Comparison of PAS and adenoids in patients with and without maxillary micrognathia before orthodontic treatment.

OBJECTIVE: Craniofacial anomalies are widely discussed as predisposing factors of breathing disorders. Since many more cofactors exist, this study investigated the association between maxillary micrognathia and morphological changes of posterior airway space and adenoids in these patients. MATERIAL AND METHODS: Cephalometric radiographs of n = 73 patients were used for data acquisition. The patients were divided into two groups according to certain skeletal characteristics: maxillary micrognathia (n = 34, 16 female, 18 male; mean age 10.55 ± 3.03 years; defined by a SNA angle < 79°) and maxillary eugnathia (n = 39, 19 female, 20 male; mean age 10.93 ± 3.26 years; defined by a SNA angle > 79°). The evaluation included established procedures for measurements of the maxilla, posterior airway space and adenoids. Statistics included Kolmogorov-Smirnov-, T- and Mann-Whitney-U-Tests for the radiographs. The level of significance was set at p < 0.05. RESULTS: The cephalometric analysis showed differences in the superior posterior face height and the depth of the posterior airway space at palatal level among the two groups. The depth of the posterior airway space at mandibular level was the same for both groups, just as the size of the area taken by adenoids in the nasopharynx. CONCLUSIONS: Skeletal anomalies affect the dimension of the posterior airway space. There were differences among the subjects with maxillary micrognathia and these with a normal maxilla. However, the maxilla was only assessed in the sagittal direction, not in the transverse. This study showed that the morphology of the maxilla relates to the posterior airway space whereas the adenoids seem not to be affected. CLINICAL RELEVANCE: Maxillary micrognathia is significantly associated with a smaller depth of the posterior airway space at the palatal level compared to patients with maxillary eugnathia.

A novel SMOC1 pathogenic homozygous variant in a fetus with mesomelia of the lower limbs, micrognathia and hypertelorism and an incidental finding of CYP21A2-related congenital adrenal hyperplasia.

Trio exome sequencing was performed on a fetus with bilateral mesomelia of the lower limbs with significant angulation of the tibial bones, micrognathia and hypertelorism detected on ultrasound scan at 19 + 0 weeks gestation. The couple is consanguineous. A homozygous pathogenic frameshift variant in the SMOC1 gene (c.339_340del p.(Phe114Cysfs*40)) was detected and both parents were shown to be heterozygous. Pathogenic variants in the SMOC1 gene are associated with microphthalmia with limb anomalies which multidisciplinary team discussion determined to be causal of the scan anomalies detected. The fetus was also a compound heterozygote for CYP21A2 pathogenic variants, confirming a second diagnosis of non-classical congenital adrenal hyperplasia, which was felt incidental to the scan findings. The risk that this couple's next pregnancy would be affected by either of these disorders is 1 in 4 (25%) and demonstrates the importance of genetic diagnoses for the family and implications for future pregnancies.

Prenatal Diagnosis of Gómez-López-Hernández Syndrome.

INTRODUCTION: Gómez-López-Hernández syndrome (GLHS), also known as cerebello-trigeminal-dermal dysplasia, is an extremely rare neurocutaneous disease, classically described by the triad of rhombencephalosynapsis (RES), bilateral focal alopecia, and trigeminal anesthesia. The clinical and radiographic spectrum of GLHS is now known to be broader, including craniofacial and supratentorial anomalies, as well as neurodevelopmental issues. CASE PRESENTATION: Here, we present a case of antenatally diagnosed GLHS with RES, hydrocephaly, and craniofacial anomalies identified on ultrasound (low-set ears with posterior rotation, hypertelorism, midface hypoplasia, micrognathia, and anteverted nares) which were confirmed by autopsy after termination of pregnancy at 23 weeks of gestation. DISCUSSION: As no known genetic causes have been identified and the classical triad is not applicable to prenatal imaging, prenatal diagnosis of GLHS is based on neuroimaging and the identification of supporting features. In presence of an RES associated with craniofacial abnormalities in prenatal (brachycephaly, turricephaly, low-set ears, midface retrusion, micrognathia), GLHS should be considered as "possible" according to postnatal criteria.

