Mandibular distraction osteogenesis for the management of upper airway obstruction in children with micrognathia: a systematic review

Does Mandibular Distraction Osteogenesis for Robin Sequence Create Altered Craniofacial Morphology and Disrupt Tooth Development?

BACKGROUND

Robin Sequence (RS) infant patients may require mandibular distraction osteogenesis (MDO) to improve airway. The distracted mandible may grow vertically and the developing dentition may be disrupted.

PURPOSE

The study purpose was to measure the association of MDO on craniofacial morphology and tooth development in RS subjects.

STUDY DESIGN, SETTING, SAMPLE

This was a retrospective cohort study of RS infants treated with or without MDO. Inclusion criteria were RS diagnosis, complete imaging, and treatment at our pediatric regional hospital. Exclusion criteria were treatment elsewhere and insufficient imaging.

EXPOSURE VARIABLE

Exposure was airway management; subjects were grouped by use of MDO or not. Subjects were compared to age-matched normal infants presurgically and to age-matched normal controls at follow-up.

MAIN OUTCOME VARIABLES

Main outcome variables were craniofacial morphology measured using cephalometric gonial angle and ramus height to mandibular body length ratio presurgically (T1), postsurgically (T2), and at the mixed dentition (T3). Disrupted tooth development was assessed by absence/abnormality of teeth on radiographs at T3.

COVARIATES

Covariates were age, sex, body mass index, comorbidities, and cephalometric measurements.

ANALYSES

Appropriate univariate, bivariate, and regression models were computed, and significance level was set at P < .05.

RESULTS

The sample contained 14 RS-MDO subjects with median age of 1.1 months and 10 (71.4%) were female. Presurgery, RS-MDO subjects had significantly more obtuse gonial angles (145° vs 137°, P = .04) and shorter mandibular bodies (32 vs 41 mm, P < .01) than the 37 unaffected controls. Increased ramus height (P < .01) and mandibular body length (P < .01) and forward rotation of the mandible were seen in 12 subjects with post-MDO imaging compared to their presurgical condition. At mixed dentition, 12 post-MDO subjects had more obtuse gonial angles (P < .01) and steeper mandibular planes (P < .01) than 19 non-MDO RS subjects. Both RS groups had different cephalometric values and more vertical measures than matched cephalometric norms. Thirty-one percent of 12 RS-MDO subjects had ≥1 teeth with abnormal development compared to none of 19 RS subjects without MDO (P = .02).

CONCLUSION AND RELEVANCE

MDO increased mandibular size in infants but can disrupt the developing dentition. Postdistraction growth may result in more vertical mandibular morphology with large gonial angles.

Surgical Outcome and Treatment Trends in 1289 Infants with Micrognathia: A Multicenter Cohort

BACKGROUND

Studies of infants with micrognathia, especially Robin sequence, are limited by its rarity and both phenotypic and diagnostic variability. Most knowledge of this condition is sourced from small, single-institution samples.

METHODS

This is a cross-sectional study including infants with micrognathia admitted to 38 Children's Hospital Neonatal Consortium centers from 2010 through 2020. Predictor variables included demographic data, birth characteristics, cleft, and syndrome status. Outcome variables included length of stay, death, feeding or respiratory support, and secondary airway operations.

RESULTS

A total of 1289 infants with micrognathia had surgery to correct upper airway obstruction. Mean age and weight at operation were 34.8 ± 1.8 weeks and 3515.4 ± 42 g, respectively. A syndromic diagnosis was made in 150 (11.6%) patients, with Stickler (5.4%) and Treacher Collins (2.2%) syndromes being the most common. Operations included mandibular distraction osteogenesis (MDO) in 66.3%, tracheostomy in 25.4%, and tongue-lip adhesion (TLA) in 8.3%. Patients receiving a tracheostomy had lower birthweight, head circumference, gestational age, and Apgar scores. Patients undergoing MDO were less likely to need a second airway operation compared with patients undergoing TLA (3.5% versus 17.8%; P < 0.001). The proportion of infants feeding exclusively orally at hospital discharge differed significantly, from most to least: MDO, TLA, and tracheostomy. Hospital length of stay was not statistically different for patients who had MDO or TLA, but was longer for those with primary tracheostomy. The mortality rate was low for all operations (0.5%).

CONCLUSIONS

In this surgical patient cohort, MDO was associated with shorter hospital stay, improved oral feeding, and lower rates of secondary airway operations. Prospective multicenter studies are necessary to support these conclusions.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Management of sleep-disordered breathing in patients with syndromic hemifacial macrosomia

PURPOSE

Patients with syndromic hemifacial microsomia (SHFM) are at risk of obstructive sleep apnea (OSA). The aim of the study was to describe the prevalence of OSA and its management, especially in patients with Goldenhar syndrome (GS).

METHODS

The respiratory polygraphies and clinical management of 15 patients, aged 2 to 23 years, evaluated at a national reference center, were analyzed.

RESULTS

Four (27%) patients had no OSA, 4 (27%) had mild OSA, and 7 (46%), of whom 5 were ≤ 2 years old, had severe OSA. None of the patients had central apneas. Only one patient had alveolar hypoventilation, and another one had nocturnal hypoxemia. Two patients had severe OSA despite prior adenoidectomy or mandibular distraction osteogenesis. Median duration of follow-up was 3.5 years (range 0.5-9 years). None of the patients without OSA or with mild OSA at baseline respiratory polygraphy developed OSA during the follow up. Among the 7 patients with severe OSA, 3 required continuous positive airway pressure or noninvasive ventilation, and one patient required a tracheostomy.

CONCLUSION

In conclusion, patients with SHFM are at high risk of severe OSA at any age, underlining the importance of systematic sleep studies to diagnose and evaluate the severity of OSA. Individualized treatment should be privileged, based on a careful examination of the entire upper airway, taking in account potential associated risk factors. All patients with SHFM should be managed by a pediatric expert multidisciplinary medical/surgical team until the end of post pubertal growth.

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

AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Feeding Performance and Outcomes in Infants With Robin Sequence Undergoing Mandibular Distraction Osteogenesis

To describe perioperative feeding performance in infants with Robin sequence (RS) who underwent mandibular distraction osteogenesis (MDO).

A retrospective study of infants that underwent MDO from May 2010 to December 2019.

Tertiary pediatric hospital.

A total of 40 patients underwent MDO and 20 met inclusion criteria. Of the included infants, 6 had an associated syndrome and 80% were male.

Time to full oral feeds, rate of G-tube placement, and change in weight percentile following MDO.

