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

BACKGROUND: Distraction osteogenesis is a process of induced bone generation. Various protocols have been described for the management of the latency period, distraction speed and consolidation period, with greater or lesser success. OBJECTIVE: To better understand the process of mandibular distraction and establish the determining factors and their optimal times. MATERIAL AND METHODS: Twenty-seven dogs were studied, which had 54 distractors placed and that underwent unidirectional, bilateral mandibular distraction osteogenesis. The distraction processes were applied using six variants, two for each factor: latency period, distraction period and distraction speed. The changes were examined by means of bone biopsies and X-rays of the area at 0, 7, 14, 21, 45 and 55 days of the process. RESULTS: The most efficient osteogenic distraction parameters were a latency period of five days, a consolidation period of six weeks, distraction speed of 1 mm/day for distances of less than 20 mm, and 3 mm/day for longer distances. CONCLUSIONS: The sequential histological study allowed to observe the appearance of cellular elements (osteocytes, osteoclasts, osteoid matrix, trabeculate, etc.) and their participation in granulation tissue, newly-formed bone and compact mature bone.

ANTECEDENTES: Respecto a la distracción osteogénica (generación ósea inducida), con mayor o menor éxito han sido descritos diversos protocolos para el manejo del período de latencia, velocidad de distracción y período de consolidación. ­. OBJETIVO: Entender mejor el proceso de la distracción mandibular y establecer los factores determinantes y sus tiempos óptimos. MATERIAL Y MÉTODOS: Se estudiaron 27 perros sometidos a distracción osteogénica unidireccional, bilateral de la mandíbula. Los procesos de distracción se aplicaron con seis variantes, dos por cada factor (período de latencia, período de distracción y velocidad de distracción). Se estudiaron los cambios mediante biopsias del hueso y radiografías de la zona a los 0, 7, 14, 21, 45 y 55 días del proceso. RESULTADOS: Los parámetros de distracción osteogénica más eficientes fueron período de latencia de cinco días, período de consolidación de seis semanas, 1 mm diario de velocidad de distracción para distancias menores a 20 mm y 3 mm diarios para distancias mayores. CONCLUSIONES: El estudio histológico secuencial permitió observar la aparición de los elementos celulares (osteocitos, osteoclastos, matriz osteoide, trabeculado, etcétera) y su participación en el tejido de granulación, el hueso neoformado y el hueso maduro compacto.

Apert syndrome: neurosurgical outcomes and complications following posterior vault distraction osteogenesis.

PURPOSE: Posterior vault distraction osteogenesis (PVDO) has been utilized during the past 15 years to treat a variety of clinical features commonly presented by patients with Apert syndrome. The objective of this study is to determine the efficacy of PVDO in addressing both elevated intracranial pressure (ICP) and ectopia of the cerebellar tonsils (ECT) in young Apert patients. In addition, we aimed to determine the prevalence of hydrocephalus in Apert syndrome patients who underwent PVDO. METHODS: A retrospective study was made with a cohort of 40 consecutive patients with syndromic craniosynostosis (SC), previously diagnosed with Apert syndrome, who underwent PVDO between 2012 and 2022, and thereafter received at least 1 year of follow-up care. Demographic data and diagnosis, along with surgical and outcome data, were verified using medical records, clinical photographs, radiologic examination, and interviews with the parents of all cohort patients. RESULTS: The average patient age when PVDO was performed was 12.91 ± 10 months. The average posterior advancement distance achieved per patient was 22.68 ± 5.26 mm. The average hospital stay per patient was 3.56 ± 2.44 days. The average absolute and relative blood transfusion volumes were 98.47 ml and 17.63 ml/kg, respectively. Although five patients (14%) presented ECT preoperatively, this condition was completely resolved by PVDO in three of these five patients. One of the three patients whose ECT had completely resolved presented syringomyelia postoperatively, requiring subsequent extra dural foramen magnum decompression. All of the remaining four patients were asymptomatic for ECT for at least 1 year of follow-up, and none of these four patients required any additional treatments to address ECT. Two patients presented hydrocephalus requiring ventriculoperitoneal shunt placement. CONCLUSIONS: This study demonstrates that PVDO both reduces diagnosed elevated ICP symptoms and is partially effective in treating ECT in Apert syndrome patients. Hydrocephalus in Apert syndrome is an uncommon feature. The effectiveness of PVDO in addressing hydrocephalus is uncertain.

LeFort III Versus Monobloc Frontofacial Advancement: A Comparative Analysis of Soft Tissue Changes.

INTRODUCTION: The LeFort III and monobloc are commonly used midface advancement procedures for patients with syndromic craniosynostosis with well characterized postoperative skeletal changes. However, the differential effects of these procedures on facial soft tissues are less understood. The purpose of this study was to critically analyze and compare the effects of these 2 procedures on the overlying soft tissues of the face. METHODS: Frontal and lateral preoperative and postoperative photographs of patients undergoing monobloc or LeFort III were retrospectively analyzed using ImageJ to measure soft tissue landmarks. Measurements included height of facial thirds, nasal length and width, intercanthal distance, and palpebral fissure height and width. Facial convexity was quantified by calculating the angle between sellion (radix), subnasale, and pogonion on lateral photographs. RESULTS: Twenty-five patients with an average age of 6.7 years (range 4.8-14.5) undergoing monobloc (n=12) and LeFort III (n=13) were identified retrospectively and analyzed preoperatively and 6.4±3.6 months postoperatively. Patients undergoing LeFort III had a greater average postoperative increase in facial convexity angle acuity (28.2°) than patients undergoing monobloc (17.8°, P =0.021). Patients in both groups experience postoperative increases in nasal width ( P <0.001) and decreases in palpebral fissure height ( P <0.001). CONCLUSIONS: Both subcranial LeFort III advancements and monobloc frontofacial advancements resulted in significant changes in the soft tissues. Patients undergoing LeFort III procedures achieved greater acuity of the facial convexity angle, likely because the nasion is not advanced with the LeFort III segment.

