Facial skeletal morphology in growing children with Pierre Robin sequence

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.

Management of cleft palate among patients with Pierre Robin sequence

Pierre Robin Sequence (PRS) is a congenital craniofacial anomaly distinguished by the presence of micrognathia, glossoptosis, and upper airway obstruction. Cleft palate occurs in over 3/4 of patients with PRS. The wide U-shape cleft and airway dysfunction create challenges in clinical management. Currently, disputes exist on the treatment protocol and prognosis of cleft palate management among patients with PRS. This review is focused on the deformity features, intervention timing, technique selection, airway support, and outcome evaluation of cleft palate among patients with PRS, aiming to provide reference to further evolution in the management of PRS-related cleft palate.

Comparison Between Treacher Collins Syndrome and Pierre Robin Sequence: A Cephalometric Study

OBJECTIVE

The aim of this study was to compare the dentoskeletal pattern of Treacher Collins syndrome (TCS) and nonsyndromic Pierre Robin sequence (PRS).

DESIGN

Retrospective.

SETTING

Single center.

PATIENTS

Eighteen patients diagnosed with TCS (Group TCS) or PRS (Group PRS) in rehabilitation treatment at a single center. Group TCS was composed of 9 patients (4 male, 5 female) with a mean age of 12.9 years (standard deviation = 4.8). Group PRS was composed of 9 patients paired by age and sex with group TCS.

MAIN OUTCOME MEASURE(S)

Cone beam computed tomography-derived cephalometric images taken before the orthodontic or the orthodontic-surgical treatment were analyzed using Dolphin Imaging (Dolphin Imaging 11.0 & Management Solutions). Variables evaluating the cranial base, the maxillary and mandibular skeletal components, maxillomandibular relationship, the vertical components and the dentoalveolar region were measured. Intergroup comparisons were performed using t tests. The significance level considered was 5%.

RESULTS

Intergroup differences in the mandible size and growth pattern were observed. Group TCS showed a smaller mandibular length (Co-Go, Co-Gn) and a higher palatal plane (SN-Palatal Plane) and mandibular plane angles (SN-Go.Gn) compared to group PRS. No differences between TCS and PRS were observed for the sagittal position of the maxilla, maxillomandibular relationship, and dental components.

CONCLUSIONS

Treacher Collins syndrome presented a decreased mandible and a more severe vertical growth pattern compared to PRS.

Quantification of Mandibular Morphology in Pierre Robin Sequence to Optimize Mandibular Distraction Osteogenesis

Background:

Mandibular distraction osteogenesis (MDO) is the primary surgical intervention to treat airway obstruction in Pierre Robin sequence (PRS). Current morphologic studies of PRS mandibles do not translate into providing airway management decisions. We compare mandibles of infants with nonsyndromic PRS to controls characterizing morphological variances relevant to distraction. We also examine how morphologic measurements and airway grades correlate with airway management.

Methods:

Patients with PRS under 2 months old were age and sex matched to controls. Demographic and perioperative data, and Cormack-Lehane airway grades were recorded. Computed tomography scans were used to generate mandibular models. Bilateral condylions, gonions, and the menton were identified. Linear and angular measurements were made. Wilcoxon rank sum and 2-sample t tests were performed.

Results:

Twenty-four patients with PRS and 24 controls were included. Seventeen patients with PRS required MDO. PRS patients had shorter ramus heights (16.7 vs 17.3 mm; P = .346) and mandibular body lengths (35.3 vs 39.3 mm; P < .001), more acute gonial angles (125.3° vs 131.3°; P < .001), and more obtuse intergonial angles (94.2° vs 80.4°; P < .001) compared to controls. No significant differences were found among patients requiring MDO versus conservative management nor among distracted patients with high versus low airway grades.

Conclusion:

Our study examines the largest and youngest PRS population to date regarding management of early airway obstruction with MDO. Our findings indicate that univector mandibular body distraction allows for normalization in nonsyndromic patients with PRS, and airway obstruction management decisions should remain clinical.

A Novel Geometric Morphometric Analytical Method for Classifying Mandibular Morphology in Infants With Isolated Pierre Robin Sequence

PURPOSE

There is a lack of uniformity in the diagnostic criteria and system for the morphologic classification of micrognathia in infants with isolated Pierre Robin sequence (IPRS). Therefore, the aim of this study was to create a morphologic classification system for IPRS-affected mandibles that may guide surgical management and osteotomy design.

