Conséquences défavorables sur l’équilibre sagittal du rachis du système de neutralisation dynamique

PURPOSE OF THE STUDY

The dynamic neutralization system (Dynesis) has been proposed for the treatment of symptomatic lumbar discopathy. This system preserves the mobility of the instrumented vertebral segment and restores discal height by posterior distraction on pedicular screws, stabilization being ensured by compression on a spacer. The potential kyphosing effect of this system and the impact on sagittal morphology of the spine were analyzed.

MATERIAL AND METHODS

Twenty-six patients were studied. Lateral x-rays of the lumbar spine in the upright position were obtained before and after the surgical procedure and at mean 9.5 +/- 3.3 months follow-up. Comparisons were made between the pre- and postoperative presentation with measurement of the pelvic and spinal sagittal parameters described by Duval-Beaupère: inclination of the pelvic segment on the sacrum, lordosis, and disc wedge angles at each level (particularly the instrumented levels). Sagittal morphology was assessed pre- and postoperatively.

RESULTS

Mean kyphosing effect was 6 +/- 1.4 degrees, induced by the posterior distraction system. This accentuated the initial lumbar hypolordosis related to the degenerative disease. Comparison of the pre- and postoperative films revealed four types of sagittal reaction of the lumbopelvic segment: no modification (type A), significant loss of lordosis without change at the pelvis level (type B) or with compensatory pelvic retroversion (type C), accentuation of the lordosis with pelvic anteversion (type D).

CONCLUSION

The dynamic neutralization system (Dynesis) can stabilize degenerative discopathy and protect the adjacent levels. Posterior distraction perturbs the initial hypokyphosis and can lead to pelvic compensation to achieve better dynamic balance. This loss of lordosis is however a cause of excessive mechanical stress on the lumbar structures and can lead to long-term degradation. Future developments of this dynamic system should take into account the essential factor of sagittal balance.

Bone formation is impaired in a model of type 1 diabetes

The effects of type 1 diabetes on de novo bone formation during tibial distraction osteogenesis (DO) and on intact trabecular and cortical bone were studied using nonobese diabetic (NOD) mice and comparably aged nondiabetic NOD mice. Diabetic mice received treatment with insulin, vehicle, or no treatment during a 14-day DO procedure. Distracted tibiae were analyzed radiographically, histologically, and by microcomputed tomography (microCT). Contralateral tibiae were analyzed using microCT. Serum levels of insulin, osteocalcin, and cross-linked C-telopeptide of type I collagen were measured. Total new bone in the DO gap was reduced histologically (P < or = 0.001) and radiographically (P < or = 0.05) in diabetic mice compared with nondiabetic mice but preserved by insulin treatment. Serum osteocalcin concentrations were also reduced in diabetic mice (P < or = 0.001) and normalized with insulin treatment. Evaluation of the contralateral tibiae by microCT and mechanical testing demonstrated reductions in trabecular bone volume and thickness, cortical thickness, cortical strength, and an increase in endosteal perimeter in diabetic animals, which were prevented by insulin treatment. These studies demonstrate that bone formation during DO is impaired in a model of type 1 diabetes and preserved by systemic insulin administration.

[Design and application of internal devices for automatic elasticity distraction osteogenesis]

OBJECTIVE

To improve the design of the devices used for autoatic elasticity distraction osteogenesis, and to preliminarily testify their feasibility for clinical application.

METHODS

The internal automatic distraction devices were constructed by three parts, including sinusoid shape memory alloy distractor, reconstructive plate and mini-plate. The animal model of trifocal bone transport reconstruction of canine mandibular mentis was duplicated, in which a 6 cm mandibular mentis segment was removed and the transport disc was created by osteotomy in both ends of the mandibular defect. The plates were used for internal fixation and shape reconstruction of the mandible. They also served as transport distraction guidance for the elasticity distractor.

RESULTS

The new devices could complete bone transport as expected. Regenerated bone segments were formed in two months and both sides of the mandibular body were lengthened. Because of the narrow angle and obstruction from the thick soft tissues in the mentis area, the ultimate symphysis mentalis was not reconstructed.

CONCLUSION

The design of the internal elasticity distraction devices showed potential feasibility for clinical practice. But further studies are still needed for better control of the strength and balance of distraction forces.

