Distraction osteogenesis as followed by CT scan in Pierre Robin sequence

Focused Investigation of Facial Nerve Dysfunction After Mandibular Distraction Osteogenesis for Robin Sequence

Facial nerve dysfunction (FND) is a well-recognized but poorly documented complication of mandibular distraction osteogenesis (MDO) for Robin sequence (RS). This study aims to document the authors' experiences with FND and identify risk factors associated with this adverse event. A retrospective review of a prospectively gathered database was performed to identify patients with RS who underwent MDO at the authors' institution from March 2016 to June 2023. The authors included all infants with at least 3 months of follow-up after device removal. Data collected included patient demographics, incidence, laterality and onset of FND, and time to resolution. Thirty-six patients met the inclusion criteria. The median age at MDO was 2.7 (interquartile range: 0.7, 129) months. The median latency, distraction, and consolidation phases were 3.0 days, 17.5 days, and 77.5 days, respectively. The median length of distraction was 19.8 (interquartile range: 11, 30) mm. Thirteen infants (36.1%) demonstrated FND. While the majority (n = 10, 27.8%) experienced temporary palsy with a mean time to resolution of 98.6 (± 124.3) days, 3 infants (8.3%) had persistent FND at a mean of 29.3 (±35.6) months after hardware removal. The majority of FND occurred during the distraction phase and involved the marginal mandibular nerve. The current study demonstrated that over 1/3 of patients with RS experience FND after MDO. Most cases of FND were transient and occurred during the active distraction phase.

Postoperative Upper Airway Volume Measurements Among Children With Craniofacial Abnormalities

OBJECTIVE

To measure postoperative airway volumes among patients with craniofacial abnormalities and compare them to normative values.

STUDY DESIGN

Retrospective, comparative study.

SETTING

Academic Medical Center.

METHODS

Retrospective analysis of imaging of children with craniofacial abnormalities treated at NYU Langone Health from January 2013 to February 2021. Upper airway volumes postcraniofacial surgery were measured using 3D processing software (Dolphin 3D, version 11.95). These values were compared with published normative values.

RESULTS

Twenty-one subjects were identified and compared to normative values. The postoperative oropharyngeal volumes were on average 43.7% smaller than the normative values (P < .001), and the total upper airway volumes were 31.6% smaller (P = .003). No significant differences were observed in the nasopharyngeal or hypopharyngeal volumes of the study cohort compared to the normative data. Among children ages 12 to 17 years (n = 13), the mean oropharyngeal volumes were 47.6% smaller than normal (P < .001), and the mean total upper airway volumes were 34.6% smaller than normal (P < .001). Among children ages 7 to 11 years (n = 8), the mean oropharyngeal volumes were 35.1% smaller than normal (P = .049), but no difference in mean total upper airway volume was observed.

CONCLUSION

In children with craniofacial anomalies, postoperative airway volumes remain lower than normative values. However, even a slight increase in airway volume can yield a substantial increase in flow rate. 3D airway evaluations are a valuable tool for surgical planning and analysis and can help with optimizing airway dynamics.

Measurement of Upper Airway Volume in Children with Craniofacial Abnormalities

OBJECTIVE(S)

Previous literature has established a high prevalence of upper airway obstruction in children with craniofacial abnormalities. This study aims to perform quantitative airway volume measurements in patients with craniofacial abnormalities and compare them to age and sex-matched controls.

METHODS

We performed a retrospective review of the records of all children with craniofacial abnormalities who underwent head-and-neck computed tomography (CT) imaging at a single tertiary-care center between 1/1/13 and 12/31/20 using the ICD-10 codes Q75.1, Q75.4, and Q87.0. These patients were then matched by age and sex to patients with isolated craniosynostosis (Q75.0). CT scans were imported into Dolphin Imaging software, and airway volumes were measured for the nasal cavity, nasopharynx, oropharynx, and hypopharynx. The primary outcome was the total airway volume, defined as the sum of these measurements.

RESULTS

Thirty subjects with craniofacial syndromes were matched to 30 patients with isolated craniosynostosis (controls). In both groups, 18 subjects (60%) were male (p = 0.99). The average ages for syndromic patients and controls were 12.1 and 12.9 months, respectively (p = 0.84). On average, the total airway volumes of syndromic patients were 25% lower than those of controls (p = 0.02). Syndromic patients had 39% smaller nasal cavity volumes (p < 0.001) and 32% smaller nasopharyngeal volumes (p < 0.01). Significant volume differences were not observed for the oropharynx or hypopharynx.

