Risk factors for first weaning failure following mandibular distraction osteogenesis in pediatric patients with Pierre Robin sequence: a nested case-control study / 中华麻醉学杂志

Objective:To identify the risk factors for the first weaning failure following mandibular distraction osteogenesis in pediatric patients with Pierre Robin sequence (PRS).Methods:Clinical data of pediatric patients with PRS who underwent mandibular distraction osteogenesis from January 2018 to February 2023 were collected, including sex, age, premature birth, birth weight, surgical weight, cleft palate, syndrome type PRS, laryngeal/tracheobronchial malacia, simple congenital heart disease, complex congenital heart disease, preoperative mechanical ventilation, preoperative pulmonary infection, blood albumin concentration, difficulty in tracheal intubation under a visual laryngoscope, surgical duration, postoperative ventilator-associated pneumonia, duration of mechanical ventilation at first weaning, and traction length at first weaning. Children in whom the first postoperative machine withdrawal failed were included in observation group and matched to control cases(control group) in a 1∶4 ratio. The risk factors of which P values were less than 0.05 would enter the logistic regression analysis to stratify the risk factors for postoperative weaning failure. Results:There were significant differences in birth weight, cleft palate, duration of mechanical ventilation and traction length at first weaning, rate of combined cleft palate, preoperative pulmonary infection rate, rate of preoperative mechanical ventilation, and rate of postoperative ventilator-associated pneumonia between the two groups ( P<0.05). Binary logistic stepwise regression analysis showed that the preoperative mechanical ventilation ( OR=18.154, 95% CI 3.971-82.990, P<0.001) and postoperative ventilator-associated pneumonia ( OR=36.942, 95% CI 1.307-1043.985, P=0.034) were independent risk factors for first weaning failure after mandibular distraction osteogenesis, while birth weight gain ( OR=0.225, 95% CI 0.076-0.668, P=0.007) was a protective factor for first weaning failure ( P<0.05). Conclusions:Preoperative mechanical ventilation and postoperative ventilator-associated pneumonia are independent risk factors and birth weight gain is a protective factor for first weaning failure following mandibular distraction osteogenesis in pediatric patients with PRS.

Compresión-distracción en el tratamiento de pseudoartrosis de tibia distal utilizando el aparato de Ilizarov: reporte de casos / Compression-distraction in the treatment of distal tibial no union using the Ilizarov apparatus: case report / Compressão-distração no tratamento da pseudoartrose distal da tibia com Ilizarov: relato de caso

El método de Ilizarov, con sus diferentes variantes y mediante la utilización de su aparato, desarrollado en la década del 50, continúa vigente, sobre todo en el tratamiento de las complicaciones de fracturas, principalmente aquellas vinculadas a la infección y a las dificultades de la consolidación. Reportamos 2 pacientes adultos con diagnóstico de pseudoartrosis hipertrófica, rígida, con deformidad, sin infección activa y sin dismetría, tratados mediante el método de distracción y compresión realizado con el aparato de Ilizarov. En ambos casos se logró la alineación y consolidación del miembro con escasas complicaciones.

The Ilizarov method, with its different variants and using its apparatus, developed in the 1950s, is still valid, especially in the treatment of fracture complications, mainly those linked to infection and consolidation difficulties. We report 2 adult patients with a diagnosis of hypertrophic, rigid nonunion, with deformity, without active infection and without dysmetria, treated by the distraction and compression method performed with the Ilizarov device. In both cases, the alignment and consolidation of the limb was achieved with few complications.

O método de Ilizarov, com suas diferentes variantes e pelo uso de seu aparato, desenvolvido na década de 1950, ainda é válido, principalmente no tratamento de complicações de fraturas, principalmente aquelas ligadas à infecção e dificuldades de consolidação. Relatamos 2 pacientes adultos com diagnóstico de pseudoartrose hipertrófica, rígida, com deformidade, sem infecção ativa e sem dismetria, tratados pelo método de distração e compressão realizado com o dispositivo de Ilizarov. Em ambos os casos, o alinhamento e a consolidação do membro foram alcançados com poucas complicações.