PATIENTS AND METHODS

We designed and implemented a retrospective cross-sectional study. The study sample included infants with IPRS. The predictor variables included shape variables of the IPRS-affected mandibles. The outcome of interest was morphologic differences among the IPRS-affected mandibles in the infancy stage. The original coordinate data of the mandibular images were analyzed by a generalized Procrustes analysis and 2-block partial least squares analysis to identify the focal and nonfocal areas in the IPRS-affected mandibles. The original feature points were modified according to the results of 2-block partial least squares analysis. The modified feature points were further analyzed by principal component analysis, K-means cluster analysis, and canonical variate analysis to obtain a morphologic classification of the IPRS-affected mandibles.

RESULTS

One hundred fifty infants with IPRS were enrolled in this study. Principal component analysis showed that the variations among IPRS-affected mandibles were mostly in terms of the shapes of the mandibular ramus, mandibular body, and angle of the mandible. On the basis of the results of K-means cluster analysis and canonical variate analysis, the mandibles in group A3 showed characteristics such as a simply shorter mandibular body. Group B3 was adjusted to show characteristics such as a shorter mandibular body with a more obtuse mandibular angle, whereas group C3 showed characteristics such as a shorter mandibular body with a shorter mandibular ramus.

CONCLUSIONS

Our study confirmed the hypothesis that there are quantifiable morphologic differences among the IPRS-affected mandibles, and it provided a morphologic classification of the IPRS-affected mandibles that will help to promote the clinical diagnosis and treatment.

Cleft Palates and Occlusal Outcomes in Pierre Robin Sequence

Objective

To assess the dental class occlusion and lateral cephalometry of children with conservatively treated Pierre Robin sequence (PRS) and to identify associations between these findings and prepalatoplasty cleft palate measurements.

Study Design

Retrospective cohort study.

Subjects and Methods

Among 22 patients with PRS, the following data were prospectively collected: demographics and preoperative cleft palate measurements. After patients reached age 6 years, an orthodontist assessed dental occlusion class and performed a lateral cephalometric analysis. PRS cephalometric data were compared with reference population values. Bivariate logistic regression was used to test the association with malocclusion class. Results are presented as odds ratios with 95% profile likelihood confidence intervals. The association between cleft measurements and cephalometric parameters was tested with Spearman’s correlation ( rs).

Results

All 22 patients had bimaxillary hypoplasia and were prone to hyperdivergency, with a 41% rate of dental class III malocclusion. An increased anterior growth of the still retrusive mandible mostly accounts for the occurrence of the class III malocclusion in PRS (class II SNB = 74.3° vs class III SNB = 77.6°, P = .04). A larger cleft at the time of the cleft repair (mean, 11 months) was associated with increased mandibular retrusion (smaller SNB angle, rs = −0.5, P = .02).

Conclusions

The 41% rate of class III malocclusion among these conservatively treated patients needs to be considered in the choice of the initial airway approach. The future impact of early mandibular advancement will have to be determined.

Impact of early intravelar veloplasty at six months on mandibular growth in patients with Pierre Robin Sequence

Pierre Robin Sequence (PRS) combines mandible microretrognathia, asynchronism of the pharynx and tongue, glossoptosis and, in some cases, cleft palate. Its principal functional consequences are respiratory and feeding problems during the neonatal period. In this study, we focused on the impact of early closure of the cleft at six months on mandibular growth in patients with PRS. We performed a retrospective study of 15 patients followed for PRS and undergoing surgery performed by the same senior surgeon (HB) at our cleft center between 2005 and 2012. These patients underwent early closure of the cleft (at a mean age of 5.87 months) by intravelar veloplasty, as described by Sommerlad. Only one article with exploitable data analyzing facial and mandibular growth in a cephalometric study of children with PRS has been published. The children in this series, constituting the control group for our study, underwent veloplasty between the ages of 12 and 18 months, often accompanied by labioglossoplasty, and the cephalometric study was carried out between the ages of four and seven years. We compared this control group in which surgery was performed at 12-18 months with our series of children undergoing surgery at six months, in a cephalometric study based on teleradiographic profile measurements performed between the ages of four and seven years. We found that early closure of the cleft soft palate yielded results identical to those for the control group in terms of mandibular growth, without the need for labioglossopexy. Finally, early intravelar veloplasty led to early functional improvement in terms of speech and phonation.

