A systematic review on the outcome of mandibular distraction osteogenesis in infants suffering Robin sequence

Preliminary study on change in the upper airway dimension in growing patients with Pierre-Robin sequence

Objective

This study aimed to evaluate the changes in upper airway (UA) dimensions in growing patients with Pierre-Robin sequence (PRS).

Methods

The subjects were 23 PRS patients who had not undergone growth modification therapy or surgical intervention. Their lateral cephalograms were obtained longitudinally at mean ages of 8.81 (T0) and 14.05 (T1). Patients were categorized based on their SNB value at T0 (Criteria: -2 SD): Group-1 (very retrusive mandible, n = 13) and Group-2 (moderately retrusive mandible, n = 10). Skeletal and UA variables at T0 and T1, as well as ΔT0-T1, were statistically analyzed.

Results

At T0, Group-1 exhibited more retrusive maxilla and mandible (SNA, P < 0.01; SNB, P < 0.001), a more hyperdivergent pattern (facial height ratio, P < 0.05), and a more posteriorly positioned hyoid bone (H-PTV, P < 0.05), while Group-1 showed larger UA spaces (superior pharyngeal airway space [SPAS] and inferior pharyngeal airway space, all P < 0.05) than Group 2, which might indicate the existence of a compensatory response to maintain the UA patency. At T1, Group-1 maintained significantly retrusive maxilla and mandible (SNA and SNB, all P < 0.01), exhibited a less anteriorly positioned tongue (TT-PTV, P < 0.05), and displayed a more obtuse soft palate angle (SPA, P < 0.05) than Group-2. Between T0 and T1, Group-1 demonstrated significant increases in the hyoid symphysis distance (ΔH-RGN, P < 0.001), tongue length (ΔTGL, P < 0.01), and pharyngeal UA spaces (ΔSPAS and ΔPNS-ad2, all P < 0.001).

Conclusions

Even in growing PRS patients with severe mandibular retrusion, the UA dimensions increased due to forward growth of the mandible, repositioning of tongue and hyoid bone, and existence of compensatory mechanism.

Cost Determinants of Mandibular Distraction Osteogenesis in Infants With Robin Sequence

Background

Robin sequence is an anomaly of micrognathia, glossoptosis, and airway obstruction. Mandibular distraction osteogenesis (MDO) performed in early infancy relieves airway obstruction and improves feeding difficulties. Though clinical outcomes data for MDO are strong, studies examining the cost drivers of the procedure are scarce.

Methods

A retrospective 10-year single-institution chart review examined medical and billing records of infants undergoing MDO at an urban tertiary care center. Data included hospital charges, patient characteristics, comorbidities/complications, intubation duration, and length of stay (LOS). Multivariate regression analysis determined significant cost contributors over the course of admission. Conclusions from this smaller sample were compared with analyses from a larger, less detailed, population-based inpatient registry using the Kids' Inpatient Database (2016 and 2019).

Results

In the single-institution analysis, 29 cases were identified with a mean age of 12 days at hospital admission. Mean postoperative and overall LOS were 19 ± 10 and 31 ± 13 days, respectively. Mean total charges were $287K-$118K. The most significant driver of total charges was floor charges (P < 0.01). LOS was a proxy for floor charges, as they were highly correlated (r = 0.98). LOS was significantly driven by intubation duration (P = 0.01). In the nationwide analysis, 165 weighted cases were identified; mean age was 2 months at hospital admission. Mechanical ventilation >96 hours was associated with increased LOS and hospitalization costs.

Conclusions

Of infants with Robin sequence undergoing MDO, the most significant driver of total charges was LOS. Intubation duration was highly associated with LOS.

Mandibular Distraction Osteogenesis in Children and Adolescents: A Clinical and Radiographic Research Using Cone-Beam Computed Tomography

AIM

The aim of this cross-sectional study was to evaluate, via cone-beam computed tomography, the long-term postoperative outcome in children treated with mandibular distraction osteogenesis.

MATERIALS AND METHODS

All young patients treated with mandibular distraction osteogenesis (MDO), during a 16-year period, at the University Department of Oral and Maxillofacial Surgery of a Pediatric Hospital, were recalled, and various clinical and radiographic parameters were recorded.

RESULTS

Eleven patients were included: 5 with hemifacial microsomia (HFM) and 6 with mandibular micrognathia. In all cases, MDO had been successful in regular follow-up and decannulation, soon after MDO, was achieved in all tracheostomy cases. The long-term result in cases of HFM was found stable, functionally and esthetically accepted, although less satisfactory than in regular follow-up; in micrognathia patients, relapse of different degrees was registered in 4 of 6 cases, without any need for tracheostomy though. Detailed and accurate information was obtained by cone-beam computed tomography (CBCT). The shape of the regenerated bone was irregular in HFM cases and relatively normal in the micrognathia cases. Quality of the regenerated bone was normal in all patients. The irregular shape registered in HFM cases did not compromise a safe orthognathic operation.

CONCLUSIONS

Distraction osteogenesis remains an early treatment choice in cases of mandibular deformities. Long-term findings showed that there is a degree of relapse with growth, which was more obvious in mandibular micrognathia cases. Computed tomography contributes to detailed evaluation of changes at the distraction site.

Growth Patterns of the Maxillomandibular Complex in Preadolescent Patients With Pierre-Robin Sequence Using Cluster Analysis and Longitudinal Follow-Up Cephalometric Data

OBJECTIVE

To investigate the growth patterns of the maxillomandibular complex in preadolescent patients with Pierre-Robin sequence (PRS).