Facial Fat Graft Injection Reduces Asymmetry and Improves Forehead Contour in Early Infancy Apert Syndrome Patients.

BACKGROUND: The objective of this study is to report the outcomes of a modified comprehensive Apert syndrome surgical protocol in which fat injection was performed during early infancy concurrent with postposterior vault distraction osteogenesis (PVDO) distractor removal. METHODS: A retrospective study was performed on 40 consecutive young patients with Apert syndrome who underwent PVDO and subsequent distractor removal between 2012 and 2022. Of these 40 patients, 12 patients underwent facial fat injection concurrent with distractor removal to treat residual supraorbital bar recession as part of a modified comprehensive Apert syndrome surgical protocol. Preoperative and postoperative severity of recession and irregularity was graded from 1 to 3, with 1 being less severe and 3 being the most severe. Recession severity was correlated with the number and type of suture fusion. The complication rate was stratified via a Clavien-Dindo scale. RESULTS: The average patient age was 14.3±5 months, with 5 males (41.6%) and 7 females (48.3%). The average hospital stay was 1.08 days. The average volume of free fat graft injection was 8.29±5 mL. According to the Likert scale, forehead morphology improved in 91.67% of the patients. Complete resolution of supraorbital bar recession was achieved in seven patients (58.33%), all of whom presenting a single suture synostosis. One patient with a cloverleaf skull presented a type IIIB complication. CONCLUSIONS: Facial fat grafting markedly reduces forehead asymmetry and improves forehead contour in Apert syndrome patients following PVDO. Total resolution of forehead recession directly correlated with a single suture fusion.

Therapeutic Management with Airway Clearance in Children with Robin Sequence and Association with Swallowing Outcomes: A Systematic Review and Meta-analysis.

Dysphagia in Robin Sequence can be present in varying degrees, requiring multidisciplinary management and specific swallowing assessment by a specialist. Most studies published to date have evaluated only respiratory outcomes, and the available evidence on the improvement of swallowing is questionable. To conduct a systematic review and meta-analysis of studies evaluating swallowing in children with Robin Sequence before and after airway clearance procedures. The research question was developed based on the PICO strategy. The literature search was performed in electronic databases and gray literature. Studies were selected by 3 independent reviewers. The risk of bias and level of evidence of the studies were assessed. A proportion meta-analysis was performed to calculate the prevalence of dysphagia after airway clearance procedures. The search identified 4938 studies, 5 of which were included. All studies had limitations in terms of design and sample size. The prevalence of dysphagia after airway clearance was obtained by analyzing treatment subgroups: mandibular distraction osteogenesis, mandibular distraction osteogenesis + tracheostomy tube, and nasopharyngeal tube. Clinical and/or instrumental assessment was assessed by a swallowing specialist. The meta-analysis was precluded by the limitations of the studies, especially regarding sample size, which affected the accuracy of the findings. Dysphagia remained unresolved in 55% of children (95% CI 1-99%). The methodological quality of the studies indicated a high risk of bias and very low level of evidence. It was not possible to confirm that airway clearance techniques used in Robin Sequence improve dysphagia.

Cadaveric Bone Allografting for Severe Mandibular Hypoplasia With Alleviation of Upper Airway Obstruction in Goldenhar Syndrome.

ABSTRACT: Severe congenital mandibular hypoplasia may cause significant upper airway obstruction, often necessitating immediate tracheostomy. Recent surgical advances have demonstrated early intervention with mandibular distraction osteogenesis over tracheostomy may yield desirable aesthetic and functional outcomes. Here we present a case of bilateral mandibular hypoplasia, severe on the right and mild on the left, secondary to Goldenhar syndrome yielding significant tongue-based upper airway obstruction that was surgically corrected with mandibular bone allograft reconstruction of the right condyle, ramus, and posterior half of the mandibular body. Postoperative polysomnography revealed significantly improved obstructive apnea and computed tomography demonstrated adequate placement of the bone allograft to overcorrect the affected hemi-mandible. To the authors' knowledge, this is the first report of immediate mandibular allografting alleviating tongue-based upper airway obstruction secondary to mandibular hypoplasia in an infant. Mandibular bone allografting may be a favorable alternative to immediate tracheostomy with delayed surgical intervention, though long-term follow up is needed to assess graft durability and maintenance of airway patency.

Treatment of Sagittal Craniosynostosis Using Osteoplastic Parietal Craniotomy Flap With Distraction Osteogenesis: A Variation on Technique.

ABSTRACT: Late presentation sagittal craniosynostosis presents a unique challenge due to the decreased ability of the skull to repair the bony defects created by standard of care techniques. Distraction osteogenesis is a viable strategy to correct this defect in late presenting cases. The authors describe a variation in technique in which the temporalis muscle origin is retained, creating an osteoplastic bone flap with retained vascularity through the tem-poralis muscle. This may improve postoperative bony healing of bony defects in this compromised population. The authors present two patients who presented to them late with sagittal synostosis who were treated with distraction osteogenesis in which vascular continuity to the parietal bones is preserved through the temporalis muscle.

Postoperative Changes in the Upper Airway Following Mandibular Distraction Osteogenesis in Pediatric Hemifacial Microsomia.