Average oral intake prior to MDO was 22.1% of individual goal feeds. Among the 15 (75%) children that did not require G-tube placement, mean time to full oral feeds after MDO was 11 days ± 5.7 days, with 80% of infants reaching full oral feeds within 2 weeks after extubation. The proportion of G-tube placement in patients with a syndrome was higher than in isolated RS (-0.6; 95% CI: -1.0, -0.2). Mean percentages of weight-for-age percentile decreased during the first 3 months after the procedure. This was followed by a mean upturn in weight starting after the third month after MDO with a recovery to preoperative mean weight-for-age percentiles by 6 months after surgery.

This study suggests that infants with RS may achieve full oral feeds despite poor feeding performance before MDO. Infants with syndromic RS are more likely to require G-tube. These findings may be used to inform G-tube discussion and offer a timeline to work toward goal oral feeds for infants with RS after MDO.

Craniofacial Distraction Osteogenesis

Distraction osteogenesis (DO) of the craniofacial skeleton has become an effective technique for the treatment of both nonsyndromic and syndromic conditions. The advent of craniofacial DO has allowed for earlier intervention in pediatric patients with less complication risk and morbidity compared to traditional techniques. In this review, we will discuss current application and technique for craniofacial DO by anatomical region and explore future applications in craniofacial surgery.

Impact of Syndromes on Sleep-Disordered Breathing in Children After Cleft Palate Repair

OBJECTIVE

Prior research suggests that children with cleft palate (CP) are at increased risk of obstructive sleep-disordered breathing (SDB). However, few studies differentiate the effects of CP repair on SDB based on syndrome status. The goal of this study was to evaluate differences in SDB after palatoplasty among children with nonsyndromic CP, syndromic CP, and isolated Robin sequence (RS).

DESIGN

Retrospective chart review.

SETTING

Tertiary academic children's hospital.

PATIENTS/PARTICIPANTS

A total of 145 children who underwent primary CP repair from 2014 to 2021.

MAIN OUTCOME MEASURE

Post-palatoplasty SDB is defined as parent-reported symptoms and/or evidence of obstructive sleep apnea (OSA).

RESULTS

Median age at palatoplasty was 11.1 [IQR 10.2-13.6] months. Most patients (61.4%) had nonsyndromic CP, 26.9% had a syndrome, and 11.7% had RS. Children with syndromic CP and RS had more post-palatoplasty SDB symptoms (56.4% vs 58.8% vs 30.3%, P = .006) and higher rates of OSA (25.6% vs 29.4% vs 5.6%, P = .001) compared to children with nonsyndromic CP after palatoplasty. Children with syndromic CP and RS had nearly 3 to 4 higher odds of post-palatoplasty SDB than children with nonsyndromic CP (adjusted odds ratio [aOR] 2.88, 95% CI 1.29-6.47, P = .010; aOR 3.73, 95% CI 1.19-11.70, P = .024).

CONCLUSION

This study showed that children with CP experience higher rates of SDB after palatoplasty than the general pediatric population. Within the cohort, children with syndromic CP and isolated RS were more likely to have obstructive sleep disorders than nonsyndromic children after palatoplasty. Clinicians should counsel caregivers accordingly and closely monitor these groups for SDB after palate repair.

Prevalence and Management of Laryngomalacia in Patients With Pierre Robin Sequence

OBJECTIVE

To characterize the prevalence and presentation of laryngomalacia and efficacy of supraglottoplasty (SGP) in a cohort of patients with Pierre Robin Sequence (PRS).

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care children's hospital.

PATIENTS, PARTICIPANTS

Consecutive patients with PRS born between January 2010 and June 2018.

MAIN OUTCOME MEASURES

Chart review included demographics, comorbid airway obstruction including laryngomalacia, timing of surgical interventions, clinical symptoms, sleep study data, and modified barium swallow study data.

126 patients with PRS were included; 54% had an associated syndrome, 64% had an overt cleft palate, and 22% had a submucous cleft palate. 64/126 were noted to have laryngomalacia (51%). Patients with concurrent PRS and laryngomalacia were significantly more likely to have submucous cleft palate (P = .005) and present with aspiration with cough (P = .01) compared to patients with PRS without laryngomalacia. Patients with concurrent laryngomalacia and PRS showed a significant decrease in apnea-hypopnea index (AHI) and obstructive AHI (OAHI) after mandibular distraction, with a median AHI and OAHI improvement of 22.3 (P = .001) and 19.8 (P = .002), respectively. Patients who underwent only SGP did not show significant improvement in these parameters (P = .112 for AHI, P = .064 for OAHI).

The prevalence of laryngomalacia in our PRS cohort was 51%. Patients with PRS and laryngomalacia are more likely to present with overt aspiration compared to patients with PRS without laryngomalacia. These data support that laryngomalacia does not appear to be a contraindication to pursuing MDO.

Pharyngeal Airway Changes Following Mandibular Distraction Osteogenesis as Evaluated with Laryngoscopy

PURPOSE

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Comprehensive Long-Term Outcomes Following Mandibular Distraction Osteogenesis

OBJECTIVE

To describe long-term outcomes and complications following mandibular distraction osteogenesis (MDO) in a diverse patient cohort.

DESIGN

Cross-sectional study.

SETTING

Single tertiary-care pediatric center.

PATIENTS

Forty-eight patients previously undergoing MDO with minimum 4-year follow-up.

MAIN OUTCOME MEASURES

Respiratory outcomes, feeding patterns, dental development, motor/sensory nerve function, temporo-mandibular joint function, and postsurgical scarring.

RESULTS

Forty-six patients with a median age of 7 years were evaluated. Of 20 nonsyndromic patients, none required additional airway procedures, none required continuous positive airway pressure (CPAP) during sleep, and 19 (95%) fed exclusively by mouth. Among 26 syndromic patients, 7 (27%) required CPAP and 8 (31%) were tube fed. Permanent first molar differences were seen in the majority of subjects; patterns of damage interfering with function were more common in syndromic (13/28, 46%) compared to nonsyndromic (5/24, 21%; P = .014) subjects. MDO prior to age two was associated with more frequent and worse dental damage (P = .001). Inferior alveolar nerve and marginal mandibular nerve function were fully intact in 37 (80%) and 39 (85%) of patients, respectively. Three patients (6%), all with associated genetic syndromes, demonstrated severe nerve impairment. By the Vancouver scar scale, ≥ 80% of surgical scars were rated in the most favorable category for each quality assessed. Temporomandibular joint dysfunction was rare.

CONCLUSIONS

MDO shows highly favorable long-term respiratory, feeding, nerve, and scar outcomes in nonsyndromic patients, although permanent molar changes not precluding tooth viability are commonly seen. Patients with associated syndromes demonstrate respiratory and feeding benefits, but higher rates of dental and nerve abnormalities.

