Foetal alcohol syndrome: a cephalometric analysis of patients and controls

Sexually dimorphic effects of prenatal alcohol exposure on the murine skeleton

BACKGROUND

Prenatal alcohol exposure (PAE) can result in lifelong disabilities known as foetal alcohol spectrum disorder (FASD) and is associated with childhood growth deficiencies and increased bone fracture risk. However, the effects of PAE on the adult skeleton remain unclear and any potential sexual dimorphism is undetermined. Therefore, we utilised a murine model to examine sex differences with PAE on in vitro bone formation, and in the juvenile and adult skeleton.

METHODS

Pregnant C57BL/6J female mice received 5% ethanol in their drinking water during gestation. Primary calvarial osteoblasts were isolated from neonatal offspring and mineralised bone nodule formation and gene expression assessed. Skeletal phenotyping of 4- and 12-week-old male and female offspring was conducted by micro-computed tomography (µCT), 3-point bending, growth plate analyses, and histology.

RESULTS

Osteoblasts from male and female PAE mice displayed reduced bone formation, compared to control (≤ 30%). Vegfa, Vegfb, Bmp6, Tgfbr1, Flt1 and Ahsg were downregulated in PAE male osteoblasts only, whilst Ahsg was upregulated in PAE females. In 12-week-old mice, µCT analysis revealed a sex and exposure interaction across several trabecular bone parameters. PAE was detrimental to the trabecular compartment in male mice compared to control, yet PAE females were unaffected. Both male and female mice had significant reductions in cortical parameters with PAE. Whilst male mice were negatively affected along the tibial length, females were only distally affected. Posterior cortical porosity was increased in PAE females only. Mechanical testing revealed PAE males had significantly reduced bone stiffness compared to controls; maximum load and yield were reduced in both sexes. PAE had no effect on total body weight or tibial bone length in either sex. However, total growth plate width in male PAE mice compared to control was reduced, whilst female PAE mice were unaffected. 4-week-old mice did not display the altered skeletal phenotype with PAE observed in 12-week-old animals.

CONCLUSIONS

Evidence herein suggests, for the first time, that PAE exerts divergent sex effects on the skeleton, possibly influenced by underlying sex-specific transcriptional mechanisms of osteoblasts. Establishing these sex differences will support future policies and clinical management of FASD.

Dentofacial characteristics of children and adolescents with foetal alcohol spectrum disorders: a comparison with matched controls

BACKGROUND

Foetal alcohol spectrum disorders (FASD) include somatic and neurological developmental disturbances after prenatal alcohol exposure, including facial anomalies. However, the knowledge of the orthodontic skeletal and dental cephalometric relations in this group is limited. The aim of the study was to assess the dentofacial characteristics of children and adolescents with FASD and to compare them with a matched control group.

METHODS

The study group comprised all available children and adolescents diagnosed with FASD (> 7 years of age) in whom good quality cephalograms were available. The control group comprised non-syndromic, orthodontically untreated children with normal occlusion and skeletal relations matched with age and gender. Cephalometric analysis included eighteen linear and angular measurements. The general linear model for repeated measures regarding age, gender and the type of FASD was applied.

RESULTS

The group with FASD included 35 individuals (21 girls and 14 boys) aged 7-18 years including 21 with foetal alcohol syndrome. The mean age in the study and the control group was 12.8 years (SD, range 3.2, 7.1-18.1) and 13.0 (SD, range 2.9, 9.1-18.1), respectively. Statistically significant differences between the groups were found in 15 out of 18 of the cephalometric measurements (83%). In children with FASD the mandible was more retrusive, the incisors were more proclined and the mandibular incisors and the lips were more protruded when compared with controls. There was no significant evidence of an influence of age, gender or FASD type.

CONCLUSIONS

Dentofacial characteristics of children and adolescents with FASD significantly differ from controls. Early orthodontic diagnosis and prophylaxis should play a part of the interdisciplinary care of patients in this group.

