Mycn deficiency underlies the development of orofacial clefts in mice and humans.

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is the most common subphenotype of non-syndromic orofacial clefts arising from genetic and/or environmental perturbations during embryonic development. We previously identified 2p24.2 as a risk locus associated with NSCL/P in the Chinese Han population, and MYCN is a candidate risk gene in this region. To understand the potential function of MYCN in craniofacial development, we generated Wnt1-Cre;Mycnflox/flox mice that exhibited cleft palate, microglossia and micrognathia, resembling the Pierre Robin sequence (PRS) in humans. Further analyses indicated that the cleft palate was secondary to the delayed elevation of palatal shelves caused by micrognathia. The micrognathia resulted from impaired chondrogenic differentiation in Merkel's cartilage, which limited tongue development, leading to microglossia. In terms of mechanism, Mycn deficiency in cranial neural crest cells (CNCCs) downregulated Sox9 expression by inhibiting Wnt5a in a CNCC-derived chondrogenic lineage in Merkel's cartilage. To investigate whether MYCN deficiency contributed to NSCL/P, we performed direct sequencing targeting all exons and exon-intron boundaries of MYCN in 104 multiplex families with Mendelian NSCL/P and identified a novel pathogenic variant in MYCN. Taken together, our data indicate that ablation of Mycn in mouse CNCCs could resemble PRS by suppressing the Wnt5a-Sox9 signaling pathway in Merkel's cartilage and that mutations in MYCN may be novel potential causes of NSCL/P.

Prognostic Risks for Tracheostomy in Pierre Robin Sequence: A Cohort From a Tertiary Hospital in Thailand.

BACKGROUND: Pierre Robin sequence (PRS), characterized by micrognathia, glossoptosis, cleft palate, and obstructed airways, is one of the craniofacial conditions challenging various approaches to managing compromised airways, ranging from conservative measures to invasive airway surgery. This study was conducted to identify predictive risk factors for tracheostomy in the PRS. METHODS: A retrospective chart review was conducted at a tertiary referral hospital in Thailand. Children diagnosed with PRS from January 2010 to December 2021 were enrolled. Univariate and multivariate analysis methods were used to identify the risk factors. RESULTS: Sixty-five patients with PRS were identified in electronic medical records, but 6 were excluded. Thirteen of the remaining 59 patients underwent tracheostomy. There were no significant differences in sex, preterm gestational age, cleft palate, associated syndromes, chromosome abnormalities, or cardiac or neurological involvement between patients who received tracheostomy and those who did not. However, patients with oropharyngeal dysfunction who received tracheostomy tended to use a nasogastric tube or percutaneous gastrostomy 92.3% of the time ( P = 0.043). In addition, patients with abnormal airways from endoscopy were more likely to undergo tracheostomy (odds ratio, 2.17; 95% confidence interval [CI], 1.20-3.90). Interestingly, patients with a sum of Apgar scores at 1 and 5 minutes <15 were more likely to undergo tracheostomy (adjusted odds ratio, 9.91; 95% CI, 1.32-74.52). Furthermore, patients with at least 3 identified comorbidities were more likely to undergo tracheostomy (adjusted odds ratio, 11.34; 95% CI, 1.16-111.15). CONCLUSIONS: The need for tracheostomy depends on comorbidities, Apgar scores, and abnormal airway anatomy. Feeding methods can become more complex with tracheostomy. Prognostic risk factors can help guide treatment and counseling for health care workers and caregivers.

Mandibular Distraction in Patients With Pierre Robin Sequence: A Multisurgeon Experience.

OBJECTIVE: Mandibular distraction osteogenesis (MDO) is rapidly becoming a standard of care for management of patients with severe Pierre Robin sequence. The tongue is brought forward to alleviate airway obstruction. This study will look at an institutional, multisurgeon experience with MDO over 10 years. DESIGN: A retrospective chart review was conducted. SETTING: All patients who underwent MDO at the authors' institution from 2012 to 2022 were included. Three craniofacial surgeons performed all interventions. PATIENTS: Demographics, preoperative and postoperative respiratory and feeding status, and distraction data were collected for 27 patients meeting inclusion criteria. MAIN OUTCOME MEASURES: Primary outcomes were avoidance of a gastrostomy tube, avoidance of a tracheostomy, discharge from hospital on room air, and complications. A significance value of 0.05 was utilized. RESULTS: The average age at MDO was 135 days, mean activation phase was 13.6 days, mean distraction length was 14.9 mm, and mean consolidation phase was 64.2 days. A longer activation phase was associated with discharge with a gastrostomy tube and a shorter activation phase was associated with discharge on full oral feeds. The ability to discharge on room air was associated with a shorter latency phase, shorter activation phase, and decreased distance of distraction. CONCLUSIONS: The goal of MDO is to achieve full oral feeds with no respiratory support. Several different latency periods were used in this study, and a short latency period was demonstrated to be safe.