An infant with congenital micrognathia and upper airway obstruction was diagnosed as Hutchinson-Gilford progeria syndrome caused by a novel LMNA mutation: Case report and literature review

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare disease characterized by appearance of premature aging, including the skin, bones, heart, and blood vessels caused by LMNA mutation. In this study, the patient presented with congenital micrognathia and progressively aggravated upper airway obstruction as the initial symptom, which required bilateral mandibular distraction osteogenesis (MDO) surgery intervention. This was not commonly described in the literature, and the primary clinical diagnosis of Pierre Robin sequence (PRS) was made. However, other clinical features included sclerotic skin, dry skin, growth failure, lipoatrophy, joint stiffness, prominent scalp veins, small ear lobes, hair loss, and craniofacial disproportion gradually emerged, the diagnosis of HGPS was preferred when the patient was 5 months old. The genetic testing result with a novel and de novo LMNA mutation (c.1968 + 3_1968+6delGAGT) further confirmed the diagnosis and expanded the clinical and mutational spectrum of HGPS. During the 12-month follow-up period after surgery, the patient no longer suffered dyspnea. Complications of other organs and systems have not happened at the moment. In addition, the pathogenesis, the role of LMNA gene mutation, the progress in clinical treatment, and breakthrough studies about genetic treatment in animals of HGPS are described in the literature review.

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.

Feeding Outcomes After Mandibular Distraction for Airway Obstruction in Infants

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

Distraction Osteogenesis as a reliable method in management of Obstructive Sleep Apnoea (OSA) secondary to TMJ Ankylosis: A Case Report

Obstructive sleep apnoea (OSA) is identified as repetitive and intermittent upper airway collapse or narrowing during sleep. Skeletal advancement through maxillomandibular surgery remains the most effective surgical treatment for OSA but is radical with certain relapse rate. Distraction Osteogenesis of mandible is a single-jaw surgical treatment alternative to bi-jaw surgeries having lesser complications. This case report describes successful management of a 46-year-old patient who reported with a chief complain of obstruction in breathing while sleeping since one year. Obstructive Sleep Apnoea (OSA) secondary to a retrognathic mandible was the final diagnosis, which was successfully treated by Distraction Osteogenesis (DO) of the mandible. The case showed enhancement in airway by 13mm and marked forward movement of Point-B (SNB increased by 6 degrees). The Epworth Sleepiness Scale value decreased from 19mm to 8 mm indicating substantial increase in the airway with stable results after 18 months of follow-up (elimination of symptoms and subsequent sound sleep). Distraction osteogenesis is an effective and reliable method to treat obstructive sleep apnoea secondary to retrognathic mandible.

Adapting Elements of Cleft Care Protocols in Low- and Middle-income Countries During and After COVID-19: A Process-driven Review With Recommendations

A consortium of global cleft professionals, predominantly from low- and middle-income countries, identified adaptations to cleft care protocols during and after COVID-19 as a priority learning area of need.

A multidisciplinary international working group met on a videoconferencing platform in a multi-staged process to make consensus recommendations for adaptations to cleft protocols within resource-constrained settings. Feedback was sought from a roundtable discussion forum and global organizations involved in comprehensive cleft care.

Foundational principles were agreed to enable recommendations to be globally relevant and two areas of focus within the specified topic were identified. First the safety aspects of cleft surgery protocols were scrutinized and COVID-19 adaptations, specifically in the pre- and perioperative periods, were highlighted. Second, surgical procedures and cleft care services were prioritized according to their relationship to functional outcomes and time-sensitivity. The surgical procedures assigned the highest priority were emergent interventions for breathing and nutritional requirements and primary palatoplasty. The cleft care services assigned the highest priority were new-born assessments, pediatric support for children with syndromes, management of acute dental or auditory infections and speech pathology intervention.

A collaborative, interdisciplinary and international working group delivered consensus recommendations to assist with the provision of cleft care in low- and middle-income countries. At a time of global cleft care delays due to COVID-19, a united approach amongst global cleft care providers will be advantageous to advocate for children born with cleft lip and palate in resource-constrained settings.

The management of upper airway obstruction in Pierre Robin Sequence

Pierre Robin Sequence (PRS) is defined by a constellation of characteristics including micrognathia, glossoptosis and airway obstruction. PRS can occur in isolation or can be associated with syndromes and another anomalies. Airway obstruction and feeding difficulties are the major presenting issues, and the severity of the condition ranges from mild, with minimal to no symptoms, to severe, with overt obstruction resulting in apnoeas, severe respiratory distress and cyanosis. The presence of airway obstruction can result in obstructive sleep apnoea and abnormalities in gas exchange, as well as exacerbation of already present feeding difficulties and failure to thrive, secondary to mismatch of caloric intake to energy usage associated with increased effort of breathing. Management of airway obstruction for infants with PRS varies between centres. This paper explores the surgical and non-surgical management options available, their effectiveness and pitfalls in children with PRS. Despite the pros and cons of each management option, it is evident that resource availability and multidisciplinary clinical support are key factors to successful management.

A bibliometric analysis of research on craniomaxillofacial distraction osteogenesis from 2000 to 2021

Objective

This study collected and summarized publications related to craniomaxillofacial distraction osteogenesis(DO) from 2000 to 2021, investigated trends in related research, and compared publications from different countries, institutions and journals. The aim is showcasing hotspots and frontiers in the field and providing a reference for future research.

Background

Craniomaxillofacial DO serves to treat different types of craniomaxillofacial dysplasia and bone defects and deformities. DO can significantly reduce surgical trauma, complications, and recurrence rate compared to conventional surgery. However, there is a lack of bibliometric analyses regarding Craniomaxillofacial DO.

Methods

CiteSpace and VOSviewer were used to analyze and visualize 3,141 articles and reviews searching through the Web of Science Core Collection(WOSCC) to obtain publications on craniomaxillofacial DO from 1 January 2000 to 31 December 2021.

Results

In the last 21 years, there has been a significant increase in the number of publications. The United States, the People's Republic of China, and Italy produce the vast majority of publications. University of Milan and University of Bologna are the most influential in this field. McCarthy JG is the most influential author. Obstructive sleep apnea, TMJ ankylosis and cleft lip and palate are potential research direction in this field.