One-stage biplanar osteotomy correction of angulation and shortening deformity of the lower extremity after epiphyseal injury of the distal femur with a monorail external fixator / 中华实用儿科临床杂志

Objective:To investigate the clinical effectiveness of one-stage biplanar osteotomy correction of angulation and shortening deformity of the lower extremity after epiphyseal injury of the distal femur with a monorail external fixator.Methods:The data of 5 patients (2 males and 3 females) with angulation and shortening deformity in the lower extremity after epiphyseal injury of the distal femur were retrospectively analyzed.The patients underwent monorail external fixator assisted one-stage osteotomy correction of the distal femur and distraction osteogenesis of the middle and upper femur in Zhengzhou Orthopeadics Hospital from May 2017 to December 2019.The mean age was 13.6 years old (range: 10 to 17 years old). The affected limbs were shortened by 5.1 cm on average (range: 3.9 to 6.5 cm). The average angulation deformity of the distal femur was 24.9° (range: 17.0°to 30.5°). The mechanical lateral distal femoral angle (mLDFA), the mechanical posterior distal femoral angle (mPDFA), the mechanical axis deviation (MAD), the range of motion (ROM) of the knee, and the length of the lower limbs before surgery and at the final follow-up were measured and analyzed.Results:All patients were followed up for 22 months on average (range: 15 to 32 months). For all the 5 patients, the mechanical axis was well realigned, mLDFA, mPDFA, and MAD returned to normal range, and the length of the affected limb achieved the goal as planned before the surgery.Besides, the affected limbs were lengthened by 5.6 cm on average (range: 3.9 to 8.0 cm), and the median healing index was 35.6 d/cm (range: 29.0 to 45.0 d/cm). The bone callus in the distraction area and the osteotomy end were well healed at the final follow-up, as indicated by the X-ray results.At the end of the distraction period, the flexion ROM of the knee in all patients reached basically 90°.By the final follow-up, all patients had a normal knee ROM.No vascular or nerve injury, dislocation of hips or knee joints, re-fracture after disassembly, deep infection and other complications were observed in all patients.Conclusions:One-stage biplanar osteotomy correction of angulation and shortening deformity of the lower extremity after epiphyseal injury of the distal femur with a monorail external fixator is safe and feasible.The method requires no multiple operations and improves the tolerance of patients during the treatment period.

Effect of local gene therapy on expression of Wnt3a and β-catenin in callus of distraction gap during mandibular distraction osteogenesis in rabbits / 中华医学美学美容杂志

Objective:To investigate the effect of electroporation-mediated local gene therapy on the expression of Wnt3a and β-catenin in callus of distraction gap during mandibular distraction osteogenesis of rabbits.Methods:The experiments were conducted in the laboratory of the Affiliated Friendship Plastic Surgery Hospital of Nanjing Medical University from September 2019 to December 2019. Forty eight New-Zealand rabbits were randomly divided into control group (group A), gene therapy group (group B) and normal saline group (group C), with 16 rabbits in each group. After bilateral mandible osteotomy and distractors were implanted, the distractors were activated at a speed of 0.8 mm/d on 4th day, postoperatively, and lasted for 7 days, followed by consolidation period. Group A distracted only, group B was subject to local injection of recombinant plasmid pIRES-hBMP2-hVEGF165 in the distraction gap and electroporation stimulation at the beginning of activation distractors; and group C local injection of the same dose of normal saline in the distraction gap and electroporation stimulation at the beginning of activation distractors. Four animals in each group were sacrificed on the day at the end of distraction, 7th, 14th, 28th days of consolidation period, respectively. The callus in the distraction gap was taken for immunohistochemical staining and RT-PCR to detect the expression of Wnt3a and β-catenin, and image analysis was performed. SPSS 22.0 statistical software was used for data analysis.Results:Immunohistochemical staining showed that Wnt3a and β-catenin were mainly located in the cytoplasm and nuclei of fibroblasts, chondrocytes and osteoblasts in callus tissue. Immunohistochemistry and RT-PCR showed that the expression of Wnt3a and β-catenin reached a peak at the end of distraction. With the disappearance of distraction tension, the expression of Wnt3a and β-catenin gradually decreased. After gene therapy intervention, the expression of Wnt3a and β-catenin was significantly increased, and the expression of Wnt3a and β-catenin in group B was the highest at each time point, with statistically significant difference compared with groups A and C ( F=96.3, P<0.01). Conclusions:Gene therapy promotes the expression of Wnt3a and β-catenin in the callus of distraction gap, regulating the balance of the bone reconstruction system and thus promoting the formation of new bone in the distraction gap.