METHODS

The samples consisted of 20 preadolescent PRS patients who had cleft palate and did not undergo growth-modification therapy or surgical intervention [6 boys and 14 girls; mean age of lateral cephalograms taken, 8.8 y (T1) and 13.7 y (T2)]. According to k-means cluster analysis, four clusters were defined over 3 major groups at T1: (1) Both very retrusive maxilla and mandible group: Cluster-4 [n=4, very large gonial angle, very low facial height ratio (FHR)] and Cluster-1 (n=5, small gonial angle, normal FHR); (2) Retrusive maxilla and very retrusive mandible group (Cluster-3, n=7, normal gonial angle, very low FHR); and (3) Both normal maxilla and mandible group (Cluster-2, n=4, very large gonial angle, low FHR). Seven angular and ratio variables [sella-nasion-A point (SNA), sella-nasion-B point (SNB), A point-nasion-B point (ANB), saddle angle, gonial angle, mandibular-body-length/anterior-cranial-base-length (MBL/ACBL), and FHR] at T1 and T2 and growth change from T1 to T2 were investigated.

RESULTS

At T1, SNA, SNB, saddle angle, gonial angle (all P<0.05), and FHR (P<0.01) showed significant difference among 4 clusters. At T2, SNA, SNB and gonial angle (all P<0.05) still showed significant difference among 4 clusters. During T1 to T2, there was no significant change in variables at each cluster except an increase in MBL/ACBL in Cluster-1 and FHR in Cluster-3 (all P<0.05).

CONCLUSIONS

Preadolescent PRS patients exhibited diverse skeletal phenotypes at T1, which did not change significantly from their original skeletal patterns by growth during T1 to T2.

Mandibulotomy Technique and Permanent Molar Injury After Mandibular Distraction Osteogenesis in Infants

OBJECTIVE

The risk that mandibular distraction osteogenesis (MDO) poses to the developing mandibular dentition is well-known; however, less is understood about how the choice of instrumentation used for mandibular osteotomy might affect the development of permanent molars.

METHODS

Retrospective chart review examining infants with micrognathia who underwent MDO from 2010 to 2018 at a single tertiary care children's hospital using external, multivector devices. The first and second permanent mandibular molars were radiographically examined years after surgery to determine whether osteotomy cutting techniques affect the risk of injury to the permanent dentition.

RESULTS

Thirty-seven infants and children underwent MDO from 2010 to 2018. Follow-up dental radiographs were available for 17 patients; 6 patients were excluded based on the use of preoperative computed tomography, utilization of virtual surgical planning technology, use of buried internal distractors, or older age at the time of distraction surgery. This yielded a total of 11 patients who underwent MDO with external hardware without virtual surgical planning representing 22 osteotomies. Sixteen osteotomies were performed using a side-cutting burr and 6 with a piezoelectric saw. The median age at distraction surgery was 3 weeks. The rate of an abnormal permanent first or second mandibular molar finding per osteotomy was 88% (14/16) in the side-cutting group versus 17% (1/6) with the piezoelectric technique (P = 0.004).

CONCLUSION

Mandibular distraction osteogenesis risks injury to the mandibular molars; however, this study suggests a significant risk reduction in molar injury if the piezoelectric device is utilized.

Complications of Mandibular Distraction Osteogenesis in Infants with Isolated Robin Sequence

Mandibular Distraction Osteogenesis (MDO) is now the preferred procedure to alleviate airway obstruction in infants with severe Robin Sequence (RS). However, there have been very few studies investigating complications related to MDO surgery performed on patients affected by isolated RS. In this study, age at distraction, weight at distraction, preoperative intubation, repeat MDO and complications associated with MDO were included as variables. Minor, moderate and major problems were evaluated and recorded as surgical site infections (SSI), injuries to the facial nerve, self-extinction hypertrophic scars, temporomandibular joint ankylosis, device failures, early ossification and fibrous non-union. One hundred and fifty one patients with isolated RS were included. At distraction, the mean age was 72 days (12-540 days) and the mean weight was 4.05 kg (2.4-12.2 kg). Only one patient needed tracheostomy after MDO, and none required further distraction. Ultimately, the complication rate was 15.23%, and there was a total of 7.95% minor, 9.27% moderate and 0% major complications. Minor incidents included surgical site infection (SSI) managed with antibiotics taken orally (n = 8), neuropraxia in the VII cranial nerve (CN) (n = 1), and hypertrophic scarring (n = 3). Incidents reported as moderate were SSIs managed with intravenous antibiotics (n = 9), incision and drainage (n = 3) and self-extubation (n = 2). There was no case of TMJ ankylosis. There were no cases of early or premature ossification, fibrous non-union and device fracture. In conclusion, MDO is an effective and appropriate management technique for infants with isolated RS and severe airway obstruction. Infections at the surgery site accounted for the vast majority of the complications. Further investigations may be needed to determine the long-term consequences of MDO.

Non-Surgical Respiratory Management in Relation to Feeding and Growth in Patients with Robin Sequence; a Prospective Longitudinal Study

OBJECTIVE

To reflect upon our non-surgical respiratory management by evaluating clinical outcomes regarding airway, feeding, and growth during the first year of life in patients with Robin Sequence.

DESIGN

Prospective study.

SETTING

Sophia Children's Hospital, Rotterdam, the Netherlands.

PATIENTS/ PARTICIPANTS

36 patients with Robin Sequence who were treated between 2011 and 2021.

INTERVENTIONS

Positional therapy and respiratory support.

MAIN OUTCOME MEASURE(S)

Data on respiratory outcomes included polysomnography characteristics and capillary blood gas values. Feeding outcomes were based on the requirement of additional tube feeding. Outcomes on growth were expressed as standard-deviation-scores (SDS) for weight-for-age (WFA) and height-for-age (HFA).

