The growth of the nasal septum in the 6-9 week period of foetal development--Warfarin embryopathy offers a new insight into prenatal facial development

Septal chondrocyte hypertrophy contributes to midface deformity in a mouse model of Apert syndrome

Midface hypoplasia is a major manifestation of Apert syndrome. However, the tissue component responsible for midface hypoplasia has not been elucidated. We studied mice with a chondrocyte-specific Fgfr2^S252W mutation (Col2a1-cre; Fgfr2^S252W/+) to investigate the effect of cartilaginous components in midface hypoplasia of Apert syndrome. In Col2a1-cre; Fgfr2^S252W/+ mice, skull shape was normal at birth, but hypoplastic phenotypes became evident with age. General dimensional changes of mutant mice were comparable with those of mice with mutations in EIIa-cre; Fgfr2^S252W/+, a classic model of Apert syndrome in mice. Col2a1-cre; Fgfr2^S252W/+ mice showed some unique facial phenotypes, such as elevated nasion, abnormal fusion of the suture between the premaxilla and the vomer, and decreased perpendicular plate of the ethmoid bone volume, which are related to the development of the nasal septal cartilage. Morphological and histological examination revealed that the presence of increased septal chondrocyte hypertrophy and abnormal thickening of nasal septum is causally related to midface deformities in nasal septum-associated structures. Our results suggest that careful examination and surgical correction of the nasal septal cartilage may improve the prognosis in the surgical treatment of midface hypoplasia and respiratory problems in patients with Apert syndrome.

Maternal Folic Acid Deficiency Is Associated to Developing Nasal and Palate Malformations in Mice

Craniofacial development requires extremely fine-tuned developmental coordination of multiple specialized tissues. It has been evidenced that a folate deficiency (vitamin B9), or its synthetic form, folic acid (FA), in maternal diet could trigger multiple craniofacial malformations as oral clefts, tongue, or mandible abnormalities. In this study, a folic acid-deficient (FAD) diet was administered to eight-week-old C57/BL/6J female mouse for 2-16 weeks. The head symmetry, palate and nasal region were studied in 24 control and 260 experimental fetuses. Our results showed a significant reduction in the mean number of fetuses per litter according to maternal weeks on FAD diet (p < 0.01). Fetuses were affected by cleft palate (3.8%) as well as other severe congenital abnormalities, for the first time related to maternal FAD diet, as head asymmetries (4.6%), high arched palate (3.5%), nasal septum malformed (7.3%), nasopharynx duct shape (15%), and cilia and epithelium abnormalities (11.2% and 5.8%). Dysmorphologies of the nasal region were the most frequent, appearing at just four weeks following a maternal FAD diet. This is the first time that nasal region development is experimentally related to this vitamin deficiency. In conclusion, our report offers novel discoveries about the importance of maternal folate intake on midface craniofacial development of the embryos. Moreover, the longer the deficit lasts, the more serious the consequent effects appear to be.

Critical Growth Processes for the Midfacial Morphogenesis in the Early Prenatal Period

BACKGROUND

Congenital midfacial hypoplasia often requires intensive treatments and is a typical condition for the Binder phenotype and syndromic craniosynostosis. The growth trait of the midfacial skeleton during the early fetal period has been assumed to be critical for such an anomaly. However, previous embryological studies using 2-dimensional analyses and specimens during the late fetal period have not been sufficient to reveal it.

OBJECTIVE

To understand the morphogenesis of the midfacial skeleton in the early fetal period via 3-dimensional quantification of the growth trait and investigation of the developmental association between the growth centers and midface.

METHODS

Magnetic resonance images were obtained from 60 human fetuses during the early fetal period. Three-dimensional shape changes in the craniofacial skeleton along growth were quantified and visualized using geometric morphometrics. Subsequently, the degree of development was computed. Furthermore, the developmental association between the growth centers and the midfacial skeleton was statistically investigated and visualized.

RESULTS

The zygoma expanded drastically in the anterolateral dimension, and the lateral part of the maxilla developed forward until approximately 13 weeks of gestation. The growth centers such as the nasal septum and anterior portion of the sphenoid were highly associated with the forward growth of the midfacial skeleton (RV = 0.589; P < .001).

CONCLUSIONS

The development of the midface, especially of the zygoma, before 13 weeks of gestation played an essential role in the midfacial development. Moreover, the growth centers had a strong association with midfacial forward growth before birth.