Mutation in the Bone Morphogenetic Protein signaling pathway sensitize zebrafish and humans to ethanol-induced jaw malformations

Fetal Alcohol Spectrum Disorders (FASD) describe ethanol-induced developmental defects including craniofacial malformations. While ethanol-sensitive genetic mutations contribute to facial malformations, the impacted cellular mechanisms remain unknown. Bmp signaling is a key regulator of epithelial morphogenesis driving facial development, providing a possible ethanol-sensitive mechanism. We found that zebrafish mutants for Bmp signaling components are ethanol-sensitive and affect anterior pharyngeal endoderm shape and gene expression, indicating ethanol-induced malformations of the anterior pharyngeal endoderm cause facial malformations. Integrating FASD patient data, we provide the first evidence that variants in the human Bmp receptor gene BMPR1B associate with ethanol-related differences in jaw volume. Our results show that ethanol exposure disrupts proper morphogenesis of, and tissue interactions between, facial epithelia that mirror overall viscerocranial shape changes and are predictive for Bmp-ethanol associations in human jaw development. Our data provide a mechanistic paradigm linking ethanol to disrupted epithelial cell behaviors that underlie facial defects in FASD.

Genetically programmed retinoic acid deficiency during gastrulation phenocopies most known developmental defects due to acute prenatal alcohol exposure in FASD

Fetal Alcohol Spectrum Disorder (FASD) arises from maternal consumption of alcohol during pregnancy affecting 2%-5% of the Western population. In Xenopus laevis studies, we showed that alcohol exposure during early gastrulation reduces retinoic acid (RA) levels at this critical embryonic stage inducing craniofacial malformations associated with Fetal Alcohol Syndrome. A genetic mouse model that induces a transient RA deficiency in the node during gastrulation is described. These mice recapitulate the phenotypes characteristic of prenatal alcohol exposure (PAE) suggesting a molecular etiology for the craniofacial malformations seen in children with FASD. Gsc ^+/Cyp26A1 mouse embryos have a reduced RA domain and expression in the developing frontonasal prominence region and delayed HoxA1 and HoxB1 expression at E8.5. These embryos also show aberrant neurofilament expression during cranial nerve formation at E10.5 and have significant FASD sentinel-like craniofacial phenotypes at E18.5. Gsc ^+/Cyp26A1 mice develop severe maxillary malocclusions in adulthood. Phenocopying the PAE-induced developmental malformations with a genetic model inducing RA deficiency during early gastrulation strongly supports the alcohol/vitamin A competition model as a major molecular etiology for the neurodevelopmental defects and craniofacial malformations seen in children with FASD.

A systematic review: facial, dental and orthodontic findings and orofacial diagnostics in patients with FASD

Background

The fetal alcohol spectrum disorder is a group of developmental disorders caused by maternal alcohol consumption. Patients with fetal alcohol syndrome show abnormal orofacial features. This review presents an overview over the facial, oral, dental or orthodontic findings and diagnostic tools concerning these features.

Methods

For this systematic review Cochrane, Medline and Embase databases were considered and the review was performed according to the PRISMA checklist. Two independent reviewers evaluated all studies and recorded results in a summary of findings table. Risk of bias was analyzed via Quadas-2 checklist.

Results

61 studies were eligible for inclusion. All included studies were clinical studies. Methods and results of the studies were not comparable, guidelines or methods for the detection of FASD varied across studies. Facial features most often measured or found as distinguishing parameter were: palpebral fissure length, interpupillary or innercanthal distance, philtrum, upper lip, midfacial hypoplasia or head circumference.

Conclusions

This review shows that to date a multitude of heterogeneous guidelines exists for the diagnosis of FASD. Uniform, objective diagnostic criteria and parameters for the orofacial region in FASD diagnosis are needed. A bio database with values and parameters for different ethnicities and age groups should be made available for diagnosis.

The Accuracy of Computer-Assisted Surgical Planning in Predicting Soft Tissue Responses After Le Fort I Osteotomy: Retrospective Analysis

PURPOSE

Mismatch between preoperative planning and surgical outcome in maxillofacial surgery relate to on-table replication of presurgical planning and predictive algorithm inaccuracy: software error was hereby decoupled from planning inaccuracy to assess a commercial software. The hypothesis was that soft tissue prediction error would be minimized if the surgical procedure was replicated precisely as planned and is independent of the extent of bone repositioning.