A novel method for measuring and monitoring monobloc distraction osteogenesis using three-dimensional computed tomography rendered images with the 'biporion-dorsum sellae' plane. Part I: Precision and reproducibility

The results of craniofacial and orthognathic surgery have traditionally been monitored using lateral cephalometry. In the age of computed tomography (CT) and magnetic resonance imaging (MRI), newer methods of measuring surgical outcome have arisen. This has been further enhanced by the use of computer software to render CT images in a three-dimensional format. The authors present a novel method of measuring the outcome of monobloc distraction osteogenesis advancement using the biporion-dorsum sellae plane. The perpendicular distance of eight facial skeletal points to this plane were made automatically using the Vworks 4.0 program. A total of 10 measurements were made against six planes of reference. Planes 1, 2, 3, 1+2 degrees, and 1-2 degrees were constructed, and measurements were made by observer 1. Plane 6 was constructed and measurements were made by observer 2. Plane 1 was used as the denominator on which calculations were made. The results revealed a mean intra- and interobserver percentage difference from plane 1 of less than 5%. In addition, the overall mean intraobserver variance of all eight points from observer 1 was 0.91%, and the mean interobserver variance between observer 1 and 2 was 0.73%. In summary, based on the authors' method, repeated measurements made from the biporion-dorsum sellae plane have proven precision and reproducibility.

Immunohistochemical study of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2, -4 (BMP-2, -4) on lengthened rat femurs

BACKGROUND

With a hypothesis that "angiogenesis occurs before osteogenesis," an experimental study using a rat model was carried out. Histological and immunohistochemical examinations of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2, -4 (BMP-2, -4) were performed at the margins of bone formation after femoral bone lengthening.

MATERIAL AND METHODS

Thirty-five Wistar rats weighing 380-400 g (11-week-old males) were used. An external fixator was applied on the femur, and an osteotomy performed under general anaesthesia. Five days after the operation, femoral lengthening was initiated at a rate of 0.8 mm/day for 8 days. The rats were sacrificed just after distraction was completed, and at 1, 3, 5, 7, 9 and 14 days after distraction. The specimens from these rats were stained with haematoxylin-eosin, VEGF, and BMP-2, -4 immunohistochemical staining, and were investigated.

RESULTS

Expression of VEGF was observed in the woven bone at the osteogenetic front and near to osteoblasts around the newly formed bone. On the other hand, expressions of BMP-2, -4 were seen in the hypertrophic chondrocytes. In the same specimen, the VEGF area was further away from the bone stump than the BMP-2, -4 areas.

CONCLUSION

These results confirm the hypothesis that angiogenesis is induced before osteogenesis.

[A histological study of three-dimensional external zygomatic suture distraction osteogenesis]

OBJECTIVE

To explore the histological change in suture of zygomatic bone for the zygomatic suture direct distraction osteogenesis.

METHODS

The zygomatic bone was distracted by 3-D external distraction appliance without osteotomy. The specimens were taken 1, 3, 5 and 8 weeks after, and then examined histologically and compared with the blank contralateral side.

RESULTS

There were lots of fibroblasts, osteoblasts and capillary vessels in the distracted suture tissues one week after distraction, and the fibers were observed to connect the sides of suture and arranged orderly. The surfaces of the expanded suture were irregular. Bone formation was active in the expanded side. The bone trabeculae were mature and oriented in the direction of distraction in the distracted sides at 3 weeks. A great amount of new woven bones were found in 5-week specimen. New bones were formed completely 8 weeks after the distraction.

CONCLUSIONS

New bone formed rapidly in the distracted side of zygomatic bone under suture distraction osteogenesis without osteotomy.

[Distraction osteogenesis as treatment for craniofacial deformities]

Distraction osteogenesis is a surgical technique for treating different craniofacial deformities. The sophisticated clinical expression of craniosynosotosis in the face, as well as in the skull can be corrected using different osteotomies, in which we can include the frontal bone, orbits, the malar bones and the maxillae. Once the osteotomy has been completed, we can use the distraction devices to achieve the planned bone advancement. This procedure can be also performed with endoscopic techniques producing less morbidity, with minimal complications, simultaneously producing a highly satisfactory correction of the frontal deformity, the exorbitismus, the malar and the mid-face retrusion in these patients. As the distraction procedure is gradual, soft tissues resistance against the advancement can be easily superated achieving larger antero-posterior bone advancement that can vary between 16 to 32 mm in the frontal area and between 9 to 16 mm in the maxillae. The new position of the bones are maintained in place for new bone formation areas over the osteotomy lines. The aesthetic and functional changes after the procedure have been highly satisfactory in these patients.

