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PubMed2000

Effects of transforming growth factor-beta and mechanical strain on osteoblast cell counts: an in vitro model for distraction osteogenesis.

Factors known to regulate bone production during distraction osteogenesis include mechanical strain on bone forming cells and up-regulation of transforming growth factor-beta (TGF-beta) during the distraction, or strain phase of distraction osteogenesis. In the present study, an in vitro model was used to evaluate the functional effect of exogenous TGF-beta1 on mitogenesis in murine-derived MC3T3 osteoblasts during the period of active mechanical strain. The first hypothesis to be tested was that mitogenic suppression of MC3T3 osteoblasts by TGF-beta1 is further enhanced when these cells are also subjected to mechanical strain. To test this hypothesis, MC3T3 osteoblasts were seeded on flexible and rigid membranes. These were subjected to cyclic, vacuum-induced strain, simulating physiologic stress loads. After 24 hours, all cells were transferred to media containing TGF-beta1, and strain was continued for an additional 48 hours. The study was repeated by using two doses of TGF-beta1. This study demonstrated that final cell counts were significantly decreased in the presence of TGF-beta1 in both the nonstrained and strained groups (p < 0.0001). The final cell count in the strained group was significantly less than that in the nonstrained group (p < 0.0001) for both concentrations of TGF-beta1 tested, confirming the initial hypothesis. The second hypothesis to be tested was that alteration in the mitogenic response of MC3T3 osteoblasts after strain is not directly due to autocrine factors produced by the strained osteoblasts. To test this hypothesis, a proliferation assay was performed on nonconfluent MC3T3 osteoblasts by using conditioned media collected from strained and nonstrained osteoblasts. This study demonstrated no significant differences in cell counts after addition of conditioned media collected from strained versus nonstrained cells, confirming the latter hypothesis. The present study demonstrates the functional significance of mechanical strain on osteoblast cell counts. Furthermore, this may help to explain the temporal relationship observed during the early distraction (strain) phase of distraction osteogenesis in rodent models in which peak up-regulation of TGF-beta1 gene expression correlates with peak suppression of osteoblast function as measured by gene expression of extracellular matrix proteins.

Animals↗
PubMed2001

Cranial distraction osteogenesis in sheep using a totally implantable hydraulic mechanism: early results.

Conventional distraction osteogenesis has been performed by using either percutaneous pins attached to a thread and screw mechanism, or a thread and screw mechanism that is implanted but still requires turning by a percutaneous instrument or device. In these situations there is always the risk of infection passing to the bone via the percutaneous connection. We have developed a totally implantable hydraulic mechanism, which is activated in much the same way as injection into the port of a tissue expander. Preliminary in vitro testing has suggested that our mechanism can produce sufficient force at appropriate rates of distraction to have a promising role in distraction osteogenesis. We examined the effect of osseous distraction on the cranial vault. Expansion of the cranial vault by distraction osteogenesis is not widespread in clinical practice, in part because of the risk of infective complications of the extra-dural space. We were, therefore, presented with an ideal opportunity both to test the new distraction device and to examine the effect of distraction osteogenesis on the cranial vault. A sheep animal model was used in a pilot study to test the plausibility and examine the physiology of cranial-vault distraction osteogenesis using a totally implantable hydraulic device. Two sheep had a device implanted in the temporal fossa so as to push the craniotomised cranial cap upwards. Distraction was performed for 13 days beginning 1 week after craniotomy. After 9 weeks of consolidation, 5.5 mm and 7.4 mm of new woven bone of normal cranial thickness were demonstrated.

Animals↗
PubMed2004

Use of a plate-guided distraction device for transport distraction osteogenesis of the mandible.

BACKGROUND: Transport distraction osteogenesis has been used to reconstruct continuity defects by regenerating bone and soft tissues. A challenge has been to maintain the correct vector during the distraction process. A new type of distraction device was recently developed that uses a standard reconstruction plate to "guide" the transported segment of the bone. This plate-guided distractor device (PGD) intimately follows the shape of the plate, thus allowing for 3-dimensional vector control during the distraction process. PATIENTS AND METHODS: Four patients underwent transport distraction osteogenesis for reconstruction of segmental mandibular defects ranging in size from 4 to 7 cm. The age of the patients ranged from 27 to 62 years. Two patients had been treated with radiotherapy as part of treatment for oral malignancy. A standard locking reconstruction plate was placed to bridge the continuity gap. An osteotomy was performed to create a bone transport segment. The PGD was secured to both the reconstruction plate and the transport bone. After a latency period of 7 days, the device was activated at a rate of 1 mm/d. The distraction process continued until the transport segment reached the opposing bone or sufficient bone and soft tissue were reconstructed for oral rehabilitation. RESULTS: All patients achieved hard and soft tissue formation. Two patients had premature consolidation of the distraction regenerate but had sufficient tissue for rehabilitation. CONCLUSION: A PGD can be used to regenerate missing hard and soft tissues. An advantage of this technique is that it uses a reconstruction plate that is routinely placed to bridge mandibular continuity defects. This device allows for ultimate vector control by intimately following a carefully adapted plate.