RESULTS

Twenty patients were treated with positional therapy (PT), whilst the other 16 patients required respiratory support. Twenty-two patients presented with non-isolated Robin Sequence (RS). During the first year of life, obstructive apnea hypopnea index decreased, oxygen levels enhanced, and capillary blood gas values improved. Eighty-six percent (31/36) experienced feeding difficulties, which completely resolved in 71% (22/31) during their first year of life. From start treatment, to stop treatment, to the age of 1 year, the SDS WFA worsened from -0.40 to -0.33 to -1.03, respectively.

CONCLUSIONS

Non-surgical respiratory treatment resulted in an improvement of respiratory outcomes to near normal during the first year of life in patients with RS. These patients often experience feeding difficulties and endure impaired weight gain up to 1 year of age, despite near normalization of breathing. The high prevalence of feeding difficulties and impaired weight for age indicate the urgency for early recognition and adequate treatment to support optimal growth.

Delayed Sublingual Edema Following Neonatal Mandibular Distraction Osteogenesis

The authors aim to report a rare sequela following neonatal mandibular distraction osteogenesis (MDO) involving delayed onset sublingual swelling. They performed a retrospective chart review of 3 patients who presented with delayed onset sublingual edema following neonatal MDO. The 3 patients presented at 2, 4, and 12 months following MDO for micrognathia secondary to Robin sequence with intermittent sublingual swelling associated with sialorrhea and feeding difficulties. There was no associated recent illness, fevers, or purulent drainage. All 3 children underwent magnetic resonance imaging which demonstrated asymmetric sublingual gland edema. The edema was located on the left sublingual gland in 2 children and was bilateral in the third. The symptoms continue to recur 25.5±3.3 months (range, 22.3-28.9) postoperatively and all are being managed conservatively. Chronic delayed onset intermittent sublingual edema is a possible long-term complication following neonatal MDO and further studies should explore the incidence and management of this finding.

Feeding Outcomes After Mandibular Distraction for Airway Obstruction in Infants

Robin sequence is a congenital issue resulting in airway obstruction, difficulty feeding, and failure to thrive. Mandibular Distraction Osteogenesis is used to improve airway obstruction in these patients, but little data exists characterizing feeding outcomes following surgery. This study aims to evaluate feeding outcomes and weight gain following mandibular distraction for airway correction in infants. A single-center retrospective chart review was conducted, and patients under 12 months old who underwent mandibular distraction between December 2015 and July 2021 were included in the study. The presence of cleft palate, distance of distraction, and polysomnography results were recorded. The primary outcomes were the length of distraction, need for nasogastric tube or G-tube at discharge, time lapsed to achieve full oral feeds, and weight gain (kilogram). Ten patients met the criteria. Of those 10 patients, 4 were syndromic, 7 had a cleft palate, and 4 had a congenital cardiac diagnosis. The average length of stay postsurgery was 28 days. Eight patients achieved full oral feeds in an average of 65.6 days. Five patients required nasogastric tube or G-tube at discharge, with 3 of these patients later transitioning to full oral feeds. All patients gained weight 3 months postsurgery with an average of 0.521 kg/mo. Patients who achieved full oral feeds gained an average of 0.549 kg/mo. Patients with supplementation gained an average of 0.454 kg/mo. All patients demonstrated improvement in airway obstruction with an average postoperative apnea hypopnea index of 1.64. Further investigation is necessary to identify challenges seen in feeding after mandibular distraction osteogenesis and improve care.

Novel Use of an Internal Distractor for Metacarpal Lengthening

BACKGROUND

In patients who have had proximal digit amputation, metacarpal distraction osteogenesis is an option to improve digital length and function. One drawback is that traditional external distraction devices are large and cumbersome; the option of a low-profile internal device is therefore appealing. Internal distractors are commonly used in craniofacial reconstruction, but use in the hand has not been reported. We describe a case series of the novel use of an internal distractor in metacarpal lengthening.

METHODS

In this single-center case series, patients who underwent metacarpal distraction by the senior author using a uniplanar internal distractor were reviewed, and indications, outcomes, and complications were analyzed.

RESULTS

There were 5 cases in 4 patients (age range: 7-33 years). Indications were traumatic amputation in 4 cases and congenital hypoplasia in 1. All were successfully distracted, with a mean final length gain of 1.3 cm (range: 1.0-1.7 mm). Mean time from device placement to consolidation was 3.5 months. Complications included activation arm site infection in 2 cases, both occurring after the distraction period, necessitating device removal before full consolidation. In these cases, the device was removed after the distraction period and replaced with a Kirschner wire for stabilization through the consolidation period.

CONCLUSIONS

Metacarpal distraction was successfully achieved with an internal distraction device. Although infection was common, it occurred after the distraction period and did not preclude length gain. We feel that this low-profile device offers advantages over cumbersome external devices typically used for metacarpal lengthening.

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.

Mandibular Distraction in Neonatal Pierre Robin Sequence: Is Immediate Extubation Both Feasible and Safe?

BACKGROUND

The timing of extubation following placement of mandibular distractors in the setting of Pierre Robin sequence is variable across institutional algorithms. Postoperative maintenance of intubation allows for an improvement in airway dimension and tongue positioning before extubation, theoretically decreasing the impact of postoperative airway edema. Maintenance of intubation, however, is not without risk. The authors analyze their institutional experience with neonatal mandibular distraction followed by immediate extubation to assess feasibility and safety profiles.

