Proposal of a Cephalometric Method in Computed Tomography to Mandibular Analysis in Infants with Pierre Robin Sequence Treated by Fast and Early Mandibular Osteo-Distraction: Pilot Study

For Pierre Robin sequence (PRS) patients, there is incomplete characterization of 3D differences and effects of mandibular distraction osteogenesis (MDO) on the mandible compared to normal controls. PRS infants who underwent MDO at 2 craniofacial referral centerals with pre- and postoperative computed tomography (CT) scans were identified. A group of age-matched control patients with CTs were identified in the PACS database. Demographic and perioperative data were recorded. Mandibular lengths, angles, and volumes were measured. Morphologic and outcomes data were analyzed in a case-control comparison. Sixty-three CT scans were analyzed. Fifteen pre-op PRS patient and 15 control CTs were well matched in terms of age and sex. Mandibular volume (78%), ramus length (87%), and body length (95%) were all decreased in the PRS patients. Anterior symphyseal angle (84%) was significantly reduced in PRS patients while mandibular angle (102%) was maintained. Eighteen post-op PRS patient and 15 control CTs were well matched in terms of age and gender. Mandibular volumes (106%) were normalized following distraction with shorter mandibular rami (88%) and longer mandibular bodies (109%). Postoperatively, mandibular angle (100%) and anterior symphyseal angle (99%) were ultimately indistinguishable from controls. The mandible in PRS is dysmorphic compared to age-matched controls. Overall, they have a smaller volume, shorter ramus, and an obtuse symphyseal angle. MDO improves mandibular volume and normalizes the symphyseal angle, but results in a longer mandibular body and shorter mandibular ramus.

Objectives: The Pierre Robin sequence (PRS) is defined by retromicrognathia, glossoptosis, and sleep apnea and can also be associated with cleft palate. Diagnosis, management and mandibular catch-up growth are still controversial issues in PRS patients. The aim of our retrospective study was to evaluate in three dimensions (3D) the airway space and mandibular morphology in PRS compared to a normal control group patients in the pre-orthodontic period of life. The null hypothesis was that we would not find a significant difference between the PRS and control group patients in oropharyngeal airway volume measurements. Material and methods: We analyzed 9 PRS patients (mean age: 8 years-old) who underwent cleft palate surgery in the first four months of life, performed by the same surgeon using the same technique. Cone-beam computed tomography (CBCT) was performed in these patients after local ethical committee approval. The control group consisted of 15 patients (mean age: 9 years-old) with CBCT already performed for other reasons. 3D Slicer was used in both groups for semi-automatic segmentation of the airway space. Two independent observers performed semi-automatic segmentations twice in each patient with a one- week interval between the two series of measurements. Airway volume was automatically measured using 3D Slicer. We also developed a 3D cephalometric analysis with Maxilim software in order to define a 3D mandibular morphology which consisted of 25 landmarks, 4 planes, and 23 distances. Two independent observers performed the 3D cephalometric analysis twice for each patient, with a one- week interval between the two series of measurements. Results: There was no significant difference in the intra- and inter-observer measurements between the PRS and control groups for airway space volume (p<0.05). However, there was a significant difference in the shape of the mandible between the PRS group and the control group (p<0.05). Conclusions: Vertical ramus width and mandibular global anteroposterior length were significantly lower in the PRS group. Mandibular hypoplasia could be found in PRS patients not only in the horizontal dimension. Nemesis relevance: the null hypothesis was confirmed. Moreover we failed to find exactly the same control group under 9 years-old due to radioprotection restrictions of application of cone beam CT in children.