Distraction osteogenesis versus autogenous onlay grafting. Part I: outcome of implant integration

PURPOSE

The primary goal of this study was to compare bone-to-implant contact (BIC) in alveolar bone augmented by distraction osteogenesis with BIC in alveolar bone augmented by onlay iliac crest grafting.

MATERIALS AND METHODS

Alveolar bone defects were created bilaterally in 5 American foxhounds, and after healing, bone augmentation was accomplished using distraction osteogenesis on 1 side of the jaw and onlay grafting on the other. Twelve weeks after consolidation, implants were placed in augmented and control sites. The animals were sacrificed and the jaws harvested for histologic analysis after an additional 8 weeks.

RESULTS

The mean BIC was 54.7% +/- 14.6% for implants placed in distracted sites, 53.8% +/- 11.8% for sites where an onlay graft was used, and 51.2% +/- 14.4% for control sites. Significant differences in BIC were noted between experimental and control sites only at the apical third of the implant (19.8 +/- 1.8 for distracted sites; 15.5 +/- 1.5 for grafted sites; 8.0 +/- 0.5 for control sites; P < .05).

DISCUSSION

The data showed that both distraction osteogenesis and onlay grafting produce sufficient bone for implant placement. There were no differences between procedures in regard to BIC after 8 weeks.

CONCLUSION

These data suggest that both onlay grafting and vertical distraction are appropriate methods for bone augmentation prior to implant placement.

Alveolar distraction osteogenesis of bone graft reconstructed mandible

This case report describes a patient who had severe mandibular bony deficiency as a result of excision of aggressive central giant cell granuloma. The defect was reconstructed with iliac bone graft. Four years later vertical distraction osteogenesis was performed on the grafted mandible in order to obtain a satisfactory bony height of mandibular ridge. Distraction osteogenesis can be a good alternative for the reconstruction of mandibular deficiencies.

Early administration of hyperbaric oxygen therapy in distraction osteogenesis--a quantitative study in New Zealand rabbits

BACKGROUND

We investigated the effect of hyperbaric oxygen (HBO) therapy on the early phase of tibial lengthening in our established rabbit model.

METHODS

Twenty-four male rabbits (six per group) underwent right tibial lengthening by 5 mm. Group 1 then underwent 2.5 atmospheres of absolute hyperbaric oxygenation for 2 hours daily for 6 weeks postoperatively; group 2, for early 5 weeks (weeks 1-5), group 3, for late 5 weeks (weeks 2-6), and group 4 had no HBO therapy. Bone mineral density (BMD) was measured before surgery and weekly thereafter from weeks 2 through 6. The mechanical strengths of the lengthened tibias were measured.

RESULTS

Significantly higher mean %BMDs were obtained for groups 1 and 2 compared with groups 3 and 4. There was no difference in the mean %BMD between groups 1 and 2 (p > 0.05). The results were similar for mean percentage maximal torque; group 1 had the maximum torque, followed sequentially by groups 2 though 4.

CONCLUSION

The study results suggest that early and full-term administration of HBO therapy on tibial lengthening may achieve better benefits.

[Quantitative histomorphometric observation of distraction osteogenesis during mandibular lengthening]

PURPOSE

To evaluate the regenerating bone during mandibular distraction osteogenesis by bone histomorphometry combining tetracycline bone labeling fluorescence microscopy.

METHODS

Osteotomy was performed on bilateral mandibles in ten goats. A custom-made distractor was applied to lengthen the mandible at a rate of 1 mm/d (0.5 mm/12 hrs) for ten days. Every two animals were sacrificed at 10 d, 15 d, 25 d, 35 d and 45 d postoperatively. Two additional goats were used as normal control. The bony specimens were collected and prepared for bone histomorphometry and tetracycline bone labeling fluorescence microscopy with analysis of variance.

RESULTS

From 10 days subgroup to 45 days subgroup, bone volume fraction,trabecular thickness,trabecular number and volume density were gradually increased (P<0.05), while trabecular separation distance and surface density were gradually decreased (P<0.05). Between 15 days subgroup and 45 days subgroup,the index of osteoblast was significantly higher than normal control (P<0.05) and index of osteoclast was increased gradually (P<0.05). Compared with normal control, bone formation rate was accelerated by thousand times between 15 days subgroup and 45 days subgroup (P<0.05).