CONCLUSION

We present a unique technique to measure airway volumes in patients with craniofacial abnormalities. These findings will help practitioners to further understand the anatomy and pathophysiology of disturbed breathing in children with craniofacial syndromes.

LEVEL OF EVIDENCE

III Laryngoscope, 134:2915-2921, 2024.

Hyoid bone morphology in patients with isolated robin sequence - A case-control study utilizing 3D morphable models

Background

Abnormalities of the hyoid bone are associated with impairment of oropharyngeal functions including feeding, swallowing, and breathing. Few studies have characterized anatomic abnormalities of the hyoid in patients with Robin sequence (RS), e.g. a less mineralized and voluminous hyoid. The purpose of this study was to compare normal hyoid bone morphology and hyoid bone morphology in children with isolated RS.

Methods

Three-dimensional (3D) reconstructions of the hyoid bone were obtained from CT-imaging of children with RS and unaffected controls. A 3D morphable model was constructed using Principal Component Analysis (PCA). Partial least squares - Discriminant Analysis (PLS-DA) and multivariate analysis of variance (MANOVA) were used to characterize and compare hyoid shape differences between patients with RS and an age-matched control group.

Results

The study included 23 subjects with RS (mean age 9.8 ± 10.3 months) and 46 age-matched control samples. A less voluminous hyoid was observed for the RS group with a larger lateral divergence of the greater horns compared to controls (MANOVA, p-value<0.001). The first shape variable from the PLS-DA model showed a significant correlation for the observed variance between the two groups (Spearman R = -0.56, p-value<0.001). The control samples and 151 CT-scans of subjects up to age 4 years were used to create a 3D morphable model of normal hyoid shape variation (n = 197, mean age 22.1 ± 13.1 months). For the normal 3D morphable model, a high degree of allometric shape variation was observed along the first principal component.

Conclusions

The 3D morphable models provide a comprehensive and quantitative description of variation in normal hyoid bone morphology, and allow detection of distinct differences between patients with isolated RS and controls.

Does distraction osteogenesis improve the airway volume and quality of life of obstructive sleep apnoea patients secondary to temporomandibular joint ankylosis?

Temporomandibular joint (TMJ) ankylosis leads to mandibular micrognathia that severely collapses the upper airway causing obstructive sleep apnoea (OSA), resulting in deterioration and compromise in the quality of life (QoL) of patients. In this study, we aimed to calculate airway volume changes, apnoea-hypopnoea index (AHI), and improvement in quality of life before and after distraction osteogenesis (DO). Fourteen Patients with OSA secondary to TMJ ankylosis at a mean (SD) age of 17.5 (5.43) years were enrolled in this prospective study. Multivector mandibular distractors were used in all patients following the standard Ilizarov distraction protocol with a mean (SD) anteroposterior distraction of 16.21 (4.37) mm and a consolidation period of 116.92 (14.35) days. The patients were followed up for six months. A polysomnography test (PSG) was done to quantify AHI and a low-dose computed tomographic scan was done to calculate airway volume using Dolphin medical imaging software pre and post-DO. The QoL of the patients was calculated using the OSA-18 questionnaire. Results analysis depicted that the mean (SD) preoperative AHI was 51.44 (37.99)/h which was improved to 9.57 (9.74)/h (p = 0.001) after DO. Airway volume was calculated on Dolphin software before and after DO showed a significant improvement in airway volume by 121.12% (98.30)%. Similarly, the OSA-18 questionnaire showed significant improvement in QoL from severe to normal. This study suggested that DO increases the corpus length of the mandible, leading to an increment in airway volume, which improves the QoL.