MATERIALS AND METHODS

Cone-beam computed tomography scans of 16 Le Fort I osteotomy patients were collected at Boston Children's Hospital. Preoperative and postoperative models of bone and soft tissue were constructed and the maxilla repositioning was replicated. Each model was subdivided into 6 regions: mouth, nose, eyes, and cheeks. Soft tissue prediction (performed using Proplan CMF-Materialise) for each patient was compared with the relative postoperative reconstruction and error was determined. P <0.05 was considered significant.

RESULTS

Le Fort I segment repositioning was replicated within 0.70±0.18 mm. The highest prediction error was found in the mouth (1.49±0.77 mm) followed by the cheeks (0.98±0.34 mm), nose (0.86±0.23 mm), and eyes (0.76±0.32). Prediction error on cheeks correlated significantly with mouth ( r =0.63, P < 0.01) and nose ( r =0.67, P < 0.01). Mouth prediction error correlated with total advancement ( r =0.52, P =0.04).

CONCLUSIONS

ProPlan CMF is a useful outcome prediction tool; however, accuracy decreases with the extent of maxillary advancement even when errors in surgical replication are minimized.

Facial imaging to screen for fetal alcohol spectrum disorder: A scoping review

Facial imaging tools have rapidly advanced in recent years and show potential for use in fetal alcohol spectrum disorder (FASD) screening and diagnosis. This scoping review describes the current state of evidence regarding the use of facial imaging being as a screening tool for FASD at a community level. This review follows the guidelines for the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) extension for scoping reviews and is registered with the Open Science Framework (osf.io/e4xw6). An electronic search of five databases was conducted. The time frame was limited to the period 2006 to 2022. The search included any form of imaging of the head, neck, oral cavity, and dentition. Animal and antenatal studies were excluded, as were those using only brain imaging. The search retrieved 730 unique titles. After title, abstract, and full-text screening, 28 primary studies were included in this review. Most studies were conducted with South African participants. Imaging included 2D photographs, 3D stereophotogrammetry, 3D laser scanning, and radiographs. Various measurements and landmarks were used to discriminate FASD from non-FASD participants, which included anthropometry, face shape analysis, and facial curvatures. Methods of data processing, analysis, and modeling ranged from manual methods to fully automated systems utilizing artificial intelligence. The use of facial imaging to screen for and diagnose patients with FASD is a rapidly advancing field. Most studies in the field remain exploratory, attempting to find accurate, reliable, and consistent landmarks and measures across different populations. For community screening, none of the tools in this review in their current form completely fulfill all the identified properties of an ideal screening tool. More research and development are needed prior to advocating for the use of any tool listed and the ethical implications are yet to be fully explored.

Malocclusion Can Give Additional Hints for Diagnosis of Fetal Alcohol Spectrum Disorder

Aims

Fetal alcohol spectrum disorder (FASD) is a developmental disorder caused by maternal alcohol intake (prevalence: 0.77%). Malocclusion has been described in case reports of patients with FASD, but reliable evidence for associations between FASD and malocclusion is not documented. Malocclusion is defined as tooth irregularity (prevalence: 14.6%) or incorrect relationship between the jaws such as lateral crossbites (prevalence: 3.1%). The purpose of this study was to investigate possible associations between malocclusion and FASD.

Short summary

FASD prevalence is high and diagnosis is very difficult; Malocclusions can give additional hints for FASD diagnosis; Patients with FASD show growth deficits concerning the maxilla; Early and consistent orthodontic supervision and therapy can prevent facial asymmetries in FASD patients.

Methods

Thirty patients with FASD and 30 patients of a healthy control group were examined. Inclusion criteria were mixed dentition, verified FASD/absence of FASD (control group), exclusion criteria were orthodontic treatment and disorders other than FASD. The extent and type of malocclusion were quantified with the peer assessment rating (PAR) index based on an analysis of orthodontic plaster models. In addition, anthropometric data such as gestational age, body weight and height at birth as well as present body weight, height and head circumference at examination date were assessed.