METHODS

A 4-year retrospective review of patients diagnosed with Pierre Robin sequence who underwent mandibular distraction within the first 3 months of life was performed. Patients intubated preoperatively were excluded.

RESULTS

Fifty-two patients met inclusion criteria. Thirty-eight patients (73 percent) were extubated immediately, whereas 14 patients (27 percent) remained intubated. No differences between these groups were found when comorbidities, cleft pathology, preoperative respiratory support, or grade of view on direct laryngoscopy were analyzed. Case duration greater than 120 minutes, operation start time after 3 pm, and the subjective designation of a difficult airway by the anesthesiologist were associated with maintaining intubation (p < 0.05). Eight patients (21 percent) in the extubated group required an increase in respiratory support in the postoperative interval. Four of these patients (11 percent) required reintubation. Increased postoperative respiratory support was more likely in patients with certain comorbidities and higher preoperative respiratory support requirements (p < 0.05).

CONCLUSIONS

The authors' data suggest that immediate extubation following neonatal mandibular distraction is feasible in patients who are not intubated preoperatively. Careful consideration should be given to patients who require significant respiratory support preoperatively and in those with certain comorbidities.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Mandibular Distraction Osteogenesis in Robin Sequence Using Three-Dimensional Analysis and Planning

SUMMARY

The optimal management of patients with Robin sequence may include neonatal mandibular distraction osteogenesis, which has been used to achieve excellent functional and aesthetic outcomes in appropriate patients. This article and video vignette depict the treatment of micrognathia and airway obstruction secondary to Robin sequence, demonstrating the planning and surgical approach of the senior author (D.M.S.) using mandibular distraction osteogenesis.

Mandibular distraction to correct severe non-isolated mandibular hypoplasia: The role of drug-induced sleep endoscopy (DISE) in decision making

OBJECTIVES

In patients with mandibular hypoplasia, mandibular distraction osteogenesis (MDO) aims to relieve tongue-based airway obstruction. Drug-induced sleep endoscopy (DISE) provides a dynamic assessment of the upper airway and visualizes anatomical site and cause of airway obstruction. The aim of this study was to evaluate the effect of MDO on tongue-based airway obstruction found by DISE within a non-isolated patient population with severe upper airway obstruction (UAO). Furthermore, we aimed to assess the additional value of DISE in clinical decision making by correlating DISE findings to functional airway outcomes after MDO.

METHODS

Findings on DISE in children who underwent MDO were retrospectively gathered and evaluated. According to DISE findings, severity of tongue-based obstruction was scored using a 4-step classification similar to the one that is used by Bravo et al.. Intubation conditions were scored according to the Cormack Lehane score (CLS). Pre-and postoperative DISE findings were compared and correlated with functional airway outcomes following MDO.

RESULTS

In 19 out of 28 MDO procedures, both a pre-and postoperative DISE was available. Tongue-based obstruction scores improved in 13 procedures, which correlated to a functional improvement in seven. Postoperative tongue-based obstruction differed significantly between patients with successful MDO and patients treated unsuccessfully (2.00 ((Interquartile range (IQR) 1.00-2.00) vs. 3.00 (IQR 2.00-4.00), p = 0.028), whereas this difference was not significant for the CLS (1.00 (IQR 1.00-1.50) vs. 2.00 (IQR 1.00-4.00), p = 0.066). If no improvement of tongue-based obstruction was seen, MDO is very unlikely to be successful on the functional airway.

CONCLUSIONS

DISE provides information on the site and nature of airway obstruction and can visualize the effect of MDO on the severity of tongue-based airway obstruction. Therefore, it can be of additional value in understanding the differences in functional airway outcomes after MDO and aids in deciding appropriate and targeted treatment. Hence, standardized use of DISE, in addition to the clinical assessment of mandibular position and a polysomnography, during MDO management is highly recommended.

Advantages and disadvantages of mandibular distraction in Robin sequence

Robin sequence (RS) is diagnosed in infants born with micrognathia, glossoptosis and varying degrees of upper airway obstruction (UAO). Due to the variable levels of hypoxia, severe breathing and feeding problems can occur. Treatment is determined by clinical severity, ranging from conservative interventions for mild cases to surgical interventions for severe cases. Mandibular distraction osteogenesis (MDO) is a surgical technique that gradually lengthens the mandible after an osteotomy by using an internal or external distraction device, directly correcting the micrognathia. This review will focus on advantages and disadvantages of mandibular distraction in infants with RS.

The Safety and Efficacy of Mandibular Distraction Osteogenesis Among Infants Less Than 3 kg

OBJECTIVES/HYPOTHESIS

Mandibular distraction osteogenesis (MDO) is a safe and effective surgery to address respiratory and feeding issues due to micrognathia in patients with Robin Sequence (RS). Previous studies examining postoperative complications in neonates receiving MDO have considered 4 kg as the cut-off for low weight; however, an increasing number of MDO interventions are performed in infants <4 kg. To determine if a weight <3 kg at time of MDO is a risk factor for postoperative complications or need for subsequent tracheostomy or gastrostomy tube (G-tube).

STUDY DESIGN

Retrospective chart review.

METHODS

A retrospective review of all infants <6 months of age undergoing MDO at two tertiary pediatric hospitals from 2008 to 2018. Demographic data, syndromic status, weight, and age at time of surgery, length of postoperative hospital stay, and postoperative outcomes were recorded including tracheostomy placement, G-tube placement, hardware infection, reintubation, facial/marginal mandibular nerve damage, and need for revision MDO.