Mandibular morphology and distraction osteogenesis vectors in patients with Robin sequence

The aims of this cohort study were to compare the mandibular morphology between patients with Robin sequence (RS) and controls, and to examine the effects of mandibular distraction osteogenesis (MDO) using different vectors. Measurements of the mandibles of 80 patients with RS and 46 controls aged< 90 days were made using computed tomography. The data were compared among isolated RS patients (n = 58), syndromic RS patients (n = 22), and controls. Patients with RS exhibited significantly shorter ramus and body lengths and larger symphyseal angles than controls (all P < 0.001). Patients with isolated RS had shorter body lengths (P < 0.001), while syndromic patients had shorter ramus and body lengths (both P < 0.001) than controls. Seventy RS patients underwent MDO. Pre-MDO (n = 37) and post-MDO (n = 29) mandibular measurements were compared between patients undergoing MDO with a vertical vector and those undergoing MDO with a horizontal vector. Polysomnography data from part of the cohort highlighted the effectiveness of both vectors. MDO with a horizontal vector conferred 11% and 36% increases in ramus and body length, respectively, while these increases were 34% and 27.5%, respectively, with a vertical vector. MDO with a vertical vector was effective in lengthening ramus and body components and should be considered in the presence of ramus hypoplasia.

Facial Nerve Dysfunction After Mandibular Distraction Osteogenesis in Patients with Robin Sequence: A Systematic Review and Meta-Analysis

OBJECTIVE

Robin Sequence (RS), characterized by micrognathia, glossoptosis, and upper airway obstruction, is an increasingly recognized diagnosis. An effective surgical intervention is mandibular distraction osteogenesis (MDO). This study analyzes published evidence regarding facial nerve dysfunction (FND) associated with MDO.

DESIGN AND SETTING

According to PRISMA guidelines, a systematic review was carried out with databases queried in June 2019 using MESH terms, or equivalent terms, as follows: "distraction osteogenesis" and "Robin Sequence". A review of original Spanish and English articles, were included. Outcome measures included the prevalence of FND; the affected branches; the rate of permanent vs. transient FND; the use of an internal vs. external device; the daily distraction rate; and finally, the overall distraction length. Subsequently, a meta-analysis was conducted to collate results regarding the prevalence of FND and the factors associated with it.

RESULTS

Of 239 unique studies identified, 19 studies with 729 patients met inclusion criteria; 52 patients developed FND after MDO. A random-effects meta-analysis yielded a pooled prevalence of FND of 6.40%, with moderately heterogeneous studies (I2 = 41%, τ2 = 0.006). Marginal mandibular nerve involvement was most commonly noted. Nine studies reported transient FND, six permanent, one both, and two unspecified. Internal distractors were used in 8 studies and external in 3 and both in 2. Distraction rate was 1.00 to 2.00 mm/day and total distraction length ranged from 13.00 to 22.3 mm. Sample size was the only parameter inversely associated with rate of FND (p = 0.04).

CONCLUSION

This analysis of FND associated with MDO for patients with RS demonstrates a lack of consistent documentation. MDO-associated FND does not appear to be uncommon, and permanent dysfunction can occur. This review underscores the importance of thorough documentation to elucidate the mechanism of FND.

Effects of mandibular distraction osteogenesis on anesthetic implications in children with hemifacial microsomia

BACKGROUND

Hemifacial microsomia (HFM) is a congenital craniofacial malformation, and its features include hypoplasia and asymmetry in skeletal tissue and soft tissue. These features are usually associated with a difficult airway. Mandibular distraction osteogenesis can achieve mandibular advancement, but its effect on the subsequent laryngoscopic views has not been adequately documented.

AIM

The aim of this study was to determine the change in laryngoscopic views after mandibular distraction osteogenesis (MDO) in children with HFM and to examine the radiological changes after MDO by using computed tomography (CT)-based three-dimensional (3-D) airway reconstruction.

METHODS

An observational prospective study was carried out in children with HFM undergoing MDO. All children underwent 3-D airway reconstruction preoperatively before the placement and removal of the distractor. The temporomandibular joint lesions in children were classified by the Pruzansky-Kaban classification. The Cormack-Lehane grade was assessed after induction under direct laryngoscopy. The relationship between difficult laryngoscopy and the Pruzansky-Kaban classification was assessed. Changes in the upper pharyngeal airway parameters and laryngoscopic views were analyzed.

