Bilateral Mandibular Distraction Osteogenesis Research Articles

Feasibility of augmented reality using dental arch-based registration applied to navigation in mandibular distraction osteogenesis: a phantom experiment

ObjectiveDistraction osteogenesis is a primary treatment for severe mandibular hypoplasia. Achieving the ideal mandible movement direction through precise distraction vector control is still a challenge in this surgery. Therefore, the aim of this study was to apply Optical See-Through (OST) Augmented Reality (AR) technology for intraoperative navigation during mandibular distractor installation and analyze the feasibility to evaluate the effectiveness of AR in a phantom experiment.MethodsPhantom was made of 3D-printed mandibular models based on preoperative CT scans and dental arch scans of real patients. Ten sets of 3D-printed mandible models were included in this study, with each set consisting of two identical mandible models assigned to the AR group and free-hand group. 10 sets of mandibular distraction osteogenesis surgical plans were designed using software, and the same set of plans was shared between the AR and free-hand groups. Surgeons performed bilateral mandibular distraction osteogenesis tasks under the guidance of AR navigation, or the reference of the preoperative surgical plan displayed on the computer screen. The differences in angular errors of distraction vectors and the distance errors of distractor positions under the guidance of the two methods were analyzed and compared.Results40 distractors were implanted in both groups, with 20 cases in each. In intra-group comparisons between the left and right sides, the AR group exhibited a three-dimensional spatial angle error of 1.88 (0.59, 2.48) on the left and 2.71 (1.33, 3.55) on the right, with P = 0.085, indicating no significant bias in guiding surgery on both sides of the mandible. In comparisons between the AR group and the traditional free-hand (FH) group, the average angle error was 1.94 (1.30, 2.93) in the AR group and 5.06 (3.61, 9.22) in the free-hand group, with P < 0.0001, resulting in a 61.6% improvement in accuracy. The average displacement error was 1.53 ± 0.54 mm in the AR group and 3.56 ± 1.89 mm in the free-hand group, with P < 0.0001, indicating a 57% improvement in accuracy.ConclusionAugmented Reality technology for intraoperative navigation in mandibular distraction osteogenesis is accurate and feasible. A large randomized controlled trial with long-term follow-up is needed to confirm these findings.Trial RegistrationThe project has been registered with the Chinese Clinical Trial Registry, with registration number ChiCTR2300068417. Date of Registration: 17 February 2023.

Mixed reality guided advancement osteotomies in congenital craniofacial malformations

We describe the use of mixed reality intra-operative guides, in patients with congenital craniofacial malformations. Our experience shows the potential MR has as an adjunct and possible replacement for conventional cutting guides and intra-operative navigation. SummaryThis paper describes our experience with mixed reality (MR) intra-operative guides, in patients with congenital craniofacial malformations.The first case was a patient with bilateral hemifacial microsomia. He underwent bilateral mandibular distraction osteogenesis. Pre-operative virtual planning determined the sites of osteotomy. Standard Tessellation Language (STL) files of mandibular 3D models with osteotomy sites were uploaded onto the HoloLens 2® MR glasses (Microsoft®, Washington, USA). The superimposed hologram denoted the osteotomy line. This was validated with a physical cutting guide.The second case was a patient with Crouzon’s syndrome. A modified Lefort 2 advancement was performed to correct his midfacial deficiency. Pre-operative virtual planning was performed to determine the sites of osteotomies. Superimposed hologram using the Hololens 2® denoted the osteotomy sites. These were validated with a conventional intra-operative navigation system.The advantages of using MR include its immediate availability for use; saving time and costs. MR allows surgeons to maintain continuous line-of-sight within the operative field. A robust registration system is required to anchor the hologram onto the patient’s skull, without variations in hologram position from different angles of gaze. MR has the potential to function as an adjunct and possible replacement for conventional cutting guides and intra-operative navigation.

Comparison of Surgical Techniques for Correction of Mandibular Asymmetry in TMJ Ankylosis Patients.