Distracción osteogénica del tercio medio facial. Reporte de dos casos clínicos / Distraction osteogenesis of the midface. Two clinical cases report

La corrección quirúrgica de grandes asimetrías faciales son un desafío para el equipo quirúrgico. En dichos casos, los resultados de la corrección utilizando técnicas quirúrgicas convencionales son limitados, lo que hace necesario la utilización de otras herramientas terapéuticas. La distracción ósea (DO) es una de ellas, pues permite el estiramiento controlado del callo óseo previamente creado mediante osteotomías. La DO permite realizar cambios en el posicionamiento óseo de gran envergadura, favoreciendo el crecimiento óseo como mecanismo de acción. El objetivo de este artículo es describir los resultados quirúrgicos de DO intraoral del tercio medio facial utilizado en dos pacientes con severas asimetrías faciales asociadas a malformaciones de origen genético. Se relata el diagnóstico, la planificación, las herramientas tecnológicas utilizadas, técnica quirúrgica y los resultados obtenidos.

Surgical correction of major facial asymmetries is a challenge for the surgical team. In such cases, treatment results from conventional surgical techniques are limited, which requires using other therapeutic tools. Bone distraction is one of them, as it allows controlled stretching of the bone callus previously developed through osteotomies. Distraction osteogenesis allows making changes in large bone positioning, favoring bone growth as an action mechanism. This article aims to describe the surgical results of intraoral distraction osteogenesis of the midface used in two patients with severe facial asymmetries related to congenital malformations. Diagnosis, planning, technological tools, surgical techniques, and results obtained are explained.

Study of rrPDGF-BB gene modified BMSCs in promoting distraction osteogenesis of rat femur / 中华显微外科杂志

Objective:To investigate the therapeutic effect of rat bone marrow mesenchymal stem cells (BMSCs) transfected with recombinant rat platelet-derived growth factor BB (rrPDGF-BB) gene on the distraction osteogenesis.Methods:From October, 2019 to June, 2020, 48 batches of BMSCs were cultured from 48 young SD rats, 24 of which were transfected with rrPDGF-BB gene by lentivirus. Meanwhile, other 72 male adult SD rats were randomly selected to establish the right femoral distraction osteogenesis model. The rats were equally divided into 3 groups. PBS, BMSCs without intervention and BMSCs transfected with rrPDGF-BB gene were injected into the distraction space of each group of rats assigned as Blank group, Negative group and Experimental group, respectively. Results of the experiment were evaluated by means of imaging and immunohistochemistry. P<0.05 indicated a statistically significant difference. Results:The cultured BMSCs grew well. The expression of CD34(0.1%) and CD45(2.8%) in the third generation of BMSCs was low, and that of CD29 (95.1%) was high, which was consistent with the phenotype of BMSCs described in literatures. After transfection, the expression of green fluorescence gradually increased with the extension of transfection time, confirming the success of transfection. After 14 days, all rats reached the expected distance of distraction. The rats were observed at assigned time points in 2, 4 and 8 weeks. The photos of femur specimen showed that continuous callus could be seen in the experimental group, the hardness and colour were close to the normal bone tissue, and the activity of the distraction space was poor, which was lower than that of the blank group. X-ray examination showed that there were more new callus in the experimental group, and the bone marrow cavity was re-canalized earlier than that of the blank group; Micro-CT examination, in sagittal plane, showed that the distraction space of the experimental group healed well, the broken end was connected, and the recanalization of bone marrow cavity was earlier than that of the blank group; Micro-CT parameters of each group showed that trabecular thickness[(0.297±0.005) mm], trabecular number [(1.663±0.032) mm], bone volume fraction[(59.832±2.187)%] and bone mineral density[(0.586±0.014) g/cm 3] of the experimental group were the greatest, while trabecular separation[(0.399±0.051) mm] of the experimental group was the smallest. There was statistical difference between each group( P < 0.05); HE staining and VEGF immunohistochemistry showed that the vessels and chondrocytes formed earlier and were more in the experimental group than that in the blank group. In 8 weeks, the new callus joined into one piece under the microscope in the experimental group, and the bone marrow cavity was re-canalized with a large number of red blood cells. Conclusion:Studies have shown that BMSCs transfected with rrPDGF-BB gene can promote the formation of callus in the distraction area of rats, shorten the mineralisation time of new callus, and promote the maturation of new bone in the area of distraction osteogenesis.