RESULTS

Forty children (ages ranging from 5 to 16 years, males = 26, females = 14) with HFM underwent 80 anesthesia for MDO. The incidence of difficult laryngoscopy before mandibular distraction was 5/12 (41.7%) in type IIa, 19/24 (79.2%) in type IIb and 1/4 (25%) in type III HFM. The mean difference in the incidence of difficult laryngoscopy before and after MDO was 33.3% (95% CI: -6.7% to 73.3%), 50.0% (95% CI: 8.4% to 91.6%), and 0% for type IIa, type IIb, and type III, respectively. In type IIb, 12/19 cases of difficult laryngoscopy became easy after mandibular distraction: this was associated with an increase in the palatopharyngeal and glossopharyngeal CT parameters (p < .05). In type IIa, 5/5 cases of difficult laryngoscopy became easy after mandibular distraction, and 1/7 cases of easy laryngoscopy became difficult laryngoscopy. However, there were no significant changes in the palatopharyngeal, glossopharyngeal, and hypopharyngeal CT parameters in type IIa and type III HFM (p > .05).

CONCLUSIONS

MDO can improve the laryngoscopic views in children with HFM. According to the Pruzansky-Kaban classification, children with type IIb showed the highest incidence of difficult laryngoscopy before MDO. After MDO, the improvement in laryngoscopic views under direct laryngoscopy in type IIb was related to the increase in the palatopharyngeal and glossopharyngeal volume.

Timing and Duration of Facial Nerve Dysfunction After Mandibular Distraction Osteogenesis for Robin Sequence

Objective

Collect data from craniofacial surgeons to analyze mandibular distraction osteogenesis (MDO) protocols, and facial nerve dysfunction (FND) to characterize this common, but poorly documented complication after MDO in infants with Robin Sequence (RS).

Design, Setting, and Participants

A 16-question anonymous survey designed through REDCap was digitally distributed to members of the American Cleft Palate-Craniofacial Association and International Society of Craniofacial Surgery (ISCFS).

Main Outcome Measure(s)

Demographic information, MDO perioperative variables, surgeon experience with FND after MDO for patients with RS, and the timing and duration of FND were analyzed.

Results

Eighty-four responses were collected, with 80 included for analysis. Almost two-thirds of respondent surgeons reported FND as a complication of MDO in patients with RS (51, 63.8%); 58.8% (n   =   47) transient FND and 5% (n   =   4) with permanent facial nerve palsy only. Both transient and permanent FND was documented by 13 (16.3%) respondents. Among respondents, FND was observed immediately following initial device placement/osteotomies in 45.1%, during distraction in 45.1%, during consolidation in 19.6%, and following device removal in 43.1%. Twenty-five of these respondent surgeons reported resolution of FND between 1 and 3 months (53.2%, n   =   25).

Conclusions

FND after MDO in patients with RS was noted by most respondents in this survey study. While most surgeons noted temporary FND, one-fifth reported long-term dysfunction. FND was documented most commonly following device placement/osteotomies or during active distraction. Further research should seek to establish risk factors associated with FND and identify surgical and perioperative prevention strategies

Airway and Feeding Outcomes in Pierre Robin Sequence: A Comparison of Three Management Strategies

BACKGROUND

Controversy remains regarding optimal management of Pierre Robin sequence (PRS). The goal of this study was to compare airway and feeding outcomes in infants with PRS who underwent surgical intervention, specifically mandibular distraction osteogenesis (MDO) or tongue-lip adhesion (TLA), or who had conservative management (CM) without surgery.

METHODS

All consecutive patients treated for PRS at a pediatric academic medical center, with at least one year follow-up, were included. Patients who underwent tracheostomy as an index procedure were excluded. Patients were divided into those who underwent MDO, TLA or CM. Feeding status and data from initial and follow-up polysomnograms were collected. Comparisons between groups were made using the Kruskal-Wallis test, followed by Mann-Whitney pairwise comparison with a Bonferroni correction, when appropriate.

RESULTS

67 neonates were included. 19 underwent TLA, 29 underwent MDO and 19 underwent CM. The proportions of syndromic patients were similar between groups. Patients undergoing CM had the lowest baseline AHI (9.1), but there were no significant differences between TLA (20.1) and MDO (25.4). At follow-up, the three groups had similar mean AHI (MDO 1.3, TLA 4.2, CM 4.5). A similar proportion of patients achieved AHI 5 or less (TLA 89.5%, MDO 96.6%, CM 84.2%). At one year, there were no significant differences in weight percentiles or in risk of failure-to-thrive between groups. One patient from the TLA group required a tracheostomy.