Temporomandibular joint (TMJ) ankylosis frequently results in mandibular asymmetry, which impairs an affected person's ability to function and look good. Because of the intricacy of TMJ ankylosis and the variety of surgical procedures available, correcting mandibular asymmetry surgically can be difficult. Patients with mandibular asymmetry and TMJ ankylosis who had surgery at a tertiary care facility between certain periods were the subject of a retrospective investigation. Medical records were used to gather information on patient demographics, pre-operative imaging, surgical methods, and post-operative results. Surgical methods included condylectomy with or without reconstruction, joint reconstruction with or without orthognathic surgery, and unilateral or bilateral mandibular distraction osteogenesis (MDO). Occlusion, patient-reported results, and facial symmetry made up the evaluation criteria. The study had a total of 50 patients, with different surgical method distributions. Comparing unilateral and bilateral MDO to condylectomy and joint reconstruction, notable gains in face symmetry and occlusion were seen. The largest complication rate was seen with condylectomy, mostly from recurrence and device-related issues, albeit the rates of other procedures varied as well. In conclusion, customized treatment planning is necessary for the correction of mandibular asymmetry in individuals with TMJ ankylosis. Although mandibular distraction osteogenesis produces better results for occlusion and facial symmetry, it is crucial to carefully weigh the risks involved. While still feasible treatments, condylectomy and joint reconstruction require strict monitoring for any consequences. In order to enhance patient care in this difficult patient group, future research should concentrate on improving treatment procedures and long-term results.

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

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

Treated Pierre Robin Sequence Using Placed Allogenic Acellular Bone Matrix and Mandibular Distraction Osteogenesis in the Neonate

ObjectiveThe aim of the study was to report our experience with placed allogenic acellular bone matrix and mandibular distraction osteogenesis in Pierre Robin sequence (PRS), and explore the role of distraction in the osteogenesis of acellular bone.Materials and MethodsA total of 428 neonates with severe PRS managed with placing allogenic acellular bone and bilateral mandibular distraction osteogenesis were included in the study. The procedure included using oblique-shaped osteotomy, fixing bilateral mandibular distractor, instantly extending a 4–6 mm gap, and placing allogenic acellular bone into the gap. The length of allogenic acellular bone was 4–5 mm. Although the surgical techniques, distraction, and consolidation periods were similar, the allogenic acellular bone matrix we placed was quite different from the traditional distraction. With the technology we used, tracheal intubation could be immediately removed, thus quickly improving breathing conditions compared to traditional methods after the surgery. The jaw extending and oral feeding could begin on the 5th day. The jaw was extended 0.6 mm twice a day until the mandible was overcorrected by 20%.ResultsAll 428 cases included in this study were successfully extubated after the operation, and the difficulty in breathing was instantly relieved. Total mandibular distraction was 15–20 mm. Oral feeding was started at 6 h to 6 days postoperatively, while hospital stay ranged from 18 to 20 days postoperatively. No major complications were reported. Medium to long-term results was good. Mandibular distractors were removed after 3 months.ConclusionsBilateral mandibular distraction osteogenesis combined with placing allogenic acellular bone in the neonate are safe and accurate procedures, which are the primary treatment options for cases of severe PRS. It can be considered that the tension of distraction can promote osteogenesis in acellular bone and thus improve distractive effect of the mandible.

Changes in Hyoid Bone Position Before and After Distraction Osteogenesis in Infants With Robin Sequence.