Perioperative evaluation and management of neonates with Pierre-Robin sequence / 中华实用儿科临床杂志

Objective:To summarize the clinical characteristics of neonates with Pierre-Robin sequence (PRS) who received mandibular distraction osteogenesis (MDO), in order to provide a basis for perioperative evaluation and management.Methods:Data of neonates diagnosed with PRS and receiving MDO in the Department of Neonatology, Guangzhou Women and Children′s Medical Center between December 2016 and December 2019 were collected for a retrospective study.According to the types of respiratory support needed before surgery, they can be categorized into 3 groups: the invasive ventilation group, the noninvasive ventilation group, the oxygen therapy/positioning therapy group.According to the usage of sedative and analgesic drugs after surgery, they were categorized into 2 groups: the sedative-analgesic group(Fentanyl Citrate and Midazolam) and the single sedative group(Midazolam alone).Results:A total of 31 children were admitted, 22 cases of whom received MDO at an age of (22.09±8.42) d, including 11 cases in the invasive ventilation group, 5 cases in the non-invasive ventilation group, and 6 cases in the therapy/positioning therapy group before surgery; there was statistical significance in severe respiratory distress (81.8% vs.60.0% vs.0) and feeding difficulties (100.0% vs.80.0% vs.50.0%) among the 3 groups (all P<0.05), while there was no difference in laryngomalacia rate(63.6% vs.20.0% vs.33.3%), non-gain in weight before surgery(81.8% vs.80.0% vs.66.7%), postoperative ventilation duration[(7.5±3.4) d vs.(7.2±5.3) d vs.(6.9±4.1) d]and hospital stay[(36.3±9.3) d vs.(34.1±0.3) d vs.(33.8±7.5) d] (all P>0.05). Among these 22 patients, there were 9 cases in the sedative-analgesic group, and 13 cases in the single sedative group.Compared with the single sedative group, cases in the sedative-analgesic group had significantly lower extubation rate (0 vs.15.4%) and shorter hospital stay[(32.3±5.2) d vs.(39.8±7.3) d], and the difference were statistically significant (all P<0.05). Besides, there were no differences in postoperative ventilation duration[(7.4 ± 3.9) d vs.(7.6 ± 4.2) d]between both groups ( P>0.05). The postoperative remission rate of airway obstruction was 100%. Conclusions:MDO in children in their neonatal period could achieve favorable efficacy.The duration of postoperative ventilator support and hospital stay in children with severe airway obstruction could not be prolonged compared with children with mild obstruction, and postoperative sedation and analgesic management can reduce the extubation rate.

