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 Treacher Collins syndrome: A case report and literature review.

Treacher Collins syndrome (TCS) should be suspected if the triad of micrognathia, glossoptosis, and posterior cleft palate, and deformed external ears are observed during prenatal ultrasonography, excepting Pierre Robin sequence. Visualization of the fetal zygomatic bone and down-slanting palpebral fissures are conducive to differentiation. Molecular genetics testing can establish a definite diagnosis. A 28-year-old pregnant Chinese woman was referred for systematic ultrasound examination at 24 weeks. Two-dimensional and three-dimensional ultrasound showed polyhydramnios, micrognathia, absence of nasal bone, microtia, secondary cleft palate, mandibular hypoplasia, glossoptosis, and normal limbs and vertebrae. Pierre Robin sequence was misdiagnosed with the triad of micrognathia, glossoptosis, and posterior cleft palate. Final diagnosis of TCS was confirmed by whole-exome sequencing. Visualization of the fetal zygomatic bone and down-slanting palpebral fissures can facilitate a differential diagnosis between Pierre Robin sequence and TCS, with the triad of micrognathia, glossoptosis, and posterior cleft palate.

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.

Identification of micrognathia by prenatal ultrasound may improve timely diagnosis and management of infants with Robin sequence.

OBJECTIVE: Robin sequence (RS) is a craniofacial anomaly characterized by small jaw (micrognathia) with associated tongue base airway obstruction. With advances in fetal imaging, micrognathia may be detected prenatally. This study aims to determine if prenatal recognition of micrognathia offers any advantage over being unaware of the condition until after delivery and to assess if prenatal consultation for micrognathia adds benefits beyond merely noting the presence of the condition. METHOD: Retrospective chart review examining cases from 01/01/2010 to 12/31/2020 at an urban tertiary medical center. RESULTS: Forty seven infants with RS were included. 40.4% (n = 19) had micrognathia/retrognathia noted on prenatal ultrasound. 47.4% (n = 9) of those 19 pregnancies saw a maternal fetal medicine (MFM) program with craniofacial consultation. Compared to 28 infants not diagnosed with micrognathia until after birth, the 19 infants identified prenatally required fewer transfers from birth hospital (p = 0.02). Additionally, those referred to MFM with craniofacial consultation had shorter lengths of stay when airway intervention was required (p = 0.05). CONCLUSION: Prenatal recognition of micrognathia may lead to early detection and management of RS. When RS is suspected, prenatal consultation with MFM and craniofacial team may further optimize care of the infant following delivery.

Pre-Epiglottic Baton Plate in the Management of Upper Airway Obstruction in an Infant with Femoral Facial Syndrome: A Case Report.

Femoral facial syndrome (FFS) is a rare condition which may present with hypoplasia or aplasia of the femora and unusual facies characterized by long philtrum, thin upper lip and micrognathia. We present the case of a ten-month old infant with FFS who had retroglossal obstruction and who was treated with a pre-epiglottic baton plate. The pre-epiglottic baton plate can be a simple, non-invasive and effective tool for the clinical management of syndromic patients with mild-to-moderate upper airway obstruction due to micrognathia.

Mandibular Measurements at the 20-Week Anatomy Ultrasound as a Prenatal Diagnostic Predictor of Pierre Robin Sequence.

BACKGROUND: Pierre Robin Sequence (PRS) is characterized by micrognathia, glossoptosis, and upper airway obstruction. Early recognition and appropriate perinatal management is crucial for optimizing outcomes. This study aimed to evaluate 20-week fetal ultrasounds to determine if specific mandibular measurements could predict PRS diagnosis and disease severity. METHODS: A retrospective case-control study of 48 patients with PRS and gender-matched controls was performed. Medical records were reviewed for respiratory and surgical interventions. Three parameters to assess micrognathia were measured on mid-sagittal profile ultrasound images: frontal nasal-mental angle (FNMA), facial-maxillary angle (FMA), and alveolar overjet. Student's t-test and univariate logistic regression was performed. P ≤ 0.05 was considered statistically significant. RESULTS: Patients with PRS demonstrated a significantly smaller mean FNMA compared to the control group, 129.3 ± 8.6° and 137.4 ± 3.2°, respectively (p < 0.0001), as well as significantly smaller mean FMA, 63.2 ± 9.2° and 74.8 ± 6.1°, respectively (p < 0.0001). The PRS group also demonstrated significantly larger mean alveolar overjet compared to the control group, 3.9 ± 1.4 mm and 2.1 ± 0.9 mm, respectively (p < 0.0001). The odds of respiratory intervention increased among cases when FMA was <68°. Additionally, there was a significant difference in median overjet between patients with PRS who did and did not require respiratory intervention. CONCLUSIONS: Mandibular features on the 20-week ultrasound can be measured to predict diagnosis and severity of PRS. This is an important first step to prepare for potential respiratory intervention at delivery to minimize perinatal hypoxia. Alveolar overjet, previously not described in prenatal ultrasound literature, is measurable and has utility in prenatal screening for PRS, as do FMA and FNMA.

Treatment of severe mandibular deficiency following TMJ ankyloses by distraction osteogenesis and orthodontic treatment with microimplants.