Quantitation of nasal development in the early prenatal period using geometric morphometrics and MRI: a new insight into the critical period of Binder phenotype

OBJECTIVES

Disturbance of the development of the nasal septum in the early prenatal period causes congenital facial anomalies characterized by a flat nose and defects of the anterior nasal spine (ANS), such as Binder phenotype. The present research aimed to assess the development of the nasal septum and the ANS with growth in the early prenatal period.

METHODS

Magnetic resonance images were obtained from 56 specimens. Mid-sagittal images were analyzed by using geometric morphometrics for the development of the nasal septum, and angle analysis was performed for the development of the ANS. Additionally, we calculated and visualized the ontogenetic allometry of the nasal septum.

RESULTS

Our results showed that the nasal septum changed shape in the anteroposterior direction in smaller specimens, while it maintained an almost isometric shape in larger specimens. Furthermore, mathematical evidence revealed that the maturation periods of the shapes of the ANS and the nasal septum were around 12 and 14 weeks of gestation, respectively.

CONCLUSION

The anteroposterior development of the nasal septum is specific until 14 weeks of gestation, and it is important for nasal protrusion and the development of the ANS. Therefore, the disturbance of such development could induce low nasal deformity, including Binder phenotype. © 2017 John Wiley & Sons, Ltd.

Matrix Gla protein deficiency impairs nasal septum growth, causing midface hypoplasia

Genetic and environmental factors may lead to abnormal growth of the orofacial skeleton, affecting the overall structure of the face. In this study, we investigated the craniofacial abnormalities in a mouse model for Keutel syndrome, a rare genetic disease caused by loss-of-function mutations in the matrix Gla protein (MGP) gene. Keutel syndrome patients show diffuse ectopic calcification of cartilaginous tissues and impaired midface development. Our comparative cephalometric analyses of micro-computed tomography images revealed a severe midface hypoplasia in Mgp-/- mice. In vivo reporter studies demonstrated that the Mgp promoter is highly active at the cranial sutures, cranial base synchondroses, and nasal septum. Interestingly, the cranial sutures of the mutant mice showed normal anatomical features. Although we observed a mild increase in mineralization of the spheno-occipital synchondrosis, it did not reduce the relative length of the cranial base in comparison with total skull length. Contrary to this, we found the nasal septum to be abnormally mineralized and shortened in Mgp-/- mice. Transgenic restoration of Mgp expression in chondrocytes fully corrected the craniofacial anomalies caused by MGP deficiency, suggesting a local role for MGP in the developing nasal septum. Although there was no up-regulation of markers for hypertrophic chondrocytes, a TUNEL assay showed a marked increase in apoptotic chondrocytes in the calcified nasal septum. Transmission electron microscopy confirmed unusual mineral deposits in the septal extracellular matrix of the mutant mice. Of note, the systemic reduction of the inorganic phosphate level was sufficient to prevent abnormal mineralization of the nasal septum in Mgp-/-;Hyp compound mutants. Our work provides evidence that modulation of local and systemic factors regulating extracellular matrix mineralization can be possible therapeutic strategies to prevent ectopic cartilage calcification and some forms of congenital craniofacial anomalies in humans.

Augmented BMP signaling in the neural crest inhibits nasal cartilage morphogenesis by inducing p53-mediated apoptosis

Bone morphogenetic protein (BMP) signaling plays many roles in skull morphogenesis. We have previously reported that enhanced BMP signaling through the BMP type IA receptor (BMPR1A) in cranial neural crest cells causes craniosynostosis during postnatal development. Additionally, we observed that 55% of Bmpr1a mutant mice show neonatal lethality characterized by a distended gastrointestinal tract. Here, we show that severely affected mutants exhibit defective nasal cartilage, failure of fusion between the nasal septum and the secondary palate, and higher levels of phosphorylated SMAD1 and SMAD5 in the nasal tissue. TUNEL demonstrated an increase in apoptosis in both condensing mesenchymal tissues and cartilage of the nasal region in mutants. The levels of p53 (TRP53) tumor suppressor protein were also increased in the same tissue. Injection of pifithrin-α, a chemical inhibitor of p53, into pregnant mice prevented neonatal lethality while concomitantly reducing apoptosis in nasal cartilage primordia, suggesting that enhanced BMP signaling induces p53-mediated apoptosis in the nasal cartilage. The expression of Bax and caspase 3, downstream targets of p53, was increased in the mutants; however, the p53 expression level was unchanged. It has been reported that MDM2 interacts with p53 to promote degradation. We found that the amount of MDM2-p53 complex was decreased in all mutants, and the most severely affected mutants had the largest decrease. Our previous finding that the BMP signaling component SMAD1 prevents MDM2-mediated p53 degradation coupled with our new data indicate that augmented BMP signaling induces p53-mediated apoptosis by prevention of p53 degradation in developing nasal cartilage. Thus, an appropriate level of BMP signaling is required for proper craniofacial morphogenesis.