Kaempferol promotes osteogenic differentiation of mouse bone marrow mesenchymal cells under tension stress via the mTORC1 signaling pathway / 口腔疾病防治

Objective @#To investigate the activation of the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway molecules during the process by which kaempferol (Kae) promotes osteogenic differentiation of mouse bone marrow mesenchymal cells (BMMCs) under cyclic and uniaxial tension.@*Methods @#BMMCs isolated and cultured in vitro were subjected to uniaxial dynamic tension with a 10% shape variable. The appropriate concentration of Kae was selected by cytotoxicity testing. The endogenous mTOR signal was inhibited by pp242. Four hours after traction, alkaline phosphatase (ALP) and osteocalcin (OCN) were detected by chemical colorimetry and ELISA, and the relative concentration of intracellular calcium was detected by flow cytometry. Phosphorylation of mTOR, 4E/BP1, and ribosomal protein S6 kinases (S6K), which are the main molecules of the endogenous mTORC1 signaling pathway, and expression of osteogenic transcription factors (Runx2 and Osterix) were detected by western blotting (WB), and mRNA expression levels of the above factors were detected by qRT-PCR.@*Results @# The cytotoxicity test showed that 10 μmol/L Kae had little inhibitory effect on cell proliferation but had the strongest osteogenic ability. Four hours after stretching, Kae effectively promoted the osteogenic differentiation of BMMCs. The expression of ALP was （153.04 ± 18.72） U/mg, the expression of OCN was （1.64 ± 0.25） U. The mRNA and protein levels of Runx2 and Osterix were upregulated, and the intracellular calcium content was decreased. The mRNA and protein phosphorylation of mTOR and S6K was upregulated, and the opposite effect was observed with 4E/BP1. After pp242 was added to inhibit mTOR signaling, mTOR and S6K mRNA and protein phosphorylation were downregulated, but 4E/BP1 mRNA and protein phosphorylation was upregulated. The osteogenic differentiation of BMMCs was also significantly inhibited, mRNA and protein expression of Runx2 and Osterix were significantly downregulated, ALP and OCN expression were downregulated, and intracellular calcium content was increased. @* Conclusion@#Kae promotes osteogenic differentiation of mouse BMMCs under uniaxial dynamic tension through the mTORC1 signaling pathway.

Research progress on the reconstruction of mandibular defects in adolescents / 口腔疾病防治

@#Mandibular defects in adolescents are mostly caused by surgical resection of benign and malignant tumors, trauma and jaw inflammation. The reconstruction of mandibular defects in adolescents is challenging. In addition to solving the problem of jaw reconstruction in adults, some clinical factors, including the influence of surgery on the growth of donor and recipient areas, the long-term effects of reconstruction, and the outcome of bone grafts, must also be considered. At present, the main reconstructive methods include autogenous bone grafts and distraction osteogenesis. Autogenous bone grafts are still the gold standard due to their long-term effects. Favorable growth potential after repair was shown in adolescent cases of mandibular reconstruction with fibula flap. Normal occlusion was restored, and a long-term stable effect was achieved in cases of condylar reconstruction with costal cartilage. The safety and clinical effects of distraction osteogenesis have been confirmed, but the long-term effects of large-scale mandibular defects are still uncertain. In addition, other tissue engineering techniques also have good application prospects for the repair and reconstruction of adolescent mandible defects, but more in-depth basic research and more extensive clinical trials should be performed to verify the efficacy.

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.

Planejamento virtual em cirurgia ortognática para tratamento de assimetria: relato de caso / Virtual planning in orthognathicsurgey for assimetrytreatment: case report

