Journey to chew: a case of maxillary duplication and bony syngnathia

Cardiovascular anomalies in patients with Tessier syndrome: a systematic review

Tessier clefts are skeletal and soft tissue abnormalities of a neonate's facial structures. They could be classified as syndromic and non-syndromic clefts, which can be attributed to disruptions in fetal development and genetic mutations, respectively. Reported cases of these clefts typically document the presence of additional abnormalities associated with these clefts. In this systematic review, we analyzed reports of Tessier clefts accompanied by cardiovascular anomalies, as one of the commonly encountered anomalies. We systematically searched PubMed (MEDLINE), Scopus, Web of Science, Science Direct, and Google Scholar. We selected and included case reports, case series, and case reviews on patients with Tessier cleft and cardiovascular anomalies. The critical appraisal of the included studies was performed by two independent investigators using the Consensus-based Clinical Case Reporting Guideline Development (CARE) checklist. Overall, 20 reports (18 case reports and 2 case series) were eligible for inclusion in this review. Tessier clefts 3 and 30 were the most commonly observed. In addition, the most prevalent cardiovascular anomalies consisted of the ventricular septal defect (VSD), double-outlet right ventricle, and atrial septal defect (ASD). Most of the patients received cosmetic and cardiovascular surgeries. However, some were not proper candidates for cardiovascular surgery because of their unstable condition and therefore did not survive.   Conclusion: Regardless of the focus placed on the cleft and subsequent plastic surgery procedures in these cases, it is important to prioritize other abnormalities that may be associated with mortality. A complete cardiovascular system and associated disorders assessment should be performed before facial cosmetic surgeries. What is Known: • Tessier clefts are congenital defects in the soft tissues and bones of the face and like many other congenital defects, they are accompanied by defects in other parts of the body. • In the current literature, the emphasis is on clefts and the cosmetic issues rather than the coinciding defects, particularly cardiovascular anomalies. What is New: • Review the cardiovascular anomalies that are commonly encountered in patients with Tessier clefts.

Biallelic truncating variants in VGLL2 cause syngnathia in humans

BACKGROUND

Syngnathia is an ultrarare craniofacial malformation characterised by an inability to open the mouth due to congenital fusion of the upper and lower jaws. The genetic causes of isolated bony syngnathia are unknown.

METHODS

We used whole exome and Sanger sequencing and microsatellite analysis in six patients (from four families) presenting with syngnathia. We used CRISPR/Cas9 genome editing to generate vgll2a and vgll4l germline mutant zebrafish, and performed craniofacial cartilage analysis in homozygous mutants.

RESULTS

We identified homozygous truncating variants in vestigial-like family member 2 (VGLL2) in all six patients. Two alleles were identified: one in families of Turkish origin and the other in families of Moroccan origin, suggesting a founder effect for each. A shared haplotype was confirmed for the Turkish patients. The VGLL family of genes encode cofactors of TEAD transcriptional regulators. Vgll2 is regionally expressed in the pharyngeal arches of model vertebrate embryos, and morpholino-based knockdown of vgll2a in zebrafish has been reported to cause defects in development of pharyngeal arch cartilages. However, we did not observe craniofacial anomalies in vgll2a or vgll4l homozygous mutant zebrafish nor in fish with double knockout of vgll2a and vgll4l. In Vgll2 -/- mice, which are known to present a skeletal muscle phenotype, we did not identify defects of the craniofacial skeleton.

CONCLUSION

Our results suggest that although loss of VGLL2 leads to a striking jaw phenotype in humans, other vertebrates may have the capacity to compensate for its absence during craniofacial development.

Tessier 3 and 4 Clefts and Choanal Atresia: An Unusual Association?

INTRODUCTION

Craniofacial clefts are rare congenital anomalies that might involve both soft tissue and skeletal components. The association of Tessier cleft number 3 and 4 with choanal atresia appears to be unusual and only few clinical cases have been reported in published literature.

OBJECTIVES

Report a series of 13 cases of choanal atresia in patients with Tessier numbers 3 or 4 clefts and the literature review on this topic.

METHODS

A literature review was undertaken via PUBMED database before April 2020 addressing the association between Tessier numbers 3 or 4 clefts and choanal atresia. Retrospective chart review of patients diagnosed with both comorbidities at a tertiary hospital expertised in craniofacial anomalies.

RESULTS

Literature review yielded 10 studies describing the relationship between choanal atresia and Tessier 3 and 4 facial clefts. We identified 98 patients diagnosed with medial oro-ocular facial clefts (Tessier 3 and 4) and 119 with choanal atresia at our institution over a 20 years time period. Altogether, 13 individuals were diagnosed with both malformations, 3 patients with number 3 cleft, and 10 patients with number 4 cleft. It represents 13.26% of the cases.

CONCLUSION

This study highlights the features of Tessier 3 and 4 facial clefts associated with choanal atresia. Although the publications regarding this association are very scarce, the authors present the largest series of cases of Tessier number 3 and 4 clefts with choanal atresia showing that association between these conditions could be not so unusual.

Congenital Maxillomandibular Syngnathia: Review of Literature and Proposed New Classification System

PURPOSE

Maxillomandibular fusion (syngnathia) is a rare craniofacial anomaly. It occurs as either fibrous (synechiae) or bony (synostosis) fusion of jaw or fusion of mandible to zygoma, tuberosity, hard palate and temporal bone. There are several documentations delineating this condition but owing to its varying presentation, association with both intraoral and extraoral anomalies and syndromes, reviewing it has been as uphill task. The non-unanimous description of cases in the literature and the use of different nomenclatures make it difficult to classify this condition.