Bleeding and non-bleeding phenotypes in patients with GGCX gene mutations

Functional limitations for the vitamin K cycle, caused either by mutations in gamma-glutamyl carboxylase or vitamin K epoxide reductase genes, result in hereditary deficiency of vitamin K-dependent coagulation factors (VKCFD1 and VKCFD2, respectively). Patients suffering from VKCFD often share several other anatomical irregularities which are not related to haemostasis. Here we report on nine patients, eight of them previously unreported, who presented with VKCFD1. All were examined with special attention to vitamin K-dependent coagulation factors as well as to bone and heart development and to other anatomical signs of embryonal vitamin K deficiency. In total, we detected ten mutations in the gamma-glutamyl carboxylase gene of which seven have not been previously reported. Most interestingly, additional non-bleeding phenotypes were observed in all patients including midfacial hypoplasia, premature osteoporosis, cochlear hearing loss, heart valve defects, pulmonary stenosis, or pseudoxanthoma elasticum-like phenotype. Undercarboxylated matrix Gla protein, osteocalcin, and periostin appear to be responsible for these defects which are also observed in cases of fetal warfarin syndrome.

Binder phenotype in mothers affected with autoimmune disorders

OBJECTIVE

To report four foetal cases of the Binder phenotype associated with maternal autoimmune disorders.

PATIENTS AND METHODS

In three mothers with autoimmune diseases, 2D and 3D ultrasonographic measurements were made on four foetuses with the Binder profile, and were compared with postnatal phenotypes.

RESULTS

The Binder phenotype can be detected in early pregnancy (14.5 WG). All foetuses had verticalized nasal bones and midfacial hypoplasia. Punctuate calcifications were found in almost all the cases. No specific maternal auto-antibody has been associated with foetal Binder phenotype.

CONCLUSION

Since the Binder phenotype can be diagnosed at ultrasound examination during pregnancy, it is important to establish the underlying cause so as to assess the foetal prognosis. This study stresses the importance of systematic checks for maternal autoimmune disease in cases of prenatally diagnosed Binder phenotypes.

Warfarin embryopathy: fetal manifestations

During the period 1991-2007, autopsy was undertaken in 13 fetuses with warfarin embryopathy. Pregnancy data and radiographic babygrams were available in each instance. Gestational age ranged from 17 to 37 weeks. Eleven of the fetuses had the characteristic nasal hypoplasia, but only three had radiological epiphyseal stippling. Cerebral hemorrhage was a major feature of autopsy in 8 of the fetuses, and it is evident that bleeding is a significant factor in the pathogenesis of warfarin embryopathy. A wide variety of additional visceral manifestations which were observed at autopsy have been tabulated. There was no obvious correlation between maternal or gestational age and the presence and severity of any specific embryopathic feature. No information was available concerning the dose and timing of warfarin administration in this series.

The significance of fetal maxillary length in the first trimester screening for trisomy 21

OBJECTIVE

The present study aims to specify the significance of fetal maxillary length by establishing a nomogram for a Turkish population and by investigating its relationship with the ultrasonographic and biochemical parameters which are commonly used to screen trisomy 21 in the first trimester of pregnancy.

METHODS

The present observational study investigates 1,308 Turkish women who had 11- to 14-week-old singleton healthy pregnancies. Fetal crown-rump length (CRL), nuchal translucency (NT), nasal bone length (NBL) and maxillary length are measured by ultrasonography and maternal serum concentrations of pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotropin (HCG) are determined.