CONCLUSIONS

During the process of mandibular distraction osteogenesis, the bone formation is active, the newly formed bone trabecula gradually become mature, and the remodeling activities of regenerated bone are enhanced gradually. The rate of bone formation within distraction period is faster than consolidation period.

Ethanol-Induced Inhibition of Bone Formation in a Rat Model of Distraction Osteogenesis: A Role for the Tumor Necrosis Factor Signaling Axis

BACKGROUND

Chronic ethanol exposure inhibits the rapid bone formation demonstrated during limb lengthening by distraction osteogenesis (DO). This inhibition is attenuated by simultaneous administration of antagonists to the cytokines interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. The individual effects on inhibition of osteogenesis by these cytokines were tested. We hypothesized that administration of individual antagonists to these cytokines [IL-1 receptor antagonist (IL-1ra) or polyethylene glycol-conjugated soluble TNF receptor type 1 (sTNFR1)] would enhance DO and that the individual administration of each cytokine [recombinant rat (rr) IL-1 or recombinant rat (rr) TNF] would inhibit DO.

METHODS

Rats were either infused with a liquid diet with or without ethanol (antagonist studies) or given rat chow (recombinant studies) and underwent tibial fractures stabilized with external fixators for DO. The bioactive substances were administered by systemic (antagonist studies) or local (recombinant) diffusion.

RESULTS

A comparison of histologic sections from these distracted tibias demonstrated a protective effect on bone formation by sTNFR1 (p<0.05), unexpectedly, an IL-1ra-related decrease in bone formation (p<0.02), significant decreases in bone formation with rrTNF compared with the vehicle controls (p<0.02), and no significant changes in bone formation with rrIL-1. The cellular responses (fibroblastic and inflammatory cells) were unique for each recombinant cytokine administered.

CONCLUSIONS

These results suggest that the osteoinhibitory effects of chronic ethanol exposure are mediated in part by the TNF signaling axis.

Pediatric Obstructive Sleep Apnea Syndrome

OBJECTIVE

To review evidence-based knowledge of pediatric obstructive sleep apnea syndrome (OSAS).

DATA SOURCES AND EXTRACTION

We reviewed published articles regarding pediatric OSAS; extracted the clinical symptoms, syndromes, polysomnographic findings and variables, and treatment options, and reviewed the authors' recommendations.

DATA SYNTHESIS

Orthodontic and craniofacial abnormalities related to pediatric OSAS are commonly ignored, despite their impact on public health. One area of controversy involves the use of a respiratory disturbance index to define various abnormalities, but apneas and hypopneas are not the only abnormalities obtained on polysomnograms, which can be diagnostic for sleep-disordered breathing. Adenotonsillectomy is often considered the treatment of choice for pediatric OSAS. However, many clinicians may not discern which patient population is most appropriate for this type of intervention; the isolated finding of small tonsils is not sufficient to rule out the need for surgery. Nasal continuous positive airway pressure can be an effective treatment option, but it entails cooperation and training of the child and the family. A valid but often overlooked alternative, orthodontic treatment, may complement adenotonsillectomy.

CONCLUSIONS

Many complaints and syndromes are associated with pediatric OSAS. This diagnosis should be considered in patients who report the presence of such symptoms and syndromes.

Comparison of canine mandibular bone regeneration by distraction osteogenesis versus acute resection and rigid external fixation

The present study was performed (1) to explore the mechanism of skeletal healing following distraction osteogenesis of the mandible and to evaluate whether the same process is involved following acute mandibular resection and rigid external fixation, and (2) to examine the role of the periosteum in skeletal healing in both models. The study was performed using 16 mongrel dogs divided into two equal groups. In the first group, distraction of 20 mm was performed at a rate of 1 mm/day. In the second group, bone resection of 20 mm was performed, followed by rigid external fixation. The buccal periosteum was stripped in four dogs from each group, and the periosteum was left intact in the remaining four dogs. Dogs were euthanized after a survival period of either 2 or 3 months, and the new bone regenerate was evaluated. Analysis consisted of three-dimensional computed tomography scanning, histometric analysis, and immunostaining. Analysis of bone mineral content in the residual gap was conducted. Bone mineral content was increased in 3- versus 2-month survival for all groups (p < 0.05). The distracted groups had greater bone mineral content than their acutely resected counterparts, with the difference achieving statistical significance by 3-month survival (p < 0.05). Although periosteal preservation resulted in increased bone mineral content over time for all groups (p = 0.044), periosteal preservation had no significant effect on bone mineral content in the distracted groups. After periosteal stripping, however, bone mineral content was significantly increased in dogs that underwent distraction rather than acute resection and rigid external fixation (p = 0.022). Regarding histometric analysis, analysis of fibrous tissue content in the bone regenerate demonstrated that by 3 months the distracted groups had significantly less fibrous tissue in the new bone regenerate than did the acutely resected groups (p < 0.001). Regarding immunostaining, diffuse localization of transforming growth factor-beta1 was observed in all groups at 2 months, returning to nearly baseline levels by 3 months. These data demonstrate that significant bone formation in a segmental gap can be achieved after acute mandibular resection and rigid external fixation if the periosteum is preserved. However, after periosteal injury or stripping, significant bone formation can only be achieved by distraction osteogenesis. In both processes, bone formation is preceded by up-regulation of transforming growth factor-beta1.