RESULTS

Sixty-nine patients with RS were included. The mean age at MDO was 25 ± 20 days and mean weight was 3.32 ± 0.44 kg. There was no statistically significant correlation between weight (P = .699) or age (P = .422) and unfavorable postoperative outcomes. No patients (0%) underwent tracheostomy pre-MDO. Two patients (2.9%) required tracheostomy postsurgery; neither was <3 kg. Eight patients (11.6%) required a G-tube postoperatively.

CONCLUSION

Newborns <3 kg who undergo MDO experience the same rates of success and complication as larger infants, suggesting that MDO is a safe and efficacious procedure in infants less than 3 kg. Laryngoscope, 2021.

Characterization of phenotypes and predominant skeletodental patterns in pre-adolescent patients with Pierre-Robin sequence

Objective

To investigate the phenotypes and predominant skeletodental pattern in pre-adolescent patients with Pierre–Robin sequence (PRS).

Methods

The samples consisted of 26 Korean pre-adolescent PRS patients (11 boys and 15 girls; mean age at the investigation, 9.20 years) treated at the Department of Orthodontics, Seoul National University Dental Hospital between 1998 and 2019. Dental phenotypes, oral manifestation, cephalometric variables, and associated anomalies were investigated and statistically analyzed.

Results

Congenitally missing teeth (CMT) were found in 34.6% of the patients (n = 9/26, 20 teeth, 2.22 teeth per patient) with 55.5% (n = 5/9) exhibiting bilaterally symmetric missing pattern. The mandibular incisors were the most common CMT (n = 11/20). Predominant skeletodental patterns included Class II relationship (57.7%), posteriorly positioned maxilla (76.9%) and mandible (92.3%), hyper-divergent pattern (92.3%), high gonial angle (65.4%), small mandibular body length to anterior cranial base ratio (65.4%), linguoversion of the maxillary incisors (76.9%), and linguoversion of the mandibular incisors (80.8%). Incomplete cleft palate (CP) of hard palate with complete CP of soft palate (61.5%) was the most frequently observed, followed by complete CP of hard and soft palate (19.2%) and CP of soft palate (19.2%) (p < 0.05). However, CP severity did not show a significant correlation with any cephalometric variables except incisor mandibular plane angle (p < 0.05). Five craniofacial and 15 extra-craniofacial anomalies were observed (53.8% patients); this implicated the need of routine screening.

Conclusions

The results might provide primary data for individualized diagnosis and treatment planning for pre-adolescent PRS patients despite a single institution-based data.

Device Malfunction Associated With Mandibular Distraction for Infants With Robin Sequence

INTRODUCTION

Mandibular distraction osteogenesis (MDO) effectively treats upper airway obstruction (UAO) in young patients with Robin sequence (RS). The most commonly used MDO devices have internal and external components that require manual activation. Although complications associated with MDO in infants with RS have been well documented, hardware/device malfunction has not been precisely described. The present study reports the authors' recent experiences with such problems, in an effort to shed light on these complications and identify potential steps to mitigate future related issues.

DESIGN

The authors reviewed a prospectively gathered database to identify all young children under the age of 3 years who underwent MDO using buried internal devices for UAO associated with grade 3 RS from March 2007 to September 2019. We specifically focused on complications attributable to the hardware itself.

RESULTS

Nineteen patients with 40 devices met inclusion criteria. The median age at MDO was 2.3 months (interquartile range 1.4-6.3 months). Intraoperative activation of all devices under direct vision resulted in satisfactory distraction. Four devices (10.5%) developed postoperative complications directly related to the device, including break down of component parts (N = 3) and failure to maintain distraction distance (N = 1). Two patients required surgical replacement of one device each, whereas the remaining complications occurred during the consolidation phase and did not require intervention.

CONCLUSIONS

This report documents a series of device/hardware malfunction in infants and young children undergoing MDO for severe UAO associated with RS. Despite rigorous testing and development, these devices may fail, resulting in patient morbidity.

Robin Sequence: Neonatal Mandibular Distraction

Pierre Robin sequence is defined by the clinical triad: mandibular hypoplasia, glossoptosis, and airway obstruction. Mandibular distraction osteogenesis (MDO) is a standard treatment of Robin sequence associated with severe airway obstruction and is the only intervention that directly corrects the underlying anatomic pathologic condition. Compared with tongue-lip adhesion, MDO has demonstrated more success in treating airway obstruction in infants with Pierre Robin sequence, including patients with syndromic diagnoses and concomitant anomalies. This article provides a current, comprehensive review of neonatal mandibular distraction and offers treatment guidelines based on a combined surgical experience of more than 400 patients.

Optimal duration of mechanical ventilation and influencing factors following mandibular distraction osteogenesis in infants with Pierre Robin sequence

Mandibular distraction osteogenesis (MDO) is an effective treatment for tongue-based airway obstruction in infants with severe Pierre Robin sequence (PRS). Most infants receiving MDO require postoperative mechanical ventilation (MV) to assist breathing. Optimal MV time for each individual patient and factors influencing the time must be identified to guide clinical decision-making.A retrospective analysis was performed on 75 infants with PRS receiving MDO from November 2016 to August 2018. Twenty-six were females and 47 were males. Data extracted from the hospital information system included sex, age, weight, history of preterm labor, preoperative pulmonary infection, laryngomalacia/tracheomalacia, laryngoscope exposure classification, anesthesia duration, operation duration, postoperative treatment site, situation of distraction, postoperative complications and MV duration. Statistical analyses were conducted to investigate the potential associations of these factors with MV time.Seventy-three PRS syndrome patients received anesthesia for MDO device procedures were considered eligible for study. Patient sex, history of preterm labor, preoperative pulmonary infection, laryngomalacia/tracheomalacia, laryngoscopy exposure difficulty, postoperative treatment site (neonatal or pediatric intensive care unit), ventilator-associated pneumonia, age, weight, anesthesia duration, and operation duration had no significant influence on postsurgical MV time (P > .05). Amount of distraction at the time of extubation had statistically significant influence on postoperative MV time (P < .05). In addition, scatter plots revealed linear relationships between postoperative MV time and amount of distraction at extubation.According to this analysis, amount of distraction was associated with MV time following MDO for severe PRS and roughly 6 days post-surgery is a generally safe extubation time.