CONCLUSION

The three treatment modalities achieved high airway and feeding success rates. All three modalities should have a place in the armamentarium of the craniofacial surgeon.

Changes in Hyoid Bone Position before and after Distraction Osteogenesis in Infants with Robin Sequence

PURPOSE

To study the changes of hyoid position in infants with Robin sequence before and after mandibular distraction osteogenesis, and to explore the related factors.

MATERIAL AND METHODS

Twenty-six infants with Robin sequence underwent bilateral mandibular distraction osteogenesis from May 2016 to April 2020. Three-dimensional computed tomography data of patients before and after surgery were analyzed with Materialise Mimics 17.0. Changes in the three-dimensional position of the hyoid bone were studied.

RESULTS

The angle between the long axis of the tongue body and hard palate plane, and the angle between the long axis of the tongue body and mandibular plane were significantly decreased after surgery than before surgery. The hyoid bone-cranial base vertical distance, hyoid bone-mental point distance, and hyoid bone-epiglottis distance were significantly increased after surgery. The differences in the above-mentioned data were statistically significant (P < 0.05). Changes in the angle between the long axis of the tongue body and the hyoid bone-mental point line correlated with changes in the position of the hyoid bone relative to the cervical spine (P = 0.006). Postoperatively, the hyoid bone moved forward and the increase in the hyoid bone-mental point osseous distance interval (41.28%) was significantly greater than the increase in the hyoid bone-epiglottis distance (18.73%). Differences in the total mandibular length and the hyoid bone-cranial base vertical distance are related to the age at the operation (P < 0.05). The younger the age at the time of surgical intervention, the greater the difference before and after surgery for the same follow-up interval.

CONCLUSIONS

The three-dimensional direction of the hyoid bone changes after the distraction osteogenesis of the mandible, and the hyoid bone moves downward and forward. Because the mandibular length and airway changed, the relative positions of the long axis of the tongue body on the sagittal plane rotated clockwise.

Dynamical Changes of Mandible and Upper Airway After Mandibular Distraction Osteogenesis in Pierre Robin Sequence

OBJECTIVE

To present the dynamical evaluation of mandible and upper airway size among Chinese infant patients following mandibular distraction osteogenesis in a short-term follow-up and compare predistraction measurements with a normal age- and sex-matched control.

METHODS

All the patients have undergone the computed tomography (CT) scan before mandibular distraction osteogenesis (T0), at the end of the distraction phase (T1), and 3 months after the end of the distraction phase before the distractor removal (T2). A CT analyzing computer software MIMICS was utilized to analyze the anatomic variables of upper airway size and mandible size. All analysis was based on a significance level of 0.05.

RESULTS

Eight patients with Pierre Robin sequence differed mainly in the mandibular body length and the minimum anteroposterior dimension of the retroglossal airway from the control. After mandibular distraction osteogenesis, the mandibular body length and the ramus height both increased significantly, the ramus height also increased after 3 months of consolidation. Only small increase in the airway dimension of the retroglossal area at T2 was observed compared with T1.

CONCLUSION

Mandibular distraction osteogenesis is an effective modality in treating Pierre Robin sequence. Compared with normal control, the main difference may be the length of mandibular body and the area of the retroglossal airway. There may not be an increase in the diameter of airway and the length of mandibular body after 3 months of growth and development in Pierre Robin sequence. Individual surgical plan should be made to gain a better prognosis.

The Reproducibility of the Jaw Index in the Measurement of Healthy Newborns

Objective:

Establish the reliability of the jaw index to objectify the relationship between the maxilla and mandible in healthy newborns.

Design:

Cohort study.

Setting:

Tertiary setting.

Patients:

A total of 52 healthy newborns were included to detect an inter and intraclass correlation coefficient (ICC) of 0.8 with a 95% confidence interval (95% CI) of width 0.3. Inclusion criteria were children born full term without respiratory or feeding problems, and without congenital malformations or facial deformities due to birth trauma. Uncooperative patients were excluded.

Interventions:

The jaw index, a measuring tool for objectifying micrognathia in children suspected of having Robin sequence, was used. An ICC of greater than 0.8 was considered clinically relevant.

