Mandibular Distraction Osteogenesis Research Articles

Computerized Surgical Planning for Mandibular Distraction Osteogenesis

AbstractMandibular distraction osteogenesis is a technically challenging procedure due to complex mandibular anatomy, especially in the treatment of Pierre-Robin Sequence due to variable bone thickness in the infant mandible and the presence of tooth buds. Computerized surgical planning (CSP) simplifies the procedure by preoperatively visualizing critical structures, producing cutting guides, and planning distractor placement. This paper describes the process of using CSP to plan mandibular distraction osteogenesis, including discussion of recent advances in the use of custom distractors.

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

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

Determination of mandibular distraction osteogenesis most suitable parameters. An experimental study

Determination of mandibular distraction osteogenesis most suitable parameters. An experimental study

Pre-Operative Characteristics Helping to Avoid Gastrostomy Tube After Mandibular Distraction in Neonates With Pierre-Robin Sequence: A Institutional Case-Series and Review of the Literature.

to investigate the ability of mandibular distraction osteogenesis (MDO) to avoid gastrostomy tube (G-tube). PubMed, EBSCOhost, Cochrane, and Embase. We retrospectively reviewed the number of MDO cases performed at our institution for patients with Robin Sequence (RS) over the past 10 years. In our institutional review, patients were excluded if they had a G-tube already placed at the time of surgery. We also performed a systematic review of the literature. Articles were excluded if they did not detail feeding outcomes after MDO, or if MDO was performed on patients that did not have RS. In our systematic review, 12 articles were included that comprised a total of 209 neonates with RS that underwent MDO. A total of 174 (83.3%) patients avoided a G-tube once MDO was performed. A total of 14 patients met the inclusion criteria at our institution. Of the 14 RS patients, 9 (64%) avoided having a G-tube placed and all (14/14) avoided tracheostomy. The average birth weight of patients avoiding a G-tube was 3.11 kg compared to 2.25 kg (P = .045) in the group requiring a G-tube. In the group avoiding a G-tube, the average weight at time of operation was 3.46 kg compared to 2.83 kg (P = .037) in the group requiring a G-tube. MDO may be considered as a surgical option to prevent G-tube placement for neonates with non-syndromic RS who have difficulty with PO feeding but whose airway obstruction is not severe enough to require respiratory support. Based on our institutional experience, a minimum weight of 3.00 kg correlated with higher success rates of PO intake and avoiding a G-tube.

Impact of upper airway obstruction management in Robin Sequence on need for myringotomy tubes

ObjectiveInvestigate an association between upper airway obstruction (UAO) management in Robin Sequence (RS) and need for bilateral myringotomy and tubes (BMT). MethodsRetrospective chart review of RS patients treated at a tertiary free-standing pediatric hospital from 1995 to 2020 was performed. Patients were grouped based on airway management: conservative, tracheostomy, tongue-lip adhesion (TLA), and mandibular distraction osteogenesis (MDO). Demographic data, cleft palate (CP) association, numbers of BMT and ear infections, and audiogram data including tympanograms were collected. One-way ANOVA and Chi-square/Fisher's exact tests were used to compare continuous and categorical data, respectively. Multivariable regression analysis was used to compare BMT rates between treatment groups. ResultsOne hundred forty-eight patients were included, 70.3 % of which had CP. Most patients (67.6 %) had at least one BMT; 29.1 % required two or more BMT. The rate of BMT was higher in patients with CP compared to those with intact palates (p = 0.003; 95 % CI 1.30–3.57) and those treated with tracheostomy (p = 0.043; 95 % CI 1.01, 2.27). Surgically managed patients were more likely to have hearing loss (67.5 % vs. 35.3 %, p = 0.017) and ear infections (42.1 % vs. 20.0 %, p = 0.014) pre-compared to post-procedure for airway management. ConclusionMost RS patients require at least 1 set of BMT. Those with CP and/or treated with tracheostomy had a higher likelihood of needing BMT. Rate of hearing loss and ear infection was higher in surgically managed RS patients. Patients with RS and overt CP require a statistically higher number of BMTs compared to those with either submucous cleft palate or intact palate.