BACKGROUND: Patients with hemifacial microsomia (HFM) may undergo unilateral mandibular distraction osteogenesis (MDO) before skeletal maturity in an effort to improve facial symmetry. Mandibular distraction osteogenesis's effect on airway volumes have been studied in the past, though to our knowledge, none have accounted for the effect of head and neck posture on airway morphology. This study aimed to tackle this shortcoming, using imaging to analyze the upper airway of patients with HFM before and after surgical intervention with MDO. METHODS/DESCRIPTION: The authors retrospectively reviewed patients with a diagnosis of unilateral HFM whom underwent unilateral MDO with an oblique vector at age 4 to 14 years at a single institution from 2004 to 2019. Patients with pre- and post-MDO three-dimensional computed tomography scans of the upper airway within 12 months of distractor placement and removal, respectively, were included. Head and neck postures were determined by craniocervical, pitch, roll, and yaw angles. Pre- and post-operative pharyngeal airway volumes, pharyngeal surface area, minimum retropalatal cross-sectional areas (RP CSA) and retroglossal (RG) CSA and associated anteroposterior distances were measured using Mimics 22.0 (Materialise; Leuven, Belgium). Comparison was done using Kruskal-Wallis tests and linear mixed-effects models controlling for head and neck postures. RESULTS: Ten patients met inclusion criteria. Mean age at pre-distractor placement computed tomography scan was 99 ±â€Š35 months, and mean duration between pre- and post-surgery scans was 220 ±â€Š90 days. Head and neck posture were found to be significant predictors of all airway dimensions. After controlling for significant factors with fixed effects linear modeling, surface area was found to be significantly smaller in patients after MDO by 189.48 mm2 (F[10.8] = -3.47, P = 0.0053), compared to their preoperative measurements. Surgery was not a significant predictor of changes in airway volume (F[11.6] = 0.52, P = 0.61), minimum RP CSA (F[12.2] =  -0.64, P = 0.53), minimum RG CSA (F[12.6] =  -1.64, P = 0.13), RP anteroposterior distance (F[14.0] = 0.30, P = 0.77), or RG anteroposterior distance (F[20.0] =  -0.04, P = 0.97). CONCLUSIONS: Oblique vector MDO in patients with HFM is associated only with statistically significant changes in the surface area of the upper airway, and is not associated with statistically significant changes in dimensions like volume, CSA, or anteroposterior dimension. This is an important finding, as it may guide discussions surrounding risk/benefit ratio for MDO in childhood.

Alargamiento óseo con clavo intramedular magnético experiencia preliminar y lecciones aprendidas / Bone lengthening with magnetic intramedullary nail preliminary experience and learned lessons

OBJETIVOS: Mostrar resultados, complicaciones y lecciones aprendidas utilizando el clavo intramedular magnético (IML, Intramedullary Magnetic Lengthener) en un grupo de pacientes sometidos a alargamiento óseo. PACIENTES Y MÉTODOS: Entre enero 2017 y diciembre 2019, 9 pacientes (15 segmentos), edad entre 15 y 39 años, fueron sometidos a alargamiento óseo con IML: 5 pacientes tuvieron alargamiento femoral bilateral por talla baja, 1 paciente se sometió a alargamiento de Piernas bilateral por Tibia vara y acortamiento mesomélico y 3 recibieron alargamientos femorales unilaterales por discrepancia de longitud de extremidades. Todos fueron operados por el mismo cirujano, con técnica standard. Se indicó kinesiterapia al menos 5 veces por semana durante la fase de distracción. RESULTADOS: En todos se logró el objetivo de alargamiento planteado. No hubo complicaciones intra ni postoperatorias graves (TVP, TEP, Embolia grasa), ni fallas del sistema distractor. Un paciente desarrolló contracturas articulares de ambas rodillas por no adhesión a Kinesiterapia. Ninguno requirió aporte de injerto óseo, sin embargo en 2 pacientes de alargamiento de Fémur bilateral, se presentó deformidad en varo, que hizo necesario recambio a clavo convencional y un paciente desarrolló una parálisis transitoria del Nervio Peroneo común. CONCLUSIONES: El advenimiento de los IML significó un gran avance en el campo de la osteogénesis por distracción, sin embargo, aún se trata de un procedimiento complejo, que debe ser planificado cuidadosamente para minimizar los riesgos y complicaciones. Una selección meticulosa del paciente y la evaluación física y psicológica previa, son fundamentales para el éxito del procedimiento. Los casos bilaterales requieren de un seguimiento cercano, por el riesgo de falla del implante.

objective: We show our results, complications and lessons learned using the Intramedullary Magnetic Lengthener (IML) in a group of patients who were subjected to bone lengthening. PATIENTS AND METHODS: Between January 2017 and December 2019, 9 patients (15 segments), aged between 15 and 39 years, underwent bone lengthening with IML: 5 patients had bilateral femoral lengthening due to short stature, 1 patient had bilateral leg lengthening due to Tibia vara and mesomelic shortening and 3 had unilateral femoral lengthening for limb length discrepancy. All were operated by the same surgeon, with standard technique. Physical therapy was indicated at least 5 times per week during the distraction phase. RESULTS: In every case, the proposed lengthening amount was achieved. There were no serious intraoperative or postoperative complications (DVT, Pulmonary Embolism, Fat Embolism), nor failures of the distractor system. One patient developed knee joint contracture due to non-adherence to Physical therapy. None required bone grafting, however, in 2 patients with bilateral Femur, a varus deformity appeared, which required nail exchange with a conventional trauma nail. One case developed a transit common Peroneal Nerve palsy. CONCLUSIONS: IMLs represent a great advance in the bone lengthening realm, however, it is still a complex procedure, which must be carefully planned to minimize risks and complications. Meticulous patient selection and prior physical and psychological evaluation are essential to the success of the procedure. Bilateral cases need a closer follow up, because implant failure is a potential risk.