Adult↗
PubMed1999

Reconstruction of a neocondyle using transport distraction osteogenesis.

The process of slow bone expansion by distraction osteogenesis in conjunction with functional remodeling can also be used for the reconstruction of a neomandible and neocondyle. This is the technique of transport distraction osteogenesis. A transport disc is surgically created adjacent to the area of a discontinuity defect, and the transport disc is advanced by the process of distraction osteogenesis, using the Ilizarov principles. The mandible therefore acts as the bony template for reconstruction such that the neomandible created from the distraction process has the same size and shape as the native mandible covered by gingiva. This allows for enhanced prosthetic reconstruction. A reverse-L osteotomy of the ramus can also be performed to create a transport disc to reconstruct a neocondyle. Because the leading edge of the transport disc becomes enveloped by a fibrocartilagenous cap, the ramal transport disc can be moved superiorly to create a new articulation. Patients are encouraged to open and close their mouths during the distraction process, such that the transport disc remodels to form a neocondyle. This technique was successfully used to treat patients with degenerative joint disease, condylar resorption, and bony ankylosis.

Bone Remodeling↗
PubMed1993

Experimental mandibular regrowth by distraction osteogenesis. Long-term results.

The use of gradual distraction to grow bone (distraction osteogenesis) has gained widespread orthopedic acceptance, but has only recently been applied to craniofacial skeletal defects. The use of bifocal distraction osteogenesis to fill experimental segmental mandibular defects with regenerate bone was recently reported. Though all canines in that study demonstrated normal oromandibular function, they were observed for only 4 weeks following defect closure. The study that is now reported describes the long-term (12-month) functional, morphologic, and biomechanical results when bifocal distraction osteogenesis was applied to the same model. In this long-term study, three canines had 2.5-cm unilateral segmental mandibular body defects filled with structurally stable bone using bifocal distraction osteogenesis. These dogs exhibited normal oromandibular function for 1 year following segment regrowth and external fixator removal. Macroscopic and histologic evaluation of the regrown segments revealed a re-formation of the cortical and medullary architecture. Stress testing demonstrated the average ultimate strength of the regrown segment at 53 MPa, which corresponded to 77% +/- 5.7% of normal mandibular bone. The data suggest that clinical trials applying this technique to segmental mandibular reconstruction are warranted.

Animals↗
PubMed2003

Effect of neoadjuvant chemotherapy on distraction osteogenesis in the goat model.

Neoadjuvant chemotherapy potentially can have an adverse effect on bone healing in distraction osteogenesis whether given before or concomitant with distraction osteogenesis. It was the purpose of the current study to determine if administration of chemotherapy before distraction adversely affects bone generation in distraction osteogenesis. Twenty-four adult dairy goats were divided randomly into two groups: a control group having distraction osteogenesis only and a chemotherapy group, receiving one course of Adriamycin before distraction osteogenesis. The animals were sacrificed at 6 weeks, 12 weeks, or 24 weeks and the lengthened tibias were evaluated by radiologic studies, biomechanical testing, and histologic analysis. All goats receiving chemotherapy showed systemic adverse effects. In a multifactorial analysis of the lengthened bones, there was no statistically significant difference between the control goats versus goats that received chemotherapy; indicating that there was no sustained inhibitory effect on bone formation by the chemotherapy. These findings suggest that a prior course of chemotherapy with Adriamycin may not be a contraindication to limb lengthening for limb salvage after resection of an osteosarcoma.

Animals↗
PubMedDate not supplied

[Distraction osteogenesis of the cranio-maxillo-facial bones].