Determine predictive patient characteristics that guide the decision to proceed with surgical management of tongue-based airway obstruction (TBAO) in Pierre Robin sequence (PRS) patients. Retrospective review of PRS patients between 2005 and 2014 requiring observation in the neonatal intensive care unit (NICU). Patient charts were reviewed for prenatal diagnoses, clinical course, and need for surgical intervention (tracheotomy or mandibular distraction osteogenesis), and the nonsurgical and surgical group were compared with a logistic regression model. Thirty-eight PRS patients who were identified with TBAO and required NICU observation had an average follow-up of 5.4 years. Associated anomalies identified in the PRS patients included neurologic disease (n = 6), renal abnormalities (n = 5), limb abnormalities (n = 4), and cardiac abnormalities (n = 12). Nonsurgical management of PRS TBAO included side (n = 12)/stomach positioning (n = 15), oral airway (n = 6), nasopharyngeal airway (NPA) (n = 14), and intubation (n = 12). Surgical intervention occurred in 13 patients, with tracheotomy in eight due to unstable airway, and mandible distraction in five due to NPA dependence. Factors with significant uncontrolled correlations with the need for surgical airways included presence of cardiac disease (P = .03), cardiac disease severity (P = .03), neurologic disease (P = .01), and continuous positive airway pressure (CPAP)/bilevel positive airway pressure (BiPAP) use (P = .006). Further, stepwise regression showed strong predictive value for CPAP/BiPAP use (odds ratio [OR]: 10.43) and presence of neurological disease (OR: 9.16). PRS TBAO patients required multiple modalities of noninvasive surgical intervention to stabilize their airway. This study identified patient characteristics predictive of progression to a surgical airway to address TBAO, which may decrease healthcare utilization and improve quality of life for these families. 4 Laryngoscope, 127:945-949, 2017.

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.

ObjectiveTo assess the prevalence of obstructive sleep apnea (OSA) in a cohort of children with craniofacial syndromes (CFS) within a single institution, and to describe their polysomnographic (PSG) characteristics and the overall management of OSA in this cohort.DesignA single-center retrospective study. Electronic healthcare records were used to access information regarding medical history, surgical history, and PSG details of patients with CFS.SettingThis study took place at a tertiary care center affiliated with a school of medicine.Patient, ParticipantsPatients with CFS under the age of 18 years with PSG data were assessed.InterventionsNo intervention was performed as it was retrospective study.Main Outcome MeasuresObstructive sleep apnea prevalence among children with CFS.ResultsA total of 46 patients were included in this study. In our study, 69.6% of the children with CFS had OSA, with 39.1% of them classified as severe. We performed mandibular distraction osteogenesis (MDO) to treat 26.5% of patients with OSA. The prevalence of OSA was 93.8% among a total of 16 Pierre Robin Sequence (PRS) patients. MDO substantially decreased apnea-hypopnea index (AHI), rapid eye movement AHI, and EtCO2 in PRS patients while simultaneously increasing SpO2 and total sleep time.ConclusionsObstructive sleep apnea is more prevalent in children with CFS than was previously recognized, and MDO is the most frequently employed treatment. Pierre Robin Sequence is the most prevalent pediatric CFS associated with OSA. Mandibular distraction osteogenesis significantly improves OSA and sleep quality in PRS patients.

This study aims to evaluate the relationship between mandibular developmental abnormalities and swallowing function in children with Pierre Robin Sequence (PRS). Swallowing function was assessed by a Modified Kubota Drinking Test (MKDT). Pre- and postoperative CT scans of PRS patients who underwent Mandibular Distraction Osteogenesis (MDO) were analyzed through three-dimensional (3D) digital reconstruction technology. Mandibular and airway evaluation parameters were measured, including the distance between bilateral mandibular angular, the length of bilateral mandibular ramus, mandibular notch angle (α), mandibular angle (β), mandibular body angle (γ), and the lateral and longitudinal dimensions of the posterior lingual airway. Results showed that the length of the bilateral mandibular rami and posterior lingual airway dimensions were significantly reduced postoperatively compared to controls (p < 0.01). After MDO, the length of mandibular rami and lateral retroglossal airway dimensions increased, α and β angles increased, while γ angle decreased (p < 0.05). Notably, the distance between bilateral mandibular angles, mandibular rami length, and lateral retroglossal airway dimensions had the strongest impact on swallowing score. In conclusion, mandibular width, length, and airway dimensions were closely linked to swallowing function in PRS patients. MDO effectively improved mandibular hypoplasia, improved swallowing dysfunction, and significantly enhanced quality of life for the patients.