Mandibular Catch-Up Growth in Pierre Robin Sequence: A Systematic Review

Objective:

The concept of mandibular catch-up growth is often quoted in the literature regarding Pierre Robin sequence (PRS). We endeavored to perform a systematic review of whether the literature supports this concept.

Design:

Systematic review.

Interventions:

A PubMed-based systematic review of the English literature was performed of articles objectively measuring mandibular growth or position after nonoperative management of PRS.

Main Outcome Measures:

Rate and end point of mandibular length, ramus length, gonial angle, and maxillomandibular discrepancy.

Results:

The initial search delivered 607 English-language abstracts. Of these, 16 met inclusion criteria. Eight articles evaluating 143 patients followed longitudinal patient data and therefore allowed comparison of growth rates to controls. Ten articles evaluating 228 patients presented cross-sectional data and therefore could only evaluate a single time point. Two of the 8 longitudinal studies reported faster than normal growth of mandibular length in a significant portion of their cohort. Five of 8 reported equal growth rates. One of 16 studies reported that mandibular length of patients with PRS normalized compared to controls. Two of 16 studies reported no difference in maxillomandibular discrepancy between PRS and controls, whereas 10 reported a posteriorly displaced mandible relative to the maxilla in PRS. Significant differences in control groups, patients, and age existed between studies.

Conclusions:

While the concept of catch-up growth in PRS is often quoted, a minority of objective studies suggest increased mandibular growth rates in isolated PRS. Even fewer studies suggest that the maxillomandibular discrepancy in PRS completely resolves.

Facial Growth at 5 and 10 Years After Veau-Wardill-Kilner Versus Minimal-Incision Technique Repair of Isolated Cleft Palate

OBJECTIVE

To compare the Veau-Wardill-Kilner technique with the Minimal-Incision technique repair of isolated clefts of the hard and soft palate regarding facial growth at 5 and 10 years of age.

DESIGN

Retrospective study of lateral cephalograms.

SETTING

Hospital and university based.

PATIENTS

A consecutive series of 145 Caucasian nonsyndromic children born with isolated cleft palate between 1980 and 1996 were studied. Children with Pierre Robin sequence (PRS) were included in the study. The patients were divided into 4 groups: 2 groups regarding surgical technique and 2 groups regarding cleft length.

INTERVENTION

Veau-Wardill-Kilner or Minimal-Incision palatoplasty.

MAIN OUTCOME MEASURES

Eleven skeletal and 1 soft tissue measurement were evaluated from lateral cephalograms taken at 5 and 10 years of age.

RESULTS

Only minor differences in cephalometric morphology were found between the Veau-Wardill-Kilner technique group and the Minimal-Incision technique group. Similar results were found independent of cleft length or the inclusion of PRS in the sample.

CONCLUSION

The craniofacial cephalometric morphology at 5 and 10 years of age in patients with isolated cleft palate is similar between the Veau-Wardill-Kilner and the Minimal-Incision technique group.

Pediatric Obstructive Sleep Apnea: Consensus, Controversy, and Craniofacial Considerations

Pediatric obstructive sleep apnea, characterized by partial or complete obstruction of the upper airway during sleep, is associated with multiple adverse neurodevelopmental and cardiometabolic consequences. It is common in healthy children and occurs with a higher incidence among infants and children with craniofacial anomalies. Although soft-tissue hypertrophy is the most common cause, interplay between soft tissue and bone structure in children with craniofacial differences may also contribute to upper airway obstruction. Snoring and work of breathing are poor predictors of obstructive sleep apnea, and the gold standard for diagnosis is overnight polysomnography. Most healthy children respond favorably to adenotonsillectomy as first-line treatment, but 20 percent of children have obstructive sleep apnea refractory to adenotonsillectomy and may benefit from positive airway pressure, medical therapy, orthodontics, craniofacial surgery, or combined interventions. For children with impairment of facial skeletal growth or craniofacial anomalies, rapid maxillary expansion, midface distraction, and mandibular distraction have all been demonstrated to have therapeutic value and may significantly improve a child's respiratory status. This Special Topic article reviews current theories regarding the underlying pathophysiology of pediatric sleep apnea, summarizes standards for diagnosis and management, and discusses treatments in need of further investigation, including orthodontic and craniofacial interventions. To provide an overview of the spectrum of disease and treatment options available, a deliberately broad approach is taken that incorporates data for both healthy children and children with craniofacial anomalies.