Distraction osteogenesis is a surgical technique: its main purpose is to induce a mechanically stimulated bone tissue augmentation. A controlled tension, developed by a slow and gradual separation of the corticotomized/osteotomized bone segments, induces new bone formation and related soft tissue augmentation. In this way, we can observe a more harmonious tissue augmentation, better than with traditional techniques as osteotomies with grafts. This procedure, initially applied in orthopedic field for limb lengthening, is now also applied in the cranio-facial field. The most important features of distraction osteogenesis consist in the simplicity of execution, the lack of donor site morbidity and the simultaneous expansion of bone and related soft tissue. Besides, the technique is still at the beginning and requires further acknowledgements, before being widespread used to treat cranio-facial malformations. Disadvantages in bone distraction are related to the external device and consist in esthetic discomfort during treatment, and cutaneous scars. Recently, to solve these problems an intraoral distraction device was proposed. Distraction osteogenesis has now an expanding role in cranio-facial surgery.

Facial Bones↗
PubMed2003

Complications associated with gradual cranial vault distraction osteogenesis for the treatment of craniofacial synostosis.

Distraction osteogenesis has become a standard technique for craniomaxillofacial reconstruction. The authors performed gradual cranial vault distraction osteogenesis in 19 patients with craniosynostosis to study the outcome and complications of this procedure. Postoperative infections developed around the shaft puncture wounds in four patients, including one who required surgical removal of the device. Advanced bone was deformed in one patient. In another, the expansion device was exposed, resulting in a postoperative scar. Despite these complications, the cranium was successfully expanded in all patients.

Child↗
PubMed2007

Distraction osteogenesis promotes angiogenesis in the surrounding muscles.

Distraction osteogenesis is used to treat atrophic nonunion and focal osteomyelitis. It enhances blood vessel formation in the distracted callus and in the surrounding soft tissues. Long-term angiogenesis, however, is not well described. We hypothesized newly formed blood vessels persist in the surrounding muscles until the late consolidation period. We performed unilateral tibial lengthening in eight adult Beagles. Seven days after tibial osteotomy, we began lengthening for 30 days, following which consolidation was allowed to proceed for another 60 days. We took bilateral microangiograms of the bilateral tibialis anterior, extensor digitorum longus, and gastrocnemius muscles. We determined the blood vessel volume density and the longitudinal and transverse microangiographic scores. The number of blood vessels in specified diameter ranges was determined histologically. The blood vessel volume density of the distracted limb was higher in all three muscles. The longitudinal microangiographic score was higher for the tibialis anterior and extensor digitorum longus muscles on the distracted side, whereas the transverse microangiographic score was not higher. Histologically, the number of blood vessels less than 100 mum in diameter on the distracted side was higher in the tibialis anterior and extensor digitorum longus muscles. Our data suggest distraction osteogenesis activates angiogenesis and maintains increased vascularity until the late consolidation period.

Angiography↗
PubMed2006

[The histomorphological changes of tubular bone following widening distraction osteogenesis].

OBJECTIVE: The purpose of this experimental study was to investigate the histomorphological changes of tubular bone following widening distraction osteogenesis. METHODS: Twelve Chinese mountain goats were subjected to the study. After the procedure of vertical and horizontal osteotomy, two widening distraction osteogenesis devices were put in each goat's left tibiae. After an 8-day latency period, nine tibiae were widening distracted; another three tibiae served as sham control group. Every three animals from the experimental group were sacrificed in different consolidated periods including 1-month, 2-month, and 3-month. Radiography, tetracycline double labeling, histomorphology, as well as biomechanics were used to evaluate the quality and quantity of new generated bone in different consolidated period after distraction osteogenesis. RESULTS: After a distraction period, the average width of the tibiae is increased 7.83mm. From the end of distraction to 3-month after the consolidation period, radiography demonstrated that the distraction gaps gradually became vague. Tetracycline double labeling showed that the double labeling brands were rarely seen in normal cortex bone, but strongly increased in the distracted callus. Mineralization rates (MR) has a significant difference (P < 0.05) within distracted callus region compared with control cortex bone. Histomorphological study shows that there was a different result in two sides of vertical distracted gaps. The non-exposure side had a good bone formation, while a non-union of bone occurred at the exposure side. Three months after consolidation period, part of the gap in exposure side was filled with dense connection tissue, whereas the distracted callus had been remodeled and become lamellar bone in non-exposure side. The control group showed normal fracture healing procedure. CONCLUSIONS: There was a different outcome in two sides distraction gaps of tubular bone following widening distraction osteogenesis. A viable and well-perfused soft-tissue envelope in the area of distraction osteogenesis is important for creation of sufficient amount of new bone during distraction osteogenesis.

