Cephalometric Analysis of the Consolidation Phase Following Bilateral Pediatric Mandibular Distraction

Bimaxillary Orthognathic Approach to Correct Skeletal Facial Asymmetry of Hemifacial Microsomia in Adults

BACKGROUND

Hemifacial microsomia (HFM) is the second most common congenital craniofacial deformity after cleft lip and palate. Distraction osteogenesis (DO) is regarded as an alternative and efficient treatment option for patients with HFM. However, DO was not proven effective for all cases, and the results of long-term follow-up were not satisfactory as expected. Compared with DO, the orthognathic surgery approach may offer more stable clinical outcomes for this kind of disease. The purpose of this study is to evaluate the long-term clinical and radiographic outcome of bimaxillary orthognathic surgery in the treatment of adult HFM.

METHODS

Eight patients with HFM who had undergone bimaxillary orthognathic surgery between 2008 and 2012 were included in the study. The surgical procedures included Le Fort I osteotomy, inverted-L osteotomy, sagittal split ramus osteotomy, genioplasty, and iliac bone grafting. Pre- and postoperative orthodontic treatments were performed, respectively. Clinical and radiographic examinations were carried out to assess postoperative outcomes.

RESULTS

No obvious complications appeared postoperatively and no recurrences occurred during follow-up. All patients obtained satisfactory aesthetic results. Marked improvement in facial contour and occlusion were observed. Plain radiographs showed that the height ratios between the affected and unaffected ramus were ameliorated significantly.

CONCLUSION

The bimaxillary orthognathic approach to correct the deformity of adult HFM can obtain stable results in the long-term follow-up, and should be considered as a priority method for the treatment of adult patients with dentofacial deformity.

LEVEL OF EVIDENCE V

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The role of distraction osteogenesis in the management of craniofacial syndromes

In patients with craniofacial syndromes, the skeletal discrepancy is often severe, and the ability to achieve the desired movement by immediate surgical repositioning is difficult because of restrictions of the soft-tissue envelope. The technique of distraction osteogenesis has provided an additional option for managing congenital and acquired craniofacial deformities. The use of distraction osteogenesis is, however, still within its infancy as a treatment modality. It is unlikely that the procedure will obviate the need for definitive orthognathic surgery at skeletal maturity in most patients with craniofacial anomalies. The role of distraction osteogenesis in craniofacial surgery will continue to evolve rapidly with increasing experience and technological advancement. Because distraction osteogenesis in the facial skeleton is a relatively new approach, analysis of the contemporary literature is imperative, and future long-term studies on the effects and outcome of distraction are essential.

Evaluation of distracted mandibular bone using computed tomography scan and ultrasonography: technical note

OBJECTIVES

Distraction osteogenesis is considered an important reconstruction armamentarium in the management of mandibular deformities and deficiency disorders. The duration of the consolidation period is still a debatable issue among the clinicians. Evaluation of the newly formed bone is the cornerstone for terminating the consolidation period safely. The aim of this study is to find a more conservative protocol for the evaluation of callus distraction by monitoring bone healing using two different examination tools: ultrasonography and dental CT.

METHODS

Four adult patients (three women and one man) underwent mandibular distraction (using two intraoral and two extraoral devices). The latency period was 5-7 days and the distraction was at a rate of 2 mm per day, with 12-14 weeks of consolidation. All patients were evaluated during activation, 3 months, 6 months and 1 year post-distraction. Evaluation included clinical examination, plain radiographs, CT and ultrasonography examinations.

RESULTS

Ultrasonographic examination of the healing callus revealed four different phases of maturation. These phases were similar to the degree of tissue calcification as measured by CT. Tissue density across the distraction wound at the time of distractor removal (12-14 weeks) was equal to or less than one-third of normal bone density.

CONCLUSIONS

Clinical monitoring of mandibular distraction wounds can be successfully achieved through frequent use of ultrasonographic examinations. Standardization of ultrasonography based on CT findings will expand the reliability of ultrasound in monitoring callus maturation. An algorithm for evaluation of distraction wound healing is suggested.

Ten-year follow-up of a patient with hemifacial microsomia treated with distraction osteogenesis and orthodontics: an implant analysis

INTRODUCTION

Distraction osteogenesis (DO) has become an accepted treatment method for patients requiring mandibular lengthening because of congenital malformations. However, the skeletal growth pattern of a distracted mandible in the long term has still not been clearly shown in the literature. The purpose of this report was to analyze the dentofacial changes observed during a 10-year follow-up period in a patient treated with mandibular DO.

METHODS

The patient was a 12-year-old girl with hemifacial microsomia who had undergone DO with an external device. Morphologic changes during the observation period were evaluated on panoramic radiographs and posteroanterior and lateral cephalograms. Six Björk-type titanium implants were placed bilaterally in the mandible under local anesthesia to analyze the mandibular skeletal changes over time.

RESULTS

Marked lengthening was achieved during the active phase of mandibular distraction. The ratio between the ramus heights of the affected and normal sides improved significantly in the affected side's favor as the mandible was lengthened, but this ratio returned to its initial value after 10 years.

CONCLUSIONS

Although there was some growth on the affected side during the follow-up period, it was not enough to catch up with the growth on the normal side. The original asymmetry recurred as a consequence of the growth pattern in this patient with hemifacial microsomia.

Resorbable bone distraction: current status and future directions

Distraction osteogenesis of the craniofacial skeleton has been one of the most exciting developments of the last decade. Parallel development of new biocompatible and resorbable materials inspired the authors to combine these technologies to create a new class of single-stage resorbable bone distraction devices. The authors present their experience to date in 50 patients whom have undergone distraction osteogenesis using resorbable devices.