Respiratory outcomes after cleft palate closure in Robin sequence: a retrospective study.

OBJECTIVES: There is a paucity of information about the possible risk factors that could identify patients with Robin sequence (RS) who are more prone to developing obstructive airway complications after palate closure. This study aimed to compare the respiratory complication rates in patients with RS and isolated cleft palate (ICP). MATERIALS AND METHODS: In this retrospective study, we reviewed the medical records of 243 consecutive patients with RS and ICP who were treated at Amsterdam University Medical Centers over the past 25 years. We collected preoperative data on previous treatment, diagnostic findings, surgical technique, weight, and presence of congenital anomalies. RESULTS: During cleft palate closure, patients with RS were older (11.9 versus 10.1 months; p = 0.001) and had a lower gestational age than those with ICP (37.7 versus 38.5 weeks; p = 0.002). Patients with RS had more respiratory complications (17 versus 5%; p = 0.005), were more often non-electively admitted to the pediatric intensive care unit (PICU) (13 versus 4.1%; p = 0.022), and had a longer hospital stay duration (3.7 versus 2.7 days; p = 0.011) than those with ICP. The identified risk factors for respiratory problems were a history of tongue-lip-adhesion (TLA) (p = 0.007) and a preoperative weight of < 8 kg (p = 0.015). Similar risk factors were identified for PICU admission (p = 0.015 and 0.004, respectively). CONCLUSIONS: The possible risk factors for these outcomes were a low preoperative weight and history of TLA. Closer postoperative surveillance should be considered for patients with these risk factors. CLINICAL RELEVANCE: Identifying risk factors for respiratory complications could provide clinicians better insight into their patients and allows them to provide optimal care for their patients.

Incidence, Characteristics, and Outcomes of Robin Sequence: A Population-Based Analysis in the United States.

INTRODUCTION: While the literature is replete of clinical studies reporting on the Robin sequence (RS), population-based analyses are scarce with significant variability within the literature in terms of reported incidence, demographic parameters, and outcomes. The authors have conducted a 20-year population-based analysis to guide clinical practice. METHODS: A birth cohort was created from the available datasets in the Healthcare Cost and Utilization Project-Kids' Inpatient Database (HCUP-KID; 2000-2019). Robin sequence patients were identified and further stratified by syndromic status. Incidence, demographic parameters, and outcomes including mortality and tracheostomy rates were computed. A subset analysis comparing the isolated and syndromic cohorts was conducted. Data was analyzed through a χ 2 or t test. RESULTS: The incidence of RS was 5.15:10,000 (95% CI: 4.99-5.31) from a birth cohort of 7.5 million. Overall, 63.3% of the cohort was isolated RS and 36.7% had syndromic RS. Robin sequence patients had a significantly higher rate of cardiac (25.9%) and neurological (8.6%) anomalies compared with the general birth cohort and were most commonly managed in urban teaching hospitals ( P <0.0001). The pooled mortality and tracheostomy rates were 6.6% and 3.6%, respectively. Syndromic status was associated with a longer length of hospital stay (27.8 versus 13.6 d), tracheostomy rate (6.2% versus 2.1%), and mortality (14.1% versus 2.2%) compared with isolated RS ( P <0.0001). CONCLUSIONS: The true incidence of RS is likely higher than previously reported estimates. Isolated RS patients have a low associated mortality and tracheostomy rate and are typically managed in urban teaching hospitals. Syndromic status confers a higher mortality rate, tracheostomy rate, and length of stay compared with nonsyndromic counterparts.

European Guideline Robin Sequence An Initiative From the European Reference Network for Rare Craniofacial Anomalies and Ear, Nose and Throat Disorders (ERN-CRANIO).

A European guideline on Robin Sequence was developed within the European Reference Network for rare and/or complex craniofacial anomalies and ear, nose, and throat disorders. The guideline provides an overview of optimal care provisions for patients with Robin Sequence and recommendations for the improvement of care.