Animals↗
PubMed2007

Stimulation of EP4 receptor enhanced bone consolidation during distraction osteogenesis.

The objective of this study was to confirm whether an agonist of prostaglandin E receptor subtype EP4 can enhance bone consolidation in distraction osteogenesis. A rat distraction osteogenesis model was generated. A unilateral external fixator was fixed to the left femur of the rats of this model after osteotomy. Seven days later, 0.25 mm/12 h or 0.5 mm/12 h elongation was performed for 2 weeks. A systemic administration of an EP4 receptor agonist (ONO 4819 . CD, 3, 10, 30 microg/kg) or normal saline by subcutaneous injection was also performed for 2 weeks. The animals were sacrificed 10, 14, 17, 21, and 42 days after the operation. Radiographic examination, histological examination, and measurements of bone mineral density (BMD) and distraction-callus hardness were performed to qualitatively and quantitatively evaluate new bone formation. Twenty-one days after the operation, the experimental group had a higher BMD and a higher distraction-callus hardness than that of the control group. Forty-two days after the operation, BMD was similar among all of the groups. But the hardness of the experimental groups increased more than that of the control group, so the statistical differences in distraction-callus hardness became more distinct between the two groups, indicating an improved remodeling of the distraction callus. These findings are also supported by histological examination. Subcutaneous injection of an EP4 receptor agonist can promote bone formation and remodeling during distraction osteogenesis. ONO 4819 * CD might be a potential candidate for shortening the treatment time of distraction osteogenesis.

Animals↗
PubMed2005

Mid-tibial distraction osteogenesis redistributes bone blood flow: a microsphere study in rabbits.

BACKGROUND: Distraction osteogenesis can be used for the treatment of osteomyelitis and nonunion, conditions thought to benefit from increased blood flow in the bone tissue of the distracted limb. We have questioned whether such an increase occurs, and investigated the spatial distribution of bone blood flow after distraction osteogenesis. METHODS: The tibiae of 8 rabbits were lengthened 10 mm by a standard midtibial distraction osteogenesis procedure. 2 weeks into the consolidation phase, the bone and soft tissue blood flow of the distracted and the contralateral extremity were measured using radioactive microspheres. RESULTS: The absolute bone blood flow of the distracted tibia was 4% lower than that of the non-distracted side, representing a 41% decrease in the proximal metaphysis, a smaller decrease in the proximal epiphysis, distal metaphysis and distal epiphysis, and an increase in the diaphysis. INTERPRETATION: Mid-tibial distraction osteogenesis redistributed the bone blood flow of the distracted tibia, but absolute tibial blood flow did not increase. Our results do not confirm previous research in this field.

Animals↗
PubMed2007

Reconstruction of juxta-articular huge defects of distal femur with vascularized fibular bone graft and Ilizarov's distraction osteogenesis.

BACKGROUND: We evaluate the effect of reconstructing huge defects (mean, 15.8 cm) of the distal femur with Ilizarov's distraction osteogenesis and free twin-barreled vascularized fibular bone graft (TVFG). METHODS: We retrospectively reviewed a consecutive series of five patients who had cases of distal femoral fractures with huge defects and infection that were treated by the Ilizarov's distraction osteogenesis. After radical debridement, two of the five cases had free TVFG and monolocal distraction osteogenesis, and another two cases had multilocal distraction osteogenesis with knee fusion because of loss of the joint congruity. The other case with floating knee injury had bilocal distraction osteogenesis and a preserved knee joint. The mean defect of distal femur was 15.8 cm (range, 14-18 cm) in length. RESULTS: The mean length of distraction osteogenesis by Ilizarov's apparatus was 8.2 cm. The mean length of TVFG was 8 cm. The average duration from application of Ilizarov's apparatus to achievement of bony union was 10.2 months (range, 8-13 months). At the end of the follow-up, ranges of motion of three knees were 0 to 45 degrees, 0 to 60 degrees, and 0 to 90 degrees. Two cases had knee arthrodesis with bony fusion because of loss of the joint congruity. There were no leg length discrepancies in all five patients. In addition, three patients had pin tract infections and one case had a 10 degree varus deformity of the femur. CONCLUSIONS: Juxta-articular huge defect (>10 cm) of distal femur remains a challenge to orthopedic surgeons. Ilizarov's technique provides the capability to maintain stability, eradicate infection, restore leg length, and to perform adjuvant reconstructive procedure easily. In this study, we found that combining Ilizarov's distraction osteogenesis with TVFG results in improved patient outcome for patients with injuries such as supracondylar or intercondylar infected fractures or nonunion of distal femur with huge bone defect.