Temporal bone dysplasia in Coffin-Siris syndrome.

We report a child, diagnosed with Coffin-Siris syndrome (CSS), with chronic right otorrhoea. CT and DR-MRI were performed to further investigate, diagnose and determine relevant surgical anatomy. CT temporal bones assessment was performed, and the measurements compared with previously published data for normal temporal bone anatomy. These comparisons highlighted various differences which were not initially expected; it showed that there were multiple inner ear abnormalities in addition to middle ear disease. This case highlights the importance of considering temporal bone abnormalities in all children with CSS or any dysmorphia, when they may require mastoid procedures. Reviewing the management of this case provides relevant learning opportunities for both primary, secondary and tertiary care institutions.

Dynamic orthognathic surgical procedure (DOSP) in asymmetric maxillomandibular dysmorphism secondary to unilateral micrognathia: Outcomes of 12 consecutive cases.

This study aimed to evaluate the outcomes following a dynamic orthognathic surgical procedure performed at the end of growth to treat asymmetric maxillomandibular deformities linked to unilateral micrognathia when conventional orthognathic surgery was not feasible. The dynamic orthognathic surgical procedure (DOSP) combined concomitant mandibular distraction osteogenesis with contralateral poorly stabilized sagittal split osteotomy and Le Fort I osteotomy. Cephalometric studies were retrospectively conducted on pre- and postoperative lateral and frontal cephalographs, and maxillomandibular movements were calculated. Outcome scores were computed by both experts and laypersons based on photographic analyses. There was a significant postoperative increase in height of the micrognathic ramus in all patients (n = 12; p = 0.002). The angle between the occlusal cant and horizontal reference plane decreased significantly in all of the patients, as did the angle between the midline sagittal plane and mandibular tilt (p < 0.001). Postoperative outcome scores showed significant improvements in all cases, according to both expert and layperson groups. This procedure allows correction of maxillomandibular asymmetries linked to micrognathia. However, it cannot resolve all the factors participating in facial asymmetry, such as those originating in the oculo-auriculo-ventricular spectrum or complex tumor sequelae, and second-step procedures may be required.

Novel de novo ARCN1 intronic variant causes rhizomelic short stature with microretrognathia and developmental delay.

The archain 1 (ARCN1) gene encodes the coatomer subunit delta protein and is a component of the COPI coatomer complex, which is involved in retrograde vesical trafficking from the Golgi complex to the endoplasmic reticulum. Variants in ARCN1 have recently been associated with rhizomelic short stature with microcephaly, microretrognathia, and developmental delay. Here we report a 3.5-yr-old boy with microcephaly, global developmental delay, and multiple congenital abnormalities and the ARCN1-related syndrome caused by a novel de novo intronic variant. Whole-exome sequencing of the proband and his parents was utilized to determine the genetic origin of the patient's disorder and identified a de novo variant, NM_001655.5:c.654-15A > G, in the ARCN1 gene. Follow-up functional characterization of mRNA from the patient demonstrated that this variant creates a splicing defect of the ARCN1 mRNA. ARCN1-related syndrome represents an emerging disorder of developmental delay, and this report represents the sixth described patient. Despite the few instances reported in literature, the phenotype is consistent between our patient and previously reported individuals.

Clinical outcomes of prenatal diagnosis of the fetal micrognathia: A case report.

RATIONALE: Micrognathia is a subtle facial malformation characterized by a small mandible and receding chin. Fetal micrognathia is often associated with chromosomal abnormalities, skeletal dysplasia, and various syndromes. Once it is dignosised, detailed fetal malformation screening and chromosome examination should be carried out. PATIENT CONCERN: One pregnant woman with suspicion of fetal micrognathia was referred from her local hospital to our hospital for detailed fetal malformation screening and fetal echocardiography. Examination of the fetus was performed using a two-dimensional and three-dimensional ultrasound probe in multiple planes. The fetus showed micrognathia without glossoptosis with features of the inferior facial angle (IFA) ≤50° and his tongue reached anterior mandibular border box during normal movement. DIAGNOSES: The fetus was diagnosed as isolated micrognathia prenatally without multisystem abnormalities. INTERVENTIONS: Amniocentesis was performed and the fetus was found to carry 46XN with 6q14.1 duplication, the significance of which was unclear. OUTCOMES: The fetus was labored through vagina at 38 weeks gestation. A small soft cleft palate was diagnosed after delivery. LESSONS: This case suggests that once prenatal diagnosis of the fetal micrognathia has been made, we should carefully examine the presence of fetus's multisystem developmental abnormalities and due consideration should be given for associated soft cleft palate.