Conclusion

Future research should focus on the precise indications and optimal timing of craniomaxillofacial DO and the evaluation of the long-term outcomes of various modified procedures. This study provides a relatively objective reference for related researchers, medical practitioners, and global health systems.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

The Effect of Timing of Mandibular Distraction Osteogenesis on Weight Velocity in Infants Affected by Severe Robin Sequence

Background: Impaired weight gain is prevalent in Robin Sequence (RS) newborns. Although mandibular distraction osteogenesis (MDO) has been proven to improve oral feeding, its impact on postoperative weight gain remains unclear. The purpose of this study is to explore whether MDO can help RS babies reach a normal weight, as well as the effect of MDO timing on weight velocity. Methods: One hundred infants with severe RS and one hundred with normal controls met the inclusion criteria for the study. Included patients underwent MDO. Weights at different timing points were recorded and analyzed and compared to normal controls. Results: After the distractor removal weights of patients undergoing MDO at <1 month and 1−2 months were close to the normal control (6.81 ± 0.93 kg versus 7.18 ± 0.61 kg, p = 0.012, and 6.82 ± 0.98 kg versus 7.37 ± 0.75 kg, p = 0.033, respectively), the weights of patients undergoing MDO at 2−3 months and 3−4 months still lagged behind (7.56 ± 1.29 kg versus 8.20 ± 0.61 kg, p = 0.000206 and 7.36 ± 1.05 kg versus 8.25 ± 0.77 kg, p = 0.004, respectively). The weights of all RS infants undergoing MDO showed no significant difference compared to the controls when they aged to 1 year (9.34 ± 0.99 kg versus 9.55 ± 0.45 kg, p = 0.254 for MDO at <1 month; 9.12 ± 0.91 kg versus 9.33 ± 0.46 kg, p = 0.100 for MDO at 1 to 2 months; 9.38 ± 0.29 kg versus 9.83 ± 0.53 kg, p = 0.098 for MDO at 2 to 3 months; and 9.38 ± 0.29 kg versus 9.83 ± 0.53 kg, p = 0.098 for MDO at 3 to 4 months). Conclusion: The MDO procedure helped patients with severe RS to reach a normal weight; and MDO intervention was recommended at an early stage for early weight gain.

Early weight gain in infants with Robin sequence after mandibular distraction

This retrospective cohort study was performed to assess weight gain in infants with Robin sequence (RS) treated by mandibular distraction osteogenesis (MDO). The primary outcome variable was average daily weight gain for the following time periods: (1) birth to MDO (T1), (2) MDO to distractor removal (T2), (3) distractor removal to 6 months later (T3), and (4) 6 months to 12 months following distractor removal (T4). Published growth curves were used for comparison. Differences were assessed using the Wilcoxon matched-pairs signed rank test. Twenty-two infants were included in the study. During T1, the infants had 9.47 ± 12.61 g/day less weight gain than expected (P = 0.001). However, for T2, T3, and T4, the infants demonstrated 3.48 ± 6.17 g/day (P = 0.028), 2.19 ± 4.47 g/day (P = 0.030), and 1.83 ± 3.25 g/day (P = 0.028) more weight gain than expected. Feeding tube use resulted in improved weight gain during T1 (P < 0.001), but was associated with poorer weight gain in T3 (P = 0.003) and T4 (P = 0.001). In conclusion, infants with RS treated by MDO demonstrated poorer weight gain relative to their peers between birth and the MDO operation. However, from the MDO procedure to 12 months post-distractor removal, infants who had MDO showed faster weight gain than their age-matched peers.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Mandibular Distraction Osteogenesis for Tongue-Based Airway Obstruction Without Micrognathia

PURPOSE

Mandibular distraction osteogenesis (MDO) effectively treats tongue-based airway obstruction (TBAO) in micrognathic patients with Robin Sequence. Mandibular distraction osteogenesis may also address TBAO in certain nonmicrognathic patients who have severe obstructive apnea, although there is no current literature to guide MDO use in these atypical patients. This study describes outcomes of MDO in a series of patients with TBAO without micrognathia.

METHODS

Patients who underwent MDO for TBAO from 2013-20 were reviewed, and patients with micrognathia were excluded. Study subjects received baseline/follow up polysomnography. Polysomnography variables, including Obstructive Apnea Hypopnea Index, oxyhemoglobin saturation nadir (SpO2 nadir), percent sleep time end tidal CO2 greater than 50 mm Hg (%ETCO2 > 50), and respiratory-related arousals were compared before and after MDO. Demographics, syndromic/cleft palate status, airway anomalies, respiratory support, and feeding outcomes were collected.

RESULTS

One hundred and twenty-four patients underwent MDO during this study period; 5 were nonmicrognathic and included in analysis. Sixty percent (n = 3) of the cohort was syndromic: 1 patient each had Trisomy 9, Beckwith Wiedemann syndrome, and duplicated pituitary gland plus syndrome. Forty percent (n = 2) of patients had a cleft palate, 60% (n = 3) had laryngomalacia, and 40% had tracheomalacia. Median (range) age at MDO was 53 days (47-167 days), and median length of distraction was 16 mm (14-20 mm). After MDO, median Obstructive Apnea Hypopnea Index decreased from x̃ = 60.7/h (11.6-109.4) to x̃ = 5.3/h (3.5-19.3) (P = 0.034). SpO2 nadir increased (69% [58-74] to 85% [80-88], P = 0.011), and median %ETCO2 > 50 mm Hg decreased (5.8% [5.2-30.1] to 0.0% [0.0-1.3], P ≤ 0.043). Continuous positive airway pressure was used by all patients immediately after MDO, and at 6 months postoperatively, 1 patient remained on continuous positive airway pressure and 1 patient required supplemental oxygen. At last follow up, no patients had significant residual airway obstruction or required a tracheostomy.

CONCLUSIONS

Mandibular distraction osteogenesis can effectively treat severe TBAO in some patients without micrognathia that would otherwise be candidates for tracheostomy. When used in select patients, MDO significantly improves obstructive sleep apnea and reduces need for ventilatory support, although feeding support is still needed in most patients at 6 months. Further study in a larger cohort will help identify appropriate candidates for MDO and characterize outcomes of unique patient populations.

Feeding and swallowing outcomes following mandibular distraction osteogenesis: an analysis of 22 non-isolated paediatric cases

Patients with mandibular hypoplasia and upper airway obstruction are at an increased risk of feeding and swallowing difficulties. Little has been described regarding these outcomes following mandibular distraction. The aim of this study was to evaluate the effect of mandibular distraction on feeding and swallowing function. A retrospective study was performed on 22 patients with non-isolated mandibular hypoplasia and severe upper airway obstruction treated with mandibular distraction. Median age at first mandibular distraction was 3.1 years (interquartile range 2.3-6.0 years) and the median follow-up time was 3.5 years (interquartile range 2.0-9.4 years). Prior to mandibular distraction, feeding difficulties were present in 18 patients. Swallowing difficulties were present in 20 patients, all of whom had problems in the oral phase of swallowing, while 11 patients had additional problems in the pharyngeal phase. Following mandibular distraction, at the time of follow-up, feeding difficulties persisted in 13 patients. Swallowing difficulties in the oral phase remained present in all 20 patients, while pharyngeal phase problems persisted in seven patients. In conclusion, feeding and swallowing difficulties are highly prevalent in non-isolated patients and often persist following mandibular distraction. Moreover, these can be the reason that decannulation cannot be accomplished. Hence, awareness and close follow-up by a specialized speech therapist is of paramount importance.