Adolescent↗
PubMed2006

Changes in nasorespiratory function in association with maxillary distraction osteogenesis in subjects with cleft lip and palate.

OBJECTIVE: The current study aimed to determine how nasorespiratory function changes in association with maxillary distraction osteogenesis (DO). Furthermore, with regard to impaired nasorespiratory function, the possibility of a relationship between the cleft side and laterality and any effect of maxillary distraction osteogenesis was investigated. DESIGN: In this descriptive, prospective clinical report, subjective and objective data regarding nasorespiratory function before and after maxillary distraction osteogenesis were compared. SUBJECTS: Data from 13 subjects with cleft lip and palate were used. Subjects had a severe maxillary deficiency and underwent distraction osteogenesis using a rigid external device system. OUTCOME MEASURES: The subjective measure was the score on a questionnaire regarding nasorespiratory function using a visual analog scale. The objective measure was nasal resistance. RESULTS: The visual analog scale score for two items significantly decreased just after distraction osteogenesis. Nasal resistance also significantly decreased 1 year after distraction osteogenesis. Moreover, nasal resistance on the cleft side was significantly greater than that on the noncleft side just before and 1 year after distraction osteogenesis. There was a significant positive correlation between changes in the visual analog scale score and nasal resistance. CONCLUSIONS: These results suggest that nasorespiratory function changes in association with maxillary distraction osteogenesis in subjects with cleft lip and palate. Moreover, it appears that nasal obstruction on the cleft side does not change in subjects with unilateral cleft lip and palate.

Adolescent↗
PubMed2001

Craniofacial distraction osteogenesis: a review of 3278 cases.

The nascent field of craniofacial distraction osteogenesis has not yet been subjected to a rigorous evaluation of techniques and outcomes. Consequently, many of the standard approaches to distraction have been borrowed from the experience with long bones in orthopedic surgery. The ideal "latency period" of neutral fixation, rate and rhythm of distraction, and consolidation period have not yet been determined for the human facial skeleton. In addition, because the individual craniofacial surgeon's experience with distraction has generally been small, outcomes and meaningful complication rates have not yet been published. In this study, a four-page questionnaire was sent to 2476 craniofacial and oral/maxillofacial surgeons throughout the world, asking about their experiences with distraction osteogenesis. Information about the types of cases, indications for surgery, surgical techniques, postoperative management, outcomes, and complications were tabulated. Of 274 respondents (response rate, 11.4 percent), 148 indicated that they used distraction in their surgical practice. One hundred forty-five completed surveys were entered into a database that provided information about 3278 craniofacial distraction cases. Statistical analyses were performed comparing the rates of premature consolidation, fibrous nonunion, and nerve injury, on the basis of the use of a latency period and different rates and rhythms of distraction. In addition, the rates of all complications were determined and compared on the basis of the number of distraction cases performed per surgeon. The results of the study clearly show a wide variation in the surgical practice of craniofacial distraction osteogenesis. Although the cumulative complication rate was found to be 35.6 percent, there is a pronounced learning curve, with far fewer complications occurring among more experienced surgeons (p < 0.001). The presence of inferior alveolar nerve injury as a result of mandibular distraction was much lower for respondents whose distraction regimens consisted of no more than 1 mm of distraction per day (19.5 percent versus 2.4 percent; p < 0.001). No evidence was found to support the use of a latency period or to divide the daily distraction regimen into more than one session per day. Conclusions could not be drawn from this study regarding the length of the consolidation period. Overall, the surgeon-reported outcomes are comparable with those published for other craniofacial procedures, despite the higher incidence of complications. Although conclusions made on the basis of a subjective questionnaire need to be interpreted cautiously, this study has strength in the large numbers of cases reviewed. Because of the anonymity of responses, it has been assumed that surgeons who responded to the survey reported accurate numbers of complications and successful outcomes. Finally, additional clinical and animal studies that will be of benefit in advancing the field of craniofacial distraction osteogenesis are outlined.

