Long-Term Results of Mandibular Distraction Osteogenesis with a Resorbable Device in Infants with Robin Sequence: Effects on Developing Molars and Mandibular Growth

Mandibular distraction osteogenesis in children with Pierre Robin sequence: long-term analysis of teeth and jaw growth

Treatment of children with Pierre Robin sequence (PRS) having a hypoplastic mandible and upper airway distress after birth may consist of external distraction devices. Shape anomalies of the permanent molars and positional changes due to surgery have been documented. The aim of this study is to compare the long-term effects (>5 years) on the growth pattern of PRS-patients treated with an external mandibular distraction device with no-surgery cases and to investigate the dental development or damage. A retrospective cohort study was performed. PRS-patients with and without surgery were included. A digital cephalometric analysis was made to evaluate the growth pattern of the mandible between groups as well as with normal values. Nine of 19 patients underwent an external mandibular distraction. All children were extubated after 4-5 days with no signs of respiratory distress. Screw and device loosening presented in one patient. The articular and sellar angles were significantly larger and smaller, respectively, in the Surgery group. Mandibular distraction surgery might result in a 'growth boost' compared to the No-surgery group. No significant difference in dental development was found. Mandibular distraction osteogenesis is an effective way of relieving severe upper airway obstruction.

Minimally-invasive airway management and early cleft palate repair in infants born with Robin sequence

The objective of this study was to report outcomes of early cleft palate repair in infants born with Robin sequence (RS). A retrospective case series in a tertiary referral paediatric hospital was carried out, examining a consecutive series of 69 infants born with RS and cleft palate. A minimally invasive approach was taken to upper airway obstruction, with liberal nasopharyngeal airway (NPA) and non-invasive ventilation (NIV) use, guided by sleep studies. The palate was repaired between 6 and 9 months with a modified Malek technique. The most frequently used airway adjunct (59.4% of patients) was an NPA and the median duration of use was 5.6 months. All patients underwent a modified Malek cleft palate repair at a median of 7 months of age. Overnight oximetry demonstrated higher mean oxygen saturation (SpO2) across the group from initial neonatal admission to discharge (median 96.5% (interquartile range [IQR] 95-98%) vs 97.45% (IQR 96.5-98%) (P = 0.2, N = 34). Of those with a cardiorespiratory polysomnogram, the obstructive apnoea-hypopnea index (OAHI) was significantly lower postoperatively (5.9 vs 2.8, P = 0.028). This study supports the use of non-surgical airway strategies and early cleft palate repair in infants born with RS and cleft palate.

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.

Prospective Evaluation of Children with Robin Sequence following Tübingen Palatal Plate Therapy

BACKGROUND

To assess the long-term functional orthodontic outcome of the Tübingen palatal plate (TPP) in children with Robin sequence (RS) in comparison to age- and sex-matched healthy controls.

METHODS

Between 09/2019 and 10/2020, we performed orthodontic assessments in 41 children at our Department of Orthodontics. Included were patients with RS (17 non-syndromic; four syndromic) and healthy controls (n = 22, average age in both groups 9.9 y). Facial analyses of 2D images, digital study casts and cephalometric measurements were made.

RESULTS

The orthodontic examinations showed no statistically significant group differences regarding functional extraoral, intraoral and pharyngeal parameters, or in skeletal patterns. The relationship between the upper and lower incisors was significantly increased (overjet 4 (2-10) vs. 3 (0-9) mm; p = 0.01) with a significant deficit in the lower face proportions (Jaw Index 4.15 (1.9-9.6) vs. 2.98 (0-9); p = 0.02; Facial convexity angle 157 (149-173) vs. 159 (149-170); p = 0.01).

CONCLUSION

Children with RS treated with the TPP showed normal long-term functional orthodontic outcomes, thanks to the functional adaption of the stomatognathic system. However, soft tissue growth did not completely match skeletal growth, resulting in a more convex facial profile.