Robin Sequence Facial Profile After Conservative Treatment: A Long-Term Follow-Up.

INTRODUCTION: Robin sequence (RS) is a congenital clinical condition characterized by micrognathia, glossoptosis, and respiratory distress. Conservative methods could be responsible for releasing feeding and respiratory impairment but little information about mandibular growth is known in long-term follow-up. OBJECTIVE: Assessing the longitudinal behavior of the facial profile of individuals with isolated RS who underwent conservative micrognathia treatment using photographs during the whole craniofacial growth. METHODS: Photographs of the right facial profile of 100 patients were used (50 individuals with isolated RS and 50 individuals without craniofacial anomaly). The individuals with RS were evaluated at 3 different times (T1: infant, T2: mixed dentition, T3: permanent dentition) by measuring the facial convexity angle (FCA; G.Sn.Pog´). A comparison between T3 and control group (C), individuals without craniofacial anomalies and in permanent dentition, was also performed, checking the FCA, nasolabial angle (Ls.Sn.Cm), mentolabial fold (Li.Si.Pog´), facial inferior third (Sn.Gn´.C) angles and the ratio between middle anterior facial height and lower anterior facial height. RESULTS: The T3 group showed an increased angle of facial convexity and increased facial inferior third angle and middle anterior facial height/lower anterior facial height ratio compared with the control group. In the longitudinal evaluation of individuals with isolated RS, significant differences were identified between T1 and T2 groups and T1 and T3 groups showing that the increased facial convexity was higher in the infants and that did not change significantly between the phases of mixed and permanent dentition. CONCLUSIONS: RS showed increased facial convexity in all phases evaluated, but their convexity decreased with growth. When compared with individuals without craniofacial anomalies, the individuals continue to exhibit retrognathism in the permanent dentition. The lack of a mandible projection has led to a considerable number of orthognathic surgeries for the correction of discrepancies.

Transoral Endoscopy-Assisted Tongue-Lip Adhesion With Modified Tongue Base Suspension in a Pierre-Robin Sequence: A Safe and Effective Technique.

Life-threatening airway obstruction is a major concern in patients with Pierre-Robin sequence. Tongue-lip adhesion (TLA) has been used to manage airway obstruction. The authors present the case of a female neonate with Pierre-Robin sequence who presented with airway obstruction and a cleft palate. She underwent a TLA procedure with modified tongue base suspension (TBS). Endoscopy was used to check and control the traction of the tongue base to enable unobstructed self-ventilation. Positive outcomes including improved O2 saturation and weight gain were noted. The effectiveness of TLA was enhanced by using TBS with real-time endoscopy to evaluate the oropharyngeal airway space required to alleviate airway obstruction. The use of endoscopy enabled us to check and determine how much the tongue base should be tracted by manipulating the tongue anteriorly and posteriorly. The authors report transoral endoscopy-assisted TLA and modified TBS.

Intellectual Functioning of Children With Isolated PRS, PRS-Plus, and Syndromic PRS.

OBJECTIVE: Describe the intelligence quotient (IQ) of children with Pierre Robin sequence (PRS). DESIGN: Prospective cohort study. SETTING: Neurodevelopmental follow-up clinic within a hospital. PATIENTS: Children with PRS (n = 45) who had been in the Neonatal Intensive Care Unit (NICU) were classified by a geneticist into 3 subgroups of isolated PRS (n = 20), PRS-plus additional medical features (n = 8), and syndromic PRS (n = 17) based on medical record review and genetic testing. MAIN OUTCOME MEASURE: Children with PRS completed IQ testing at 5 or 8 years of age with the Wechsler Preschool and Primary Scale of Intelligence, Third Edition (WPPSI-III) or Fourth Edition (WPPSI-IV) or the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) or Fifth Edition (WISC-V). RESULTS: IQ scores were more than 1 to 2 standard deviations below the mean for 36% of the overall sample, which was significantly greater compared to test norms (binomial test P = .001). There was a significant association between PRS subtype and IQ (Fisher's exact P = .026). While only 20% of children with isolated PRS were within 1 standard deviation below average and 35% of children with syndromic PRS were below 1 to 2 standard deviations, 75% of PRS-plus children scored lower than 1 to 2 standard deviations below the mean. CONCLUSION: PRS subgroups can help identify children at risk for cognitive delay. The majority of children with PRS-plus had low intellectual functioning, in contrast to the third of children with syndromic PRS who had low IQ and the majority of children with isolated PRS who had average or higher IQ.