The Surgical Treatment of Robin Sequence: Neonatal Mandibular Distraction Osteogenesis in the Unfavorable Patient

INTRODUCTION

Neonates with severe Pierre Robin sequence (PRS) can be treated by mandibular distraction osteogenesis (MDO), tongue-lip adhesion, or tracheostomy; however, there is an active debate regarding the indications of MDO in this patient population. Published algorithms identify tracheomalacia, bronchomalacia, laryngomalacia, hypotonic syndromes, and central sleep apnea as contraindications for MDO and indications for tracheostomy, but these comorbidities may exist along a spectrum of severity. The authors propose that appropriately selected neonates with PRS who concurrently express 1 or more of these traditional contraindications may be successfully treated with MDO.

METHODS

The authors performed a 5-year retrospective chart review of all neonates who underwent MDO for treatment of severe PRS. All patients expressed a comorbidity previously identified as an indication for tracheostomy. Pre- and postoperative characteristics were recorded. Apnea/hypopnea index (AHI) before and after MDO were compared using 2-tailed repeated measures t-test.

RESULTS

The authors identified 12 patients with severe PRS and conditions associated with contraindications to MDO: 9 (75.0%) patients had laryngomalacia, 6 (50.0%) patients had tracheomalacia, 2 (16.6%) patients had bronchomalacia, 1 (8.3%) patient had central sleep apnea, and 3 (25.0%) patients had hypotonia. Five (41.7%) patients underwent concurrent gastrostomy tube placement due to feeding insufficiency. Average birthweight was 3.0 kg. Average pre-op AHI was 34.8. Average post-op AHI was 7.3. All patients successfully underwent MDO with avoidance of tracheostomy.

CONCLUSIONS

By employing an interdisciplinary evaluation of patient candidacy, MDO can safely and effectively treat upper airway obstruction and avoid tracheostomy in higher-risk neonatal patients with traditional indications for tracheostomy.

A Standardized Extubation Schedule Reduces Respiratory Events After Extubation Following Mandibular Distraction in Infants

PURPOSE

The rational time for intubation during early mandibular distraction osteogenesis (MDO) in infants is unknown. To investigate the differences in clinical outcomes following MDO before and after a standardized extubation protocol implementation in infants.

METHODS

A retrospective cohort study was performed for infant patients under 1 year old undergoing MDO. The study population was composed of all patients presenting for evaluation and management who underwent MDO between November 2016 and February 2021. We divided them into 2 groups: the pre-protocol group and the protocol group. The inpatient charts of infants were assessed. The primary outcome was respiratory events after extubation. The secondary outcomes were duration of mechanical ventilation (MV), postoperative length of stay (LOS), and success rate of the first extubation. Other variables included age, sex, weight, height, and information related to diagnosis, distraction, anesthesia, and operation. The logistic regression model and linear regression model were used to calculate unadjusted and adjusted relative risk (RR) and mean difference (MD) for associations between 2 groups and the primary and secondary outcomes.

RESULTS

There were 142 infants in the pre-protocol group and 135 infants in the protocol group. The patients in the protocol group were heavier in weight than those in the pre-protocol group (P<.05). The Cormack-Lehane grade and the duration of operation and anesthesia were higher and longer in the pre-protocol group than in the protocol group (P<.05). Respiratory events after extubation were significantly more common in the pre-protocol group than in the protocol group [21.1 vs. 9.6%, adjusted relative risk 0.46 (95% CI 0.22-0.89), P <.01].

CONCLUSIONS

Among infants undergoing MDO, the standardization of extubation practices can reduce respiratory events after extubation compared with traditional management.

Impact of Hospital Characteristics on Mandibular Distraction Osteogenesis Outcomes Among Patients With Pierre Robin Sequence Utilizing a National Inpatient Database

OBJECTIVES

This study collected national inpatient data to investigate the impact of hospital specialty and size on patient outcomes following mandibular distraction osteogenesis (MDO).

DESIGN

Kids' Inpatient Database was used to identify patients less than 12 months of age with Pierre Robin sequence (PRS) who underwent MDO in one of the following years: 2006, 2009, and 2012.

SETTING

Inpatient database from the United States.

PARTICIPANTS

Two hundred seventy-six patients with PRS underwent MDO with 134 (48.6%) identified as nonsyndromic and 142 (51.4%) as syndromic.

INTERVENTIONS

Mandibular distraction osteogenesis.

MAIN OUTCOME MEASURES

Length of hospital stay, adjunct airway and nutritional interventions and disposition.

RESULTS

The average length of stay was 24 and 30 days for patients with nonsyndromic and syndromic PRS, respectively (P = .066). Patients with a syndromic as compared to nonsyndromic diagnosis had a higher incidence of gastrostomy tube placement (21.8 vs 12.7%, P = .045). Univariate analysis showed that a lower proportion of patients at children's hospitals as compared to non-children's hospitals necessitated 1 or more airway or nutrition-related intervention (19/148 [12.8%] vs 31/127 [24.4%]; P = .012) and had a lower incidence of a nonroutine discharge (transfer or patient death; 7.4% vs 40.0% nonroutine; P < .001). Multivariable analysis additionally revealed that patients at children's hospitals were less likely to discharge nonroutine (OR = 0.07, 95% CI: 0.02-0.32).

CONCLUSIONS

Results from this national cohort demonstrated that at children-specific hospitals patients with PRS were less likely to require additional airway and nutritional procedures and more likely to discharge to home.

Nonsurgical Orthodontic Airway Plate Treatment for Newborns With Robin Sequence

Despite promising outcomes for >50 years, nonsurgical orthodontic airway plates (OAP) are only infrequently offered for babies with Robin sequence in a few parts of the world. This article demonstrates possibility of providing functional improvement using an OAP to help these babies overcome their functional and structural difficulties on their own. Two consecutively treated cases are presented exemplifying that OAP treatment that had originated from Europe is reproducible and effective in an institution in the United States.

[Obstructive sleep apnea in microtia children with maxillofacial dysostosis]

Children with microtia are often associated with maxillofacial dysostosis, such as Treacher Collins syndrome, Goldenhar syndrome, and Nager syndrome, and they are prone to suffer from obstructive sleep apnea（OSA）. Obstruction widely occurred in the upper airway is the main mechanism of OSA in these children, and dysplasia of the pharynx and neurodevelopmental abnormalities may also participate. Early diagnosis requires symptom screening and polysomnography. Imaging techniques and endoscopy can be adopted to fully assess the upper airway status to guide further treatment. According to the child's condition and the main obstruction site, treatment methods include maxillofacial deformity correction, continuous positive pressure ventilation and tracheotomy. OSA in microtia children with maxillofacial dysostosis needs to be identified and treated in time to reduce the adverse effects on the growth and development of children.