METHODS

Extensive search of the literature was done from the year 1936 to 2018 which included a total of 118 cases with 62 cases of bony fusion, 48 cases of fibrous fusion and 8 cases of combined fusion, i.e., fibrous on one site and bony on another side.

RESULTS

This paper proposes a novel, simple and explicit classification system on the basis of nature of fusing tissues, location and extent, association with syndrome after reviewing the existing literature. Furthermore, this review reports 4 new cases of syngnathia along with their clinical, radiographic features and their management protocol.

CONCLUSIONS

This classification can be generalized to all the cases of syngnathia and can further facilitate in its appropriate diagnosis and treatment plan.

Syngnathia in Spectrum of Oromandibular Limb Hypogenesis Syndrome

Syngnathia is a rare facial anomaly associated with neonatal problems, including a compromised airway, and the inability to take in solids and/or liquids. Syngnathia is included within the spectrum of oromandibular limb hypogenesis syndrome, an extremely rare condition characterized by varying degrees of congenital malformation involving the tongue, mandible, and limbs. In this report, we describe the case of a 41-day-old Caucasian female infant who was unable to open her mouth beginning at birth. The authors performed osteotomies to separate fused bone, and placed a bite block at the osteotomy sites to prevent bone fusion recurrence. At 2 years of follow-up patient remained with 14 mm of mouth opening.

Partial duplication of the jaw: case reports and review of relevant publications

Craniofacial duplication is a rare congenital malformation with a wide phenotypic range. The signs and symptoms range from partial craniofacial duplication to bicephalus. We describe two cases of partial duplication of jaw: a girl with a duplication of the maxilla, and a boy with duplication of the mandible. We review the relevant publications and discuss the pathogenesis.

Syngnathia

Syngnathia is a congenital fusion of the upper and lower jaws. Its occurrence poses a significant challenge to feeding and its management is challenging to both the surgeon and the anaesthetist. Reports in the literature are mainly clinical reports or case series. To the knowledge of the authors and from the available literature, this is only the fourth report from Nigeria. The presentation and successful management of a Nigerian female neonate with congenital syngnathia is described and reviewed with literature.

Maxillomandibular Syngnathia: 3D Planning and Review of the Literature

Congenital maxillomandibular fusion or syngnathia is a rare craniofacial disorder with only 26 cases reported in the literature. We present a case of a congenital complex zygomatico-mandibular syngnathia associated with a palatal cleft, posterior maxilla and turbinate agenesia, mild hemifacial microsomia, and a disordered dental eruption. The patient has the highest age (15 years) at diagnosis described in the literature. 3D planning of the surgery was performed to study the patient's anatomy and design the necessary osteotomies to separate the jaws. En bloc removal of the fused fragment with bilateral coronoidectomy and aggressive long-term physiotherapy for 3 months led to a stable increase in mouth opening from 0 to 21 mm inter-incisor distance. The patient reported an improvement in speech, was able to eat without restriction regarding food consistency, and could maintain a good oral hygiene.

Separate development of the maxilla and mandible is controlled by regional signaling of the maxillomandibular junction during avian development

BACKGROUND

Syngnathia is a congenital craniofacial disorder characterized by bony or soft tissue fusion of upper and lower jaws. Previous studies suggested some causative signals, such as Foxc1 or Bmp4, cause the disruption of maxillomandibular identity, but their location and the interactive signals involved remain unexplored. We wanted to examine the embryonic origin of syngnathia based on the assumption that it may be located at the separation between the maxillary and mandibular processes. This region, known as the maxillomandibular junction (MMJ), is involved in segregation of cranial neural crest-derived mesenchyme into the presumptive upper and lower jaws.

RESULTS

Here we investigated the role of Fgf, Bmp, and retinoid signaling during development of MMJ in chicken embryos. By changing the levels of these signals with bead implants, we induced syngnathia with microstomia on the treated side, which showed increased Barx1 and neural cell adhesion molecule (NCAM) expression. Redistribution of proliferating cells was also observed at the proximal region to maxillary and mandibular arch around MMJ.

CONCLUSIONS

We propose that interactive molecular signaling by Fgfs, Bmps, and retinoids around MMJ is required for normal separation of the maxilla and mandible, as well as the proper positioning of beak commissure during early facial morphogenesis. Developmental Dynamics 246:28-40, 2017. © 2016 Wiley Periodicals, Inc.

Mouse Models of Rare Craniofacial Disorders

A rare disease is defined as a condition that affects less than 1 in 2000 individuals. Currently more than 7000 rare diseases have been documented, and most are thought to be of genetic origin. Rare diseases primarily affect children, and congenital craniofacial syndromes and disorders constitute a significant proportion of rare diseases, with over 700 having been described to date. Modeling craniofacial disorders in animal models has been instrumental in uncovering the etiology and pathogenesis of numerous conditions and in some cases has even led to potential therapeutic avenues for their prevention. In this chapter, we focus primarily on two general classes of rare disorders, ribosomopathies and ciliopathies, and the surprising finding that the disruption of fundamental, global processes can result in tissue-specific craniofacial defects. In addition, we discuss recent advances in understanding the pathogenesis of an extremely rare and specific craniofacial condition known as syngnathia, based on the first mouse models for this condition. Approximately 1% of all babies are born with a minor or major developmental anomaly, and individuals suffering from rare diseases deserve the same quality of treatment and care and attention to their disease as other patients.