Craniofacial Abnormalities↗
PubMed2003

Rapid new bone tissue remodeling during distraction osteogenesis is associated with apoptosis.

During the process of distraction osteogenesis new bone forms and undergoes rapid remodeling. Apoptosis may be one of the regulatory mechanisms governing the removal of the redundant callus during distraction osteogenesis. A rabbit tibial lengthening model was used and lengthened at 0.7 mm/day for 3 weeks. The regenerating tissues from the distraction gap were examined for apoptotic changes by transmission electron microscopy (TEM) and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method. Osteoclastic bone resorption activities were demonstrated by tartrate resistant acid phosphatase (TRAP) staining. The apoptotic cells were mainly present in the transitional regions between the fibrous tissue and the new bone in the mineralization front, and close to or on the new bone surfaces near the center of the regenerate. The TUNEL labeling was greatly reduced in the mature bone near the osteotomied bone ends. TEM examination confirmed the presence of cells with apoptotic changes at various regions of the regenerate. TRAP staining revealed that osteoclastic bone resorption activities in the regenerate were in a similar pattern of distribution to those of the TUNEL labeling. The localization of apoptotic cells at the different regions of the regenerate, accompanied by the osteoclast activities, suggest that apoptosis is closely related to bone formation and remodeling during distraction osteogenesis.

Animals↗
PubMed2004

Long-term skeletal stability after maxillary advancement with distraction osteogenesis using a rigid external distraction device in cleft maxillary deformities.

Rigid external distraction is a highly effective technique for correction of maxillary hypoplasia in patients with orofacial clefts. The clinical results after correction of sagittal maxillary deformities in both the adult and pediatric age groups have been stable. The purpose of this retrospective longitudinal cephalometric study was to review the long-term stability of the repositioned maxilla in cleft patients who underwent maxillary advancement with rigid external distraction. Between April 1, 1995, and April 1, 1999, 17 consecutive patients with cleft maxillary hypoplasia underwent maxillary advancement using rigid external distraction. There were 13 male patients and four female patients, with ages ranging from 5.2 to 23.6 years (mean, 12.6 years). After a modified complete high Le Fort I osteotomy and a latency period of 3 to 5 days, patients underwent maxillary advancement with rigid external distraction until proper facial convexity and dental overjet and overbite were obtained. After active distraction, a 3- to 4-week period of rigid retention was undertaken; this was followed by removable elastic retention for 6 to 8 weeks using, during sleep time, an orthodontic protraction face mask. Cephalometric radiographs were obtained preoperatively, after distraction, at 1 year after distraction, and 2 or more years after distraction. The mean follow-up was 3.3 years (minimum, 2.1 years; maximum, 5.3 years). The following measurements were obtained in each cephalogram: three linear horizontal and two linear vertical maxillary measurements, two angular craniomaxillary measurements, and one craniomandibular measurement. Differences between the preoperative and postoperative cephalometric values were analyzed by paired t tests (p < 0.05). The cephalometric analysis demonstrated postoperatively significant advancement of the maxilla. In addition, the mandibular plane angle opened 1.2 degrees after surgery. After the 1- to 3-year follow-up period, the maxilla was stable in the sagittal plane. Minimal anteroposterior growth was observed in the maxilla compared with that exhibited in the anterior cranial base. However, there was significant vertical maxillary growth over the 3-year observation period. The mandibular plane angle tended to decrease during the follow-up period. The cephalometric data from this study support the clinical impression of maxillary stability after maxillary advancement with rigid external distraction in cleft patients. This effective and stable technique is now considered for all pediatric patients with severe cleft maxillary hypoplasia and for adolescent and adult patients with moderate to severe deformities.

Abnormalities, Multiple↗
PubMed2000

Manipulation of callus after linear distraction: a "lifeboat" or an alternative to multivectorial distraction osteogenesis of the mandible?

Despite impressive results, distraction osteogenesis of the mandible is still compromised by difficulties with vector control. Because of the action of the masticatory muscles, the gonion angle has the tendency to open, resulting in an open bite. We report two patients, aged 10 and 12 years, who developed a severe open bite during mandibular distraction. As a salvage procedure, manual shaping of the soft regenerate was done immediately after distraction. Uneventful bony consolidation was observed, which resulted in anatomically shaped gonion angles. The fact that a regenerate created by distraction osteogenesis can be molded to virtually any shape offers interesting perspectives for the correction of complex mandibular deformities.

Bony Callus↗