Severe mandibular deficiency caused by temporomandibular joint (TMJ) ankyloses produces functional and aesthetic problems that require complicated long-term treatment. In this case report, we describe the benefits of using microimplant mechanics for controlling the direction of distraction during distraction osteogenesis and for performing the movement of teeth. We also present its remarkable results and long-term stability. A 20-year-old girl presented with a convex profile due to severe mandibular retrognathia after a history of several TMJ surgeries for bilateral TMJ ankyloses. Mandibular distraction osteogenesis (MDO) was performed, and elastics were placed between the microimplants to control the direction of distraction. Subsequently, after retraction of the maxillary anterior teeth and distalisation of the whole mandibular dentition, the facial profile was markedly improved, and good interdigitation was obtained. The six-year follow-up retention and overall stability were satisfactory with good interdigitation and jaw function.

Prenatal diagnosis of auriculocondylar syndrome with a novel missense variant of GNAI3: a case report.

BACKGROUND: Auriculocondylar syndrome (ACS) is a rare disorder characterized by micrognathia, mandibular condyle hypoplasia, and auricular abnormalities. Only 6 pathogenic variants of GNAI3 have been identified associated with ACS so far. Here, we report a case of prenatal genetic diagnosis of ACS carrying a novel GNAI3 variant. CASE PRESENTATION: A woman with 30 weeks of gestation was referred to genetic counseling for polyhydramnios and fetal craniofacial anomaly. Severe micrognathia and mandibular hypoplasia were identified on ultrasonography. The mandibular length was 2.4 cm, which was markedly smaller than the 95th percentile. The ears were low-set with no cleft or notching between the lobe and helix. The face was round with prominent cheeks. Whole-exome sequencing identified a novel de novo missense variant of c.140G > A in the GNAI3 gene. This mutation caused an amino acid substitution of p.Ser47Asn in the highly conserved G1 motif, which was predicted to impair the guanine nucleotide-binding function. All ACS cases with GNAI3 mutations were literature reviewed, revealing female-dominated severe cases and right-side-prone deformities. CONCLUSION: Severe micrognathia and mandibular hypoplasia accompanied by polyhydramnios are prenatal indicators of ACS. We expanded the mutation spectrum of GNAI3 and summarized clinical features to promote awareness of ACS.

Fetal micrognathia in the first trimester: An ominous finding even after a normal array.

OBJECTIVE: To evaluate the prognosis of fetuses with a prenatal diagnosis of micrognathia in the first trimester. STUDY DESIGN: Over a 3-year period, patients with fetal micrognathia were detected at the time of nuchal translucency screening. The medical records of these pregnancies were reviewed, including maternal demographics, sonographic findings, genetic testing results and pregnancy outcomes. RESULTS: Forty-three cases of first-trimester micrognathia were included in this study. Chromosomal abnormalities were detected in seven cases. Of the fetuses with a normal array, further investigation of monogenic disorders with whole-exome sequencing was undertaken in 13 cases. Monogenic syndromes were identified in eight cases, including six with de-novo dominant alleles and two with recessive conditions. Whole-exome sequencing was refused in 23 cases; among these, other additional anomalies were found on anatomic ultrasound in 10 cases. CONCLUSION: This study demonstrated that caution should be adopted when finding an apparently isolated micrognathia in early gestation, even with a normal array. A diagnosis of genetic syndrome or multiple anomalies on subsequent scans is most likely, and will affect the final prognosis.

Prenatal diagnosis of Meier-Gorlin syndrome 7: a case presentation.

BACKGROUND: Meier-Gorlin syndrome 7 (MGS7) is a rare autosomal recessive condition. We reported a fetus diagnosed with Meier-Gorlin syndrome 7. The antenatal sonographic images were presented, and compound heterozygous mutations of CDC45 on chromosome 22 were identified by whole-exome sequencing (WES). CASE PRESENTATION: Fetal growth restriction (FGR), craniosynostosis, and brachydactyly of right thumb were found in a fetus of 28th gestational weeks. The fetus was diagnosed as MGS7 clinically. After extensive counseling, the couple opted for prenatal diagnosis by cordocentesis and termination of pregnancy. Karyotype analysis and WES were performed. Chromosomal karyotyping showed that the fetus was 46, XY. There were 2 mutations of CDC45, the causal gene of MGS7 on chromosome 22, which were inherited from the couple respectively were identified by WES. Facial dysmorphism, brachydactyly of right thumb, and genitalia abnormally were proved by postpartum autopsy, and craniosynostosis was confirmed by three-dimensional computed tomography (3D-CT) reconstruction. CONCLUSIONS: It is possible to detect multiple clinical features of Meier-Gorlin syndrome in prenatal sonography. Deteriorative FGR complicated with craniosynostosis indicates MGS7. Combination of 2D and 3D ultrasonography helps to detect craniosynostosis. The affected fetus was confirmed a compound heterozygote of CDC45 related MGS by whole-exome sequencing, which is critical in identifying rare genetic diseases.

Metacarpophalangeal profile pattern analysis in a further patient with a novel ARID1B variant.