Analysis of remodeling and degenerative changes in the condylar process on the contralateral side in children with unilateral ankylosis post-mandibular ramus distraction

Relevance. Patients with a history of unilateral ankylosis of the temporomandibular joint (TMJ) exhibit significant functional and anatomical abnormalities, leading to diminished quality of life and social adaptation. This condition necessitates a complex, multi-stage rehabilitation process. The contralateral, non-operated joint often bears the brunt of functional loads for an extended period post-surgery. Frequently, due to ankylosis-related interventions such as distraction osteogenesis and osteoplasty using various biomaterials, as well as orthognathic surgery, the bone structure of the contralateral joint is subjected to loads exceeding their biological capacity, resulting in notable degenerative changes around the condylar process head.Materials and methods. An analysis was conducted on data from 55 patients who, within the age range of 7 to 18 years, had undergone multiple mandibular ramus distraction osteogenesis surgeries due to a history of unilateral ankylosis.Results. The application of the distraction apparatus led to rotational movements of the mandible within the coronal plane, thereby increasing compression around the TMJ on the contralateral side. Subsequent degenerative alterations in the area of the condylar head were observed in 61.8% of the patients.Conclusion. To mitigate the risk of degenerative changes in the contralateral condylar process head, it is advisable to utilize an orthopedic splint to separate the articular surfaces of the TMJ. This approach helps reduce pressure on the condylar process and prevents pathological remodeling.

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

BackgroundTreatment 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 the 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. MethodsA 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. ResultsNine 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 1 patient. The articular and sellar angle was significantly larger and smaller respectively in the surgery group. ConclusionsMandibular 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.

Monitoring of Home Respiratory Polygraphy During Mandibular Distraction Osteogenesis Succeeded by LeFort I Osteotomy in Adult Patients With Obstructive Sleep Apnea

BackgroundBilateral Internal Ramus Distraction (BIRD) is now part of select protocols for treating obstructive sleep apnea (OSA). Introducing a home monitoring protocol offers a valuable alternative to overnight laboratory polysomnography (PSG). PurposeThe purpose of this study was to evaluate and compare OSA parameters obtained via home respiratory polygraphy (HRP) and hospital PSG in a cohort of patients undergoing mandibular distraction (MD) for OSA management. Study designHospital Universitario La Princesa (Madrid) researchers conducted a prospective cohort study with patients diagnosed with moderate (AHI=15-30) to severe (AHI>30) OSA undergoing BIRD followed by LeFort maxillary osteotomy. Exclusion criteria were: severe systemic diseases, central apneas, smoking, poor dental hygiene, or prior OSA interventions. Predictor variableThe predictor variable was PSG and HRP techniques. Main outcome variablesThe main outcome variable comprises a collection of OSA parameters, including the apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and time spent below 90% oxygen saturation (T90). These data were measured both before and after distraction, as well as after 6 mm, 9 mm, and 12 mm of mandibular distraction (MD). CovariatesThe covariates were age, sex, cardiovascular risk parameters, and Epworth sleepiness scale. AnalysesPearson’s correlation analyzed AHI, ODI, and T90 values from PSG and HRP. Wilcoxon Signed Rank Sum Test compared two distraction stages, and the Friedman Test evaluated three stages (p<0.05). Multiple regression analysis assessed if covariates were independent risk factors for postoperative persistent OSA. ResultsThe study included 32 patients (25% with moderate and 75% with severe OSA). Final AHI was 10.9±8.9 (events/hour) with HRP, compared to 15.2±13.4 with PSG (r=0.7, p<0.05). ODI was 9.0±8.1 (des/h) with HRP and 8.7±9.5 with PSG (r=0.85, p<0.05). T90 was 1.6±2.2 with HRP and 1.3±3.0 with PSG (r=0.6, p<0.05). Based on HRP data, AHI improved from D1 (34.0±19.5) to D2 (20.8±14.1) and D3 (12.5±10.4) (p<0.05). ODI decreased from D1 (26.1±19.0) to D2 (16.0±12.6) and D3 (9.4±8.8) (p<0.05). T90 reduced from D1 (8.2±12.6) to D2 (4.1±5.2) and D3 (1.9±2.8) (p<0.05). Multiple regression analysis of comorbidities produced non-significant results. ConclusionTo monitor BIRD through HRP has demonstrated efficacy in yielding results that align with PSG.

The mandibular distraction osteogenesis; the key dental technique to success in a neonate with Pierre Robin’s sequence – A case report

A 15-day female neonate term small for gestational age with Pierre Robin Sequence was presented with respiratory distress, requiring respiratory care. The mandibular distraction surgery was performed for micrognathia and progressive respiratory distress. Gradually, she improved and was discharged home on gastrostomy tube feeding. This case underscores the importance of dentistry in the neonatal management of complicated Pierre Robin Sequence successfully.