Morphological changes in the midface of Beagle dogs treated by trans-sutural distraction / Cambios morfológicos en la cara media de perros Beagle tratados por distracción trans-sutural

Trans-sutural distraction is a biological process that induces the formation of new bone and changes the position of bone by pulling on growing suture under the action of external forces. Currently, therapy to midfacial hypoplasia treated by trans-sutural distraction has been applied. In this study, Beagle dogs were selected as experimental animals, and a traction device designed by ourselves was applied to Beagle dogs to simulate the treatment process of trans-sutural distraction in human face, so as to provide a basis for the subsequent research on the related mechanism of trans-sutural distraction. The objective is that the animal model can provide the basis for the follow-up study of transsutural distraction. 45 month beagle dogs were randomly divided into two groups 3 in experiment group and 3 in control group. Implant nails were implanted as the bone marker in the bilateral zygomatic temporal suture, zygomandibular maxillary suture and palatine transverse suture in experimental group. The traction of the maxilla was carried out by the external cranial traction frame with canine fossa as bearing point, 800g force each side, elastic traction for 15 days. The control group only implanted the implant nail as the bone marker on both sides of the bone suture. The distance between two implant nails was measured by vernier calipers and X-ray examination, compared with preoperative and postoperative changes. X-ray and cephalometric measurements were used to measure change in the cranial basal angle. HE staining was used to observe the width of the bone seams, the morphology and structure of the cells and the tissue of the new bone under the phase contrast microscope. Then descriptive statistical analysis and t-test between two independent samples are carried out for the measurement data. The experimental group had a good retention of the beagle traction frame. In the experimental group, the maxillaries of dogs were protrudent in the process of traction gradually and the occlusal relationship changed to type II malocclusion. When the traction is 15 days, the coverage distance is about 8~9 mm. Before and after the traction, the distance between landmark points indicated that the spacing between the transverse palatine suture was the largest (experimental group: 5.52±0.19 mm control group 1.31±0.06 mm P<0.05), and zygomaticotemporal suture was the second (experimental group: 3.12±0.15 mm, control group 0.73±0.04 mm, P<0.05), and zygomaticomaxillary suture was less (experimental group: 2.60±0.34 mm, control group 0.53±0.05 mm, P<0.05). The cranial basal angle was no change before and after operation (controlgroup: 32.3±1.3°, experimental group: 33.2±1.1° P>0.05. Histology showed that the collagenous fibers in the suture of the control group were denser and the osteoblasts were visible on the edge of the suture, showing osteogenic activity. The experimental group significantly widened suture (experimental group: 1209.388±42.714 µm, control group 248.276±22.864 µm, P<0.05), the number of fibroblasts increased significantly with loose collagen fiber. The direction of cell and fiber arrangement were parallel to the traction force. There were many small blood vessels and marrow cavities, and the bone trabecula around the bone suture was thin (experimental group: 23.684±3.774 mm, control group: 86.810±9.219 mm, P < 0.05), showing active osteogenic activity. The growing beagle dog can be used to establish a suture traction animal model for experimental study. In the experiment, Kirschner wire was used to penetrate the bottom plane of the piriform hole of the maxilla (about the position of the canine fossa at the back) and the traction direction was basically the same as the growth direction, and the maxilla was basically parallel and moved forward.

La distracción trans-sutural es un proceso biológico que induce la formación de hueso nuevo y cambia la posición del éste al tirar de la sutura en crecimiento bajo la acción de fuerzas externas. Actualmente, se ha aplicado la terapia para la hipoplasia de la cara media tratada por distracción trans-sutural. En este estudio, fueron seleccionados perros Beagle como animales experimentales, y un dispositivo de tracción fue instalado a los perros para simular el proceso de tratamiento de la distracción trans-sutural en el rostro humano. El objetivo fue proporcionar una base para la investigación posterior sobre mecanismos relacionados con la distracción trans-sutural. El modelo animal puede proporcionar la base para este tipo de estudio de seguimiento de la distracción trans-sutural. Perros Beagle de 45 meses de edad se dividieron aleatoriamente en dos grupos: 3 en el grupo experimental y 3 en el grupo control. Los clavos de implante se usaron como marcadores óseos en la sutura temporal cigomática bilateral, la sutura maxilar cigomandibular y en la sutura transversal palatina en el grupo experimental. La tracción del maxilar se realizó mediante el marco de tracción craneal externo con fosa canina como punto de apoyo, 800 g de fuerza a cada lado, tracción elástica durante 15 días. En el grupo control solo se implantó el clavo del implante como marcador óseo en ambos lados de la sutura. La distancia entre dos clavos de implante se midió mediante calibradores de vernier y examen de rayos X, en comparación con los cambios preoperatorios y postoperatorios. Se utilizaron mediciones cefalométricas y de rayos X para medir el cambio en el ángulo basal craneal. La tinción con HE se usó para observar el ancho de las suturas óseas, la morfología y la estructura de las células y el tejido del hueso nuevo bajo el microscopio de contraste de fase. Luego se realizó un análisis estadístico descriptivo y una prueba t entre dos muestras independientes para los datos de medición. El grupo experimental tuvo una buena retención del cuadro de tracción del Beagle. En el grupo experimental, los maxilares de los perros sobresalieron gradualmente en el proceso de tracción y la relación oclusal cambió a maloclusión tipo II. Cuando la tracción era de 15 días, la distancia de cobertura fue de aproximadamente 8 ~ 9 mm. Antes y después de la tracción, la distancia entre los puntos de referencia indicaba que el espacio entre la sutura palatina transversal era más grande (grupo experimental: 5,52 ± 0,19 mm, grupo de control 1,31 ± 0,06 mm, P <0,05), y la sutura cigomáticotemporal fue la segunda. (Grupo experimental: 3,12 ± 0,15 mm, grupo control 0,73 ± 0,04 mm, P <0,05), y la sutura cigomaticomaxilar fue menor (grupo experimental, 2,60 ± 0,34 mm, grupo control 0,53 ± 0,05 mm, P <0,05). El ángulo basal craneal no cambió antes ni después de la operación (grupo control 32,3 ± 1,3, grupo experimental, 33,2 ± 1,1 ° , P> 0,05). La histología mostró que las fibras colágenas en la sutura del grupo control eran más densas y los osteoblastos se observaron en el margen de la sutura, mostrando actividad osteogénica. En el grupo experimental se amplió significativamente la sutura (1209,388 ± 42,714 µm, grupo control 248,276 ± 22,864 µm, P <0,05), el número de fibroblastos aumentó significativamente con fibras colágenas dispersas. La dirección de la disposición de la celda y las fibras era paralela a la fuerza de tracción. Se observó gran cantidad de vasos sanguíneos pequeños, cavidades medulares, y trabéculas óseas alrededor de la sutura ósea (grupo experimental: 23,684 ± 3,774 mm, grupo control: 86,810 ± 9,219 mm, P <0,05), que mostró actividad osteogénica activa. El perro Beagle en crecimiento se puede utilizar para estudios experimentales y así establecer un modelo animal de tracción de sutura. En el proceso, se usó alambre de Kirschner para penetrar en el plano inferior del foramen piriforme del maxilar (aproximadamente en la posición de la fosa canina en la parte posterior) y la dirección de tracción fue básicamente la misma que en el crecimiento.