Efficacy and Versatility of Intraoral Monoplanar Distractors in the Correction of Extreme Mandibular Deformities and Severe Facial Asymmetries - A Retrospective Study

Introduction:

Distraction osteogenesis, has emerged as a revolutionary concept and an effective means to treat extensive craniomaxillofacial defects and malformations. In cases of mandibular distraction for patients with extreme acquired mandibular deformities, there is so far, no recorded literature on precise quantification and scientific estimation of the percentage of the efficacy of intraoral monoplanar distractors, for an objective evaluation of their effectiveness. The objective was to study the efficacy of intraoral mandibular monoplanar distractors in the correction of severe acquired mandibular deformities and gross facial asymmetries. To objectively evaluate their effectiveness by calculating the percentage of distraction achieved as against that aimed for, and to evaluate early and late complications encountered with their use.

Materials and Methods:

Five patients in the age group of 10–22 years, with extreme mandibular deformity and gross facial asymmetry secondary to longstanding temporomandibular joint (TMJ) ankylosis, were treated. Four patients had unilateral and one patient had bilateral TMJ ankylosis, with varying degrees of acquired mandibular hypoplasia, retrogenia, retrognathia, and asymmetry. They were managed by unilateral (3 patients) and bilateral (2 patients) mandibular distraction.

Results:

Maximum horizontal corpus and vertical Ramal distraction achieved was 19 mm and 17.6 mm, respectively. The percentage of the efficacy of the intraoral monoplanar distractors used in this study ranged from 65.38% to 109.09%. Severe mandibular deformities and facial asymmetries were successfully corrected in all five patients, with no major early or late complications encountered in any of them. Results achieved were stable with nil incidence of relapse.

Discussion:

Estimation of percentage of the efficacy of distraction achieved, helped in objectively evaluating the effectiveness of the intraoral mandibular distractors. A low complication rate and good esthetic and functional outcomes achieved in all the patients demonstrated the reliability of this treatment modality in the management of extreme mandibular deformities and severe facial asymmetries.

Development of a novel mandibular distraction osteogenesis simulator using Computer Aided Design and 3D printing

INTRODUCTION

Micrognathia, a component of Robin Sequence, can cause glossoptosis, failure of palatal fusion, and critical obstruction of the airway. Mandibular distraction osteogenesis (MDO) is at times offered to anteriorly translate the mandible and tongue, relieving airway obstruction. MDO is an intricate reconstructive procedure that may be ideal for teaching using a high-fidelity educational simulator, allowing early hands-on experience in a zero-risk environment.

OBJECTIVES

To design a novel, low-cost, high-fidelity neonatal MDO simulator that can be used for trainee education and refinement of surgical technique.

METHODS

A novel MDO simulator was developed using additive manufacturing techniques. Three experts in MDO surgery completed a 20-item survey, rating the simulator's physical attributes, the realism of experience, the simulator's value, its relevance to practice and the surgeon's ability to perform tasks on a 4-point Likert scale.

RESULTS

Computer Aided Design (CAD) and 3D printing allowed for the production of a realistic surgical simulator that emulates important aspects of MDO surgery. This preliminary evaluation indicated adequate means across the five domains relevant to the simulator's fidelity and usability (M = 3.33 to 3.75) out of a maximum of 4 points. Lowest rated items were consistent with expert comments allowing future refinement on subsequent iterations. Consumable material costs per model were $9.39 USD.

CONCLUSIONS

The MDO model demonstrated adequate fidelity and holds promise as a skill-development tool for surgeons in training. Further studies are planned to determine its utility as a training and assessment tool.

[Dental complications of the mandibular distraction osteogenesis]

THE AIM OF THE STUDY

Was to reveal the prevalence of dental abnormalities in children after mandibular distraction osteogenesis (MDO).

MATERIALS AND METHODS

The study comprised 75 children aged 5-16 years (42 boys and 33 girls, mean age 9.8±4.2 years) who underwent MDO because of mandible underdevelopment associated with hemifacial microsomia (n=42), Robin syndrome (n=6), Treacher Collins syndrome (n=6), Hallermann-Streiff syndrome (n=1) or acquired conditions (n=16). The mean age at MDO was 6.3±4.4 years. Controls involved 25 children with mandibular underdevelopment (19 with hemifacial microsomis, 4 - with Robin syndrome and 2 with Treacher Collins syndrome, mean age 6.7±3.6 years) receiving orthodontic treatment and with no history of MDO.

RESULTS

In the study group abnormalities of lower molars were revealed in 42 children from 75. The prevalence of the affected first and second molars was 24.7% and 20.5%, respectively. Every tenth child (9.6%) had disorders of both molars. The risks for the first molar developmental defects after MDO was 12 times higher than in controls (OR=12.4; CI=95%). In 21 children delayed eruption or impaction of the first molars was observed. Second molars abnormalities more often included germs displacement and follicular cyst formation (OR=10.4). The age at MDO was significantly higher in children with no dental abnormalities (p<0.01).

CONCLUSION

MDO is associated with significant risk of molars disorders. The younger a child is at MDO the more probable and prominent are the dental complications.

Functional outcomes in patients with facial dysostosis and severe upper airway obstruction

An increased risk of upper airway obstruction (UAO) is seen in up to 95% of patients with facial dysostosis. Secondary to respiratory problems are feeding difficulties and increased nutritional requirements. Little has been described regarding these outcomes in this patient population. Hence, a retrospective cohort study was performed to gather data on functional outcomes. Eighteen patients with facial dysostosis and severe UAO were included. The median follow-up time was 3.42 years. A tracheostomy tube was placed in 13 patients, of whom 10 subsequently underwent mandibular distraction. Three of the five patients without a tracheostomy underwent mandibular distraction as the primary surgical treatment; the remaining two patients were treated conservatively with oxygen supplementation. At presentation, 13 patients had feeding difficulties. Overall malnutrition was present in 16 patients during follow-up. At the end of follow-up, severe UAO was present in 12 patients, feeding difficulties in seven patients, and malnutrition in four patients, while two patients died. In conclusion, patients with facial dysostosis have a high prevalence of severe UAO, feeding difficulties, and malnutrition. Importantly, mandibular distraction has limited success in treating severe UAO in these patients. Close follow-up by a specialized craniofacial team is of paramount importance to manage the long-term consequences.