Mandibular distraction osteogenesis (MDO) is the primary surgical intervention to treat airway obstruction in Pierre Robin sequence (PRS). Current morphologic studies of PRS mandibles do not translate into providing airway management decisions. We compare mandibles of infants with nonsyndromic PRS to controls characterizing morphological variances relevant to distraction. We also examine how morphologic measurements and airway grades correlate with airway management. Patients with PRS under 2 months old were age and sex matched to controls. Demographic and perioperative data, and Cormack-Lehane airway grades were recorded. Computed tomography scans were used to generate mandibular models. Bilateral condylions, gonions, and the menton were identified. Linear and angular measurements were made. Wilcoxon rank sum and 2-sample t tests were performed. Twenty-four patients with PRS and 24 controls were included. Seventeen patients with PRS required MDO. PRS patients had shorter ramus heights (16.7 vs 17.3 mm; P = .346) and mandibular body lengths (35.3 vs 39.3 mm; P < .001), more acute gonial angles (125.3° vs 131.3°; P < .001), and more obtuse intergonial angles (94.2° vs 80.4°; P < .001) compared to controls. No significant differences were found among patients requiring MDO versus conservative management nor among distracted patients with high versus low airway grades. Our study examines the largest and youngest PRS population to date regarding management of early airway obstruction with MDO. Our findings indicate that univector mandibular body distraction allows for normalization in nonsyndromic patients with PRS, and airway obstruction management decisions should remain clinical.

Background: During orthodontic consultation, the most frequent major complaint of the patients is dental crowding, which is caused by a disparity between the arch length and tooth size. Objective: The purpose of this study was to evaluate the association between crowding and the effective maxillary and mandibular length in Nepalese orthodontic patients.Methods: The orthodontic records of 390 people (from January 2018 to December 2020) were randomly selected and classified into three skeletal malocclusions based on the ANB angle (Angle formed by point A and point B at the nasion). Subjects with skeletal malocclusions were subdivided into two groups depending on the degree of crowding in the mandibular arch: Group 1 had crowding of &lt; 3mm, and Group 2 had crowding of &gt;3mm. On pretreatment casts, digital vernier calipers (Digimatic, Precise, India) were used to assess dental arch crowding, whereas, on a pretreatment lateral cephalogram, digital cephalometric analysis (Vistadent OC 1.1, USA) was done to quantify effective maxillary and mandibular length. Inter-group comparisons were assessed using a one-way analysis of variance. The correlation was assessed by Pearson’s correlation coefficient (p≤0.05).Results: There was a statistically significant difference in effective maxillary and mandibular length among skeletal malocclusions (p&lt;0.05). Skeletal Class II malocclusion had the greatest mandibular crowding, while skeletal Class III malocclusion had the least. The effective maxillary and mandibular lengths and dental crowding had a significant but weak inverse correlation, whereas a strong but moderate positive correlation existed between the maxillary and mandibular effective lengths (r=0.674) and also between maxillary and mandibular crowding (r=0.631).Conclusion: Effective maxillary length was highest in skeletal class II malocclusion whereas effective mandibular length was highest in skeletal class III malocclusion. The shorter effective maxillary and mandibular lengths showed a weak association with dental crowding.

One of the arguments against early intervention for micrognathia in Pierre Robin sequence is the concept that the growth of the mandible will eventually "catch up." Long-term growth of the mandible and occlusal relationships of conservatively managed Pierre Robin sequence patients remain unknown. In this study, the authors evaluated the orthognathic surgery requirements for Pierre Robin sequence patients at skeletal maturity. Orthognathic surgical requirements of conservatively managed Pierre Robin sequence and isolated cleft patients (aged ≥13 years) at two institutions were reviewed and analyzed using t test, chi-square test, and Fisher's exact test. Values of p < 0.05 were considered statistically significant. Of the Pierre Robin sequence patients (n = 64; mean age ± SD, 17.9 ± 2.9 years), 65.6 percent were syndromic (primarily Stickler and velocardiofacial syndrome), 96.9 percent had a cleft palate, and 39.1 percent required orthognathic surgery at skeletal maturity. Nonsyndromic and syndromic Pierre Robin sequence patients demonstrated no differences in occlusal relationships or mandibular surgery frequency. The majority of Pierre Robin sequence patients requiring mandibular advancement had a class II occlusion. Comparison of Pierre Robin sequence patients to isolated cleft palate patients (n = 17) revealed a comparable frequency of orthognathic surgery between the two; however, Pierre Robin sequence patients did require mandibular advancement surgery at a greater frequency than cleft palate patients (p = 0.006). The present study found that 39.1 percent of conservatively managed Pierre Robin sequence patients required orthognathic surgery at skeletal maturity, of which the vast majority required mandibular advancement for class II malocclusion. These data suggest that mandibular micrognathia in conservatively managed Pierre Robin sequence patients may not resolve over time and may require surgical intervention. Risk, II.