Upper Airway Computed Tomography Measures and Receipt of Tracheotomy in Infants With Robin Sequence

IMPORTANCE

Airway management in infants with Robin sequence is challenging. Objective upper airway measures associated with severe airway compromise requiring tracheotomy are needed to guide decision making.

OBJECTIVES

To define objective upper airway measures in infants with Robin sequence from craniofacial computed tomography (CT) and to identify those measures in Robin sequence associated with tracheotomy.

DESIGN, SETTING, AND PARTICIPANTS

A cohort study (2003 to 2014, over 1-year follow-up) of 37 infants with Robin sequence evaluated for surgical management and 37 selected age- and sex-matched controls without a craniofacial condition conducted in a pediatric institution's craniofacial center.

MAIN OUTCOMES AND MEASURES

Define and compare CT-generated upper airway measures in these groups: infants with Robin sequence vs controls, and infants with Robin sequence with vs without tracheotomy. A negative difference signifies lower values for the Robin sequence and tracheotomy groups. Clinical data collected included age and height at time of CT scan, sex, tracheotomy presence, associated syndrome, and laboratory indicators of hypoventilation and hypoxemia. To evaluate interrater reliability, 2 raters performed each measurement in the Robin sequence group.

RESULTS

In 74 infants, 17 of 28 measures were different between infants with Robin sequence and those in the control group. Tracheotomy was performed in 14 of 37 (38%) infants with Robin sequence. Infants with tracheotomy more commonly had associated syndromes (12 of 14 [86%] vs 11 of 23 [48%]) and a history of hypoventilation and hypoxemia (13 of 14 [93%] vs 15 of 23 [65%]). Five of the 11 measures associated with tracheotomy were reliable and simpler to measure with the following mean differences (95% CIs) between groups: tongue length, 0.87 (0.26 to 1.48); tongue position relative to palate, 0.83 (0.22 to 1.45); mandibular total length, -0.8 (-1.42 to -0.19); gonial angle, 0.71 (0.08 to 1.34); and inferior pogonial angle, 0.66 (0.02 to 1.29). Using a receiver operating characteristic analysis, a composite score of these 5 measures for predicting tracheotomy risk yielded an area under the curve of 0.83 and achieved 86% sensitivity and 74% specificity.

CONCLUSIONS AND RELEVANCE

Computed tomography measures quantifying tongue position and mandibular configuration can identify infants with Robin sequence, and importantly, differentiate those who have severe upper airway compromise requiring tracheotomy. Following validation, these measures can be used for objective upper airway assessment and for expediting clinical decision-making in these challenging cases for which no such tools currently exist.

Neonatal Mandibular Distraction Osteogenesis Reduces Cleft Palate Width and Lengthens Soft Palate, Influencing Palatoplasty in Patients With Pierre Robin Sequence

The aim of this study was to evaluate the influence of neonatal mandibular distraction osteogenesis (MDO) on cleft dimensions and on early palatoplasty outcomes in patients with Pierre Robin Sequence (PRS). In a prospective cohort study that enrolled 24 nonsyndromic patients with PRS, 12 submitted to the MDO group and 12 patients not treated (non-MDO group), the authors compared patients for cleft palate dimensions through 7 morphometric measurements at the moment of palatoplasty and for early palatoplasty outcomes. At palatoplasty, the MDO group presented a significant shorter distance between the posterior nasal spines (PNS-PNS, P < 0.001) and between uvular bases (UB-UB, P < 0.001), representing a reduction in cleft palate width. They also had significant soft palate lengthening represented by a larger distance between UB and retromolar space (UB-RM, P < 0.001) and UB and PNS (UB-PNS, P = 0.014). Their UB moved away from the posterior wall of the nasopharynx (UB-NPH, P < 0.001). The MDO group had a length of operative time significantly shorter (P < 0.001) and no early palatoplasty complications compared with the non-MDO group. In conclusion, MDO acted as an orthopedic procedure that reduced cleft palate width and elongated the soft palate in patients with PRS. These modifications enabled a reduction of around 11% in the length of operative time of palatoplasty (P < 0.001).