Main Outcome Measure(s):

Primary outcomes are the reliability of the jaw index expressed as interclass correlation coefficient and ICC. Secondary outcomes are the mean jaw index and mean length of the mandible, maxilla, and the alveolar overjet.

Results:

An interclass correlation coefficient of 0.74 (95% CI: 0.49-0.86) and an ICC of 0.81 (95% CI: 0.66-0.89) were found. The mandible had an average length of 162.6 mm (standard deviation [SD] 11.1), the maxilla 168.7 mm (SD 9.4), the alveolar overjet 2.0 mm (SD 0.60), and the mean jaw index was 2.1 (SD 0.64).

Conclusion:

The jaw index is a consistent instrument between different observers as well as for one observer measuring consecutively in the same child, to objectify the size of the lower jaw compared to that of the upper jaw in healthy newborns.

Surgical Management and Outcomes of Pierre Robin Sequence: A Comparison of Mandibular Distraction Osteogenesis and Tongue-Lip Adhesion

There is a paucity of literature directly comparing tongue-lip adhesion versus mandibular distraction osteogenesis in surgical treatment of patients with Pierre Robin sequence. This study comprehensively reviews the literature for evaluating airway and feeding outcomes following mandibular distraction osteogenesis and tongue-lip adhesion. A search was performed using the MEDLINE and Embase databases for publications between 1960 and June of 2017. English-language, original studies subjects were included. Extracted data included prevention of tracheostomy (primary airway outcome) and ability to feed exclusively by mouth (primary feeding outcome). A total of 67 studies were included. Ninety-five percent of subjects (657 of 693) treated with mandibular distraction osteogenesis avoided tracheostomy, compared to 89% of subjects (289 of 323) treated with tongue-lip adhesion. Eighty-seven percent of subjects (323 of 370) treated with mandibular distraction osteogenesis achieved full oral feeds at latest follow-up. Seventy percent of subjects (110 of 157) treated with tongue-lip adhesion achieved full oral feeds at latest follow-up. The incidence of second intervention for recurrent obstruction ranged from 4 to 6 percent in mandibular distraction osteogenesis studies, compared to a range of 22 to 45 percent in tongue-lip adhesion studies. Variability of patient selection, surgical techniques, outcomes measurement methods, and follow-up length across studies precluded meta-analysis of the data. Both mandibular distraction osteogenesis and tongue-lip adhesion are effective alternatives to tracheostomy for patients who fail conservative management and improve feeding. Mandibular distraction osteogenesis may be superior to tongue-lip adhesion in long-term resolution of airway obstruction and avoidance of gastrostomy, but is associated with notable complications.

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).

Airway and Feeding Outcomes of Mandibular Distraction, Tongue-Lip Adhesion, and Conservative Management in Pierre Robin Sequence: A Prospective Study

BACKGROUND

Pierre Robin sequence is characterized by mandibular retrognathia and glossoptosis resulting in airway obstruction and feeding difficulties. When conservative management fails, mandibular distraction osteogenesis or tongue-lip adhesion may be required to avoid tracheostomy. The authors' goal was to prospectively evaluate the airway and feeding outcomes of their comprehensive approach to Pierre Robin sequence, which includes conservative management, mandibular distraction osteogenesis, and tongue-lip adhesion.

METHODS

A longitudinal study of newborns with Pierre Robin sequence treated at a pediatric academic medical center between 2010 and 2015 was performed. Baseline feeding and respiratory data were collected. Patients underwent conservative management if they demonstrated sustainable weight gain without tube feeds, and if their airway was stable with positioning alone. Patients who required surgery underwent tongue-lip adhesion or mandibular distraction osteogenesis based on family and surgeon preference. Postoperative airway and feeding data were collected.

RESULTS

Twenty-eight patients with Pierre Robin sequence were followed prospectively. Thirty-two percent had a syndrome. Ten underwent mandibular distraction osteogenesis, eight underwent tongue-lip adhesion, and 10 were treated conservatively. There were no differences in days to extubation or discharge, change in weight percentile, requirement for gastrostomy tube, or residual obstructive sleep apnea between the three groups. No patients required tracheostomy. The greatest reduction in apnea-hypopnea index occurred with mandibular distraction osteogenesis, followed by tongue-lip adhesion and conservative management.