Screening for Obstructive Sleep Apnea and Associated Risk Factors in Adolescents and Adults With Isolated Robin Sequence.

OBJECTIVE: To investigate the subjective risk for obstructive sleep apnea (OSA) in adolescents and young adults with isolated Robin sequence (IRS). Additionally, to investigate the association of OSA risk with respiratory signs/symptoms, and retrognathia. DESIGN: Prospective, observational, and cross-sectional study. SETTING: Tertiary reference hospital for the rehabilitation of craniofacial anomalies. PARTICIPANTS: Adolescents and adults (n = 30) with IRS were clinically evaluated and screened through the Berlin Questionnaire (BQ) and Respiratory Symptoms Questionnaire. The maxillomandibular relationship was assessed on lateral cephalograms of those that reached skeletal maturity (n = 13). Polysomnography (PSG) was performed in a subgroup of 4 individuals. RESULTS: The mean age of the sample was 18.2 (±3.4) years, 17 (56.7%) were adolescents (14-19 years), and 16 were (53.3%) female, all presented a repaired cleft palate. CLINICAL PARAMETERS: Systemic arterial pressure (118.0 ± 4.1/76.3 ± 4.9 mmHg), body mass index (BMI) (20.9 ± 2.8 kg/m2), neck (33.2 ± 2.3 cm), and waist circumferences (72.0 ± 5.8 cm) were within normal ranges. A skeletal class I pattern was observed in 61.5% of the participants while a class II was seen in 15.4% of them. A high risk for OSA was detected in 16.7%, and it was associated with nasal obstruction, snoring and drowsiness, and a skeletal class II pattern (P ≤ .05). One patient presented with mild OSA (apnea-hypopnea index [AHI] = 10.1 events/hour) at the PSG exam. CONCLUSIONS: A high risk for OSA can be observed with a moderate frequency among adolescents and young adults with IRS, especially among those who are concurrently suffering from nasal obstruction, snoring and retrognathia.

Associated anomalies in Pierre Robin sequence.

Pierre Robin sequence (PRS) is frequently co-occurring with other non-PRS congenital anomalies. The types and the prevalence of anomalies co-occurring with PRS vary in the reported studies. The aims of this report was to study the types and the prevalence of the anomalies co-occurring with PRS in a well-studied population northeastern France. The types and the prevalence of anomalies co-occurring in cases with PRS were ascertained in all terminations of pregnancy, stillbirths and live births in 387,067 births occurring consecutively during the period 1979-2007 in the area covered by our registry of congenital anomalies which is population-based, 89 cases of PRS were registered during the study period with a prevalence of 2.29 per 10,000 births, 69.7% of the cases had associated non-PRS anomalies. Chromosomal abnormalities were present in 10 (11.2%) cases including three 22 q11.2 deletion. Non-chromosomal recognizable conditions were diagnosed in 27 cases (30.3%) including 10 Stickler syndrome, 8 Treacher Collins syndrome, 3 cases with short stature and 6 other syndromes. Multiple congenital anomalies (MCA) were present in 25 cases (28.1%). The most frequent MCA were in the ear, face and neck (35 out of 98 anomalies, 35.7%), cardiovascular (18 anomalies, 18.4%), musculoskeletal (11 anomalies, 11.2%), central nervous (7 anomalies, 7.1%), urinary (6 anomalies, 6.1%), and eye (6 anomalies, 6.1%) system. The high prevalence of associated anomalies justifies a thorough screening for other congenital anomalies in cases with PRS.

Obstructive sleep apnea is position dependent in young infants.