Acral clinical and radiographic characteristics of a further patient with Coffin-Siris syndrome (CSS), which is caused by mutations in the ARID1B gene, encoding a subunit of the BAF-complex, are here described. Metacarpophalangeal profile pattern analysis (MCPPPA) of the present proband and other two known ARID1B mutated individuals has been performed for the first time, demonstrating hands brachydactyly. In this novel study, the utility of an accurate appendicular radiographic examination and MCPPPA in this congenital condition is highlighted. The MCPPPA could be considered in the clinical practice, to better study the hand skeletal morphology in patients with a syndrome characterized by limb defects, including CSS.

A novel missense variant of the GNAI3 gene and recognisable morphological characteristics of the mandibula in ARCND1.

Auriculocondylar syndrome (ARCND) is an autosomal monogenic disorder characterised by external ear abnormalities and micrognathia due to hypoplasia of the mandibular rami, condyle and coronoid process. Genetically, three subtypes of ARCND (ARCND1, ARCND2 and ARCND3) have been reported. To date, five pathogenic variants of GNAI3 have been reported in ARCND1 patients. Here, we report a novel variant of GNAI3 (NM_006496:c.807C>A:p.(Asn269Lys)) in a Japanese girl with micrognathia using trio-based whole exome sequencing analysis. The GNAI3 gene encodes a heterotrimeric guanine nucleotide-binding protein. The novel variant locates the guanine nucleotide-binding site, and the substitution was predicted to interfere with guanine nucleotide-binding by in silico structural analysis. Three-dimensional computer tomography scan, or cephalogram, displayed severely hypoplastic mandibular rami and fusion to the medial and lateral pterygoid plates, which have been recognised in other ARCND1 patients, but have not been described in ARCND2 and ARCND3, suggesting that these may be distinguishable features in ARCND1.

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.

Prenatal Diagnosis of Robin Sequence: Sensitivity, Specificity, and Clinical Relevance of an Index for Micrognathia.

OBJECTIVE: Micrognathia in connection with glossoptosis (called Robin sequence) may lead to life-threatening respiratory problems immediately after birth. An objective detection during prenatal routine ultrasound sonography is possible using an index that relates fetal lower jaw length to femur length or gestational age. The aim of this study was to test the method's sensitivity and specificity and to discuss its predictive power concerning neonatal respiratory insufficiency. DESIGN: Patients with subjectively identified suspicious signs in the sagittal profile view were included in the study: Two-dimensional serial ultrasound scans of their fetal mandible were used to measure the lower jaw lengths and compare them to predicted values according to an index, derived from 313 healthy fetuses. Follow-up data provided additional information on the clinical appearance of the newborns. RESULTS: The index showed a high sensitivity: 15 of the 16 cases with a micrognathia were correctly diagnosed (sensitivity of 93.75%). Follow-up data showed that newborns with similar index values differed in terms of their upper airway obstruction and treatment need. CONCLUSION: Fetal mandibular micrognathia can be objectively evaluated with the help of the index. The method allows an early detection of micrognathia, which helps to take the necessary steps for proper treatment of potential life-threatening respiratory impairment. Observations ranging outside the prediction interval could prompt the ultrasonographer to check for other associated malformations.

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.

Outcomes of Airway Management in Micrognathia and Retrognathia Patients Born at Fetal versus Nonfetal Centers.

OBJECTIVES: There is a paucity of evidence to guide the perinatal management of difficult airways in fetuses with micrognathia. We aimed to (1) develop a postnatal grading system based on the extent of airway intervention required at birth to assess the severity of micrognathic airways and (2) compare trends in airway management and outcomes by location of birth [nonfetal center (NFC), defined as a hospital with or without an NICU and no fetal team, versus fetal center (FC), defined as a hospital with an NICU and fetal team]. METHODS: We retrospectively reviewed the prenatal and postnatal records of all neonates diagnosed with micrognathia from January 2010 to April 2018 at a quaternary children's hospital. We developed a novel grading scale, the Micrognathia Grading Scale (MGS), to grade the extent of airway intervention at birth from 0 (no airway intervention) to 4 (requirement of EXIT or advanced airway instrumentation for airway securement). RESULTS: We identified 118 patients with micrognathia. Eighty-nine percent (105/118) were eligible for grading using the MGS. When the MGS was applied, the airway grades were as follows: grade 0 (30%), grade 1 (10%), grade 2 (9%), grade 3 (48%), and grade 4 (4%). A quarter of micrognathic patients with grade 0-2 airways had postnatal hospital readmissions for airway obstruction after birth, of which all were born at NFC. Over 40% of patients with grade 3-4 micrognathic airways required airway intervention within 24 h of birth. Overall, NFC patients had a readmission rate of (27%) for airway obstruction after birth compared to FC patients (17%). CONCLUSIONS: Due to the high incidence of grade 3-4 airways on the MGS in micrognathic patients, fetuses with prenatal findings suggestive of micrognathia should be referred to a comprehensive fetal care center capable of handling complex neonatal airways. For grade 0-2 airways, infants frequently had postnatal complications necessitating airway intervention; early referral to a multidisciplinary team for both prenatal and postnatal airway management is recommended.