Long-term mandibular growth in patients with airway obstruction treated with mandibular distraction

Congenital craniofacial malformations play an important role in upper airway obstruction. One of the main causes is mandibular hypoplasia which is present in the pierre robin sequence. Mandibular distraction osteogenesis (MDO) is one of the most commonly used treatments for the resolution of upper airway obstruction in patients that do not respond to a conservative treatment. We performed a long term follow up of syndromic and non-syndromic patients with pierre robin sequence where the lateral xrays were studied before surgery (T1), after MDO (T2) and long-term follow-up (T3, at least 5 years). Possible complications of the surgery were also studied through panoramic x-rays and clinical controls. The results evidenced an increase of mandibular length comparing T1-T2 and a good stability during the long-term follow-up. The Sd patients presented smaller mandible dimensions. We had not found any complications during the follow-up. The scars outcomes are modest, but none of the patients requested a surgical correction. Mandibular distraction osteogenesis is a treatment to be considered in patients with upper airway obstruction that do not respond to conservative treatments. The results of the surgery are stable and the complications in experienced hands are low.

Positive Airway Outcomes in Syndromic Pierre Robin Sequence Infants Treated with Mandibular Distraction Osteogenesis: A Single Surgeon’s Experience

Positive Airway Outcomes in Syndromic Pierre Robin Sequence Infants Treated with Mandibular Distraction Osteogenesis: A Single Surgeon’s Experience

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.

Skeletal stability of inter-molar mandibular distraction osteogenesis in growing patients

IntroductionThe aim of this retrospective study was to firstly assess the stability of surgical advancement using inter-molar mandibular distraction osteogenesis (IMDO) and secondly to assess the impact of the surgical intervention on subsequent mandibular growth in patients with residual growth.MethodsThe sample consisted of 17 (13F and 4M) consecutively treated patients who underwent IMDO and orthodontic treatment. Cephalometric analysis was performed at three time points: T0 prior to distraction; T1 post-distraction immediately prior to surgical removal of the distractors; and T2 following completion of orthodontic treatment when the final lateral cephalogram was taken (0.86–4.37 years after T1). Statistical comparison of lower facial height, mandibular length, growth, condylar position and anterior mandibular rotation was performed.ResultsNo association was found between changes in any of the cephalometric measurements and the length of the follow-up interval. The anterior mandibular segment underwent clockwise rotation during distraction and recovered to near its pre-distraction angulation during remodelling. An increase in the lower facial height of 1.88 ± 2.81mm also occurred during distraction (T0–T1) and was maintained during the follow-up period (T1–T2). Post-distraction (T1–T2) growth of lower facial height (p value 0.872) and mandibular length (p value 0.251) showed no association when compared to an untreated control group and an overall reduction in growth was reported.ConclusionsIMDO was highly stable within a follow-up period of 2.3 ± 0.9 years; however, growth appears to have been inhibited.

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

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. 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. 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. 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.

Implementation of Mandibular Distraction Osteogenesis for Patients With Pierre Robin Sequence in a Developing Country Through International Collaboration: A Paradigm for Success.

Though it has made significant strides, Vietnam remains a resource-constrained country of 98 million people. Vietnam National Children's Hospital (VNCH) provides tertiary care to a catchment of 40 million people and is the sole national children's hospital. As such, it is one of the few referral centers in the country equipped to take care of patients diagnosed with Pierre Robin sequence (PRS) as this requires pulmonary, critical care, otolaryngology, and plastic surgery expertise. Before 2015, the only surgical options were tongue lip adhesion or tracheostomy. Only 20% of patients successfully avoided tracheostomy, mechanical ventilation, or death. From 2015 to 2019, mandibular distraction osteogenesis (MDO) was introduced by visiting international surgeons on a short-term basis. Since 2020, local surgeons at VNCH have refined their technique and widely use MDO independently. This report seeks to capitulate their experience and identify factors leading to success. A retrospective review was conducted of patients diagnosed with PRS at VNCH from 2015 to 2022. Paper records were digitized, translated, and reviewed for inclusion criteria, including demographics, indications, hospital course, and postoperative outcomes. Complete records satisfying inclusion criteria were available for 53 patients with a diagnosis of PRS who underwent MDO from 2020 to 2022. From 2015 to 2019, there were 19 cases of MDO, though records were incomplete. The median age at the time of MDO was 50 ± 43 days. Forty patients (75.5%) had isolated PRS and 13 (24.5%) were syndromic. Forty-four patients (83%) had a cleft palate. Fifty-one (96.2%) of patients required preoperative supplemental oxygen or mechanical ventilation. The active distraction and consolidation phase was 4.8 ± 1.3 months. The median days to discharge after surgery was 19.0 ± 8.3 days. Median weight at birth, at the time of surgery, and at the time of device removal were 6.8 ± 1.2, 7.7 ± 1.9, and 14.8 ± 2.8 pounds, respectively. Fifty-two patients (98.1%) had obstructive sleep apnea preoperatively with an average Apnea Hypopnea Index of 25.0 ± 10.6. Post-MDO, only 4 (7.5%) had obstructive sleep apnea and the average Apnea Hypopnea Index was 5.2 ± 0.6. No patients (0) required a tracheostomy for a 100% success rate. The tremendous success of the implementation of MDO by local surgeons in Vietnam after its introduction by visiting international surgeons illustrates a paradigm for capacity-enhancing global surgical endeavors. Mandibular distraction osteogenesis has replaced tongue lip adhesion as the surgical treatment of choice for PRS patients at VNCH. Surgical techniques can be transferred to operating environments with basic infrastructure through collaboration and resource optimization. These results demonstrate that global surgical engagement may be scalable and repeatable with direct benefits for patients in lower-middle-income countries.