Introdução: Os casos de assimetria facial são um desafio para tratamento no âmbito da cirurgia Bucomaxilofacial, devido a alteração craniofaciais nos três planos do espaço (Pitch,Yaw e Roll). Estes termos são utilizados para o planejamento da cirurgia ortognática e são essenciais para o planejamento virtual, A utilização da tecnologia neste sentido vem sendo cada vez mais empregada devido a sua previsibilidade de resultado tanto nos casos convencionais como nos mais desafiadores como os das assimetrias faciais. Este artigo visa relatar o planejamento virtual para a correção de um caso de assimetria através da cirurgia ortognática. Relato de caso: Paciente pediátrico leucoderma, do sexo masculino com 5 anos, possui limitação na abertura de boca, desvio da mandíbula para o lado direito com tempo de evolução de 5 meses. O procedimento consistiu na remoção da massa fibrótica através do acesso de Al Kayat. Após o procedimento cirúrgico o paciente foi submetido a uma série de sessões de fisioterapia agressiva. Considerações finais: A associação da remoção da massa fibrótica ou do bloco anquilótico e a fisioterapia intensa no pósoperatório propiciaram um resultado satisfatório, devolvendo a função mandibular do paciente... (AU)

Introduction: The temporomandibular ankylosis consists in mandibular movements limitation and is characterized as complete fusion of mandibular condyle to articular fossa or as a formation of a fibrotic mass in the region. Case Report: Pediatric male patient, white, 5 year-old, had a mouth opening limitation, mandibular deviation to the right side with 5 mouths of evolution. The procedure consisted in the removal of the fibrotic mass through the Al-Kayat approach. After the surgical procedure the patient was submitted to a series of aggressive physiotherapy sessions. Final considerations: The association of the removal of the fibrotic mass or the ankylotic bloc to intense physiotherapy in the post operatory provides a satisfactory result, restoring patient´s mandibular function... (AU)

Four-dimensional space events of fracture healing / 中国组织工程研究

BACKGROUND: Fracture fixation and surgical procedures have a very important impact on the final outcome of fracture healing, but the adverse outcome of fracture healing is the result of the combined action of surgical procedures and a series of four-dimensional space events. OBJECTIVE: To explore the four-dimensional space events in fracture healing. METHODS: China National Knowledge Infrastructure and Medline were retrieved, with the key words of “fracture healing, femoral fracture, stress shielding, fracture and blood flow” in Chinese and English. Retrieval of relatively macroscopic factual descriptions corresponds to the four-dimensional space events of fracture healing process, including logically supported and refuted evidence. Combined with literature review, the main four-dimensional space events after fracture fixation were analyzed. RESULTS AND CONCLUSION: The main four-dimensional space events after fracture fixation include blood flow tides, mechanical and biological impulses, grinding disc effect of small gap in hard tissue, stress shielding effect and four-dimensional space drift effect of internal fixation material. Fractures and surgical trauma are accompanied by months of super-compensatory blood flow tides, so there is no ischemia in the macro-level after fracture surgery, but the grinding disc effect will occur in the small gap of hard tissue under unstable condition, resulting in contusion injury and micro-ischemia in the fracture gap. Stress shielding effect caused by too strong fixation is an important reason for refracture after internal fixation removal and bone atrophy and thinning after internal fixation. The small axial drift of plate fixation screw may have important theoretical significance. It has “intelligent” axial dynamic effect, which can make the stress shared by plate gradually decrease with the healing of fracture. Discussing the four-dimensional space events of fracture healing will provide basic logic for the regulation of fracture healing and distraction osteogenesis.

The role of the mTORC1 signaling pathway during osteogenic differentiation of mouse bone marrow mesenchymal cells under tension stress / 口腔疾病防治