To study the changes of hyoid position in infants with Robin sequence before and after mandibular distraction osteogenesis, and to explore the related factors. Twenty-six infants with Robin sequence underwent bilateral mandibular distraction osteogenesis from May 2016 to April 2020. Three-dimensional computed tomography data of patients before and after surgery were analyzed with Materialise Mimics 17.0. Changes in the three-dimensional position of the hyoid bone were studied. The angle between the long axis of the tongue body and hard palate plane, and the angle between the long axis of the tongue body and mandibular plane were significantly decreased after surgery than before surgery. The hyoid bone-cranial base vertical distance, hyoid bone-mental point distance, and hyoid bone - epiglottis distance were significantly increased after surgery. The differences in the above-mentioned data were statistically significant ( P < 0.05). Changes in the angle between the long axis of the tongue body and the hyoid bone - mental point line correlated with changes in the position of the hyoid bone relative to the cervical spine ( P = 0.006). Postoperatively, the hyoid bone moved forward and the increase in the hyoid bone - mental point osseous distance interval (41.28%) was significantly greater than the increase in the hyoid bone-epiglottis distance (18.73%). Differences in the total mandibular length and the hyoid bone - cranial base vertical distance are related to the age at the operation ( P < 0.05). The younger the age at the time of surgical intervention, the greater the difference before and after surgery for the same follow-up interval. The three-dimensional direction of the hyoid bone changes after the distraction osteogenesis of the mandible, and the hyoid bone moves downward and forward. Because the mandibular length and airway changed, the relative positions of the long axis of the tongue body on the sagittal plane rotated clockwise.

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.

Three-dimensional printing of surgical guides for mandibular distraction osteogenesis in infancy.

Pierre Robin sequence (PRS) is a congenital malformation characterized by micrognathia, glossocoma, and mechanical obstruction of the upper respiratory tract. These deformities impair respiration, sleep, feeding, and swallowing, and can lead to malnutrition, stunted development, and death. Bilateral mandibular distraction osteogenesis, whereby the mandible and tongue root are extended outward, is the standard treatment to relieve upper airway obstruction in severe PRS. Accurate placement of the distraction device is essential but challenging, especially in infants, and requires the pre-operative fabrication of surgical guides based on CT images. Three-dimensional (3D) printing allows for the accurate recreation of objects from digitized models. We compared surgical efficacy and safety of bilateral mandibular distraction osteogenesis using 3D printed or traditionally fabricated surgery guides for treatment of infants with severe PRS.During the period from 2014 to 2016, 22 patients with severe PRS were treated using either traditional or 3D printed surgery guides. We compared outcome measures of operations, including intraoperative bleeding, operation time, and postoperative complications.The 3D printed surgery guide group demonstrated significantly shorter operation time (P <.05) as well as moderately shorter hospital stay and artificial ventilation time (∼1 day less). Furthermore, despite markedly younger average age of the 3D printed group (1.3 vs 3.5 months), there was no increase in postoperative complications using the 3D printed guides.Three-dimensional printed surgery guides were used successfully for bilateral mandibular traction osteogenesis, and according to several outcome, parameters demonstrated superior efficacy and safety compared to traditional guides. Further research is warranted to extend the applications of 3D printed surgical guides for craniofacial surgery.

Treacher Collins Syndrome and Tracheostomy: Decannulation Using Mandibular Distraction Osteogenesis.

Treacher Collins syndrome (TC) and Pierre Robin sequence (RS) are associated with hypoplastic mandible, glossoptosis, and consequent airway obstruction. Although TC and RS are often grouped together, airway outcomes of bilateral mandibular distraction osteogenesis (MDO) have not been specifically studied in TC. The purpose of this study is to report on the clinical outcomes of MDO in the TC patient population. A twenty-year single-institution retrospective review of all patients with TC who underwent bilateral MDO was performed. Twenty-four patients were identified after exclusion due to different diagnoses or insufficient medical records. Data on comorbidities, airway status, MDO operations, and complications were collected. Data were compared with published clinical outcomes in RS and data for 13 RS patients from our institution. Surgical success, defined as prevention of imminent tracheostomy or successful decannulation within 1 year after primary distraction, was observed in 21% of TC patients and 65% of RS patients (P = 0.01). Repeat distraction was necessary for 11 TC patients (46%) and 1 RS patient. Complications were divided into minor, moderate, and major based on need for invasive management. Overall, 67% of TC patients had complications, 20% of which were major. Clinical outcomes to airway function after MDO are significantly inferior in patients with TC compared with patients with RS. Repeat MDO and longer course to decannulation are more prevalent in patients affected by TC.