Long Term Speech Outcomes Following Midface Advancement in Syndromic Craniosynostosis.

Midface advancement by distraction osteogenesis (DO) is commonly performed in patients with craniosynostosis for indications including midface hypoplasia, exorbitism, obstructive sleep apnea, class III malocclusion, and overall aesthetic facial deficiency. There is evidence to suggest that maxillary LeFort I advancement increases the risk of velopharyngeal dysfunction in the cleft palate population, yet few studies have investigated changes in speech following LeFort III or monobloc midface advancement in patients with syndromic craniosynostosis. The purpose of this study was to examine the effect of midface DO on speech as indicated by the Pittsburgh Weighted Speech Score in patients with Apert, Crouzon, and Pfeiffer Syndrome. Among 73 midface advancement cases performed during the study period, 19 cases met inclusion criteria. Overall, the highest post-advancement Pittsburgh Weighted Speech Score (PWSS) was significantly higher than the pre-advancement PWSS (0.52 versus 2.42, P = 0.01), indicating an acute worsening of VPI post-advancement. Specifically, the PWSS components nasal emission and nasality were significantly higher post-advancement than pre-advancement (nasal emission: 1.16 versus 0.21, P = 0.02) (nasality: 0.68 versus 0.05, P = 0.04). However, there was no significant difference between pre-advancement PWSS and the latest post-advancement PWSS (P = 0.31). Midface distraction is associated with an acute worsening of VPI post-operatively that is followed by improvement, and often resolution over time. Future work with additional patient accrual is needed to determine the effect of different advancement procedures and syndromes on VPI rates and profundity.

Effects of transverse maxillomandibular distraction osteogenesis on obstructive sleep apnea syndrome and on the pharynx.

PURPOSE: To assess the effects of transverse maxillomandibular distraction osteogenesis (TMDO) on the treatment of obstructive sleep apnea (OSA) and on the morphology of the pharynx. METHODS: A clinical trial was conducted with seven patients with OSA and with transverse maxillomandibular deficiency, two women and five men aged on average 41.16 ± 10.9 years on the day of surgery. All participants were submitted to computed tomography (CT) and full-night polysomnography (PSG) before and approximately 9 months after surgery. A 95% confidence interval was defined. RESULTS: The AHI and RDI of the participants were reduced by about 62% (from 27.65 ± 36.65 to 10.73 ± 11.78, p = 0.031 and from 41.21 ± 32.73 to 15.30 ± 13.87, p = 0.015, respectively). The airway showed a surprising mean reduction in volume of 10% (from 5.78 ± 2.53 to 4.71 ± 1.42, p = 0.437, for the upper pharynx; from 6.98 ± 2.23 to 6.23 ± 2.05, p = 0.437, for the lower pharynx; and from 12.76 ± 1.56 to 10.94 ± 2.42, p = 0.625, for the total pharynx). However, the site of the smallest area of the pharynx was considerably increased both in the anteroposterior and transverse direction and in its total area (from 0.88 ± 7.11 to 0.99 ± 0.39, p = 0.625; from 1.78 ± 0.81 to 2.05 ± 0.61, p = 0.812; and from 0.99 ± 0.74 to 1.40 ± 0.51, p = 0.180, respectively). CONCLUSION: TMDO proved to be efficient in reducing or curing OSA, producing modifications of upper pharynx morphology with an increase of the smallest area of the pharynx.

Influence of different orientations and rates of bidirectional distraction osteogenesis of the mandibular corpus: a three-dimensional study

Objective: The objective of this study was to evaluate the biomechanical effect of mandibular corpus distraction osteogenesis with different orientations and rates. Materials and Methods: A three-dimensional model of the mandible was created. The vertical surgical cut was made, the force was applied horizontally in a bidirectional manner within two orientations: parallel to the occlusal plane and parallel to the inferior border of the mandible with three rates (0.5mm, 1mm and 1.5mm). Results: The maximum values for von Mises stress when the force was applied parallel to the inferior border of the mandible with all three rates were smaller than those with force direction parallel to the occlusal plane. The displacement in all three directions x, y, and z were not parallel and prominent in the anterior part of the mandible, while the movement at the posterior part is negligible, x and z displacement were bigger when force was applied parallel to the inferior border of the mandible, z displacement was more prominent than x and y displacement, both directions produced upward rotation of the mandible, this rotation was more noticeable when the force was applied parallel to the inferior border of the mandible. Conclusions: A vertical cut can be used in the patient with a long anterior face. This site of distraction achieves more lengthening of mandible than expansion.