BACKGROUND: Obstructive sleep apnea in infants with Pierre Robin sequence is sleep-position dependent. The influence of sleep position on obstructive events is not established in other infants. METHODS: We re-evaluated ten-year pediatric sleep center data in infants aged less than six months, with polysomnography performed in different sleep positions. We excluded infants with syndromes, genetic defects, or structural anomalies. RESULTS: Comparison of breathing between supine and side sleeping positions was performed for 72 infants at the median corrected age of 4 weeks (interquartile range (IQR) 2-8 weeks). Of the infants, 74% were male, 35% were born prematurely, and 35% underwent study because of a life-threatening event or for being a SIDS sibling. Upper airway obstruction was more frequent (obstructive apnea-hypopnea index (OAHI), p < 0.001), 95th-percentile end-tidal carbon dioxide levels were higher (p = 0.004), and the work of breathing was heavier (p = 0.002) in the supine than in the side position. Median OAHI in the supine position was 8 h-1 (IQR 4-20 h-1), and in the side position was 4 h-1 (IQR 0-10 h-1). CONCLUSIONS: Obstructive upper airway events in young infants are more frequent when supine than when sleeping on the side. IMPACT: The effect of sleep position on obstructive sleep apnea is not well established in infants other than in those with Pierre Robin sequence. A tendency for upper airway obstruction is position dependent in most infants aged less than 6 months. Upper airway obstruction is more common, end-tidal carbon dioxide 95th-percentile values higher, and breathing more laborious in the supine than in the side-sleeping position. Upper airway obstruction and obstructive events have high REM sleep predominance. As part of obstructive sleep apnea treatment in young infants, side-sleeping positioning may prove useful.

The management of upper airway obstruction in Pierre Robin Sequence.

Pierre Robin Sequence (PRS) is defined by a constellation of characteristics including micrognathia, glossoptosis and airway obstruction. PRS can occur in isolation or can be associated with syndromes and another anomalies. Airway obstruction and feeding difficulties are the major presenting issues, and the severity of the condition ranges from mild, with minimal to no symptoms, to severe, with overt obstruction resulting in apnoeas, severe respiratory distress and cyanosis. The presence of airway obstruction can result in obstructive sleep apnoea and abnormalities in gas exchange, as well as exacerbation of already present feeding difficulties and failure to thrive, secondary to mismatch of caloric intake to energy usage associated with increased effort of breathing. Management of airway obstruction for infants with PRS varies between centres. This paper explores the surgical and non-surgical management options available, their effectiveness and pitfalls in children with PRS. Despite the pros and cons of each management option, it is evident that resource availability and multidisciplinary clinical support are key factors to successful management.

Differences in analysis and treatment of upper airway obstruction in Robin sequence across different countries in Europe.

The goal of this study was to explore the availability of diagnostic and treatment options for managing upper airway obstruction (UAO) in infants with Robin Sequence (RS) in Europe. Countries were divided in lower- (LHECs, i.e., PPP per capita < $4000) and higher-health expenditure countries (HHECs, i.e., PPP per capita ≥ $4000). An online survey was sent to European healthcare professionals who treat RS. The survey was designed to determine the availability of diagnostic tools such as arterial blood gas analysis (ABG), pulse oximetry, CO2 analysis, polysomnography (PSG), and sleep questionnaires, as well as to identify the used treatment options in a specific center. Responses were received from professionals of 85 centers, originating from 31 different countries. It was equally challenging to provide care for infants with RS in both LHECs and HHECs (3.67/10 versus 2.65/10, p = 0.45). Furthermore, in the LHECs, there was less access to ABG (85% versus 98%, p = 0.03), CO2 analysis (45% versus 70%, p = 0.03), and PSG (54% versus 93%, p < 0.01). There were no significant differences in the accessibility concerning pulse oximetry, sleep questionnaires, home saturation monitoring, nasopharyngeal tubes, Tuebingen plates, and mandibular distraction.    Conclusion: This study demonstrates a large difference in available care for infants with RS throughout Europe. LHECs have less access to diagnostic tools in RS when compared to HHECs. There is, however, no difference in the availability of treatment modalities between LHECs and HHECs. What is Known: • Patients with Robin sequence (RS) require complex and multidisciplinary care. They can present with moderate to severe upper airway obstruction (UAO). There exists a large variety in the use of diagnostics for both UAO treatment indications and evaluations. In most cases, conservative management of UAO in RS is sufficient. Patients with UAO that persist despite conservative management ultimately need surgical intervention. To determine which intervention is best suitable for the individual RS patient, the level of UAO needs to be determined through diagnostic testing. • There is a substantial variation among institutions across Europe for both diagnostics and treatment options in UAO. A standardized, internationally accepted protocol for the assessment and management of UAO in RS could guide healthcare professionals in the timing of assessment and indications to prevent escalation of UAO. Creating such a protocol might be a challenge, as there are large financial differences between countries in Europe (e.g., health expenditure per capita in purchasing power parity in international dollars ranges from $600 to over $8500). What is New: • There is a substantial variation in the availability of objective diagnostic tools between European countries. Arterial blood gas analysis, CO2 analysis and polysomnography are not equally accessible for lower-healthcare expenditure countries (LHECs) compared to higher-healthcare expenditure countries (HHECs). These differences are not only limited to availability; there is also a difference in quality of these diagnostic tools. Surprisingly, there is no difference in access to treatment tools between LHECs and HHECs. • There is national heterogeneity in access to tools for diagnosis and treatment of RS, which suggests centralization of health care, showing that specialized care is only available in tertiary centers. By centralization of care for RS infants, diagnostics and treatment can be optimized in the best possible way to create a uniform European protocol and ultimately equal care across Europe. Learning what is necessary for adequate monitoring could lead to better allocation of resources, which is especially important in a low-resource setting.