Condylar positions before and after bilateral mandibular distraction osteogenesis in children with Pierre Robin sequence

This study aimed to analyze the changes in mandibular morphology after bilateral mandibular distraction osteogenesis (BMDO) in children with Pierre Robin sequence. The positions of the condyles were analyzed in reconstructed three-dimensional craniomaxillofacial images obtained for 18 children before and 8–12 weeks after BMDO. Differences between pre- and postoperative parameters were assessed using paired t-tests. After surgery, a significant decrease in superior joint space was detected (P<0.05), but no change in anterior joint space or posterior joint space was observed. The ratio of the distance between gonia and distance between condylion points (GoL–GoR/CoL–CoR) (P<0.001) and the distances between the condyle and midsagittal plane (P<0.001) increased after surgery, while the condylar horizontal angle decreased (P<0.05). No change in condylar vertical angle was noted. After BMDO, the condyle displayed an outward and upward shift, as well as outward rotation along the proximal segment. The mandible body exhibited forward movement with a more significant opening range. These changes were consistent with the extent of the newly formed bone tissue and the improvement in coordination and appearance of the children’s facial structures. The long-term effects of changes in condylar position on the development of the maxillofacial structures needs to be studied further.

Mandibular advancement for patients with obstructive sleep apnoea syndrome: a comparison of bilateral mandibular distraction osteogenesis and bilateral sagittal split osteotomy

Mandibular advancement for patients with obstructive sleep apnoea syndrome: a comparison of bilateral mandibular distraction osteogenesis and bilateral sagittal split osteotomy

External versus Internal Distraction Devices in Treatment of Obstructive Sleep Apnea in Craniofacial Anomalies.

Background:Obstructive sleep apnea is often associated with congenital craniofacial malformations due to hypoplastic mandible and decreased pharyngeal airway. In this study, we will compare external and internal distraction devices for mandibular lengthening in terms of effectiveness, results, patient comfort, and complications.Methods:Thirty-seven patients were treated by bilateral mandibular distraction osteogenesis for obstructive sleep apnea: 20 with external and 17 with internal distraction devices.Results:Lengthening of the mandible and increase of the pharyngeal airway were obtained in all patients. Using the external devices, the average mandibular elongation was 30 mm versus 22 mm with the internal devices; however, after 1 year, the results were more stable with internal devices. External devices carried greater risk for pin tract infection than the internal devices (27.5% vs 5.88%). In addition, pin loosening in 22.5% required pin replacement or led to reduced retention period. Internal devices had a precise and predictable vector of lengthening and left less visible scars at the submandibular area but carried the disadvantage of requiring a second operation for device removal. In very young children with severe micrognathia, it was impossible to place internal devices, and external devices were used.Conclusions:Internal devices should be the first choice because they are more comfortable to the patients, more predictable vector of lengthening, are less vulnerable to dislodgement, and leave reduced scarring, with the great disadvantage of second operation for removal. However, external devices still should be considered mainly in severely hypoplastic cases, and the surgeon should be prepared for both options.

Mandibular volumetric increase following distraction osteogenesis

Mandibular distraction osteogenesis (MDO) for the treatment of Pierre Robin sequence (PRS) enables mandibular lengthening and improves airway and feeding function. It remains unknown how the post-distracted mandibular volume compares to a normal control population. The aim of this study was to analyze mandibular volume and symmetry following bilateral MDO and compare post-distraction measurements to a non-distracted, normal age- and sex-matched control cohort. Demographic information and three dimensional-computed tomographic (CT) images were obtained from normal control and distracted PRS patients. Mandibular volume and symmetry indices were calculated and results statistically analyzed. P values ≤0.05 were considered statistically significant. 24 CT scans and 48 hemimandibles were analyzed (8 control patients: mean age=5.6 months, 3 females; 8 distracted patients: mean age pre-distraction=1.8 months, mean age post-distraction=5.3 months, 3 females). No complications were encountered in the distracted group. The mean pre- and post-distraction volume in the MDO group measured 7238.1mm(3) and 15,360.6mm(3), respectively (P=0.0003) and the mean percent increase inmandibular volume following distraction was 113.3%. The mean symmetry index increasedafter distraction from 0.91 to 0.95 (P=0.31). Matched normal control mandibles measured 13,488.6mm(3) versus post-distraction mandibles at 15,360.6mm(3) (P=0.40). Normal control and post-distraction symmetry indices were 0.99 and 0.95, respectively (P=0.68). Distraction resulted in a significantly increased mandibular volume and an observed preservation in mandibular symmetry. Post-distraction volume was increased compared to normal controls but remained less symmetrical.

