Immediate postdelivery airway management of neonates with prenatally diagnosed micrognathia: A retrospective observational study

INTRODUCTION

Micrognathic neonates are at risk for upper airway obstruction, and many require intubation in the delivery room. Ex-utero intrapartum treatment is one technique for managing airway obstruction but poses substantial maternal risks. Procedure requiring a second team in the operating room is an alternative approach to secure the obstructed airway while minimizing maternal risk. The aim of this study was to describe the patient characteristics, airway management, and outcomes for micrognathic neonates and their mothers undergoing a procedure requiring a second team in the operating room at a single quaternary care children's hospital.

METHODS

This was a retrospective descriptive study. Subjects had prenatally diagnosed micrognathia and underwent procedure requiring a second team in the operating room between 2009 and 2021. Collected data included infant characteristics, delivery room airway management, critical events, and medications. Follow-up data included genetic testing and subsequent procedures within 90 days. Maternal data included type of anesthetic, blood loss, and incidence of transfusion.

RESULTS

Fourteen deliveries were performed via procedure requiring a second team in the operating room during the study period. 85.7% were male, and 50% had a genetic syndrome. Spontaneous respiratory efforts were observed in 93%. Twelve patients (85.7%) required an endotracheal tube or tracheostomy. Management approaches varied. Medications were primarily a combination of atropine, ketamine, and dexmedetomidine. Oxygen desaturation was common, and three patients experienced bradycardia. There were no periprocedural deaths. Follow-up at 90 days revealed that 78% of patients underwent at least one additional procedure, and one patient died due to an unrelated cause. All mothers underwent cesarean deliveries under neuraxial anesthesia. Median blood loss was 700 mL [IQR 700 mL, 800 mL]. Only one mother required a blood transfusion for pre-procedural placental abruption.

DISCUSSION

Procedure requiring a second team in the operating room is a safe and effective approach to manage airway obstruction in micrognathic neonates while minimizing maternal morbidity.

CONCLUSIONS

Though shown to be safe and effective, more data are needed to support the use of procedure requiring a second team in the operating room as an alternative to ex-utero intrapartum treatment for micrognathia outside of highly specialized maternal-fetal centers.

Feeding and swallowing outcomes following mandibular distraction osteogenesis: an analysis of 22 non-isolated paediatric cases

Patients with mandibular hypoplasia and upper airway obstruction are at an increased risk of feeding and swallowing difficulties. Little has been described regarding these outcomes following mandibular distraction. The aim of this study was to evaluate the effect of mandibular distraction on feeding and swallowing function. A retrospective study was performed on 22 patients with non-isolated mandibular hypoplasia and severe upper airway obstruction treated with mandibular distraction. Median age at first mandibular distraction was 3.1 years (interquartile range 2.3-6.0 years) and the median follow-up time was 3.5 years (interquartile range 2.0-9.4 years). Prior to mandibular distraction, feeding difficulties were present in 18 patients. Swallowing difficulties were present in 20 patients, all of whom had problems in the oral phase of swallowing, while 11 patients had additional problems in the pharyngeal phase. Following mandibular distraction, at the time of follow-up, feeding difficulties persisted in 13 patients. Swallowing difficulties in the oral phase remained present in all 20 patients, while pharyngeal phase problems persisted in seven patients. In conclusion, feeding and swallowing difficulties are highly prevalent in non-isolated patients and often persist following mandibular distraction. Moreover, these can be the reason that decannulation cannot be accomplished. Hence, awareness and close follow-up by a specialized speech therapist is of paramount importance.

Ectopic Hedgehog Signaling Causes Cleft Palate and Defective Osteogenesis

Cleft palate is a common birth defect that frequently occurs in human congenital malformations caused by mutations in components of the Sonic Hedgehog (S HH) signaling cascade. Shh is expressed in dynamic, spatiotemporal domains within epithelial rugae and plays a key role in driving epithelial-mesenchymal interactions that are central to development of the secondary palate. However, the gene regulatory networks downstream of Hedgehog (Hh) signaling are incompletely characterized. Here, we show that ectopic Hh signaling in the palatal mesenchyme disrupts oral-nasal patterning of the neural crest cell-derived ectomesenchyme of the palatal shelves, leading to defective palatine bone formation and fully penetrant cleft palate. We show that a series of Fox transcription factors, including the novel direct target Foxl1, function downstream of Hh signaling in the secondary palate. Furthermore, we demonstrate that Wnt/bone morphogenetic protein (BMP) antagonists, in particular Sostdc1, are positively regulated by Hh signaling, concomitant with downregulation of key regulators of osteogenesis and BMP signaling effectors. Our data demonstrate that ectopic Hh-Smo signaling downregulates Wnt/BMP pathways, at least in part by upregulating Sostdc1, resulting in cleft palate and defective osteogenesis.