Analysis of the Relationship Between Micrognathia and Cleft Palate: A Systematic Review

Objective To gather data from relevant experimental and observational studies to determine the relationship between micrognathia and cleft palate. The goal is to raise awareness and motivate clinicians to consider the cause and effect relationship when confronted with patients with cleft palate, even if there is no clearly noticeable mandibular abnormality. Design Several electronic databases were systematically examined to find articles for this review, using search terms including "cleft palate," "micrognathia," "tongue," and "airway obstruction." PubMed was the source of all the articles chosen to be included. Exclusion criteria included case reports, articles focused on treatment options, and articles only tangentially related to cleft palate and/or micrognathia. Results A total of 930 articles were screened for relevance, and 82 articles were chosen for further analysis. Evidence gathered in this review includes a variety of etiological factors that are causative or associated with both micrognathia and cleft palate. Observational studies relating the two abnormalities are also included. Much of the included literature recognizes a cause-and-effect relationship between micrognathia and cleft palate. Conclusion On the basis of the published data, we suggest that micrognathia does induce cleft palate in humans and animals. With knowledge of this causative relationship, clinicians should consider the importance of gathering cephalometric data on the mandibles and tongues of patients presenting with isolated cleft palate to determine whether they have micrognathia as well. With more data, patterns may emerge that could give insight into the complex etiology of nonsyndromic cleft palate.

Assessment of speech nasality in children with Robin Sequence

PURPOSE: To report the outcomes of primary palatoplasty in Robin Sequence (RS); to verify the relationship between modalities of assessment of nasality; to compare nasality between techniques at palatoplasty. METHODS: This study involved the identification of hypernasality in four modalities: live assessment with 4-point scale; live assessment with cul-de-sac test; multiple listeners' ratings of recorded phrase; nasometric assessment. Live ratings of speech nasality and nasalance scores were retrieved from charts, while a recorded phrase was rated by listeners for occurrence of hypernasality. Agreement between the modalities was established as well as association between nasality, nasal turbulence and age at surgery and at assessment. Fisher's exact test was used to compare findings between surgical techniques. RESULTS: Agreement between nasalance, live assessment with 4-point scale, live assessment with cul-de-sac, and multiple listeners' ratings of recorded samples ranged between reasonable (0.32) and perfect (1.00). Percentage occurrence of hypernasality varied largely between assessment modalities. Mean occurrence of hypernasality was lower for the group submitted to Furlow technique (26%) than the group that received von Langenbeck technique (53%). Only findings obtained live were statistically significant (scale: p=0.012; cul-de-sac: p<0.001). Listeners identified nasal turbulence for 22 (32%) samples out of the 69 recordings, and an association was found between hypernasality and nasal turbulence. CONCLUSION: Lower occurrence of hypernasality was identified for patients with RS in Furlow group. Identification of hypernasality varied largely among the four assessment modalities.

Robin sequence: from diagnosis to development of an effective management plan

The triad of micrognathia, glossoptosis, and resultant airway obstruction is known as Robin sequence (RS). Although RS is a well-recognized clinical entity, there is wide variability in the diagnosis and care of children born with RS. Systematic evaluations of treatments and clinical outcomes for children with RS are lacking despite the advances in clinical care over the past 20 years. We explore the pathogenesis, developmental and genetic models, morphology, and syndromes and malformations associated with RS. Current classification systems for RS do not account for the heterogeneity among infants with RS, and they do not allow for prediction of the optimal management course for an individual child. Although upper airway obstruction for some infants with RS can be treated adequately with positioning, other children may require a tracheostomy. Care must be customized for each patient with RS, and health care providers must understand the anatomy and mechanism of airway obstruction to develop an individualized treatment plan to improve breathing and achieve optimal growth and development. In this article we provide a comprehensive overview of evaluation strategies and therapeutic options for children born with RS. We also propose a conceptual treatment protocol to guide the provider who is caring for a child with RS.