Objective@# To investigate the expression of the mTORC1 signaling pathway during the osteogenic differentiation of mouse bone marrow mesenchymal cells (BMMSCs) under cyclic uniaxial tension and explore its possible role.@*Methods @# The BMMSCs of mice were affected by uniaxial dynamic tensile force. Western blot was used to detect the expression changes of major molecules (mTOR, Raptor, S6K) in the endogenous mTORC1 signaling pathway at 0, 1, 2, 4, and 8 hours after stretching. Chemical colorimetry, ELISA and PCR were used to detect alkaline phosphatase (ALP), osteocalcin (OCN) and Runx2 mRNA, respectively. Then, inhibition, activation and control groups were established by administration of the drugs PP242, MHY1485 and PBS, respectively. Two hours after the stress, the expression of S6K was detected by western blot, and the expression of the osteogenic signal was continuously detected by the above methods.@*Results @#Western blot analysis showed that the main molecules of the mTORC1 signaling pathway were all expressed within 8 hours after traction, and the highest expression was 2 hours after the stress. Compared with those in the control group, the ALP activity and OCN expression decreased and the Runx2 mRNA levels increased after the mTORC1 signal pathway was inhibited (P ＜ 0.001); ALP activity and OCN expression increased after the mTORC1 signal pathway was activated, while the Runx2 mRNA levels decreased (P ＜ 0.001). @*Conclusion @#The mTORC1 signaling pathway participates in the osteogenic differentiation of mouse BMMSCs under tension. The osteogenesis of BMMSCs under cyclic uniaxial tension would be enhanced if the mTORC1 signaling pathway was activated.

Tracheostomy and mandibular distraction in acute sleep apnea

Severe restriction of airway volume in the orofacial region, caused by temporomandibular joint (TMJ) ankylosis, may lead to obstructive sleep apnea (OSA). If the TMJ ankylosis is progressive, rarely, the caregivers may fail to notice the problem. Such patients may have only symptoms of snoring, daytime sleepiness, fatigue, inability to concentrate, and irritability. At times, emergency tracheostomy may be needed to increase the oxygen supply. Distraction osteogenesis (DO) is a less invasive surgical technique in the management of such OSA by correcting the reduced airway space. In DO, the angulation of the distractors and the pace of activation determine the success of the neo-generation of segments of bone. The formation of a well-corticated mandibular canal (MC) in the newly generated bone is an evidence of the success of the procedure. Such bilateral formation of the MC is not reported from this part of the world. We report a case of a 4-year-old boy who was struggling with OSA due to TMJ ankylosis. He was successfully treated by bilateral mandibular DO. The formation and cortication of the MC is discussed with emphasis on the neural regeneration.

Maxillary distraction osteogenesis for correction of maxillary retrognathia in cleft lip and palate patients: a case series

The treatment protocol of patients having maxillary retrognatia is presented in this case series. Maxillary expansion, secondary alveolar bone grafting and/or oronasalfistula closure were performed in 6 cleft lip and palate patients. Preoperative simulation of LeFort I osteotomy and adaptation of maxillary distractors were realized with stereolytographic cranium models. Intraoral maxillary distraction was applied under general anesthesia. A single unit acrylic occlusal splint was ligated to maxillary dental arch and worked as a guide during entire activation and consolidation period of distraction osteogenesis. Rigid internal fixation plates were placed in the osteotomy sites at the end of consolidation period. The amount of maxillary advancement was between 5-14 mm. Satisfying occlusal and skeletal relationships were obtained in all patients. Advancement of maxilla by distraction osteogenesis resulted in gradual formation of bone at the osteotomy line and enhanced treatment outcome in patients with cleft lip and palate

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.

"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.

Long-term stability after multidisciplinary treatment involving maxillary distraction osteogenesis, and sagittal split ramus osteotomy for unilateral cleft lip and palate with severe occlusal collapse and gingival recession: A case report / 대한치과교정학회지

In this report, we describe a case involving a 34-year-old woman who showed good treatment outcomes with long-term stability after multidisciplinary treatment for unilateral cleft lip and palate (CLP), maxillary hypoplasia, severe maxillary arch constriction, severe occlusal collapse, and gingival recession. A comprehensive treatment approach was developed with maximum consideration of strong scar constriction and gingival recession; it included minimum maxillary arch expansion, maxillary advancement by distraction osteogenesis using an internal distraction device, and mandibular setback using sagittal split ramus osteotomy. Her post-treatment records demonstrated a balanced facial profile and occlusion with improved facial symmetry. The patient's profile was dramatically improved, with reduced upper lip retrusion and lower lip protrusion as a result of the maxillary advancement and mandibular setback, respectively. Although gingival recession showed a slight increase, tooth mobility was within the normal physiological range. No tooth hyperesthesia was observed after treatment. There was negligible osseous relapse, and the occlusion remained stable after 5 years of post-treatment retention. Our findings suggest that such multidisciplinary approaches for the treatment of CLP with gingival recession and occlusal collapse help in improving occlusion and facial esthetics without the need for prostheses such as dental implants or bridges; in addition, the results show long-term post-treatment stability.