Results

The PAR index showed a significant increase in malocclusions in FASD patients compared to the group that were not diagnosed with FASD (P = 0.002). FASD patients showed particular differences in the upper transversal dimension with a higher prevalence of crossbites (P = 0.018) and a lower head circumference (P < 0.001). Body weight (P < 0.001) and height (P < 0.001) were significantly lower for FASD patients at time of birth, but not at the present examination date (weight: P = 0.329; height: P = 0.496). When relating weight and height measures to age using percentile curves of physiological growth, clinically relevant discrepancies could be found for FASD patients.

Conclusions

Our results show that malocclusion can provide additional evidence for FASD diagnosis. When FASD is diagnosed in a child, early referral to an orthodontist is advisable to stimulate maxillary growth and consequently prevent further malocclusions.

Exposure to Sodium Valproate during Pregnancy: Facial Features and Signs of Autism

BACKGROUND

Valproic acid (VPA) is the most teratogenic anticonvulsant drug in clinical use today. Children exposed prenatally to VPA have previously been shown to have dysmorphic craniofacial features, identified subjectively but not by anthropometric methods. Exposure to VPA has also been associated with an increased frequency of autism spectrum disorder (ASD). An increased cephalic index (the ratio of the cranial lateral width to the cranial anterior-posterior length) has been observed in children with ASD.

METHODS

Forty-seven children exposed to VPA during the first trimester of pregnancy were evaluated for dysmorphic facial features, identified subjectively and by measurements. Each VPA-exposed child was evaluated for ASD using the Social Communication Questionnaire, Autism Diagnostic Interview-Revised, and Autism Diagnostic Observation Schedule. The same physical examination was carried out on an unexposed comparison group of 126 children. The unexposed children also had testing for cognitive performance by the Wechsler Intelligence Scale for Children.

RESULTS

Several dysmorphic craniofacial features, including telecanthus, wide philtrum, and increased length of the upper lip were identified subjectively. Anthropometric measurements confirmed the increased intercanthal distance and documented additional findings, including an increased cephalic index and decreased head circumference/height index. There were no differences between the craniofacial features of VPA-exposed children with and without ASD.

CONCLUSION

An increased frequency of dysmorphic craniofacial features was identified in children exposed to VPA during the first trimester of pregnancy. The most consistent finding was a larger cephalic index, which indicates a disproportion of increased width of the skull relative to the shortened anterior-posterior length. Birth Defects Research 109:1134-1143, 2017. © 2017 Wiley Periodicals, Inc.

Second-Trimester Ultrasound as a Tool for Early Detection of Fetal Alcohol Spectrum Disorders

BACKGROUND

Early detection of fetal alcohol spectrum disorders (FASDs) is desirable to allow earlier and more comprehensive interventions to be initiated for the mother and infant. We examined prenatal ultrasound as an early method of detecting markers of the physical features and neurobehavioral deficits characteristic of FASD.

METHODS

A longitudinal cohort of pregnant women in Ukraine was recruited as part of the Collaborative Initiative on Fetal Alcohol Spectrum Disorders. Women were enrolled into a moderately to heavy-alcohol-exposed group or a low- or no-alcohol exposure group and were followed to pregnancy outcome. In the second trimester, a fetal ultrasound was performed to measure transverse cerebellar diameter, occipital frontal diameter (OFD), caval-calvarial distance, frontothalamic distance (FTD), interorbital distance (IOD), outer orbital diameter, and orbital diameter (OD). Live born infants received a dysmorphological examination and a neurobehavioral evaluation using the Bayley Scales of Infant Development. These data were used to classify infants with respect to FASD. Comparisons were made on the ultrasound measures between those with and without features of FASD, adjusting for gestational age at ultrasound and maternal smoking.

RESULTS

A total of 233 mother/child dyads were included. Children classified as FASD had significantly longer IOD and lower FTD/IOD, OFD/IOD, and FTD/OD ratios (p < 0.05). Children with a Bayley score <85 had significantly shorter FTD, longer IOD, lower OFD/IOD, and FTD/IOD ratios (p < 0.05). In general, mean differences were small. Ultrasound variables alone predicted <10% of the variance in the FASD outcome.