Three-dimensional printing of surgical guides for mandibular distraction osteogenesis in infancy

Pierre Robin sequence (PRS) is a congenital malformation characterized by micrognathia, glossocoma, and mechanical obstruction of the upper respiratory tract. These deformities impair respiration, sleep, feeding, and swallowing, and can lead to malnutrition, stunted development, and death. Bilateral mandibular distraction osteogenesis, whereby the mandible and tongue root are extended outward, is the standard treatment to relieve upper airway obstruction in severe PRS. Accurate placement of the distraction device is essential but challenging, especially in infants, and requires the pre-operative fabrication of surgical guides based on CT images. Three-dimensional (3D) printing allows for the accurate recreation of objects from digitized models. We compared surgical efficacy and safety of bilateral mandibular distraction osteogenesis using 3D printed or traditionally fabricated surgery guides for treatment of infants with severe PRS.During the period from 2014 to 2016, 22 patients with severe PRS were treated using either traditional or 3D printed surgery guides. We compared outcome measures of operations, including intraoperative bleeding, operation time, and postoperative complications.The 3D printed surgery guide group demonstrated significantly shorter operation time (P <.05) as well as moderately shorter hospital stay and artificial ventilation time (∼1 day less). Furthermore, despite markedly younger average age of the 3D printed group (1.3 vs 3.5 months), there was no increase in postoperative complications using the 3D printed guides.Three-dimensional printed surgery guides were used successfully for bilateral mandibular traction osteogenesis, and according to several outcome, parameters demonstrated superior efficacy and safety compared to traditional guides. Further research is warranted to extend the applications of 3D printed surgical guides for craniofacial surgery.

A Single Lab Test to Aid Pierre Robin Sequence Severity Diagnosis

Objective:

The workup of patients with Pierre Robin sequence (PRS) consists of a physical examination, O2 saturation, and polysomnography to determine the severity of respiratory obstruction and need for surgery. We suggest that capillary blood gas (CBG) may be a better physiologic representation of airway obstruction and should be routinely used in the management of patients with PRS.

Design:

This is a multicenter study based on a retrospective review of medical records.

Setting:

The study was performed at tertiary care centers.

Interventions:

Patients with PRS <1 year old underwent mandibular distraction osteogenesis.

Main Outcome Measure:

Using successful treatment outcome as a reference standard, receiver operating characteristic (ROC) curve was used to determine the accuracy of the diagnostic test and values for the best sensitivity and specificity to determine the need for surgical intervention.

Results:

Of 73 patients, 48 had sporadic PRS, 23 had syndromes, 2 had micrognathia, not otherwise specified. Mandibular distraction osteogenesis was performed in 62 patients at a mean age of 39 days. The mean initial Apnea-Hypopnea Index (AHI) in nonsurgical versus surgical groups was 10 versus 31 ( P = .063), pH 7.41 versus 7.34 ( P = .003), pCO2 43 versus 56 ( P < .001), and HCO3 27 versus 30 ( P = .022). The ROC curve showed that pCO2 of 49.5 has the best specificity (100%) and sensitivity (72.6%) profile in terms of need for definitive airway.

Conclusion:

A simple CBG heel stick may better predict the physiologic effects of obstructive apnea; therefore, it should be added to the algorithm of PRS workup.

Mandibular Distraction for Micrognathia in Neonates

Pierre Robin sequence (PRS) comprises the clinical triad of micrognathia, glossoptosis, and upper airway obstruction, with a reported incidence of 0.5 to 2.1 per 10,000 live births. The mainstay of management involves prompt diagnosis of airway obstruction and airway management. The gold standard surgical intervention for management of symptomatic micrognathia is mandibular lengthening by distraction osteogenesis (MDO) to anteriorly reposition a retroflexed tongue and relieve obstruction. Although MDO is often successful in the short-term in relieving upper airway obstruction and/or avoiding the need for permanent tracheostomy, the long-term effects of MDO are not yet elucidated.

ERS statement on obstructive sleep disordered breathing in 1- to 23-month-old children

The present statement was produced by a European Respiratory Society Task Force to summarise the evidence and current practice on the diagnosis and management of obstructive sleep disordered breathing (SDB) in children aged 1-23 months. A systematic literature search was completed and 159 articles were summarised to answer clinically relevant questions. SDB is suspected when symptoms or abnormalities related to upper airway obstruction are identified. Morbidity (pulmonary hypertension, growth delay, behavioural problems) and coexisting conditions (feeding difficulties, recurrent otitis media) may be present. SDB severity is measured objectively, preferably by polysomnography, or alternatively polygraphy or nocturnal oximetry. Children with apparent upper airway obstruction during wakefulness, those with abnormal sleep study in combination with SDB symptoms (e.g. snoring) and/or conditions predisposing to SDB (e.g. mandibular hypoplasia) as well as children with SDB and complex conditions (e.g. Down syndrome, Prader-Willi syndrome) will benefit from treatment. Adenotonsillectomy and continuous positive airway pressure are the most frequently used treatment measures along with interventions targeting specific conditions (e.g. supraglottoplasty for laryngomalacia or nasopharyngeal airway for mandibular hypoplasia). Hence, obstructive SDB in children aged 1-23 months is a multifactorial disorder that requires objective assessment and treatment of all underlying abnormalities that contribute to upper airway obstruction during sleep.