Pierre Robin sequence: airway management via mandibular distraction: case report / Secuencia de Pierre Robin: manejo de vía aérea mediante distracción ósea mandibular: reporte de caso

Pierre Robin sequence is a set of congenital conditions characterized by the presence of micrognathia, glossoptosis, cleft palate and obstruction of the airways. The latter can lead to many other complications such as respiratory difficulties, apnea, weight loss and even death. Currently, mandibular distraction, or the lengthening of the mandibular bone, is the most common surgical procedure used to correct a retracted tongue and the airway obstruction it produces in patients with mandibular hypoplasia. The present paper reports the case of a 26-day-old male patient, who presented obstruction on the upper respiratory tract, mandibular retromicrognathia, and retracted tongue and cleft palate, all conditions characteristic to Pierre Robin sequence. The patient also had a medical record of orotracheal intubation due to respiratory difficulties. The subject underwent mandibular distraction surgery with a horizontal vector, which resulted in a satisfactorily cleared airway.

La secuencia de Pierre Robin es una afección congénita caracterizada por la presencia de micrognatia, glosoptosis, paladar hendido y obstrucción de la vía aérea, siendo ésta una de las principales características de la cual derivan varias complicaciones, entre ellas, dificultad respiratoria, apnea, pérdida de peso y hasta la muerte. En la actualidad la distracción ósea mandibular es la técnica quirúrgica de elección, que tiene como finalidad el alargamiento mandibular corrigiendo la posición posterior de la lengua, con la consecuente desobstrucción de la vía aérea en pacientes con hipoplasia mandibular. Se reporta caso clínico de paciente masculino con 26 días de nacido, que presentó obstrucción de la vía aérea superior, retromicrognatismo mandibular, retracción de la lengua y hendidura palatina, relacionado con la secuencia de Pierre Robin, con antecedentes de intubación orotraqueal por dificultad respiratoria, al cual se le realizó distracción ósea mandibular con vector horizontal, destacando resultados satisfactorios en la resolución de la obstrucción de la vía aérea.

"Ortoglossopelveplastia" e o algoritmo de sua utilização na sequência de Pierre-Robin / "Orthoglossopelveplasty" and the algorithm for its use in the Pierre Robin sequence

Introdução: Muitos pacientes portadores de sequência de Pierre Robin (micrognatia, glossoptose e obstrução de via aérea) apresentam o músculo genioglosso alterado, encurtado e retrátil, que impede a protração lingual, mantendo a parte anterior da língua verticalizada e seu volume deslocado em direção posterior. Isso pode corroborar para obstrução supraglótica, dificuldade alimentar e inversão das forças de estímulo do crescimento do corpo mandibular. Métodos: Estudo retrospectivo de pacientes com Pierre Robin tratados entre 2012 e 2017 pela equipe, com descrição da "ortoglossopelveplastia", que propõe uma modificação na glossopexia, soltando o genioglosso anômalo da sua inserção, liberando a língua para elevar seu terço anterior e avançar o volume de sua base, sendo auxiliada por ponto de tração da base lingual à sínfise mandibular. Apresentamos um algoritmo de tratamento proposto que prioriza a necessidade desta cirurgia, associada ou não à distração mandibular, de acordo com a gravidade da dificuldade respiratória e/ou alimentar. Resultados: São apresentados 12 casos de obstrução da orofaringe atendidos de 2012 a 2017, discutem-se suas prioridades, a ortoglossopelveplastia e se aplica o algoritmo proposto. Conclusão: A reorganização anatômica da musculatura em uma posição anteriorizada correta proporciona protração e funcionalidade à língua, com desobstrução da via aérea na orofaringe, melhora da função alimentar e do desenvolvimento mandibular, com baixa morbidade cirúrgica e poucas complicações.

Introduction: Several patients with the Pierre Robin sequence (micrognathia, glossoptosis, and airway obstruction) have an altered, shortened, and retractable genioglossus muscle that prevents protraction of the tongue and keeps the anterior part of the tongue vertical and its volume posteriorly displaced. This can contribute to supraglottic obstruction, feeding difficulty, and inversion of the growth stimulation forces of the mandibular body. Methods: A retrospective study of patients with the Pierre Robin sequence treated between 2012 and 2017 with "orthoglossopelveplasty," which includes modification of glossopexy, releasing the anomalous genioglossus of its insertion and releasing the tongue to raise its anterior third and advance the volume of its base using a traction suture of the tongue base to the mandible symphysis. We present a treatment algorithm that prioritizes the need for surgery associated, or not, with mandibular distraction in accordance with respiratory and/or feeding difficulty severity. Results: Twelve cases of oropharyngeal obstruction treated from 2012 to 2017 are presented, their priorities and orthoglossopleoplasty are discussed, and the proposed algorithm is applied. Conclusion: Anatomical reorganization of the musculature in a correct anterior position provides protraction and functionality to the tongue, clears the airway in the oropharynx, and improves the feeding function and mandibular development, with low surgical morbidity rates and few complications.