Surgical Results of Limb Lengthening at the Femur, Tibia, and Humerus in Patients with Achondroplasia

BACKGROUND: Results of limb lengthening in patients with achondroplasia were previously reported in many studies. However, the reports of comparison among the three long bones (femur, tibia, and humerus) are rare, especially for the results of crossed lengthening (lengthening of one femur and contralateral tibia followed by that of the opposite side) for the lower limbs. The purpose of this study was to report the surgical results of a series of limb lengthening in achondroplastic or hypochondroplasia patients at our institution. METHODS: Fifteen patients (14 with achondroplasia and 1 with hypochondroplasia) underwent lower limb lengthening of the femur (n = 32) and tibia (n = 28), and 12 of them underwent crossed lengthening. Humeral lengthening was performed in 14 patients (n = 28). The mean age at the first operation was 11.7 years, and the mean follow-up duration was 66.7 months. The healing index, consolidation period index (duration of consolidation period/gained length), and other radiographic indices were analyzed. Limb length discrepancy and hip-knee-ankle alignment in lower limbs, and the occurrence of difficulties were assessed. RESULTS: The average gain in length for the femur, tibia, and humerus was 8.3 cm, 8.5 cm, and 7.4 cm, respectively. The mean healing index was 29.6 days/cm for the femur, 29.0 days/cm for the tibia, and 27.2 days/cm for the humerus. The mean consolidation period index was 14.7 days/cm for the humerus, which was significantly lower than that in the lower limb (17.3 days/cm for the femur and 17.8 days/cm for the tibia). Of the 12 who underwent crossed lengthening, five showed limb length discrepancy ≥ 1.0 cm. Among their 24 lower limbs, three showed valgus alignment ≥ 5° and one showed varus alignment ≥ 5°. Thirty-two pin site infections and three fractures were conservatively managed. Three femoral fractures, eight equinus deformities, and four cases with premature consolidation of the fibula were surgically treated. Obstacle and true complication related to humeral lengthening were not observed. CONCLUSIONS: Humeral lengthening was relatively effective and safe. Careful attention will be needed to avoid the occurrence of limb length discrepancy or malalignment in crossed lengthening.

Application of digital technology in diagnosis and treatment of dentofacial deformities / 口腔疾病防治

@#Dento-maxillofacial deformity refers to an abnormal relationship of the volume or shape of the upper and lower jaw bones with the other bones of the craniofacial area. Its correction mainly involves hard tissues, such as the jaws and teeth. In recent years, digital techniques based on virtual surgery, real-time navigation, and 3D printing have developed rapidly in the area of craniomaxillofacial surgery. Digital technology has advantages for preoperative diagnosis, surgical plan formulation, surgical simulation, intraoperative navigation, effect prediction, doctor-patient communication, and young physician training. The Department of Orthognathic and TMJ Surgery of West China Hospital of Stomatology, Sichuan University, has conducted digitized diagnosis and treatment of dento-facial deformities since 2008 and has established a digital center for the treatment of dentofacial deformities based on equipment such as spiral CT, dental arch laser scanners, facial 3D cameras, virtual surgery software, 3D printers, and sleep-breathing monitoring. The result is a diagnostic and treatment protocol for dentofacial deformity specific to the characteristics of the population of West China. This article combines the latest domestic and foreign literature and comprehensively introduces the application of digital technology for the diagnosis and treatment of dental and maxillofacial deformities.