Striking phenotypic overlap between Nicolaides-Baraitser and Coffin-Siris syndromes in monozygotic twins with ARID1B intragenic deletion.

The chromatin remodeling AT-Rich interaction domain containing 1B protein (ARID1B) also known as BAF-associated factor, 250-KD, B (BAF250B) codified by the ARID1B gene (MIM#614556), is a small subunit of the mammalian SWI/SNF or BAF complex, an ATP-dependent protein machinery which is able to activate or repress gene transcription, allowing protein access to histones through DNA relaxed conformation. ARID1B gene mutations have been associated with two hereditary syndromic conditions, namely Coffin-Siris (CSS, MIM#135900) and Nicolaides-Baraitser syndromes (NCBRS, MIM#601358), characterized by neurodevelopment delay, craniofacial dysmorphisms and skeletal anomalies. Furthermore, intellectual impairment and central nervous system (CNS) alterations, comprising abnormal corpus callosum, have been associated with mutations in this gene. Moreover, ARID1B anomalies resulted to be involved in neoplastic events and Hirschprung disease. Here we report on two monozygotic male twins, displaying clinical appearance strikingly resembling NCBRS and CSS phenotype, who resulted carriers of a novel 6q25.3 microdeletion, encompassing only part of the ARID1B gene. The deleted segment was not inherited from the only parent tested and afflicted the first exons of the gene, coding for protein disordered region. We also provide, for the first time, a review of previously published ARID1B mutated patients with NCBRS and CSS phenotype and a computer-assisted dysmorphology analysis of NCBRS and ARID1B related CSS individuals, through the Face2Gene suite, confirming the existence of highly overlapping facial gestalt of both conditions. The present findings indicate that ARID1B could be considered a contributing gene not only in CSS but also in NCBRS phenotype, although the main gene related to this latter condition is the SMARCA2 gene (MIM#600014), another component of the BAF complex. So, ARID1B study should be considered in such individuals.

Temporomandibular Joint Ankylosis Following Mandibular Distraction Osteogenesis: A Dreadful Complication.

INTRODUCTION: Mandibular distraction osteogenesis (MDO) is an effective treatment for severe micrognathia, as it helps to avoid tracheostomy but has some adverse effects on the temporomandibular joint (TMJ). TMJ ankylosis is a serious condition leading to feeding difficulties and growth impairment, and could result in worse consequences in cases with micrognathia who already have limited growth potential. Here, we aimed to report on cases with TMJ ankylosis-a rare but devastating complication of MDO. In total, we described 3 syndromic cases with TMJ ankylosis that developed after MDO and reviewed the associated literature. MATERIAL AND METHODS: We retrospectively enrolled 3 patients who presented with TMJ ankylosis following MDO at the Oral and Maxillofacial Surgery Department of the University Hospital of Lille, France. RESULTS: All 3 patients had craniofacial syndrome with micrognathia. MDO was performed at least twice in each case, and the 3 patients developed subsequent TMJ ankylosis. They all presented with TMJ ankylosis and micrognathia in our Department. DISCUSSION: MDO leads to a certain amount of stress on the TMJ, and in cases with congenital TMJ deformation, such stress could lead to TMJ ankylosis. To our knowledge, 12 cases of TMJ ankylosis after MDO have been described in studies involving 309 patients while it is not reported in other publications. They were all syndromic patients. Thus, TMJ health should be carefully monitored during and after MDO to avoid TMJ ankylosis, and alternative treatments such as costochondral grafts should be considered.

Mutations in SMARCB1 and in other Coffin-Siris syndrome genes lead to various brain midline defects.