CONCLUSIONS

Careful selection of which patients with Pierre Robin sequence need surgery, and of the most appropriate surgical procedure for each patient, can minimize the need for postprocedure tracheostomy. A comprehensive approach to Pierre Robin sequence that includes conservative management, mandibular distraction osteogenesis, and tongue-lip adhesion can result in excellent airway and feeding outcomes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

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.

Distraction Osteogenesis for Management of Severe OSA in Pierre Robin Sequence: An Approach to Elude Tracheostomy in Infants

BACKGROUND

Severe obstructive sleep apnoea (OSA) is a life threatening condition associated with Pierre Robin sequence (PRS) due to mandibular micrognathia and glossoptosis. Often these patients require tracheostomy at an early age which has high morbidity. Distraction osteogenesis (DO) is an accepted method of treatment for patients with hypoplastic mandible to achieve mandibular lengthening without need for a bone graft. It has also been used in respiratory distressed neonates and infants to avoid tracheostomy.

CASE REPORT

An eight month old baby, a diagnosed case of PRS with severe OSA and recurrent episodes of aspiration pneumonia and on nasogastric tube feeding since birth was referred to us for evaluation and possibility of therapeutic augmentation of the mandible by DO. After a thorough clinico-radiological assessment the child was operated for bilateral extraoral placement of horizontal corpus distractor. A total distraction of 12 mm was carried out and consolidation of callus was monitored by USG. Postoperatively the patient was followed up for 12 months. Presently she has normal respiratory and feeding function without any episode of aspiration pneumonia.

CONCLUSION

Mandibular corpus DO is a safe and effective technique that can be applied to predictably relieve severe upper airway obstruction in selected PRS cases. In order to avoid the limitations of alternative surgical procedures and the tracheostomy-associated morbidity, DO should be considered among the routine treatment modalities.

Distraction osteogenesis as a treatment of obstructive sleep apnea syndrome: A systematic review

BACKGROUND

To conduct a systematic review to answer the clinical question "What are the effectiveness of mandibular distraction osteogenesis (MDO) and its complications to treat patients with obstructive sleep apnea syndrome (OSAS)?".

METHODS

A systematic search including a computer search with specific keywords, reference list search, and manual search were done. Relevant articles on MDO were assessed and selected in 3 rounds for final review based on 5 predefined inclusion criteria and followed by a round of critical appraisal. Different types of distraction and their treatment outcomes of OSAS were recorded with standardized form and analyzed.

RESULTS

Twelve articles were included in the final review. A total of 256 patients aged 7 days to 60 years were treated with either external or internal MDO, with a mean follow-up period of 6 to 37 months. The average distraction distance of 12 to 29 mm was achieved with various distraction protocols. The success rate for adult patients was 100%, and cure rates were ranged from 82% to 100%. The definition of success or cure for OSAS in children or infants was not defined. Therefore, there were no clearly reported success or cure rates for children/infants in the included studies. However, all studies reported that these patients showed significant improvement in OSAS, with many of them who avoided tracheostomy or had the tracheostomy decannulated. The complication rates were ranged from 0% to 21.4%, with most being from local wound infections or neurosensory disturbances.

CONCLUSION

This systematic review showed that MDO was effective in resolving OSAS in adults with retrognathic mandible. MDO also showed promising results in infants or children with OSAS. From the results of this systematic review, we recommend to define the criteria of success or cure for OSAS surgery in children and infants. We also recommend setting up randomized controlled trials to compare MDO with traditional maxillomandibular advancement surgery for OSAS patients and to provide a better evidence on the success and complication rates of the techniques.

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.

The effectiveness of mandibular distraction in improving airway obstruction in the pediatric population

BACKGROUND

Distraction osteogenesis is an effective technique for elongating the deficient mandible. The authors specifically evaluated its effectiveness in the treatment of airway obstruction in pediatric patients with mandibular hypoplasia.

METHOD

A comprehensive literature review of the National Library of Medicine (PubMed) database was performed. English-language studies involving isolated distraction of the pediatric mandible (younger than 18 years) with descriptive reporting of airway changes were included. Extracted data included demographics, initial diagnosis, distractor type, distraction protocol, predistraction and postdistraction airway status, and complications.