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).

Growth and prevalence of feeding difficulties in children with Robin sequence: a retrospective cohort study

OBJECTIVES

In addition to breathing problems, patients with Robin sequence (RS) often encounter feeding difficulties (FD). Data regarding the occurrence of FD and possible influencing factors are scarce. The study aim was to elucidate these factors to improve treatment strategies.

MATERIAL AND METHODS

A retrospective comparative cohort study was conducted, consisting of 69 infants diagnosed with both RS and a cleft palate and 64 isolated cleft palate only (iCPO) infants. Data regarding FD, growth, and airway intervention were collected during the first 2 years of life. A systematic review of the literature was conducted to identify reported FD in RS patients.

RESULTS

RS patients had more FD (91 %) than iCPO patients (72 %; p = 0.004). Also, nasogastric (NG)-tube feeding was necessary more frequently and for a longer period (both p < 0.001). Growth was lower in RS than iCPO infants (p = 0.008) and was not affected by the kind of airway management (conservative/surgical; p = 0.178), cleft palate grade (p = 0.308), or associated disorders (p = 0.785). By contrast, surgical intervention subtype did significantly affect growth. Mean reported FD for RS in the literature is 80 % (range = 47-100 %), and 55 % (range = 11-100 %) of infants need NG-tube feeding.

CONCLUSIONS

FD is present in a large proportion of infants with RS, which indicates the need for early recognition and proper treatment to ensure optimal growth. Growth during the first 2 years of life is significantly lower in RS patients than iCPO patients, which indicates the need for careful attention and long-term follow-up.

CLINICAL RELEVANCE

This study indicates the need for early recognition and proper treatment of FD in RS to ensure optimal growth. In addition, growth needs careful attention and long-term follow-up.

Infant Mandibular Distraction for Upper Airway Obstruction: A Clinical Audit

Background:

Mandibular distraction osteogenesis (MDO) is an effective method of treating upper airway obstruction (UAO) in micrognathic infants. The short-term outcomes include relief of UAO, avoidance of tracheostomy, and prompt discharge from hospital. However, it is a significant surgical procedure with potential associated morbidities. This study describes a cohort of infants managed using MDO over a twelve-year period.

Methods:

A retrospective chart review was undertaken for children who had MDO before the age of 5 years between 2000 and 2012. This was followed by a clinical review of the same cohort specifically looking for dental anomalies, nerve injuries, and scar cosmesis.

Results:

Seventy-three children underwent MDO at a mean age of 2 months [interquartile range (IQR), 1.7–4.2] for nonsyndromic infants and 3.3 months (IQR, 2.1–7.4) for those with syndromes. Infants were discharged from hospital, on average, 15 days after procedure. After MDO, of the 9 who were previously tracheostomy dependent, 5 (56%) were decannulated within 12 months and none of the nontracheostomy-dependent children required further airway assistance. The majority of children required supplemental feeding preoperatively but, 12 months postoperatively, 97% of the nonsyndromic infants fed orally. Thirty-nine children (53%) were reviewed clinically [median age, 5.1 y (IQR, 3.9–6.5)] with 18 being syndromic. Many of the mandibular first permanent and second primary molars had developmental defects, but there was a low rate of neurosensory deficit and good scar cosmesis.

Conclusions:

This study contributes further to the evidence base underpinning the management of micrognathic infants with UAO.

Update on mandibular distraction osteogenesis

PURPOSE OF REVIEW

Mandibular distraction osteogenesis has become one of the most powerful reconstructive tools for addressing congenital lower jaw deformities. This review will focus on clinical and basic science contributions to the literature in the last year, which have shown innovations in mandibular distraction osteogenesis techniques and advances in outcomes.

RECENT FINDINGS

The longest phase of distraction is consolidation, when newly formed bone must fully heal. If consolidation could be accelerated, the length of time required for fixation would be less and complications associated with fixation devices would decline. In the last year, animal studies were conducted reporting the application of growth factors directly to distraction gaps to accelerate bone formation. Additional research in animal models showed success with the addition of bone marrow-derived mesenchymal stem cells to the distraction gap. Distraction devices are being piloted with automated, continuous formats compared with current devices that require manual activation. The use of surgical planning software programs to determine the location of osteotomies was another focus of current studies.

SUMMARY

Rates of activation can be accelerated with the addition of stem cells and growth factors to distraction sites, as could time to full consolidation. The addition of mesenchymal stem cells and deferoxamine and the use of low-intensity ultrasound during distraction are three of the most promising approaches reported in recent studies with potential for future translation from animal models. Computer-assisted presurgical planning offers added accuracy and potential time savings. Newer distraction devices using computer automation are still in preliminary phases, but show promise.

A pragmatic approach to infants with Robin sequence: a retrospective cohort study and presence of a treatment algorithm

Objectives

Initial approaches to and treatments of infants with Robin sequence (RS) is diverse and inconsistent. The care of these sometimes critically ill infants involves many different medical specialties, which can make the decision process complex and difficult. To optimize the care of infants with RS, we present our institution’s approach and a review of the current literature.

Material and methods

A retrospective cohort study was conducted among 75 infants diagnosed with RS and managed at our institution in the 1996–2012 period. Additionally, the conducted treatment regimen in this paper was discussed with recent literature describing the approach of infants with RS.