Mutations in genes encoding components of BAF (BRG1/BRM-associated factor) chromatin remodeling complexes cause neurodevelopmental disorders and tumors. The mechanisms leading to the development of these two disease entities alone or in combination remain unclear. We generated mice with a heterozygous nervous system-specific partial loss-of-function mutation in a BAF core component gene, Smarcb1. These Smarcb1 mutant mice show various brain midline abnormalities that are also found in individuals with Coffin-Siris syndrome (CSS) caused by SMARCB1, SMARCE1, and ARID1B mutations and in SMARCB1-related intellectual disability (ID) with choroid plexus hyperplasia (CPH). Analyses of the Smarcb1 mutant animals indicate that one prominent midline abnormality, corpus callosum agenesis, is due to midline glia aberrations. Our results establish a novel role of Smarcb1 in the development of the brain midline and have important clinical implications for BAF complex-related ID/neurodevelopmental disorders.

Staged therapeutic approach for rehabilitation of severe asymmetric Class II dentofacial deformity secondary to long standing unilateral temporomandibular joint ankylosis.

Despite being one of the most pervasive debilitating skeletal problems in the craniofacial region, surgical-orthodontic management of long-standing asymmetric Class II dentofacial deformities is often a unique challenge posed to the clinicians. This case report describes the encouraging results of systematically sequenced and staged therapeutic approach adopted for successful rehabilitation of an adult patient with asymmetric Class II dentofacial deformity with mandibular micrognathia secondary to unilateral TMJ ankylosis. Concurrent gap arthroplasty and bilateral distraction of mandibular body were performed during the first operation for functional restoration of mandibular movements and correction of mandibular micrognathia and associated asymmetry. After 13 months of post-distraction orthodontic treatment, Le Fort I osteotomy for inferior repositioning and sagittal advancement of maxilla was performed during the second operation, in conjunction with adjunctive alloplastic reconstruction of inferior border of mandible for optimization of facial aesthetics. Postsurgical orthodontic detailing facilitated achievement of stable, balanced interdigitation. The total active treatment period was 29 months. After treatment, both the skeletal disharmony and the functional stability were significantly improved with establishment of functional occlusion. The morphological and functionally acceptable results were reasonably well-maintained during three-year follow-up. The merits of mandibular osteodistraction vs. conventional mandibular orthognathic surgery and the potential advantages of staged surgical approach are discussed.

Risk Factors for Perioperative Respiratory Failure following Mandibular Distraction Osteogenesis for Micrognathia: A Retrospective Cohort Study.

BACKGROUND: The frequency of respiratory events in the perioperative period, and optimal duration of intubation during early mandibular distraction osteogenesis activation, are poorly understood. This study assesses potential risk factors associated with perioperative respiratory events, particularly the need for reintubation, following mandibular distraction osteogenesis surgery. METHODS: A retrospective review was conducted for infants (younger than 1 year) undergoing mandibular distraction osteogenesis for tongue-based airway obstruction between November of 2010 and December of 2017. Univariate and multivariate analyses of sentinel events and outcomes were performed. RESULTS: Ninety infants (median age, 35 days) were included (50 percent were syndromic). Twenty-seven subjects (30 percent) experienced a respiratory event requiring intervention before discharge, including 14 subjects who failed initial extubation. Subjects extubated earlier than postoperative day 5 failed extubation more frequently (33%) compared to those extubated later (9%; p = 0.005). Respiratory events occurred more frequently when extubation was attempted at distraction lengths of 5 mm or less (42 percent) compared to greater than 5 mm (21 percent; p = 0.032). Logistic regression modeling showed that syndromic status (OR, 14.8) and secondary airway anomaly (OR, 6.1) were significant predictors for respiratory events, whereas greater length of distraction at the time of extubation was protective (OR, 0.8; p < 0.05). CONCLUSIONS: Postoperative intubation of at least 5 days with associated mean distraction of 5 mm appears to be associated with successful extubation trial following mandibular distraction osteogenesis surgery. Patients with congenital syndromes and secondary airway anomalies are more likely to experience perioperative respiratory events. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

A fetal case of microphthalmia and limb anomalies with abnormal neuronal migration associated with SMOC1 biallelic variants.