RESULTS

Seventy-four articles met the inclusion criteria, resulting in 711 patients with craniofacial abnormalities who underwent mandibular distraction osteogenesis. Mean age at the time of distraction was 18.1 months. The most common diagnoses were isolated Pierre Robin sequence (52.9 percent), syndromic Pierre Robin sequence (7 percent), and Treacher Collins syndrome (6.8 percent). Mandibular distraction osteogenesis successfully treated airway obstruction in 89.3 percent of cases. Success was defined as either decannulation of tracheostomy, avoidance of tracheostomy or continuous positive airway pressure, or alleviation or significant improvement of obstructive sleep apnea symptoms. One hundred seventy-one (84.2 percent) of the 203 tracheostomy-dependent patients were successfully decannulated. Among the 181 patients with obstructive sleep apnea, mandibular distraction osteogenesis successfully allowed for either complete resolution or significant improvement of symptoms in 95.6 percent. A 23.8 percent overall complication rate was noted. The mean follow-up time was 28.7 months.

CONCLUSION

In addition to its positive effect on facial appearance, mandibular distraction osteogenesis is an effective procedure for the treatment of airway obstruction associated with congenital craniofacial defects involving mandibular hypoplasia in appropriately selected patients.

Mandible traction with wires for the treatment of upper airway obstruction caused by Pierre Robin sequence in Chinese infants: preliminary findings

Pierre Robin sequence (PRS) is a congenital abnormality that may cause upper airway obstruction requiring surgical intervention. This preliminary study aimed to examine the feasibility and effectiveness of mandible traction with wires for the treatment of upper airway obstruction caused by PRS in Chinese infants. Measures of interest included transcutaneous oxygen saturation before and after surgery, duration of surgery and traction, complications, and CT findings. Seven infants were included in the study (mean birth weight: 2485 g, range: 2405-2570 g); four were born preterm and three were born full term. Mean age at surgery was 13.7 days (range: 2-28 days), mean duration of surgery was 16.6 min (range: 13-25 min) and mean duration of traction was 26.6 days (range: 21-35 days). Mean follow-up was 6.2 months (range: 1-11 months). No infant experienced severe complications. All infants experienced increases in transcutaneous oxygen saturation after surgery. Mean transcutaneous oxygen saturation was 82% before surgery and 98% after surgery. Follow-up morphology of the mandible was excellent. There was no upper airway obstruction, and short-term growth and development were satisfactory. These preliminary findings suggest that mandibular traction with wires may be an effective treatment for upper airway obstruction caused by PRS in Chinese infants.

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.

The role of distraction osteogenesis in the management of craniofacial syndromes

Distraction osteogenesis (DO) has been established as a useful technique in the correction of skeletal anomalies of the long bones for several decades. However, the use of DO in the management of craniofacial deformities has been evolving over the past 20 years, with initial experience in the mandible, followed by the mid-face and subsequently, the cranium. This review aims to provide an overview of the current role of DO in the treatment of patients with craniofacial anomalies.

Early Intervention

Objective. To determine benefits of early intervention in neonates with symptomatic micrognathia who underwent bilateral mandibular distraction osteogenesis within the first 90 days of life as relates to growth, need for supportive care, and further invasive procedures.

Study Design. Case series with chart review.

Setting. Tertiary care, academic children’s hospital.

Subjects and Methods. Review of neonates with symptomatic micrognathia who underwent bilateral mandibular distraction osteogenesis in the past 5 years. Inclusion criteria included mandibular distraction osteogenesis performed within the first 90 days of life. Outcome measures included hospital course, growth curves, supportive home care needs, and airway at cleft repair.

Results. Twenty-four patients met inclusion criteria. The mean age at distraction was 30 days, and the average discharge was postoperative day 14. One patient required home oxygen, 50% were able to feed exclusively by oral diet, and no patients required tracheotomy. In addition, airway results were substantial, with 90% of patients showing objective improvement in airway grade from time of mandibular distraction to time of cleft repair.

Conclusion. We present our initial outcomes on mandibular distraction osteogenesis in neonates with symptomatic micrognathia. Early intervention allows discharge to home with minimal supportive care needs by avoiding tracheostomy and facilitating transition to oral feeds. The airway improvement is significant and is sustained and allows for easier intubation at time of cleft repair.