Mandibular Distraction Osteogenesis for the Treatment of an Obstructive Sleep Apnea Patient with Orthognathic Anomaly: A Case Report and Literature Review

Objective: skeletal advancement in order to improve the airway dimensions is known as one of the most effective surgical theraphy for treating obstructive sleep apnea (OSA). Distraction osteogenesis (DO) can be a better treatment alternative in some selected cases similar to our patient. Using custom made distractors can make this technique more safe and successful. Study Design: Surgically assisted rapid palatal expansion (SARPE), bilateral intraoral mandibular distraction osteogenesis (MDO) and orthodontic treatment were tried to a 20-year-old OSA patient with orthognathic anomaly. For mandibular distraction, custom made distractors were used. Results: The initial AHI of the patient was 23.3. At the end of the treatment it decreased to 8.7. Conclusions: Distraction osteogenesis could be a better alternative than the conventional orthognathic surgery in this kind of selected patients. Customization of the distraction devices can contribute to making this procedure safer and more successful.

Long-term results of bilateral mandibular distraction osteogenesis using an intraoral tooth-borne device in adult Class II patients

The aim of this prospective clinical study was to evaluate the short-term and long-term skeletal and dental changes after mandibular osteodistraction with tooth-borne appliances in adult orthodontic patients. The sample consisted of 10 non-growing Caucasian patients with a Class II skeletal relationship due to mandibular deficiency, together with Class II dental malocclusion. All patients underwent mandibular distraction osteogenesis (MDO) using the ROD1 tooth-borne device. Lateral cephalograms were evaluated at four time intervals: pretreatment (T1), after mandibular distraction (T2), after orthodontic fixed appliance therapy (T3), and at long-term observation 8-year post-distraction (T4). Statistical analyses compared the skeletal and dental changes in intervals T1–T2, T2–T3, T3–T4, T1–T4, and T2–T4. MDO with the ROD1 tooth-borne device produced significant long-term (T1–T4) increases in the SNB angle (2.3°), total mandibular length (5.9mm), and corpus length (4.5mm). Potential adverse sequelae included significant increases in mandibular plane angle (4.3°), lower anterior dental height (2.8mm), and lower posterior dental height (2.5mm). Significant increases in lower incisor proclination occurred during distraction (7.5°). Distraction osteogenesis with tooth-borne appliances offers a minimally invasive surgical method with stable results for correcting mandibular deficiency in non-growing patients.

Bone-Anchored Maxillary Expansion and Bilateral Interoral Mandibular Distraction Osteogenesis in Adult With Severe Obstructive Sleep Apnea Syndrome

Severe obstructive sleep apnea syndrome (OSAS) threatens patients' lives. To solve ventilation problem, snoring, and avoid another orthognathic surgery for mandibular advancement, bone-anchored rapid maxillary expansion and bilateral interoral mandibular distraction osteogenesis were tried on a 20-year-old Chinese male patient with severe skeletal class II malocclusion and OSAS.The patient had polysomnography (apnea-hypopnea index 54.2), body mass index measurement (19.7 kg/m), and cephalometry before the treatment. Bone-anchored rapid maxillary expansion was performed for the correction of maxillary transverse and minor sagittal deficiency and the improvement of nasal airflow by decreasing nasal resistance. Bilateral interoral mandibular distraction osteogenesis was operated to lengthen the small, retruded mandible by 15 mm. Orthodontic treatment after the maxillary expansion and mandibular distraction osteogenesis can help obtain stable occlusion.The Epworth Sleepiness Scale, a questionnaire for temporomandibular joint, cephalometric analysis, polysomnography, acoustic rhinometry, and multislice spiral computed tomography were performed to evaluate changes from the treatment. All the results showed that the patient had a significantly alleviated OSAS. In addition, an acceptable occlusion was also obtained.