Microphthalmia with limb anomalies (MLA, OMIM, 206920) is a rare autosomal-recessive disease caused by biallelic pathogenic variants in the SMOC1 gene. It is characterized by ocular disorders (microphtalmia or anophtalmia) and limb anomalies (oligodactyly, syndactyly, and synostosis of the 4th and 5th metacarpals), variably associated with long bone hypoplasia, horseshoe kidney, venous anomalies, vertebral anomalies, developmental delay, and intellectual disability. Here, we report the case of a woman who interrupted her pregnancy after ultrasound scans revealed a depression of the frontal bone, posterior fossa anomalies, cerebral ventricular enlargement, cleft spine involving the sacral and lower-lumbar vertebrae, and bilateral microphthalmia. Micrognathia, four fingers in both feet and a slight tibial bowing were added to the clinical picture after fetal autopsy. Exome sequencing identified two variants in the SMOC1 gene, each inherited from one of the parents: c.709G>T - p.(Glu237*) on exon 8 and c.1223G>A - p.(Cys408Tyr) on exon 11, both predicted to be pathogenic by different bioinformatics software. Brain histopathology showed an abnormal cortical neuronal migration, which could be related to the SMOC1 protein function, given its role in cellular signaling, proliferation and migration. Finally, we summarize phenotypic and genetic data of known MLA cases showing that our case has some unique features (Chiari II malformation; focal neuropathological alterations) that could be part of the variable phenotype of SMOC1-associated diseases.

Fetal Evaluation and Airway Management.

Congenital causes of airway obstruction once noted at birth are now diagnosed prenatally. The adoption of ex utero intrapartum treatment has allowed for planned airway stabilization on placental support, dramatically decreasing the incidence of hypoxic injury or peripartum demise related to neonatal airway obstruction. Airway access is gained either through laryngoscopy, bronchoscopy, or a surgical airway. In complete airway obstruction, primary resection of the obstructing lesion may be performed before completion of delivery. This article reviews the current and emerging methods of fetal evaluation, indications for ex utero intrapartum treatment, and provides a detailed description of the procedure and necessary personnel.

Objectifying Micrognathia Using Three-Dimensional Photogrammetric Analysis.

BACKGROUND: Micrognathia occurs isolated and as part of entities like Robin sequence (RS). An objective measurement of mandible size and growth is needed to determine the degree of micrognathia and enable a comparison of treatment outcomes. A pilot study was conducted to investigate the usability of 3-dimensional (3D) facial photogrammetry, a fast, noninvasive method, to estimate mandible size and growth in a small cohort of newborns and infants. METHODS: Exterior mandibular volume was estimated using a tetrahedron defined by 4 facial landmarks. Twelve patients with RS with different etiologies were selected and photogrammetric images were obtained prospectively in 3 patients with RS in whom mandibular growth in the first year of life was determined. We used 3 tetrahedra defined by 6 landmarks on mandibular computed tomography (CT) scans to estimate an interior mandibular volume, which we compared to the exterior mandibular volume in 10 patients. RESULTS: The exterior mandibular volume using 3D photography could be determined in all patients. Signature heat maps allowed visualization of facial dysmorphism in 3D; signature graphs demonstrated similarities of facial dysmorphism in patients with the same etiology and differences from those with other diagnoses and from controls. The correlation between interior (3D photogrammetry) and exterior mandibular volumes (CT imaging) was 0.8789. CONCLUSION: The 3D facial photogrammetry delineates the general facial characteristics in patients with different syndromes involving micrognathia, and can objectively estimate mandibular volume and growth, with excellent correlation with bony measurement. It has been concluded that 3D facial photogrammetry could be a clinically effective instrument for delineating and quantifying micrognathia.

Versatility of uniplanar prearthoplastic distraction osteogenesis in the correction of post-ankylosis facial deformities-a report of five different cases.