Dental outcomes after neonatal mandibular distraction

PURPOSE OF REVIEW

The aim of this study was to understand dental complications associated with neonatal mandibular distraction and subsequent dental outcomes.

RECENT FINDINGS

Dental injury is often associated with neonatal mandibular distraction osteogenesis. Newer technology offers safer techniques to minimize this risk. Long-term follow up and dental outcomes in permanent dentition are needed to better understand the actual risk associated with the procedure.

SUMMARY

Surgeons performing neonatal mandibular distraction osteogenesis need to understand the associated risks to deciduous and permanent dentition as well as techniques to mitigate this risk.

Safety of Mandibular Osteotomies in Infants with Pierre Robin Sequence: Computer-Aided Modeling to Characterize the Risks of Various Techniques

BACKGROUND

Mandibular distraction osteogenesis is effective for the correction of severe tongue-based airway obstruction in infants with Pierre Robin sequence. Involved osteotomies may damage developing tooth buds and/or the inferior alveolar nerve. The authors evaluated the theoretical safety of various osteotomy techniques to better define infantile mandibular anatomy using computer-aided modeling.

METHODS

Seven mandibular osteotomy techniques (oblique, inverted-L, multiangular, walking stick, high oblique, vertical/high inverted-L, and horizontal) were simulated using computed tomography studies from infants with Pierre Robin sequence and without other associated conditions. Software was used to manually segment the mandibular bone, inferior alveolar nerve, and tooth buds.

RESULTS

Sixty-five computed tomography scans were included, yielding 130 hemimandibles. The horizontal osteotomy pattern had significantly lower theoretical risk of tooth bud (p < 0.001) and inferior alveolar nerve involvement (p < 0.001) than all other patterns. Osteotomies with high vertical components (i.e., vertical, walking stick, and multiangular) had lower theoretical tooth bud involvement than the more proximal oblique and inverted-L osteotomies (p < 0.001). Average lingula location was measured at a point 65 percent of the mandibular width from anterior mandibular border and 63 percent of the mandibular height from the inferior mandibular border.

CONCLUSIONS

Surgical planning with computed tomography scans can help evaluate an infant's mandibular anatomy to select an osteotomy that reduces morbidity risks. Regardless of technique, tooth buds and the inferior alveolar nerve are often included in osteotomies. The lingula location in this study demonstrates a position more superior and posterior than that previously described.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

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.

Tooth Development Following Mandibular Distraction Osteogenesis in Neonates With Pierre Robin Sequence

BACKGROUND

Mandibular distraction osteogenesis is a widely utilized surgical procedure in the pediatric population for the treatment of mandibular retrognathia. Patients with congenital abnormalities may display severe mandibular hypoplasia and associated functional problems. Distraction osteogenesis is effective in alleviating airway obstruction for these patients and is performed early in life, often during the neonatal period and during infancy. However, problems in tooth development may arise as a surgical complication.

EVIDENCE REVIEW

A systematic search was conducted in PubMed and EMBASE to identify retrospective studies describing long term outcomes of mandibular distraction osteogenesis on tooth development. Each article was reviewed and relevant data were extracted, collected, and examined according to the type of dental injury, specific tooth effected, and frequency of occurrence.

RESULTS

Tooth injuries include positional change (35%), shape alteration/fracture (24%), missing tooth (15%), root injury/malformation (14%), follicle/bud perforation (9%), delayed eruption (2%), and dentigerous cyst (1%). The most commonly affected tooth is the permanent first molar, followed by the primary second molar. The least common tooth affected is the third molar.

CONCLUSIONS

Although tooth injuries exist following mandibular distraction osteogenesis in the pediatric population, the risk of pathology and major complications remain relatively low. Technological advancements in presurgical planning can be expected to continue reducing the risk of adverse effects to primary and permanent tooth development.

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.