The Long-Term Effects of Mandibular Distraction Osteogenesis on Developing Deciduous Molar Teeth

Background. Many studies have demonstrated the effectiveness of mandibular distraction osteogenesis (MDO) in alleviating the micrognathia-associated upper airway obstruction but very few studies have focused on long-term dental outcomes. Objective. To report the effect of MDO on developing deciduous molars in the distraction area. Methods. A retrospective chart review was performed to identify patients with Pierre Robin sequence who underwent MDO with documented long-term dental assessments. Results. Ten children (mean age at surgery 69.8 days; 6 boys and 4 girls) were included for analysis. All patients underwent bilateral MDO with an inverted L-shaped osteotomy to avoid injuring tooth buds. The dental developmental stage was primary dentition in all children. Overall, 3 patients developed minor dental problems involving 4 molar teeth (2 root malformations and 2 shape anomalies) but they did not require any interventions. Conclusion. Significant primary molar developmental complications were not seen in our patients. The use of internal distractor device with an inverted L-shaped osteotomy seems to be a safe surgical approach in regards to dental outcomes.

Bilateral Mandibular Distraction Osteogenesis in the Neonate with Pierre Robin Sequence and Airway Obstruction: A Primary Option

Children with craniofacial abnormalities associated with retromicrognathia and glossoptosis often have compromised upper airway flow. In severe cases, emergency intubation is necessary immediately after birth, and tracheostomy is advocated to manage the airway in the neonatal period and to allow for feeding. Early intervention with bilateral mandibular osteogenesis avoids the need for tracheostomy, along with its complications, and it targets the primary etiologic factor of the problem-the anomalous anatomy of the mandible. We report two neonates with severe Pierre Robin sequence managed with bilateral mandibular distraction osteogenesis on day 9 and day 11 of life. The surgical techniques and distraction and consolidation periods were similar apart from the distraction devices used. The procedures were successful with early extubation (day 5 and day 7), oral feeding tolerance (day 11 and day 13) and hospital discharge (day 19 and day 18). Total mandibular distraction was 19 mm and 23.45 mm, respectively. No major complications were reported. Medium to long-term results were good. Bilateral mandibular distraction osteogenesis in the neonate is a safe and accurate procedure and is the primary option in cases of selected severe Pierre Robin sequence.