PURPOSE: Unilateral or bilateral ankylosis can lead to severe micrognathia and facial deformity that requires multiple, often, staged surgical corrections. To date, there is no ideal treatment modality that satisfactorily corrects the complex anatomy, restores the ramal height, and corrects the micrognathia and microgenia. Distraction osteogenesis has been acclaimed as a successful modality for the treatment of such deformities. It is a cost-effective approach with low morbidity and less relapse thus providing better functional and esthetic outcomes. It allows the surgeon to correct the deformity in various planes by using various devices by changing osteotomy designs and vectors, with simultaneous hard tissue and soft tissue reconstruction. PATIENTS AND METHODS: Here, we present a series of five cases where different types of distraction osteogenesis were combined with various other procedures to correct post-ankylotic facial asymmetry. In one case, simultaneous maxillo-mandibular distraction [Molina's technique] was used. RESULTS: All patients showed significant improvement in function and esthetics. Outcome assessment was made using clinical photographs and radiographs. CONCLUSION: Pre-arthroplastic distraction osteogenesis is a versatile cost effective approach that can be customized for every patient based on their needs.

Release of syngnathia by anticlockwise rotation and mandibular advancement using bilateral alloplastic temporomandibular joint prostheses: a new approach.

We describe a new approach to the planning of treatment and subsequent operation on a patient with syngnathia and severe mandibular retrognathism. To facilitate a large mandibular advancement we applied alloplastic temporomandibular joint (TMJ) prostheses to the coronoid processes after anticlockwise rotation of the mandible. To the best of our knowledge this is the first documented case of its kind.

Micrognathia and Oropharyngeal Space in Patients With Robin Sequence: Prenatal MRI Measurements.

PURPOSE: Micrognathia is the initiating feature of Robin sequence (RS) and leads to airway obstruction. Prenatal identification of micrognathia is currently qualitative and has not correlated with postnatal findings in previous studies. Oropharyngeal airway space has not been evaluated prenatally. The purposes of this study were to 1) quantitate mandibular characteristics and oropharyngeal size at prenatal magnetic resonance imaging (MRI) and 2) identify differences in fetuses with postnatal RS compared with those with micrognathia (without RS) and normal controls. MATERIALS AND METHODS: This is a retrospective case-control study of fetuses with prenatal MRIs performed from 2002 through 2017 who were live born and evaluated postnatally for craniofacial findings. Postnatal findings were used to divide patients into 3 groups: 1) RS (micrognathia, glossoptosis, and airway obstruction), 2) micrognathia without RS ("micrognathia"), and 3) a gestational-age matched control group with normal craniofacial morphology ("control"). Inferior facial angle (IFA), jaw index, and oropharyngeal space (OPS) were calculated and compared among groups. RESULTS: Of 116 patients in this study, 27 had RS (23%), 35 had micrognathia (30%), and 54 were control subjects (47%). IFA, jaw index, and OPS were statistically significantly smaller in the RS group compared with the comparison groups (P < .0001). CONCLUSIONS: Prenatal MRI measurements of micrognathia and OPS are considerably different in patients with RS compared with other groups, including those with micrognathia alone. These measurements might serve as reliable prenatal predictors of RS.

Maxillary Hypoplasia: Differential Diagnosis of Nasal Obstruction in Infants.

Maxillary hypoplasia (MH) is a rare cause of respiratory dysfunction in infants and may occur in association with genetic abnormalities or as an isolated condition. It is included in the differential diagnosis of congenital nasal obstruction. This paper seeks to report a case series of infants with MH, discuss methods for its diagnosis, and compare computed tomography (CT) measurements of nasal cavities of infants with MH and without craniomaxillofacial abnormalities. The therapeutic approach in each patient is also described. All infants with MH admitted to a tertiary hospital between 2012 and 2015 were included. Baseline nasal endoscopy was performed at bedside. The width of the infants' nasal cavities was measured by a radiologist with experience in CT scanning of facial bones. Control patients were infants of matched sex and similar age who underwent head CT scanning for various reasons. Overall, 8 infants with MH and 8 controls were assessed. All nasal cavity dimensions of infants with MH were significantly smaller than those of control subjects. The authors conclude that the diagnosis of MH should be considered in infants with nasal obstruction and nasal cavity narrowing at nasal endoscopy.