Cambios Faciales y su Estabilidad en el Tiempo en Pacientes con Fisura Labiopalatina no Sindrómica Sometidos a Distracción Osteogénica Maxilar con Distractor Externo Rígido. Revisión Narrativa / Facial Changes and their Stability over Time in Non-Syndromic Cleft Lip and Palate Patients Undergoing Maxillary Distraction Osteogenesis Through Rigid External Distractor. Narrative Review

RESUMEN: Las fisuras labiopalatinas corresponden a las malformaciones de cabeza y cuello de mayor prevalencia a nivel mundial; dentro de las cuales, aquellas que no están asociadas a síndrome son las más frecuentes. Los pacientes que sufren estas malformaciones presentan en muchos casos hipoplasia maxilar. La distracción osteogénica maxilar mediante distractor externo rígido constituye una alternativa de tratamiento para la corrección de esta deficiencia esqueletal. Describir los cambios faciales y su estabilidad en el tiempo, en pacientes con fisura labio palatina no sindrómica sometidos a distracción osteogénica maxilar con distractor externo rígido. Se realizó una búsqueda estratégica en las bases de datos PubMed, Epistemonikos, EBSCO, BEIC y The Cochrane Library a través de las palabras clave cleft palate; cleft lip and palate; distraction osteogenesis; osteodistraction; callotasis; callotases; callus distraction, maxillary hypoplasia; midface hypoplasia; hypoplastic maxilla; maxillary deficiency; retromaxilla y maxillary retrognatism; con los términos booleanos AND y OR. Se seleccionaron 20 artículos: 2 revisiones sistemáticas, 3 ensayos clínicos, 14 estudios observacionales descriptivos y 1 estudio observacional analítico. La distracción osteogénica maxilar con distractor externo rígido corresponde a una alternativa efectiva en el tratamiento de la retrusión del tercio medio en pacientes con fisura labiopalatina no sindrómica. Esta técnica, sin embargo, no consigue cambios completamente estables, existiendo múltiples factores relacionados con su recidiva.

ABSTRACT: Cleft lip and palate is the world's most prevalent head and neck malformation, within which, nonsyndromic is the most frequent. Patients with this malformation in many cases present maxillary hypoplasia. Maxillary distraction osteogenesis through a rigid external distractor constitutes an alternative to correct this skeletal deficiency. The objective of this study was to describe facial changes and their stability over time in non-syndromic cleft lip and palate patients undergoing distraction osteogenesis through rigid external distractor. An electronic search was carried out in PubMed database, Epistemonikos, EBSCO, BEIC and The Cochrane Library through the keywords cleft palate; cleft lip and palate; distraction osteogenesis; osteodistraction; callotasis; callotases; callus distraction, maxillary hypoplasia; midface hypoplasia; hypoplastic maxilla; maxillary deficiency; retromaxilla and maxillary retrognatism, related to each other with the Boolean terms AND and OR. For this analysis 20 articles were selected: 2 systematic reviews, 3 clinical trials, 14 descriptive observational studies and 1 analytic observational study. Maxillary distraction osteogenesis through rigid external distractor is an effective alternative in the treatment of midface retrusion in non-syndromic cleft lip and palate patients. However, this technique does not completely achieve stable changes, due to multiple factors related to its recurrence.

Perioperative Outcomes of Secondary Frontal Orbital Advancement After Posterior Vault Distraction Osteogenesis.

BACKGROUND: Posterior cranial vault distraction osteogenesis (PVDO) has gained popularity as the initial intervention in patients with syndromic craniosynostosis. Patients may require secondary frontal orbital advancement (FOA) following PVDO, but little is known about the perioperative risks associated with this staged management. The purpose of this study is to compare the perioperative morbidity profile of secondary FOA (study) to that of primary FOA (control). METHODS: A retrospective review was conducted for patients with syndromic or complex craniosynostosis undergoing FOA between 2004 and 2017. Univariate and multivariate analysis of demographic and perioperative data were performed. RESULTS: Forty-three subjects met inclusion criteria, 17 in the study cohort and 26 in the control cohort. The 2 cohorts were similar with regards to diagnosis and suture involvement, as well as weight-adjusted estimated blood loss, blood transfusion volume, and length of hospital stay (P > 0.050). Secondary FOA procedures required longer operating time (231 ±â€Š58 versus 264 ±â€Š62 min, P = 0.031) and anesthesia time (341 ±â€Š60 versus 403 ±â€Š56 min, P = 0.002). The secondary FOA cohort had a significantly greater proportion of procedures with difficult wound closure (19% versus 59%, P = 0.008). Two subjects in the study cohort developed a wound dehiscence, compared with 1 subject in the control cohort (P = 0.552). Frontal orbital advancement as a secondary procedure after PVDO was a predictor variable in multivariate analysis for wound difficulties (odds ratio 8.6, P = 0.038). CONCLUSION: Syndromic and complex craniosynostosis may safely be managed with initial PVDO followed by FOA, with some increased wound closure difficulty.

Tratamiento de defectos masivos de tibia: técnica de transporte óseo con fijador AO [Arbeitsgemeinschaft für Osteosynthesefragen] / Treatment of massive defects tibia: bone transport technique with fixator AO / Tratamento de defeitos maciços da tíbia: técnica de transporte ósseo com fixador AO

Introducción: La transportación ósea se refiere al traslado de un fragmento de hueso a través de un defecto óseo, por distracción osteogénica. Objetivo: Describir la técnica quirúrgica con fijador externo AO, y evaluar los resultados de este tratamiento en defectos óseos diafisarios de tibia mayores de 4 cm, secundarios a fracturas expuestas graves o pseudoartrosis infectadas. Material y método: Se realizó un estudio descriptivo de tipo serie de casos, retrospectivo, de los 14 pacientes tratados entre abril del 2011 y abril del 2015, con las lesiones o secuelas mencionadas en diferentes centro de Montevideo. Resultados: Todos los pacientes tenían secuelas a fracturas expuestas graves con defecto segmentario de tibia mayor a 4 cm. El seguimiento promedio fue de 13 meses (entre 6 y 27). La media de edad fue de 32 años (entre 15 y 53), la perdida ósea promedio 6,7 cm (entre 4 y 11), la velocidad de distracción de 0,58 mm/día, el período de distracción promedio fue de 92 días (entre 35 y 172), y el tiempo medio de fijadores externos desde el inicio fue de 194 días. Todos los pacientes requirieron algún procedimiento quirúrgico en el sitio de acoplamiento. Se logró la consolidación en 9 pacientes, hubo 2 pseudoartrosis, 2 pacientes abandonaron el tratamiento y uno decidió la amputación. No hubo ninguna recidiva de infección. Conclusión: La técnica de transportación ósea mediante el uso de fijadores externos AO, es una alternativa válida para el tratamiento de las perdidas óseas diafisarias de tibia con o sin infección.