Biomechanical evaluation of a novel mandibular distraction osteogenesis protocol: an in-vitro validation and the practical use of the method

The aim of this study was to optimize and experimentally validate the certain parameters affecting the operation success of Mandibular Distraction Osteogenesis (MDO). According to FEA results, the displacement of the samples showed 28.5% reduction as only the osteotomy line was separately optimized, and 64.2% less displacement was determined when the osteotomy line and the screw configuration were optimized together. In consistent with the FEA results, the samples showed 62% and 84.5% fewer displacement values, respectively. As a result, the MDO protocol suggested, which is validated by both numerical and experimental studies, offers promising outcomes for operation success.

Evaluation of Hyoid Position and Retroglossal Airway After Mandibular Alveolar Archwise Distraction Osteogenesis

The interaction between form and function in the craniofacial region is a well-accepted fact in orthodontics. The aim of the present study is to objectively evaluate if mandibular sagittal symphyseal distraction causes an increase in the retroglossal airway size and hyoid position in a retrospective clinical study. The pretreatment (T0) and 3 months post-distraction (T1) cone-beam computed tomography images of 12 patients (mean age 17.1 years) were retrieved. The retroglossal airway volume and hyoid-mandibular plane distance, hyoid-C3 distance, sella-nasion-B point angle angle, lower incisor to mandibular plane, and Mandibular plane angles were measured using 3D medical imaging software. The average amount of distraction at the superior border of the bony transport segment was 6.2 mm and 4.4 mm at the inferior border. The changes in retroglossal airway volume (2943.2 mm), incisor to mandibular plane (6.5°), and mandibular plane (2.1°) were significant. The changes in hyoid-mandibular plane distance and hyoid-C3 distances were not significant. However, a downward repositioning in Hyoid position was observed along with the mandibular clockwise rotation. This study showed that symphyseal dentoalveolar distraction osteogenesis, as a complementary to orthodontic therapy, can affect the form and size of the pharynx. Therefore, the airway size should be one of the diagnostic and decisive factors for an ideal treatment planning.

Laryngoscopy Grade Improvement and Difficult Airway Resolution in Infants With Robin Sequence Undergoing Mandibular Distraction Osteogenesis: A Multi-Institutional Study

OBJECTIVE

Mandibular distraction osteogenesis (MDO) aims to relieve tongue-based airway obstruction in Robin Sequence (RS). We investigated direct laryngoscopy grade (DLG) improvement and difficult airway (DA) resolution following MDO.

DESIGN

Retrospective cohort analysis.

SETTING

Three tertiary care institutions.

PATIENTS

Sixty-four infants with RS who underwent a single MDO procedure in their first year of life were identified from January 2010 to January 2019.

MAIN OUTCOME MEASURES

The primary outcome was DLG pre- and post-MDO. Secondary outcomes included DA designation, pre- and post-MDO polysomnographic assessment for obstructive sleep apnea (OSA), length of stay, need for gastrostomy, and major/minor adverse events.

RESULTS

Median DLG improved from II pre-MDO to I at the time of distractor removal (n = 43, P < .001). No significant change was seen in patients with a third recorded time point (eg, palatoplasty; n = 78, P = .52). Twenty-six (47%) of 55 patients were designated as DA pre-MDO, and 10 (18%) of 55 patients retained the label post-MDO (P < .01). Five (50%) of these 10 patients appeared to be inappropriately retained. Median obstructive apnea-hypopnea index improved from 38.6 (range 31.2-62.8) pre-MDO to 2.9 (range 1-3.9) post-MDO (n = 12; P = .002).

CONCLUSION

Mandibular distraction osteogenesis allowed for DLG improvement that was stably maintained as well as functional improvement in OSA, with minimal morbidity. Difficult airway designation persisted in the electronic record of some infants despite clinical resolution.

Imaging characteristics of the mandible and upper airway in children with Robin sequence and relationship to the treatment strategy

Some patients with Robin sequence (RS) may respond to conservative therapy, while others require surgery; however, there are currently no objective anatomical criteria to gauge surgical indication. The purpose of this study was to explore the imaging characteristics of the mandible and upper respiratory tract in children with RS and examine how individual morphometric parameters influence the treatment strategy. Cone beam computed tomography (CBCT) images were obtained from 57 children with RS. Twenty parameters were measured as potential surgical indicators. The children were divided into two groups according to surgical requirement: a non-surgical group (26 children) and a surgical group (31 children who underwent mandibular osteodistraction). Differences in the imaging parameters were compared between the groups. The mandibular ramus was shorter bilaterally (left, P = 0.047; right, P = 0.027) and the mandibular body was longer bilaterally (left, P = 0.030; right, P = 0.025) in the surgical group when compared to the non-surgical group. In addition, the mandibular angle bilaterally (left, P = 0.023; right, P = 0.003) and the cross-sectional area at the epiglottis tip (P = 0.010) were smaller in the surgical group. Compared to RS patients receiving conservative treatment, children requiring surgery have specific anatomical features of the mandible and upper airway that can be used as surgical indications.

Airway Morphological Changes in Pierre Robin Sequence: A Retrospective Study

Objective:

To investigate airway morphology changes in patients with Pierre Robin sequence (PRS) pre–/post–mandibular distraction osteogenesis (MDO) and to compare morphologic changes to age-matched controls.

Design:

Retrospective case–control study.

Setting:

Urban, academic, tertiary medical center.

Patients, Participants:

Fifteen patients with PRS after MDO to relieve upper airway obstruction (UAO) (2008-2018); age-matched controls for post-MDO patients.

Interventions:

Mandibular distraction osteogenesis, curvilinear internal mandibular distractors.

Main Outcome Measures:

(1) Physiologic improvement after MDO (apnea–hypopnea index; minimum oxygen saturation); (2) airway size (volume, surface area, length, mean/minimum cross-sectional area), shape (lateral:anterior–posterior ratio, cross-sectional area ratios, uniformity, sphericity), and changes with MDO; and (3) post-MDO airway size, shape versus age-matched controls.

Results:

Airway size increased after MDO (volume, P = .01; surface area, P = .02; length, P = .01), as did cross-sectional area (mean, P = .02; minimum, P = .02; minimum retropalatal, P = .05, mid-retroglossal, P = .02). Post-MDO PRS airways were larger than controls (volume, P < .01; surface area, P < .01; length, P < .01, cross-sectional area, P = .03). Airway shape remained nonuniform and flat post-MDO; control airways were round. Two syndromic patients required repeat MDO and had subphysiologic post-MDO airway cross-sectional area. Post-MDO PRS patients with supraphysiologic cross-sectional area along the entire airway had no UAO recurrence.

Conclusions:

In this small, heterogenous patient sample, MDO increases airway size, may preferentially affect the retropalatal airway, and often results in supraphysiologic airway dimensions. These retropalatal changes may be important in relieving severe UAO in patients with PRS. Generalizability of our results is limited by small cohort size and patient heterogeneity.

[Progress of diagnosis and treatment of upper respiratory obstruction in patients with Treacher Collins syndrome]

Objective

To summarize the progress of diagnosis and treatment of upper respiratory obstruction in patients with Treacher Collins syndrome (TCS).