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.

Developmental outcome of children with Robin sequence treated with the current Paris protocol.

AIM: We aimed to investigate the developmental outcome of children with Robin sequence (RS) for whom continuous positive airway pressure was the main strategy to release upper airway obstruction. METHODS: We included children with isolated RS or RS associated with Stickler syndrome who were aged 15 months to 6 years. We used the French version of the Child Development Inventory and calculated the developmental quotient (DQ) for eight different domains and the global DQ (DQ-global). We searched for determinants of risk of delay. RESULTS: Of the 87 children, for 71%, the developmental evolution was within the norm (DQ-global ≥86 or ≥-1 SD), 29% were at high risk of delay (DQ-global <86 or <-1 SD), and only 3% were at very high risk of delay (DQ-global <70 or <-2 SD). The DQs for expressive language and language comprehension were lower in our study population than the general population, but an improvement was noticed with the children's growth. CONCLUSION: Risk of a developmental delay was not greater for children with the most severe respiratory phenotype than the others. Children whose mothers had low education levels were more at risk than the others.

Is a Difficult Airway Team Needed for Intubation at Removal of Mandibular Distraction Devices for Infants With Robin Sequence?

PURPOSE: Difficult airway teams (DATs) are typically present to assist intubation at the initial mandibular distraction osteogenesis (MDO) operation for infants with Robin sequence (RS). In some institutions, the RS diagnosis triggers a "difficult airway" label for the infant, requiring DAT presence for future operations. By the time of distractor removal, however, breathing and airway anatomy are significantly improved. The objective of this study was to measure intubation difficulty and perioperative respiratory complications at MDO device removal as a proxy for the necessity for coordination with a DAT. METHODS: This is a retrospective study including infants with RS from 2013 to 2021 who had MDO during infancy. Patients were excluded if they had a tracheostomy or MDO device failure. Predictor variables included demographic data, comorbidities, and apnea-hypopnea indices (AHIs) from pre- and immediate post-MDO polysomnograms. The primary outcome measures were number of intubation attempts, laryngoscopy grade, and perioperative respiratory events at the distractor removal operation. Descriptive statistics were computed including Fisher's exact, paired sample t-tests, and Wilcoxon rank tests, and P < .05 was considered statistically significant. RESULTS: The sample included 47 (60% male) patients with a mean age at MDO of 12.0 ± 15.7 weeks. Significant improvement in AHI was seen after MDO (pre-MDO: 26.8 ± 18.4 events/hour; post-MDO 2.78 ± 2.66 events/hour; P < .001). Average number of intubation attempts decreased from 2.09 ± 1.36 to 1.30 ± 0.75 (P < .001) and the most common post-MDO laryngoscopy grade was 1 (69%). There were no intraoperative and 2 (4%) minor postoperative respiratory events, both in patients with repaired congenital cardiac disease and not related to traumatic intubation. CONCLUSION: Neither difficult intubations nor perioperative respiratory events associated with intubation trauma were seen at distractor removal, suggesting that specialty airway assistance is not routinely needed after successful MDO. DAT presence should be determined on a case-by-case basis based on specific patient risk factors.

Can Dynamic Magnetic Resonance Images Improve Prenatal Diagnosis of Robin Sequence.