Mechanical Stretch-Induced ATP Release from Osteocytes Promotes Osteogenesis of Bone Marrow Mesenchymal Stem Cells.

Mandibular distraction osteogenesis (MDO) is a highly effective method for bone regeneration, commonly employed in treating craniofacial defects and deformities. Osteocytes sense mechanical forces in the pericellular space, relay external stimuli to biochemical changes, and send signals to other effector cells, including bone marrow mesenchymal stem cells (BM-MSCs), to regulate bone resorption and formation. Piezo1 potentially affects the secretion signal molecules of bone cells under mechanical stretch. The primary aim of this study was to enhance our comprehension of the molecular biology underlying this therapeutic approach and to identify specific signaling molecules that facilitate bone formation in response to stretch forces. Mechanical stretching was applied to negative controls and Piezo1 knockdown osteocyte-like MLO-Y4 cells. Alkaline phosphatase and Alizarin Red S staining were used to survey the osteogenic potential of BM-MSCs. The production and secretion content of adenosine triphosphate (ATP) was measured using ATP content determination analysis. Pathway-related and osteo-specific genes and proteins were evaluated using real-time polymerase chain reaction (RT-PCR), Western blots, and immunofluorescence. Mitochondrial organization was examined with a transmission electron microscope. The conditioned medium of stretch-exposed MLO-Y4s significantly upregulated osteogenesis-related indicators of BM-MSCs (p < 0.001). The upregulation of BM-MSC osteogenesis was associated with ATP release from osteocytes. Mechanically induced calcium transfer and transcriptional coactivator with PDZ-binding motif (TAZ) nuclear translocation mediated by Piezo1 could promote mitochondrial fission and ATP release. Osteocytes detected stretch forces through Piezo1, triggering calcium influx, TAZ nuclear translocation, and ATP production. The stretch stimulation of Piezo1 induces calcium influx, which in turn promotes calcium-related TAZ nuclear translocation, changes in mitochondrial dynamics, and the release of ATP in osteocytes. This signaling cascade leads to an up-regulation in the osteogenic capacity of BM-MSCs. Mitochondrial energy metabolism of mechanosensitive protein Piezo1-dependent and ATP release may provide a new effective intervention method for mechanically related bone remodeling.

3D-CT measurements of facial symmetry in severe CFM patients: A comparative study between mandibular ascending ramus distraction osteogenesis and bone grafting

This study aims to compare the effects of mandibular distraction osteogenesis (MDO) and bone grafting on the facial symmetry of children with Pruzansky-Kaban type IIB and III craniofacial microsomia (CFM).Medical records and three-dimensional computed tomography (3D-CT) data of CFM patients who had primarily undergone MDO and bone grafting were collected. A retrospective analysis of pre-and post-operative 3D imaging data was conducted to compare the improvement rate in facial symmetry between the two groups based on occlusal cant, affected/unaffected ramus height ratio and chin point deviation. The data were tested for normality using the Shapiro-Wilk test. When the data followed a normal distribution, a paired sample t-test was employed for the comparison between preoperative and postoperative data. When the data did not follow a normal distribution, the Wilcoxon signed-rank test for paired samples was used for preoperative and postoperative comparison.The study included 18 children with type IIB and III CFM, 11 in the MDO group and 7 in the bone grafting group. In the MDO group, postoperative Gn-FH and Gn-Cor distances increased significantly, whereas the postoperative Gn-Mid distance decreased significantly. Occlusal cant decreased significantly and ramus height affected/unaffected ratio increased significantly after MDO. In the bone graft group, there was no statistically significant difference in the postoperative ratios of chin deviation, occlusal cant, and ramus height affected/unaffected compared to the preoperative values.Compared to bone grafting, MDO can significantly enhance ramus height ratio, level occlusal plane, and centralize the chin point among patients with CFM. Furthermore, MDO achieves superior enhancements in facial symmetry.