Methods

The domestic and abroad literature about the diagnosis and treatment of upper respiratory obstruction in patients with TCS was extensively reviewed and analyzed.

Results

TCS is an autosomal-dominant craniofacial developmental syndrome. It is often accompanied by midface and/or mandibular hypoplasia, soft tissue hypertrophy, and other respiratory tissue developmental abnormalities, which can lead to different degrees of upper respiratory obstruction symptoms. Respiratory obstruction in patients with TCS is affected by many factors, and the obstructive degree are different. Early detection of the causes and obstructive sites and adopted targeted treatments can relieve the symptoms of respiratory obstruction and avoid severe complications.

Conclusion

Due to the low incidence of TCS, there is still a lack of high-quality research evidence to guide clinical treatment. Large-scale and prospective clinical studies are needed to provide new ideas for the treatment and prevention of upper respiratory obstruction.

Mandibular distraction osteogenesis in the treatment of pediatric temporomandibular joint ankylosis with micrognathia and obstructive sleep apnea syndrome: A case report with 4-year follow-up

Temporomandibular joint (TMJ) ankylosis in pediatric patients is rare and may cause severe micrognathia and obstructive sleep apnea syndrome. The present study reports on the treatment and 4-year follow-up of a pediatric patient with early-onset bilateral TMJ ankylosis and severe secondary micrognathia, as well as obstructive sleep apnea syndrome. A typical ‘bird face’ appearance was noted with severe mandible retrognathism and a significant convex facial profile. The treatment of this patient involved TMJ ankylosis release with condylectomy and simultaneous bilateral mandibular distraction osteogenesis, which enabled the surgeons to simultaneously reconstruct the neocondyle and correct facial malformations. Following treatment, the micrognathia was corrected and the oropharyngeal airway was significantly expanded. However, the maximal incisal opening was limited. During the 4-year follow-up, no signs of mandible retraction were noted and mouth opening increased to 17 mm (passive) compared with the inability to open that was noted immediately following surgery. A certain degree of MIO shrinkage was identified in the patient. In such cases of TMJ ankylosis, early post-operative exercise, active post-operative physiotherapy and stringent follow-up are essential to prevent post-operative shrinkage and adhesions.

The Tübingen palatal plate approach to Robin sequence: Summary of current evidence

Various treatments, many of them considerably invasive, are currently applied to infants with Robin sequence (RS) and accompanying upper airway obstruction (UAO). We present a narrative review of our data on the Tübingen palatal plate (TPP) which show the following: a) in a randomized trial, the TPP was superior to a sham procedure in alleviating UAO; b) children treated with the TPP in infancy showed an intellectual development within the reference range; c) prone positioning is no alternative, as it is ineffective and associated with an increased risk of sudden death; d) the TPP reduces the mixed-obstructive apnea index to near-normal values, both in isolated and most (83%) syndromic RS, e) of 443 infants (129 syndromic) treated with the TPP in our center, 23 (5%) ultimately received a tracheostomy (all with syndromic RS), f) recent data suggest that the TPP may induce mandibular catch-up growth, g) the TPP may also help to reduce respiratory complications following cleft closure in RS, and h) TPP treatment is applied by various centers around the world, although it is unclear if its effectiveness is invariably controlled by endoscopy and sleep studies, although both are necessary. Given these data from peer-reviewed studies, it may be questioned whether the "First do no harm" principle is always adhered to when subjecting RS infants to more invasive procedures such as mandibular distraction osteogenesis or tongue-lip adhesion.

Evaluation of Obstructive Sleep Apnea in Prone Versus Nonprone Body Positioning With Polysomnography in Infants With Robin Sequence

Objective:

Management of obstructive sleep apnea in infants with Robin sequence (RS) includes prone positioning during sleep, which conflicts with safe infant sleep data. We examined changes in polysomnography (PSG) parameters for prone versus nonprone body positions in these infants.

Design:

Pre–post interventional, nonblinded study.

Participants:

Infants with RS referred for PSG were recruited from craniofacial clinic and inpatient units at Children’s Hospital Los Angeles, a tertiary pediatric center. Fourteen infants were recruited, and 12 studies were completed on both body positions; 11 studies were used in the analysis.

Interventions:

The PSG was divided into nonprone and prone sleep, moving from their usual sleep position to the other position midway in the study.

Main Outcome Measures:

Data was collected in each position for obstructive apnea–hypopnea index (oAHI), central apnea index (CAI), sleep efficiency (SE), and arousal index (AI). Signed rank test was used to evaluate the change in body position.

Results:

All infants were term except 1, age 7 to 218 days (mean: 55 days; standard deviation: 58 days), and 8 (57%) of 14 were female. From nonprone to prone sleep position, the median oAHI (16.0-14.0), CAI (2.9-1.0), and AI (28.0-19.9) decreased ( P = .065); SE increased (67.4-85.2; P = .227).

Conclusions:

Prone positioning may benefit some infants with RS. However, even those with significant improvement in obstructive sleep apnea did not completely resolve their obstruction. The decision to use prone positioning as a therapy should be objectively evaluated in individual infants.

A Standardized Care Pathway following Mandibular Distraction in Infants Less Than 3 Months of Age

OBJECTIVES

To assess for differences in postoperative care following mandibular distraction osteogenesis (MDO) in infants before and after implementation of a standardized protocol.

STUDY DESIGN

Retrospective chart review.

SETTING

Urban tertiary pediatric hospital.

SUBJECTS AND METHODS

The inpatient charts of infants who underwent MDO before 90 days of age were assessed for metrics such as postoperative length of stay (LOS), duration of mechanical ventilation, and the choice and duration of sedating medications.

RESULTS

Over a 6-year period, 16 patients met inclusion criteria. The first 4 consecutive patients were managed at the discretion of the critical care staff. The remaining 12 infants were managed with a planned 4- to 6-day period of postoperative intubation, during which a standard protocol determined the choice, dosage, and duration of sedating medications. The mean age was similar between groups (preprotocol: mean, 26.5 days; protocol: mean, 20.3 days; P = .51). The mean postoperative LOS was 13.3 days less among infants managed with the protocol (P = .06), and the mean number of midazolam boluses was fewer among protocol patients (P < .01). A more consistent postoperative LOS, duration of mechanical ventilation, and exposure to sedating medications was observed among protocol subjects (P < .01). The LOS for 2 patients in the preprotocol group was extended due to iatrogenic withdrawal syndrome. There were no instances of accidental extubation or anoxia in either group.

CONCLUSIONS

Among infants undergoing MDO, standardizing postoperative airway and sedation practices may offer a more predictable postoperative course as compared with a case-by-case management philosophy.