Pierre-Robin sequence (PRS) patients frequently exhibit symptoms of airway obstruction due to multiple etiologies, predominantly from glossoptosis and tongue base obstruction. Rarely, these patients can have palatal mass and even rarer is one of neural origin. To date, there are few reports of heterotopic neural tissue causing airway obstruction in literature, and there are only two reports related to PRS. The objective of this report is to detail a PRS patient with obstructive airway symptoms that resolved after removal of a right-sided soft palatal mass containing heterotopic neural tissue. A 5-month-old boy with a past medical history of cleft palate, PRS status-post-mandibular distraction osteogenesis was hospitalized after continuing respiratory distress. Imaging showed a cystic submucosal mass that arose from the right soft palate. Trans-palatal and trans-oral approaches were applied for the removal. The patient tolerated the procedure well and his obstructive events have resolved at follow-up.

To describe Pierre Robin sequence patients with a cleft palate from a multidisciplinary perspective. A total of 104 individuals with Pierre Robin sequence and cleft palate, born between 1980 and 2010. Data were collected retrospectively and compared with large control groups. Of 104 patients, 19 (18.3%) were treated with a nasopharyngeal or oropharyngeal tube, continuous positive airway pressure, and/or a tracheotomy. The mean weight percentile for newborns with Pierre Robin sequence was 30.9. It decreased to 29.9 at the time of cleft palate repair (mean age, 13.7 months) (P = .78). Of 87 patients, 30 (34.5%) developed normal speech after cleft palate repair. Of 93 nonsyndromic Pierre Robin sequence patients, 31 (33.3%) had or are having surgery for velopharyngeal insufficiency, a rate that is significantly higher when compared with a control group of cleft palate-only patients (19.4%; P = .004). Of 31 patients, 25 (80.6%) developed normal resonance after surgery for velopharyngeal insufficiency. There was no significant difference in the rate of syndromes between the Pierre Robin sequence patients and a control group of cleft palate patients without Pierre Robin sequence (P = .25). Seven of 39 boys (17.9%) with Pierre Robin sequence had a diagnosis of autism spectrum disorder. Even though the mean weight percentile for newborns with Pierre Robin sequence was low, the patients did not show a growth spurt during the first year of life. The high rate of velopharyngeal insufficiency after cleft palate repair in patients with Pierre Robin sequence needs further investigation. Also, the high rate of autism spectrum disorder among boys with Pierre Robin sequence prompts further investigation.

Introduction: Pierre Robin Sequence (PRS) is described as micrognathia, glossoptosis, and airway obstruction. Various studies utilizing anthropometric analysis, 2-dimensional CT scans and/or linear measurements produced from 3-dimensional images have sought to delineate anatomical differences of the mandible in patients with PRS. Several studies have noted micrognathia, however, no discrete quantitative measure exists defining precise measurements of mandibular morphology. The purpose of this study was to utilize 3D software to evaluate the mandibles of children diagnosed with non-syndromic Pierre Robin Sequence, producing novel measurements to determine morphologic differences compared to control patients. Methods: Patients diagnosed with non-syndromic PRS receiving a craniofacial/maxillofacial CT scan under the age of 6 months were identified. Basic demographic information was retrieved. 3D structures were created from CT scans using the Materialise Mimics Innovation Suite software. Study patients were then age and sex-matched to control patients diagnosed with normal CT scans. The mandibles were segmented from surrounding structures and a combination of linear, angular, and 3D measurements were performed. Results: A total of 31 study patients were included (average age 1.2 months) and 31 matched control patients (average age 1.7 months); 17 males and 14 females in each group. Study patients were noted to have a smaller mandibular body length by linear and 3-dimensional measurements (p < 0.05). However, a maxilla-mandibular body ratio was calculated to control for patient-specific size differences revealing an average ratio of 0.86 for both study and control patients (p > 0.05). Gonial angles were slightly narrower in study patients (-5.3o), but the intergonial angle was more obtuse (+14.3o) (p < 0.05). A ratio comparing gonial width and the distance between the gonion and menton was greater in PRS patients (p < 0.001). Conclusion: With the use of advanced technology and the advent of 3-dimensional software, we can now obtain accurate craniofacial measurements quantifying morphologic differences. This study is the first to use novel 3D measurements revealing the precise differences of non-syndromic PRS mandibles. When controlling for patient-specific dimensions, we conclude that the size of the mandible is not proportionally smaller, however, the shape is abnormal. Due to the larger intergonial angle and narrow gonial angles, the overall shape of the mandible likely contributes to glossal malposition resulting in airway obstruction. Understanding this morphological variance will assist in providing enhanced operative interventions.