BACKGROUND: Robin sequence (RS) is a triad of micrognathia, glossoptosis, and airway obstruction. Prenatal diagnosis of RS improves delivery planning and postnatal care, but the process for prenatal diagnosis has not been refined. The purpose of this study was to determine if dynamic cine magnetic resonance imaging (MRI) can improve the reliability of prenatal diagnosis for RS compared to current static imaging techniques. MATERIALS AND METHODS: This is a retrospective cross-sectional study including fetuses with prenatal MRIs obtained in a single center from January 2014 to November 2019. Fetuses were included if they: 1) had a prenatal MRI with cine dynamic sequences of adequate quality, 2) were live born, and 3) had postnatal craniofacial evaluation to confirm RS. Patients without postnatal confirmation of their prenatal findings were excluded. The primary predictor variable was imaging type (cine or static MRI). Outcome variables were tongue and airway measurements: 1) tongue height, 2) length and width, 3) tongue shape index, 4) observation of tongue touching the posterior pharyngeal wall, and 5) measurement of oropharyngeal space. All measurements were made independently on the cine images and on static MRI sequences for the same cohort of subjects by a pediatric radiologist. Data were analyzed using paired samples t tests and Fisher exact tests, and significance was set as P < .05. RESULTS: A total of 11 patients with RS were included in the study. The smallest airway space consistently demonstrated complete collapse on the cine series compared to partial collapse on static images (0 mm vs 1.7 ± 1.4 mm, P = .002). No other imaging variable was statistically significantly different between techniques. CONCLUSIONS: Cine imaging sequences on prenatal MRI were superior to static images in discerning complete collapse of the smallest airway space, an important marker of RS. This suggests a possible benefit to adding dynamic MRI evaluation for prenatal diagnosis of this condition.

Therapeutic Management with Airway Clearance in Children with Robin Sequence and Association with Swallowing Outcomes: A Systematic Review and Meta-analysis.

Dysphagia in Robin Sequence can be present in varying degrees, requiring multidisciplinary management and specific swallowing assessment by a specialist. Most studies published to date have evaluated only respiratory outcomes, and the available evidence on the improvement of swallowing is questionable. To conduct a systematic review and meta-analysis of studies evaluating swallowing in children with Robin Sequence before and after airway clearance procedures. The research question was developed based on the PICO strategy. The literature search was performed in electronic databases and gray literature. Studies were selected by 3 independent reviewers. The risk of bias and level of evidence of the studies were assessed. A proportion meta-analysis was performed to calculate the prevalence of dysphagia after airway clearance procedures. The search identified 4938 studies, 5 of which were included. All studies had limitations in terms of design and sample size. The prevalence of dysphagia after airway clearance was obtained by analyzing treatment subgroups: mandibular distraction osteogenesis, mandibular distraction osteogenesis + tracheostomy tube, and nasopharyngeal tube. Clinical and/or instrumental assessment was assessed by a swallowing specialist. The meta-analysis was precluded by the limitations of the studies, especially regarding sample size, which affected the accuracy of the findings. Dysphagia remained unresolved in 55% of children (95% CI 1-99%). The methodological quality of the studies indicated a high risk of bias and very low level of evidence. It was not possible to confirm that airway clearance techniques used in Robin Sequence improve dysphagia.

Fetal Profile Markers for the Detection of Robin Sequence in Fetuses with Retrognathia.

OBJECTIVE: To determine whether the prefrontal space ratio (PSFR), inferior facial (IFA) and maxilla-nasion-mandible angle (MNM), and the fetal profile line (FPL) are helpful in identifying fetuses with Robin sequence (RS) in cases with isolated retrognathia, and thus better predict the likelihood of immediate need for postnatal respiratory support. METHODS: This was a retrospective matched case-control study of fetuses/infants with isolated retrognathia with or without RS receiving pre- and postnatal treatment at the University Hospital of Tübingen, Germany between 2008 and 2020. The PFSR, IFA, MNM, and FPL were measured in affected and normal fetuses according to standardized protocols. Cases were stratified into isolated retrognathia and RS. RESULTS: 21 (n=7 isolated retrognathia, n=14 RS) affected fetuses and 252 normal fetuses were included. Their median gestational age at ultrasound examination was 23.6 and 24.1 weeks, respectively. In fetuses with isolated retrognathia and RS, the PSFR, IFA, and FPL were significantly different from the normal population. At a false-positive rate of 5%, the detection rate was 76.2% for the PFSR, 85.7% for the IFA, and 90.5% for both parameters combined. However, all parameters failed to distinguish between isolated retrognathia and RS. CONCLUSION: PSFR and IFA are simple markers for identifying retrognathia prenatally. However, they are not helpful for the detection of RS in fetuses with isolated retrognathia. Therefore, delivery should take place in a center experienced with RS and potentially life-threatening airway obstruction immediately after birth.