Results

Forty-four infants (59 %) were found to have been treated conservatively. A significant larger proportion of nonisolated RS infants than isolated RS infants needed surgical intervention (53 vs. 25 %, p = .014). A mandibular distraction was conducted in 24 % (n = 18) of cases, a tracheotomy in 9 % (n = 7), and a tongue–lip adhesion in 8 % (n = 6). Seventy-seven percent of all infants had received temporary nasogastric tube feeding. The literature review of 31 studies showed that initial examinations and the indications to perform a surgical intervention varied and were often not clearly described.

Conclusions

RS is a heterogenic group with a wide spectrum of associated anomalies. As a result, the decisional process is challenging, and a multidisciplinary approach to treatment is desirable. Current treatment options in literature vary, and a more uniform approach is recommended.

Clinical Relevance

We provide a comprehensive and pragmatic approach to the analysis and treatment of infants with RS, which could serve as useful guidance in other clinics.

Initial treatment and early weight gain of children with Robin Sequence in Germany: a prospective epidemiological study

BACKGROUND

To investigate birth prevalence of Robin Sequence (RS), distribution of implemented treatments and factors influencing weight gain during initial hospitalisation.

METHODS

Prospective population-based survey (August 2011-July 2013) on new hospital admissions of infants with RS in Germany. RS was defined as retrognathia/micrognathia and at least one of the following: upper airway obstruction, snoring or hypoxaemia; glossoptosis; feeding difficulties; failure to thrive; cleft palate or RS-associated syndrome. Birth prevalence was calculated using data from the National Bureau of Statistics and in-hospital weight gain evaluated by calculating differences in SD scores (SDS) for weight. Comparisons between cohorts were performed using the Wilcoxon/Kruskal-Wallis test or Fisher's exact test.

RESULTS

151 patients with RS could be verified resulting in a birth prevalence of 11.3 per 100,000 live births. Orthodontic therapy (feeding plate or pre-epiglottic baton plate, PEBP) was applied most frequently (107 infants), followed by prone positioning (97 infants). Tracheotomy was rarely performed (n=7). For 115 infants, implementation of more than one intervention was reported. Infants with serious respiratory difficulties during initial hospitalisation (n=58) showed a more pronounced decrease in SDS for weight (median (IQR) -0.81 (-1.32 to -0.26) vs -0.48 (-0.86 to 0.02); p=0.008) whereas treatment with PEBP was associated with better weight gain (SDS-difference for weight -0.37 (-1.06 to 0.02) vs -0.74 (-1.09 to -0.35); p=0.022).

CONCLUSIONS

Non-surgical management is preferred for infants with RS in Germany. The extent of upper airway obstruction seemed to influence in-hospital weight gain, while use of the PEBP was associated with improved early weight gain.

Mandibular volumetric increase following distraction osteogenesis

INTRODUCTION

Mandibular distraction osteogenesis (MDO) for the treatment of Pierre Robin sequence (PRS) enables mandibular lengthening and improves airway and feeding function. It remains unknown how the post-distracted mandibular volume compares to a normal control population. The aim of this study was to analyze mandibular volume and symmetry following bilateral MDO and compare post-distraction measurements to a non-distracted, normal age- and sex-matched control cohort.

METHODS

Demographic information and three dimensional-computed tomographic (CT) images were obtained from normal control and distracted PRS patients. Mandibular volume and symmetry indices were calculated and results statistically analyzed. P values ≤0.05 were considered statistically significant.

RESULTS

24 CT scans and 48 hemimandibles were analyzed (8 control patients: mean age = 5.6 months, 3 females; 8 distracted patients: mean age pre-distraction = 1.8 months, mean age post-distraction = 5.3 months, 3 females). No complications were encountered in the distracted group. The mean pre- and post-distraction volume in the MDO group measured 7238.1 mm(3) and 15,360.6 mm(3), respectively (P = 0.0003) and the mean percent increase in mandibular volume following distraction was 113.3%. The mean symmetry index increased after distraction from 0.91 to 0.95 (P = 0.31). Matched normal control mandibles measured 13,488.6 mm(3) versus post-distraction mandibles at 15,360.6 mm(3) (P = 0.40). Normal control and post-distraction symmetry indices were 0.99 and 0.95, respectively (P = 0.68).

CONCLUSION

Distraction resulted in a significantly increased mandibular volume and an observed preservation in mandibular symmetry. Post-distraction volume was increased compared to normal controls but remained less symmetrical.

Tracheostomy versus mandibular distraction osteogenesis in infants with Robin sequence: a comparative cost analysis

Many treatments have been described for infants with Robin sequence and severe respiratory distress, but there have not been many comparative studies of outcome and cost-effectiveness. The aim of this study was to compare the cost and complications of two common interventions - mandibular distraction osteogenesis and tracheostomy. Nine patients with isolated Robin sequence (mandibular distraction osteogenesis, n=5, and tracheostomy, n=4) were included in the analyses. Predetermined costs and complications were obtained retrospectively from medical records and by questionnaires to the parents over a 12-month period. Overall direct costs (admission to hospital, diagnostics, surgery, and homecare) were 3 times higher for tracheostomy (€105.523 compared with €33.482, p=0.02). Overall indirect costs (absence from work) were almost 5 times higher (€2.543 compared with €543, p=0.02). There was a threefold increase in overall total cost/patient (both direct and indirect) for tracheostomy (€108.057 compared with 34.016, p=0.02) and 4 times more complications were encountered. This study shows that mandibular distraction osteogenesis in infants diagnosed with Robin sequence costs significantly less and results in fewer complications than tracheostomy, and this contributes to our current knowledge about the ideal approach for infants with Robin sequence and might provide a basis for institutional protocols in the future.