Distraction Osteogenesis Versus Orthognathic Surgery: Demystifying Differences in Concepts, Techniques and Outcomes

Introduction

The popularity and interest evoked by orthognathic surgery and distraction osteogenesis are undisputed in the field of oral and maxillofacial surgery. However, questions regarding the individual identities of either of them with clarity in their concepts, techniques and outcomes have remained unanswered. The aim of this review is to shed light on these questions.

Methods

This review is structured as a narrative review of thirty years of literature available in the specialities of orthognathic surgery and distraction osteogenesis.

Conclusion

The authors present a review of existing literature combined with contrasting experience gained over the years in providing an overview of the merits and demerits of the two surgical techniques which will aid the clinician in justifying the use of one technique over the other.

Short-term condylar and glenoid fossa changes in infants with Pierre Robin sequence undergoing mandibular distraction osteogenesis

The purpose was to evaluate short-term changes in condylar and glenoid fossa morphology in infants with Pierre Robin sequence (PRS) undergoing early (age <4 months) mandibular distraction osteogenesis (MDO) for the management of severe airway obstruction. Computed tomography data from infants with PRS who had MDO were compared to those of age-matched control infants without facial skeletal dysmorphology. Surface/volume, linear, and angular measurements of the condyle and glenoid fossa were obtained and compared between infants with PRS and controls. Eleven infants with PRS met the inclusion criteria. There were five female and six male subjects with a mean age at the time of MDO of 41±32 days. Prior to MDO, PRS mandibles had a smaller condylar articulating surface area and volume than age-matched control mandibles, with a more laterally positioned condylar axis (P≤0.05). Following MDO, there were significant increases in condylar articulating surface area and volume, approaching those of normal controls, with further lateral translation of the condylar axis (P≤0.05). Condyle and glenoid fossa morphology is largely normalized following early MDO in infants with PRS. The condylar axis translates laterally as a result of MDO; this change is not observed with mandibular growth in infants without 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.

Neonatal Mandibular Distraction Does Not Increase Inpatient Complications

Objective:

The purpose of this study was to determine whether performing mandibular distraction osteogenesis (MDO) during the neonatal period increased inpatient complications as measured through health-care burden.

Materials and Methods:

This was a retrospective cohort study of the Kids’ Inpatient Database from 2000 to 2011. Infants receiving MDO prior to 12 months of age were included. The primary study predictor was distraction age, classified as either neonatal or non-neonatal. Secondary predictors were patient demographics, hospitalization characteristics, diagnoses, and procedures. The outcomes were the number of procedures performed, postoperative length of stay (pLOS), hospital charges, and the discharge transfer rate. Outcomes were compared between the primary predictors using χ2 and independent 2-sample t tests. Multiple linear and logistic regression models were created using clinically relevant predictors to assess the independent effect of neonatal age on each outcome.

Results:

The study sample contained 102 patients, of who 50 (49.0%) were distracted in the neonatal period. Neonatal MDO patients were more likely to have a cleft palate (86.0% vs 55.8%; P < .001) and present with feeding difficulties (38.0% vs 19.2%; P = .036) that were treated through total parenteral nutrition (26.0% vs 9.6%; P = .030) but otherwise did not have significantly different characteristics compared to non-neonatal patients. The multiple regression models confirmed that neonatal age did not influence any of the study outcomes, although other secondary predictors were found to influence the pLOS, hospital charges, and number of inpatient procedures.

Conclusions:

Neonatal MDO was not associated with increased complications. At experienced centers, neonatal status should not be considered a contraindication to treatment.

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.