Effective repair of a fresh osteochondral defect in the rabbit knee joint by articulated joint distraction following subchondral drilling

PURPOSE

Joint distraction has been used to treat osteoarthritis and was found to delay the need for arthrodesis or joint replacement. However, there has been little basic research on articulated joint distraction for the repair of osteochondral defects. We investigated the effects of joint distraction with motion after drilling on a fresh osteochondral defect in the weight bearing area of the rabbit knee joint.

METHODS

A full thickness osteochondral defect was created in the weight bearing area of both medial femoral condyles of an adult Japanese white rabbit. After drilling of the defect, the experimental knee joint was distracted for 1.5 mm using a pair of external fixators to decrease compression force. The contralateral knee joint was used as a control with no apparatus. Gross findings and histological evaluation were assessed to study morphology of the repaired cartilage.

RESULTS

A partial repair with cartilage-like tissue was observed in the joints of the experimental group at 4 weeks. While cartilage-like tissue stained with Safranin O was found in the experimental group at 8 and 12 weeks, destructive changes were observed in the control joints. Morphological changes were evaluated using the histological grading scale [Wakitani S, Goto T, Pineda SJ, et al. Mesenchymal cell-based repair of large, full-thickness defect of articular cartilage. J Bone Joint Surg Am 1994;76(4):579-92]. There was no significant difference between experimental and control groups at 4 weeks (mean 11.2 and 13.8 points, respectively). However, the mean scores of the experimental groups at 8 and 12 weeks (mean 6.8 and 7.5, respectively) were significantly better than those of the control groups at the same time points (mean 14 points each). Between the experimental groups, the scores at 8 and 12 weeks were both significantly better than those at 4 weeks.

CONCLUSION

A combination of subchondral drilling, joint motion and distraction by an articulated external fixator promoted repair of a fresh osteochondral defect in the weight bearing area. Although distraction for 4 weeks was not a long enough period to repair the defect, distraction for 8 and 12 weeks resulted in a good outcome.

[The transformation of fibroblast-like cells originating from different tissue into osteoblasts]

OBJECTIVE

To discuss whether fibroblast-like cells can transform into osteoblasts under specific condition during distraction osteogenesis.

METHODS

Fibroblast-like cells were cultured in vitro. BMP-2, TGF-beta(1), BMP-2 and TGF-beta(1) were added into the medium, and the cellular change were observed by histochemistry and immunohistochemistry methods. The distraction was given on the membrane of fibroblast-like cells, and the cellular change were observed under the distraction.

RESULTS

fibroblast-like cells from the joint could transform into osteoblasts under the effect of BMP-2 or BMP-2 with TGF-beta(1). Fibroblast-like cells from other regions could not transform into osteoblasts.

CONCLUSION

The osteoblasts during distraction osteogenesis are multi-origin.

Relapse in Alveolar Distraction Osteogenesis: An Indication for Overcorrection

PURPOSE

The aim of this study was to indicate the necessity of overcorrection regarding the occurrence of bone height relapse at the end of consolidation period in distracted alveolar bone.

MATERIALS AND METHODS

Eleven patients with a total of 17 distractions performed and 43 implants placed were included in this study. Bone height was evaluated on computed tomography before the procedure and on orthopantomographic radiographs following distraction and consolidation. Measurement was performed on the aproximal surfaces of implants and on identical points before and after distraction.