Dislocated Tongue Muscle Attachment and Cleft Palate Formation

In Pierre Robin sequence, a retracted tongue due to micrognathia is thought to physically obstruct palatal shelf elevation and thereby cause cleft palate. However, micrognathia is not always associated with palatal clefting. Here, by using the Bmp7-null mouse model presenting with cleft palate and severe micrognathia, we provide the first causative mechanism linking the two. In wild-type embryos, the genioglossus muscle, which mediates tongue protrusion, originates from the rostral process of Meckel's cartilage and later from the mandibular symphysis, with 2 tendons positive for Scleraxis messenger RNA. In E13.5 Bmp7-null embryos, a rostral process failed to form, and a mandibular symphysis was absent at E17.5. Consequently, the genioglossus muscle fibers were diverted toward the lingual surface of Meckel's cartilage and mandibles, where they attached in an aponeurosis that ectopically expressed Scleraxis. The deflection of genioglossus fibers from the anterior-posterior toward the medial-lateral axis alters their direction of contraction and necessarily compromises tongue protrusion. Since this muscle abnormality precedes palatal shelf elevation, it is likely to contribute to clefting. In contrast, embryos with a cranial mesenchyme-specific deletion of Bmp7 (Bmp7:Wnt1-Cre) exhibited some degree of micrognathia but no cleft palate. In these embryos, a rostral process was present, indicating that mesenchyme-derived Bmp7 is dispensable for its formation. Moreover, the genioglossus appeared normal in Bmp7:Wnt1-Cre embryos, further supporting a role of aberrant tongue muscle attachment in palatal clefting. We thus propose that in Pierre Robin sequence, palatal shelf elevation is not impaired simply by physical obstruction by the tongue but by a specific developmental defect that leads to functional changes in tongue movements.

Treatment of maxillary cleft palate: Distraction osteogenesis vs. orthognathic surgery

Purpose:

The purpose of this paper is to compare the treatment of hypoplastic, retruded maxillary cleft palate using distraction osteogenesis vs. orthognathic surgery in terms of stability and relapse, growth after distraction and soft tissue profile changes.

Materials and Methods:

The cleft patients showed anteroposterior maxillary hypoplasia with class III malocclusion and negative overjet resulting in a concave profile according to preoperative cephalometric measurements, dental relationship, and soft tissue analysis. The patients were divided in two groups of treatment : S0 eventeen were treated by orthognathic Le Fort I osteotomy fixed with four mini plates and 2 mm screws, and 19 were treated by maxillary distraction osteogenesis with rigid extraoral devices (RED) connected after a Le Fort I osteotomy. The rate of distraction was 1 mm per day to achieve Class I occlusion with slight overcorrection and to create facial profile convexity. Following a 10 week latency period the distraction devices were removed.

Results:

In the RED group the maxilla was advanced an average of 15.80 mm. The occlusion changed from class III to class I. The profile of the face changed from concave to convex. At a 1-year follow up the results were stable. The mean orthognathic movement was 8.4 mm.

Conclusion:

In mild maxillary deficiency a one stage orthognathic surgery is preferable. However, in patients requiring moderate to large advancements with significant structural deficiencies of the maxilla or in growing patients the distraction technique is preferred.

Case report: three farmworkers who gave birth to infants with birth defects closely grouped in time and place-Florida and North Carolina, 2004-2005

CONTEXT

There is little evidence linking adverse reproductive effects to exposure to specific pesticides during pregnancy.

CASE PRESENTATION

In February 2005, three infants with congenital anomalies were identified in Collier County, Florida, who were born within 8 weeks of one another and whose mothers worked for the same tomato grower. The mothers worked on the grower's Florida farms in 2004 before transferring to its North Carolina farms. All three worked during the period of organogenesis in fields recently treated with several pesticides. The Florida and North Carolina farms were inspected by regulatory agencies, and in each state a large number of violations were identified and record fines were levied.

DISCUSSION

Despite the suggestive evidence, a causal link could not be established between pesticide exposures and the birth defects in the three infants. Nonetheless, the prenatal pesticide exposures experienced by the mothers of the three infants is cause for concern. Farmworkers need greater protections against pesticides. These include increased efforts to publicize and comply with both the U.S. Environmental Protections Agency's Worker Protection Standard and pesticide label requirements, enhanced procedures to ensure pesticide applicator competency, and recommendations to growers to adopt work practices to reduce pesticide exposures. RELEVANCE TO PROFESSIONAL PRACTICE: The findings from this report reinforce the need to reduce pesticide exposures among farmworkers. In addition, they support the need for epidemiologic studies to examine the role of pesticide exposure in the etiology of congenital anomalies.