic support at school, when compared to patients with left-sided CL/P. Understanding the etiology of oral clefts is complicated, in part because both genetic and environmental factors contribute to the risk of developing a cleft. However, the different outcomes associated with cleft laterality suggest that right-sided clefts may have a distinct etiology. Using laterality to study cleft subgroups may advance our understanding of the etiology of this common birth defect.

Laterality of Oral Clefts and Academic Achievement

BACKGROUND AND OBJECTIVES

Children with isolated oral clefts have lower academic performance when compared with unaffected peers, yet few studies have examined specific attributes of clefts that may modify this risk. Oral clefts have nonrandom laterality, with left-sided clefts being more common than right-sided clefts, a pattern that may be genetically or environmentally influenced. The objective of this study was to evaluate the association between cleft laterality and academic achievement in a population-based sample of children with and without isolated oral clefts.

METHODS

The study included 292 children with isolated unilateral cleft lip with or without cleft palate identified by using the Iowa Registry for Congenital and Inherited Disorders matched with 908 unaffected classmates. This group provided 1953 child-grade observations for cases and 6829 for classmates. Academic achievement was evaluated by using high-quality standardized test data on multiple academic domains as well as use of special education.

RESULTS

We found that children with right-sided clefts had similar achievement scores and usage of special education services compared with their unaffected classmates. Children with left-sided clefts had lower reading scores than children with right-sided clefts by nearly 7 percentiles (P < .05). They also had lower scores on all evaluated domains by 4 to 6 percentiles and greater use of special education services by 6 percentage points than their classmates.

CONCLUSIONS

Children with left-sided clefts had poorer academic performance than their classmates or children with right-sided clefts, who showed similar academic achievement compared with their unaffected classmates.

Longitudinal Study of Growth of Children with Unilateral Cleft Lip and Palate: 2 to 10 Years of Age

Objective

To study the growth of children with complete unilateral cleft lip and palate (UCLP) from 2 to 10 years of age and to assess whether growth varied from that of children without UCLP (typical children).

Design

Physical growth was one of the outcome measures of a National Institutes of Health–sponsored longitudinal, prospective clinical trial conducted by the University of Florida and the University of São Paulo.

Setting

Hospital of Rehabilitation of Craniofacial Anomalies, University of São Paulo (HRAC-USP), Bauru, Brazil.

Main Outcome Measures

Height and weight were prospectively measured for 360 healthy children with UCLP who were nonsyndromic, belonged to median socioeconomic status, and received health care at HRAC-USP. To compare growth of children with UCLP to that of typical children, growth curves for UCLP were developed and compared with World Health Organization curves for 2006 and 2007, which were used as reference for typical children. Third-degree polynomials were used to explain the relationship of length and weight with age. Confidence limits of 95% were used for the mean curve using the statistic Z ~ N (0,1).

Results

Children with UCLP from 2 to 10 years old presented height and weight growth curves similar to those of typical children for both genders.

Conclusion

Children with UCLP from 2 to 10 years old presented physical growth similar to that of typical children.

Academic achievement in children with oral clefts versus unaffected siblings

OBJECTIVE

To compare academic achievement in children with oral-facial clefts (OFC) with their unaffected siblings.

METHODS

256 children with OFC were identified from the Iowa Registry for Congenital and Inherited Disorders, and 387 unaffected siblings were identified from birth certificates. These data were linked to Iowa Testing Programs achievement data. We compared academic achievement in children with OFC with their unaffected siblings using linear regression models, adjusted for potential confounders. In post hoc analyses, we explored modifiers of siblings' academic performance.

RESULTS

Achievement scores were similar between children with OFC and their siblings. Children with cleft palate only were significantly more likely to use special education than their unaffected siblings. Siblings' academic achievement was inversely related to distance in birth order and age from the affected child.

CONCLUSION

Children with OFC and their siblings received similar achievement scores. Younger siblings, in particular, may share a vulnerability to poor academic outcomes.

Craniomaxillofacial abnormalities in dogs with congenital palatal defects: computed tomographic findings

OBJECTIVE

To evaluate craniomaxillofacial abnormalities in dogs with congenital palatal defects.

STUDY DESIGN

Retrospective computed tomography (CT) study.

ANIMALS

Dogs with congenital palatal defects (n = 9).

METHODS

Medical records and CT reports (1995-2012) were searched for dogs with a diagnosis of cleft palate that had a CT study. Data retrieved were: breed, age, sex, weight, physical examination, and laboratory findings, number of previous palate surgeries, and oral/dental examination findings with the diagnosis of the cleft for each dog. CT studies of the head were reviewed on a structure-by-structure basis.

RESULTS

Tympanic bullae were most commonly found to be abnormal (8 dogs), followed by nasal turbinates (6), nasal septum, vomer, cribriform plate (4), frontal sinuses, and lateral ventricles (3). Other abnormalities were related to occlusion, teeth, incisive bones, maxillary bones, mandibles, hyoid apparatus, cranial bones, and nasopharynx. The soft tissue defect of the cleft was always smaller than the bony defect.

CONCLUSIONS

Craniomaxillofacial abnormalities in dogs with congenital palatal defects are common and some of these may negatively affect the quality of life. Importantly for surgical planning, the soft tissue component of the cleft may underestimate the extent of the bony defect, especially in failed repairs.