CONCLUSIONS

Some ultrasound measurements were associated with FASD, selected facial features of the disorder, and lower neurobehavioral scores. However, mean differences were relatively small, making it difficult to predict affected children based solely on these measures. It may be advantageous to combine these easily obtained ultrasound measures with other data to aid in identifying high risk for an FASD outcome.

Phenotypic diversity in white adults with moderate to severe Class II malocclusion

INTRODUCTION

Class II malocclusion affects about 15% of the population in the United States and is characterized by a convex profile and occlusal disharmonies. The specific etiologic mechanisms resulting in the range of Class II dentoskeletal combinations observed are not yet understood. Most studies describing Class II phenotypic diversity have used moderate sample sizes or focused on younger patients who later in life might outgrow their Class II discrepancies; such a focus might also preclude the visualization of adult Class II features. The majority have used simple correlation methods resulting in phenotypes that might not be generalizable to different samples and thus might not be suitable for studies of malocclusion etiology. The purpose of this study was to address these knowledge gaps by capturing the maximum phenotypic variations in a large sample of white Class II subjects selected with strict eligibility criteria and rigorously standardized multivariate reduction analyses.

METHODS

Sixty-three lateral cephalometric variables were measured from the pretreatment records of 309 white Class II adults (82 male, 227 female; ages, 16-60 years). Principal component analysis and cluster analysis were used to generate comprehensive phenotypes to identify the most homogeneous groups of subjects, reducing heterogeneity and improving the power of future malocclusion etiology studies.

RESULTS

Principal component analysis resulted in 7 principal components that accounted for 81% of the variation. The first 3 components represented variation on mandibular rotation, maxillary incisor angulation, and mandibular length. The cluster analysis identified 5 distinct Class II phenotypes.

CONCLUSIONS

A comprehensive spectrum of Class II phenotypic definitions was obtained that can be generalized to other samples to advance our efforts for identifying the etiologic factors underlying Class II malocclusion.

A review of facial image analysis for delineation of the facial phenotype associated with fetal alcohol syndrome

The facial anomalies associated with fetal alcohol syndrome (FAS), some of which are also present in individuals with less severe forms of the broader category of fetal alcohol spectrum disorders (FASD), are typically identified with the aid of linear distance measurements taken between facial landmarks. Digital facial imaging methods are increasingly being used in syndrome delineation. Distance measurements derived from stereo-photogrammetry and facial surface imaging have been used to study the FAS facial anomalies. Geometric morphometric methods capture the spatial arrangement between landmarks, providing a statistical platform for comparison of facial shapes, and have been shown to hold promise for characterizing the FAS facial shape. We review the progression in the use of imaging and image analysis methods in studies on the facial phenotype associated with FAS.

Oral anomalies associated with the oculocerebrorenal syndrome of Lowe: case report with multiple unerupted teeth and pericoronal radiolucencies

The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked recessive disorder, chiefly characterized by ocular involvement, mental retardation, and kidney disease. A literature review is provided, detailing the diversity of oral anomalies associated with the OCRL syndrome. Reported abnormalities include delayed tooth eruption, odontogenic cyst formation, and constricted dental arches. In addition, we present an unusual case of an 18-year-old male affected with the OCRL syndrome and fetal alcohol syndrome. The oral radiographic examination was significant for multiple impacted permanent teeth, many with pericoronal radiolucencies, and an underdeveloped mandible.

Cephalometric findings in patients with Papillon-Lefèvre syndrome

INTRODUCTION

Literature regarding oral conditions in patients with Papillon-Lefèvre syndrome (PLS) often covers the periodontal aspects, but no literature was found describing specific craniofacial findings in this group. The aim of this retrospective study was to investigate the cephalometric findings of patients with PLS.

METHODS

Lateral cephalograms of 8 patients with PLS were traced, and hard- and soft-tissue variables were analyzed.

RESULTS

Class III skeletal relationship was evident (ANB angle, 2 degrees +/- 3.1 degrees ; Wits appraisal, -9.1 mm +/- 3.7 mm). Other findings include maxillary retrognathia, decreased lower facial height, retroclined mandibular incisors, and upper lip retrusion.

CONCLUSIONS

Patients affected with PLS have a Class III skeletal pattern. These findings can be of clinical value not only for diagnosis, but also for proper treatment planning.