The ontogeny of Robin sequence

The triad of micrognathia, glossoptosis, and concomitant airway obstruction defined as "Robin sequence" (RS) is caused by oropharyngeal developmental events constrained by a reduced stomadeal space. This sequence of abnormal embryonic development also results in an anatomical configuration that might predispose the fetus to a cleft palate. RS is heterogeneous and many different etiologies have been described including syndromic, RS-plus, and isolated forms. For an optimal diagnosis, subsequent treatment and prognosis, a thorough understanding of the embryology and pathogenesis is necessary. This manuscript provides an update about our current understanding of the development of the mandible, tongue, and palate and possible mechanisms involved in the development of RS. Additionally, we provide the reader with an up-to-date summary of the different etiologies of this phenotype and link this to the embryologic, developmental, and genetic mechanisms.

Airway Volume Simulation in Virtual Mandibular Distraction: A Cohort Study

BACKGROUND

The authors investigated the accuracy of virtual surgical planning in predicting airway volume changes after mandibular distraction in patients with Pierre Robin sequence and associated tongue-based airway obstruction.

METHODS

The authors completed a single-institution retrospective review of patients for whom virtual surgical planning was used during mandibular distraction osteogenesis for treatment of tongue-based airway obstruction. Preoperative airway volume, virtual surgical planning-predicted airway volume, and postoperative airway volume were calculated from three-dimensional computed tomographic scans using industry software. A blinded institutional radiologist also calculated pre- and post-operative airway volumes. Pre- and post-operative polysomnography was used to titrate the endpoint of mandibular lengthening.

RESULTS

Eleven patients were included in the study. Mean apnea-hypopnea index (5.42 ± 4.53 versus 44.96 ± 20.57; p < 0.001) and mean nadir oxygen saturation (70.3 ± 9.72 percent versus 82.9 ± 9.62 percent; p = 0.003) improved with mandibular distraction. There was moderate correlation between predicted and actual mandibular distraction lengths (R = 0.65; p = 0.003). There was a strong correlation between predicted and industry-calculated actual post-distraction airway volume (R = 0.99; p < 0.001). There was no significant correlation between actual mandibular distraction length and industry-calculated actual post-distraction airway volume for the entire cohort (R = 0.05; p = 0.49), but correlation approached significance by institutional calculations. No significant correlation existed between industry and institutional-calculated percentage change in post-distraction airway volume (R = 0.06; p = 0.57).

CONCLUSIONS

Predictive airway volume calculation may be an effective adjunct to determine anatomic endpoint of mandibular distraction but small sample size, operator and software variability, and patient airway morphology may confound firm conclusions. Further studies are warranted.

Outcome following Surgical Interventions for Micrognathia in Infants with Pierre Robin Sequence: A Systematic Review of the Literature

Background

Tongue-lip adhesion (TLA), mandibular distraction osteogenesis (MDO), and subperiosteal release of the floor of the mouth (SPRFM) are the most commonly performed surgical procedures to treat severe airway obstruction in infants born with Pierre Robin sequence (PRS).

Objectives

To determine the rate of failure of each type of procedure, in terms of mortality and the need for tracheostomy, and to determine what proportion of infants have significant airway obstruction postoperatively as determined by polysomnography (PSG) and compare the data by procedure type.

Method

A comprehensive literature search (1981 through June 2015) was done of the National Library of Medicine database using PubMed. Extracted data included diagnosis, type of surgery, and outcome including mortality, need for postoperative tracheostomy and details of PSG. Persistence of significant airway obstruction was defined as an apnea-hypopnea index > 15 events/h on PSG.

Results

Both mortality rate and need for tracheostomy were low for all procedures. Many studies lacked sufficient detail to identify significant airway obstruction postoperatively. In studies with sufficient data, MDO was associated with the lowest percentage of significant airway obstruction postprocedure (3.6%) compared to 50% for infants who underwent TLA. Insufficient PSG data was available for patients who were treated with SPRFM.

Conclusions

There is a paucity of objective PSG data to definitively assess postoperative airway outcomes for PRS. MDO appears to be the most effective technique based on the available PSG data. Standardized use of PSG may lead to better identification and treatment of patients at risk for suboptimal airway outcomes postoperatively.