Haploinsufficiency of interferon regulatory factor 6 alters brain morphology in the mouse

Orofacial clefts are among the commonest birth defects. Among many genetic contributors to orofacial clefting, Interferon Regulatory Factor 6 (IRF6) is unique since mutations in this gene cause Van der Woude (VWS), the most common clefting syndrome. Furthermore, variants in IRF6 contribute to increased risk for non-syndromic cleft lip and/or palate (NSCL/P). Our previous work shows that individuals with either VWS or NSCL/P may have cerebral anomalies (larger anterior, smaller posterior regions), and a smaller cerebellum. The objective of this study was to test the hypothesis that disrupting Irf6 in the mouse will result in quantitative brain changes similar to those reported for humans with VWS and NSCL/P. Male mice heterozygous for Irf6 (Irf6(gt1/+); n = 9) and wild-type (Irf6(+/+) ; n = 6) mice at comparable age underwent a 4.7-T MRI scan to obtain quantitative measures of cortical and subcortical brain structures. There was no difference in total brain volume between groups. However, the frontal cortex was enlarged in the Irf6(gt1/+) mice compared to that of wild types (P = 0.028) while the posterior cortex did not differ. In addition, the volume of the cerebellum of Irf6(gt1/+) mice was decreased (P = 0.004). Mice that were heterozygous for Irf6 showed a similar pattern of brain anomalies previously reported in humans with VWS and NSCL/P. These structural differences were present in the absence of overt oral clefts. These results support a role for IRF6 in brain morphometry and provide evidence for a potential genetic link to abnormal brain development in orofacial clefting.

Social motivation in individuals with isolated cleft lip and palate

Social isolation is common among individuals with isolated cleft lip and palate (ICLP), but the available data on why this may be are mixed. We present a novel theory relating to reduced social motivation in ICLP, called the social abulia hypothesis. Based on this hypothesis, we predicted that reduced social motivation would lead to reduced responsiveness to negative social feedback, in terms of both explicit responses and noncontrolled, psychophysiological responses. Twenty males with ICLP and 20 normal comparison males between 13 and 25 years old participated in the study. Social motivation was examined by measuring participants' response to negative social feedback (social exclusion). Additionally, psychophysiological reactivity to positive and negative social stimuli was measured. In order to rule out other potential contributors to social isolation, we tested basic social perception, emotion recognition, and social anxiety. In line with the social abulia hypothesis, we show that negative social feedback had less of an effect on males with ICLP than on healthy male peers, which was evident in explicit responses and noncontrolled, psychophysiological responses to negative social feedback. Our results could not be attributed to problems in social perception, a lack of understanding facial expressions, or increased social anxiety, as groups did not differ on these constructs. This study suggests that current views on social isolation in ICLP may need to be reconsidered to include the possibility that isolation in this population may be the direct result of reduced social motivation.

Corpus callosum shape is altered in individuals with nonsyndromic cleft lip and palate

Individuals with nonsyndromic cleft lip with or without cleft palate (CL/P) have altered brain structure compared with healthy controls. Preliminary evidence suggests that the corpus callosum may be dysmorphic in orofacial clefting; however, this midline brain structure has not been systematically assessed in this population. The goal of the present study was to carry out a morphometric assessment of the corpus callosum and its relationship to cognitive performance in a well-characterized patient cohort with orofacial cleft. Midline brain images were obtained from previously collected MRI scans of 24 CL/P subjects and 40-adult-male controls. Eight landmarks on the corpus callosum were digitized on each image and their x,y coordinate locations saved. A geometric morphometrics analysis was applied to the landmark coordinate data to test for shape differences across groups. The relationship between corpus callosum shape and IQ was explored with nonparametric correlation coefficients. Results revealed significant differences in mean corpus callosum shape between CL/P cases and controls (P = 0.029). The CL/P corpus callosum was characterized by increased overall convexity resulting from a superior and posterior displacement. Within CL/P cases, increased corpus callosum shape dysmorphology was moderately correlated with reduced performance IQ (r = 0.546). These results provide additional evidence that midline brain changes may be an important part of the orofacial cleft phenotype.

Height, BMI, and pituitary volume in individuals with and without isolated cleft lip and/or palate

INTRODUCTION

Individuals with isolated cleft lip and/or palate (ICLP) are often reported to be of shorter stature relative to peers, and the objective of this study was to explore the role of the pituitary in relationship to growth.

METHODS

Fifty-five males and 32 females with ICLP were compared to 121 healthy males and 158 healthy females with respect to height and BMI. Magnetic resonance imaging (MRI) scans were obtained from all ICLP participants and 47% of healthy group participants.

RESULTS

Males with ICLP were shorter than healthy males and had lower BMI. However, the trajectories for height and BMI did not differ between groups. Analyses in a separate sample of adult males suggested that height normalizes in males with ICLP in their early 30s. There were no differences in mean pituitary volume and pituitary trajectories between male groups. Females with ICLP were shorter than healthy females and also had slower growth rates. They did not differ in mean BMI or BMI trajectories. Furthermore, there were no differences in mean pituitary volume, or in pituitary trajectories.

DISCUSSION

Our findings suggest that there are no gross morphological differences in pituitary volume in individuals with ICLP, although more subtle differences may exist.