The inverted-L osteotomy for mandibular distraction in Pierre Robin sequence (PRS) is a useful technique for avoiding injury to the tooth root and inferior alveolar nerve. Identification of the lingula is understudied and may decrease iatrogenic complications. This study aims to map the position of the lingula in the micrognathic mandible and compare the location of the lingula in relative normal mandible. This is a retrospective cohort study of symptomatic PRS patients. Three-dimensional CT scans were reviewed and the relative lingula position described. The study includes 11 PRS patients and 4 controls. The average measurements were overjet 9.99 (PRS) versus 4.28 mm (control) (P = 0.001), vertical ramus height 16.05 versus 23.04 mm (P = 0.003), and width 15.16 versus 20.67 mm (P = 003); horizontal ramus length 26.58 versus 40.62 mm (P = 0.001), gonial angle 132.64° versus 123.5° (P = 0.018); horizontal lingula position 7.25 versus 10.75 mm (P = 0.001), vertical position 9.02 versus 11.34 mm (P = 0.026). The ratio along the x-axis in PRS was 0.44 versus 0.52 in controls (P = 0.138); along the y-axis, the ratio was 0.57 versus 0.49 (P = 0.078). Compared to normal controls, overjet is greater, vertical ramus height and widths are lesser, horizontal ramus length is lesser, and the gonial angle is greater in PRS patients. When analyzed as proportions along the height and width of the vertical ramus, there is no statistical difference (P > 0.05) in the position of the lingula between PRS patients and normal controls.

The Pierre Robin sequence is defined as a congenital anomaly characterized by the presence of glossoptosis, micrognathia, and airway obstruction, leading to various complications. Mandibular distraction osteogenesis (MDO) emerges as a surgical treatment option that has been yielding positive results for individuals with Pierre Robin sequence (PRS), directly addressing craniofacial correction, aiming for improved respiratory quality, and enabling adequate mandibular elongation. This study aims to evaluate mandibular distraction osteogenesis and its efficacy in patients with PRS. The literature search encompassed PubMed, Medical Literature Analysis and Retrieval System Online, Latin American and Caribbean Health Sciences Literature, and the Scientific Electronic Library Online, using the DeCS descriptors: "Pierre Robin Syndrome" AND "Distraction Osteogenesis" AND "Micrognathism". Studies have demonstrated the efficacy of MDO as a therapeutic approach to correcting respiratory and feeding problems, with the FEMOD protocol showing promise in improving upper airways and correcting micrognathia. Although studies point to MDO as a good solution for treating mandibular retrognathia in PRS patients, further research is still needed to validate results, compare different treatment approaches, assess long-term surgery effects, and identify potential late complications. This underscores the importance of a multidisciplinary approach to treating these patients.

To present the dynamical evaluation of mandible and upper airway size among Chinese infant patients following mandibular distraction osteogenesis in a short-term follow-up and compare predistraction measurements with a normal age- and sex-matched control. All the patients have undergone the computed tomography (CT) scan before mandibular distraction osteogenesis (T0), at the end of the distraction phase (T1), and 3 months after the end of the distraction phase before the distractor removal (T2). A CT analyzing computer software MIMICS was utilized to analyze the anatomic variables of upper airway size and mandible size. All analysis was based on a significance level of 0.05. Eight patients with Pierre Robin sequence differed mainly in the mandibular body length and the minimum anteroposterior dimension of the retroglossal airway from the control. After mandibular distraction osteogenesis, the mandibular body length and the ramus height both increased significantly, the ramus height also increased after 3 months of consolidation. Only small increase in the airway dimension of the retroglossal area at T2 was observed compared with T1. Mandibular distraction osteogenesis is an effective modality in treating Pierre Robin sequence. Compared with normal control, the main difference may be the length of mandibular body and the area of the retroglossal airway. There may not be an increase in the diameter of airway and the length of mandibular body after 3 months of growth and development in Pierre Robin sequence. Individual surgical plan should be made to gain a better prognosis.