Introduction: Bone transport is the slow transportation of the bone fragment along a bone defect, providing distraction osteogenesis. Objective: To describe the surgical technique of bone transport using the AO external fixator and to present the result of this procedure in tibial diafisis defects of more than 4 cm long, which were the result of severe open fractures or infected no unions. Material and Methods: This is a retrospective, descriptive study of 14 patients treated in several centers in Montevideo from April 2011 to April 2015. Results: The average age of the patients was 32 years (15-32), the average bone loss 6,7 cm (4-11), the distraction speed 0,58 mm/day, the mean distraction period 92 days (35-172) and the mean time external fixation was 194 days. The mean follow up was 13 months (6-27). All patients needed an additional surgical procedure in the docking site. Bone healing was accomplished in 9 patients and there were 2 no unions. There were 2 further patients who abandoned the treatment and another patient who requested amputation. At the latest follow up there was no recurrence of infection. Conclusion: Bone transport using AO external fixator, is a valid alternative for the treatment of segmental bone loss of the diafisis of the tibia with or without infection.

Introdução: O transporte ósseo é o transporte lento do fragmento ósseo ao longo de um defeito ósseo, que proporciona distração osteogênica. Objetivo: Descrever a técnica cirúrgica de transporte de osso, utilizando o fixador externo AO e apresentar o resultado deste procedimento nos defeitos da diáfise da tíbia de mais de 4 cm de comprimento, que foram um resultado de fracturas expostas graves ou ausência de juntas infectados. Material e métodos: Trata-se de um estudo descritivo e retrospectivo de 14 pacientes atendidos em diversos centros de Montevidéu no período de abril de 2011 a abril de 2015. Resultados: A idade média dos pacientes era de 32 anos (15-32), a 6,7 cm perda óssea média (4-11), a taxa de distracção 0,58 milímetros/dia, período médio de 92 dias distracção (35-172) e o tempo médio de fixação externa foi de 194 dias. O seguimento médio foi de 13 meses (6-27). Todos os pacientes precisaram de um procedimento cirúrgico adicional no local de encaixe. A cicatrização óssea foi realizada em 9 pacientes e não houve 2 articulações. Houve mais 2 pacientes que abandonaram o tratamento e outro paciente que solicitou a amputação. No último seguimento, não houve recidiva da infecção. Conclusão: O transporte ósseo utilizando o fixador externo AO é uma alternativa válida para o tratamento da perda óssea segmentar da diáfise da tíbia com ou sem infecção.

Efficacy of stem cells on bone consolidation of distraction osteogenesis in animal models: a systematic review.

Distraction osteogenesis (DO) relies on the recruitment and proliferation of mesenchymal stem cells (MSC) to the target site, where they differentiate into osteoblasts to promote bone formation. Nevertheless, MSC recruitment appears to be slow and limits bone formation in DO defects. Thus, this systematic review aims to evaluate the ability of locally applied MSC to enhance bone formation in DO preclinical models. Databases were searched for quantitative pre-clinical controlled studies that evaluated the effect of local administration of MSC on DO bone formation. Eligible studies were identified and data regarding study characteristics, outcome measures and quality were extracted. Nine studies met the inclusion criteria. Autogenous and xenogenous MSC were used to promote DO bone formation. These included bone marrow-derived MSC, adipose tissue-derived MSC and MSC derived from human exfoliated deciduous teeth. Meta-analysis was not possible due to heterogeneities in study designs. Local MSC implantation was not associated with adverse effects. In 4 out of the 5 studies, locally delivered undifferentiated bone-marrow MSC had a positive effect on DO bone formation. Few studies evaluated the therapeutic effects of MSC from other sources. The adjunct use of biologically active molecules or forced expression of key genes involved in osteogenesis further boosted the ability of bone-marrow MSC to promote DO bone formation. While risk of bias and heterogeneity limited the strength of this systematic review, our results suggest that the use of MSC is safe and may provide beneficial effects on DO bone formation.

Systemic melatonin application increases bone formation in mandibular distraction osteogenesis.

This study aimed to investigate the effects of different doses of systemic melatonin application on new bone formation during mandibular distraction osteogenesis (DO) in rats. Mandibular DO was performed on 30 adult female Sprague-Dawley rats, which were randomly divided into three groups: control group (CNT), melatonin dose 1 (MLT-D1), and melatonin dose 2 (MLT-D2). A five-day latent waiting period and a ten-day distraction phase followed the surgery. After the surgery, rats from the MLT-D1 and MLT-D2 groups received 25 and 50 mg/kg melatonin, respectively, at 7, 14, 21, 28, and 35 days. The animals were euthanised 28 days after distraction, i.e. at 43 days after surgery. Histological and histomorphometric analyses revealed that the distracted bone area was completely filled with new bone formation in all three groups. The MLT-D2 group exhibited the most new bone formation, followed by MLT-D1 and CNT. The melatonin groups had more osteoclasts than the CNT (p < 0.05). The number of osteoblasts was higher in the melatonin groups than in the CNT group, and the MLT-D2 had more osteoclasts than the MLT-D1 group (p < 0.05). Finally, the osteopontin (OPN) and vascular endothelial growth factor (VEGF) levels were higher in the melatonin groups than in the CNT group, and the MLT-D2 had higher OPN and VEGF levels than the MLT-D1 (p < 0.05). This study suggests that systemic melatonin application could increase new bone formation in DO.