RESULTS

The mean of distraction performed was 6.08 +/- 1.82 mm at mesial points and 6.18 +/- 1.90 mm at distal points of measurement. The mean of bone relapse following consolidation period was 1.57 +/- 1.82 mm at the mesial and 1.79 +/- 1.68 mm at the distal aspects of implants. Statistical evaluation revealed that alveolar bone distraction should include 20% of overcorrection for both mesial and distal points of measurements plus 0.34 mm for mesial and 0.52 mm for distal points of measurement.

CONCLUSIONS

Occurrence of relapse found in this study indicates that overcorrection should be included when performing alveolar distraction osteogenesis.

Longitudinal Cephalometric Analysis After Maxillary Distraction Osteogenesis

The aim of this study was to analyze the long-term dentoskeletal changes in patients who received distraction osteogenesis of the maxilla. Seventeen patients aged 12 to 31 years underwent rigid external distraction osteogenesis for treatment of maxillary hypoplasia. Cephalograms were evaluated retrospectively regarding linear and angular measurements. Follow-up times ranged from 1 to 5 years. In two patients, there was no consolidation of the Le Fort I segment to the midface. After the 0- to 12-month period, the maxilla had a stable position in all patients. Nevertheless, there was further decrease of SNA and ANB and an increase of the facial concavity thereafter. Ongoing growth of the facial skeleton must be considered when distraction osteogenesis is chosen for the advancement of the maxilla in adolescents.

Strain-Dependent Control of Transforming Growth Factor-?? Function in Osteoblasts in an In Vitro Model: Biochemical Events Associated with Distraction Osteogenesis

BACKGROUND

Distraction osteogenesis is an important clinical method for increasing bone mass, but its effects on bone-forming cells are not well understood. In this study, the authors asked how the mechanical forces that occur during this procedure alter specific osteoblast activities such as matrix synthesis, the rate of cell replication, and enzyme activities. The authors further asked whether these changes relate to differences in the biochemical response of osteoblasts to transforming growth factor-beta (TGF-beta), a potent regulator of bone formation.

METHODS

Osteoblasts were plated on flexible, collagen-coated membranes. One group was unstrained, a second group experienced a single maximum strain load once every 6 hours to simulate intermittent force associated with a distraction protocol of four screw turns per day, and a third group was strained continuously for 24 hours. In the third group, some cell cultures were allowed to recover from strain before analysis. Subsequently, each group was treated with vehicle or TGF-beta at 12 pM (0.3 ng/ml) or 120 pM (3 ng/ml). Data were collected from a minimum of 15 replicate cell culture wells obtained from at least three separate primary culture preparations. Results were assessed with statistical software. Differences were considered significant with values of p < 0.05.

RESULTS

Both strain protocols increased basal osteoblast DNA synthesis but suppressed the relative stimulatory effect of TGF-beta on this event. However, neither intermittent nor continuous strain significantly altered collagen or noncollagen protein synthesis or the relative effect of TGF-beta on these processes in osteoblasts. Basal alkaline phosphatase activity, an intermediate marker of osteoblast differentiation and an early marker of matrix mineralization, decreased significantly in response to continuous strain or to TGF-beta treatment, and even more so in response to both conditions. In addition, TGF-beta binding to the type III TGF-beta receptor was increased in proportion to strain intensity.

CONCLUSIONS

This study shows that cyclic strain can alter osteoblast activity in multiple ways and predicts that TGF-beta has different effects during the distraction process on osteoblasts and therefore on their ability to effect bone formation. They further indicate that mechanical load permits early aspects of osteoblast activation but delays in part later biochemical parameters associated with mineralization to allow new bone growth before consolidation.

New technique for airway correction in neonates with severe Pierre Robin sequence

To avoid tracheostomy in 11 neonates with severe Pierre Robin sequence, we used a technique of progressive elongation of the mandible (distraction osteogenesis) to correct tongue ptosis, increase pharyngeal airway, and correct micrognathia. All 11 patients were extubated within 3 to 6 days after beginning distraction. At 1 month 54.5% were oral feeders and at 1 year, 100%. Sleep studies were obtained on 7 patients and were normal 1 week to 1 month after operation. Growth was observed to be above the 50th percentile in all patients with no comorbidities. A 5-year clinical follow-up showed the operated mandible to maintain a normal shape and produce an undisturbed tooth eruption sequence. We conclude that distraction osteogenesis to increase the length of the short mandible is an effective alternative to tracheostomy in carefully selected patients.