RESULTS

A positive and significant correlation was detected between the fetal maxillary length and gestational age (r = 0.309, P < 0.001) as was the case with fetal CRL (r = 0.357, P < 0.001) and NBL (r = 0.487, P < 0.001). Although there was a significant and positive correlation between fetal maxillary length and maternal serum PAPP-A levels (r = 0.201, P < 0.001), a significant and negative correlation was found between fetal maxillary length and the maternal serum concentrations of free beta-HCG (r = -0.238, P < 0.001). Fetal maxillary length increased in accordance with the advancing gestational age and increasing CRL. Maternal serum PAPP-A concentrations and fetal CRL and NBL were addressed as independent predictors of fetal maxillary length.

CONCLUSIONS

The length of fetal maxillary bone is a promising biometrical parameter which can be reliably and efficiently used to screen trisomy 21 in first trimester. Fetal maxillary length is also found to correlate with gestational age, CRL, NBL and PAPP-A significantly. It would be rational to use a combination of nasal and maxillary bone length measurements in case serum concentrations of PAPP-A or beta-HCG cannot be assessed.

Septoplasty retards midfacial growth in a rabbit model

OBJECTIVES/HYPOTHESIS

Septoplasty in the prepubertal age group is a controversial operation because of concerns regarding retardation of subsequent midfacial growth. This study uses a validated rabbit snout model to determine if septoplasty results in midfacial growth retardation, and if the retardation can be averted by replacing resected cartilage with a porous polyethylene implant.

STUDY DESIGN

Prospective controlled animal study.

METHODS

Sixteen 9-week-old New Zealand white rabbits were divided into four groups: two control and two experimental. The experimental groups both underwent conservative submucoperichondrial surgical excision of a portion of their septum, leaving a generous dorsal and caudal septal strut for nasal support similar to what would be done clinically in humans. One of the experimental groups had replacement of the resected area by a rigid porous polyethylene graft, and in the other experimental group the resected area was left empty. Cephalometric measurements were performed on radiographs taken at the time of implantation, and at sacrifice when the rabbits were mature at 24 weeks of age.

RESULTS

There were significant disturbances in snout growth between experimental and control groups, and no significant differences between the two experimental groups or between the two control groups.

CONCLUSIONS

These data demonstrate midfacial growth retardation after conservative septoplasty in young rabbits, and that this retardation could not be averted by replacing the resected cartilage with a porous polyethylene graft. These data are in agreement with human studies.

Nasal morphology as an indicator of vertical maxillary skeletal pattern

OBJECTIVE

To investigate the relationship between nasal morphology and vertical maxillary skeletal pattern.

DESIGN

A retrospective study.

SETTING

Department of Orthodontics and Dentofacial Orthopaedics, Armed Forces Medical College, Pune, India.

SUBJECTS AND METHODS

The sample included the lateral cephalometric radiographs of 190 Indian adults (103 women, 87 men), aged 18 to 27 years with no previous history of trauma, surgical intervention, congenital disease or orthodontic treatment. Seven skeletal parameters of vertical facial growth and six nasal parameters were measured.

RESULTS

There was a significant correlation between vertical maxillary skeletal and soft tissue nasal parameters. Nasal length significantly correlated with upper anterior facial height (r=0.850, P<0.001) and inclination of palatal plane (r=0.433, P<0.001). Upward nasal tip inclination showed a significant negative correlation with inclination of the palatal plane (r=-0.462, P<0.001).

CONCLUSION

The clinical significance of this study is that the nasolabial angle in itself may not reflect a midface vertical discrepancy, however its upper component, i.e. the degree of upturn of the nose with decreased nasal length in an adult subject may indicate an underlying change in inclination of the palatal plane. This might be of value during orthodontic diagnosis and treatment planning.

Teratoma of the nasal septum in a neonate: an endoscopic approach

Initial presentation of a white female newborn delivered after normal pregnancy demonstrated a white mass obstructing the left nare. Primary biopsy revealed a focus of fibrotic nasal mucosa that included squamous and respiratory epithelium. After endoscopic resection of the mass, histopathologic examination resulted in the diagnosis of a teratoma. According to our literature review, this is the first case of a teratoma arising from the nasal septum in a white. Worldwide, 3 additional cases have been reported, but none included endoscopic management. This case illustrates our protocol for an endoscopic approach to an obstructive nasal mass in a neonate and our experience in the management of this rare disease.