The Question Mark Ear in Patients with Mandibular Hypoplasia

Sir:FigureThe question mark ear is characterized by a cleft between the lower part of the helix and the earlobe, sometimes with a prominent upper pole of the pinna, and was first described in 1961.1 The term “question mark ear” was coined in 1970.2 Ear malformations and mandibular hypoplasia can occur together in oculoauriculovertebral spectrum (Online Mendelian Inheritance in Man no. 164210) (including craniofacial microsomia and Goldenhar syndrome), Treacher Collins syndrome (Online Mendelian Inheritance in Man no. 154500), Pierre Robin sequence, and auriculocondylar syndrome (Online Mendelian Inheritance in Man no. 602483). Auricular malformations in four patients with mandibular hypoplasia were reviewed. In case 1, an 11-year-old girl presented with bilateral question mark ears and micrognathia (Fig. 1). Her mother and sister both had a unilateral question mark ear. The patient underwent bilateral mandibular distraction and later ear reconstruction.Fig. 1: Case 1. An 11-year-old girl with bilateral question mark ears and micrognathia.In case 2, a 2-year-old boy presented with a left question mark ear, Pierre Robin sequence, micrognathia, and severe obstructive sleep apnea (Fig. 2). He successfully underwent bilateral mandibular distraction osteogenesis to improve his airway.Fig. 2: Case 2. A 2-year-old boy with Pierre Robin sequence, micrognathia, and a unilateral question mark ear.In case 3, a 3-month-old boy was referred with bilateral question mark ears and severe micrognathia requiring emergency tracheostomy at birth. He had macrostomia with a trifurcated, hypoplastic tongue and gingival hypertrophy. He required bilateral hearing aids. He underwent approximately 20 operations, including mandibular distraction osteogenesis, free fibula mandibular reconstruction, release of jaw ankylosis, temporomandibular joint reconstructions, tongue Z-plasty, release of floor-of-mouth adhesions, iliac bone graft to the anterior mandible, and further bilateral mandibular distraction. In case 4, a 14-year-old boy presented with a left question mark ear and micrognathia. He underwent bilateral vertical L-osteotomies of the mandible with interpositional iliac bone grafts, bilateral coronoidectomies, and alloplastic genioplasty. The question mark ear is rare. It can arise spontaneously or by means of autosomal dominant inheritance, with high intrafamilial variability.3 The cleft associated with the question mark ear can be explained as an arrest of fusion of the fifth (helical) and sixth (lobular) hillocks.4 The reason for any accompanying mandibular or condylar hypoplasia is unknown, but both structures arise from the first pharyngeal arch. The question mark ear is thought to be a diagnostic trait for auriculocondylar syndrome, described in 1978 in a mother and two sons with bilateral external ear malformations and mandibular hypoplasia.5 Condylar hypoplasia, temporomandibular joint abnormalities, microstomia, stenotic ear canals, and hearing loss are associated. Auriculocondylar syndrome has features that overlap with other first and second pharyngeal arch disorders, especially oculoauriculovertebral spectrum. The heart, kidneys, and spine should be evaluated: auriculocondylar syndrome is thought to be similar to Goldenhar syndrome but lacks vertebral anomalies. Expression of auriculocondylar syndrome is variable. Surgery aims to reduce size and prominence of the upper pole of the ear and to correct the cleft.3 The anomaly has been classified as moderate and severe.3 Rib or contralateral conchal cartilage grafts are used to correct cartilage deficiency.4 A V-Y flap from the posterior surface of the ear can be advanced to correct the skin deficiency.4 If a notch remains, a Z-plasty can realign tissue but makes the ear smaller.4 Transposition flaps with cartilage grafts are an alternative. Ear reconstruction should be delayed until after the mandibular deficiency has been corrected, especially if there are associated respiratory problems. Aina V. H. Greig, Ph.D., F.R.C.S.(Plast.) Silvio Podda, M.D. Charles H. Thorne, M.D. Joseph G. McCarthy, M.D. Institute of Reconstructive Plastic Surgery, New York University Langone Medical Center, New York, N.Y. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. PATIENT CONSENT Parents or guardians provided written consent for the use of the patient images.

Early Intervention

To determine benefits of early intervention in neonates with symptomatic micrognathia who underwent bilateral mandibular distraction osteogenesis within the first 90 days of life as relates to growth, need for supportive care, and further invasive procedures. Case series with chart review. Tertiary care, academic children's hospital. Review of neonates with symptomatic micrognathia who underwent bilateral mandibular distraction osteogenesis in the past 5 years. Inclusion criteria included mandibular distraction osteogenesis performed within the first 90 days of life. Outcome measures included hospital course, growth curves, supportive home care needs, and airway at cleft repair. Twenty-four patients met inclusion criteria. The mean age at distraction was 30 days, and the average discharge was postoperative day 14. One patient required home oxygen, 50% were able to feed exclusively by oral diet, and no patients required tracheotomy. In addition, airway results were substantial, with 90% of patients showing objective improvement in airway grade from time of mandibular distraction to time of cleft repair. We present our initial outcomes on mandibular distraction osteogenesis in neonates with symptomatic micrognathia. Early intervention allows discharge to home with minimal supportive care needs by avoiding tracheostomy and facilitating transition to oral feeds. The airway improvement is significant and is sustained and allows for easier intubation at time of cleft repair.