Failure of Mandibular Distraction Osteogenesis in Klippel- Feil Syndrome- 4: A Case Report of a Rare Syndromic Robin Sequence

Klippel-Feil syndrome-4 (KFS4), a rare autosomal recessive form of Klippel- Feil syndrome, is characterized by facial dysmorphism, nemaline myopathy, and short stature. Only 10 cases of KFS4 have been previously published in the literature. We report a novel case of a 1- month-old girl with known KFS4 and Robin Sequence (RS). At 2 months old, she underwent bilateral mandibular distraction osteogenesis to correct significant airway obstruction. Despite adequate mandibular advancement, the patient failed extubation twice and eventually required a tracheostomy. Due to the multiple anomalies present in KFS4, mandibular distraction osteogenesis may have a decreased likelihood of surgical success.

The Outcome of Mandibular Distraction Osteogenesis in Infants with Severe Pierre Robin Sequence in Vietnam.

The purpose of this study was to provide the experience of a single center with mandibular distraction osteogenesis (MDO) in Pierre Robin Sequence (PRS) patients. A longitudinal research analysis was conducted to identify PRS patients who underwent MDO at Vietnam National Children's Hospital between 2019 and 2021. The following criteria were used to determine inclusion: 1) those pediatric patients with PRS who were not well handled with conservative therapy, 2) those who received MDO with internal mandibular distractors, and 3) no previous treatment elsewhere. Demographic data, postoperative complications, and surgical results were all evaluated. The inclusion criteria were met by 73 patients. There were no difficulties associated with our distraction strategy. The majority of individuals with tracheostomies were successfully decannulated, and the remainder were able to avoid tracheostomies. Using MDO in PRS is an effective technique to avoid future airway issues. The success rate was lower and the complication rate higher for patients who had a tracheotomy before distraction and for those who underwent distraction at an age older than 2 months. The presence of laryngomalacia, gastric reflux disease, cardiac abnormalities, and GI anomalies did not increase the likelihood of MDO failure in PRS patients.

Pharyngeal Airway Changes Following Mandibular Distraction Osteogenesis as Evaluated with Laryngoscopy.

Mandibular distraction osteogenesis (MDO) may improve airway grade in patients with Robin Sequence (RS), but little is known about the response of the oropharyngeal airway to the distraction process in cases of tongue base obstruction (TBAO). This study used drug-induced sleep endoscopy (DISE) to evaluate the impact of MDO on the oropharynx. RS patients with severe obstructive sleep apnea (OSA) were prospectively enrolled, and underwent DISE prior to MDO, and at the time of distractor removal. Laryngoscopy views, glossoptosis degree, polysomnography (PSG) results, oxygen saturations and airway measurements were compared pre- and post-MDO. Twenty patients met inclusion criteria. At the time of distractor placement, a grade II laryngoscopic view was most frequently observed (63%), and one patient (5%) had a grade I view. Median obstructive apnea hypopnea index (OAHI) improved after MDO (49.1 [30.2-74.0] to 9.1, [3.9-18.0], p ≤ .001). Median oxygen saturation nadir also improved (preoperative 69% [60-76] to 85% [82-91], p ≤ .001). At distractor removal, mean laryngoscopic view improved (p ≤ .002) with no views that were grade 3 or higher. Median intraoperative oropharyngeal width improved, (3.1 mm [2.8-4.4] to 6.0 mm [4.4-6.8], p ≤ .021), as did median cephalometric anteroposterior oropharyngeal width (3.5 mm [2.7-4.1] to 6.3 mm [5.6-8.2], p ≤ .002). Following MDO, RS patients with TBAO have an approximate doubling of oropharyngeal width and an improvement in laryngoscopic grade. These findings likely contribute to improved oxygenation, OAHI and ease of intubation.