Distraction osteogenesis versus orthognathic surgery

Distraction Osteogenesis Versus Orthognathic Surgery: Demystifying Differences in Concepts, Techniques and Outcomes

Introduction

The popularity and interest evoked by orthognathic surgery and distraction osteogenesis are undisputed in the field of oral and maxillofacial surgery. However, questions regarding the individual identities of either of them with clarity in their concepts, techniques and outcomes have remained unanswered. The aim of this review is to shed light on these questions.

Methods

This review is structured as a narrative review of thirty years of literature available in the specialities of orthognathic surgery and distraction osteogenesis.

Conclusion

The authors present a review of existing literature combined with contrasting experience gained over the years in providing an overview of the merits and demerits of the two surgical techniques which will aid the clinician in justifying the use of one technique over the other.

Cephalometric changes in nasopharyngeal area after anterior maxillary segmental distraction versus Le Fort I osteotomy in patients with cleft lip and palate

OBJECTIVE

The present study was designed to compare the effects of two surgical methods, anterior maxillary segmental distraction (AMSD) versus conventional Le Fort I osteotomy, on cephalometric changes of velopharyngeal area of patients with cleft lip and palate.

MATERIALS AND METHODS

This study was conducted on 20 CLP in two groups. The first group had classic Le Fort I maxillary advancement and the second group had AMSD with a modified hyrax as an intraoral tooth-borne distractor. In the second group, 1 week after the surgery, activation of hyrax screw was started with the rate of 2 times a day for about 10 days. Initial and final lateral cephalograms were traced and analyzed by OrthoSurgerX software.

RESULTS

The changes in variables evaluating velopharyngeal status showed a significant difference between the two groups. In Group A (conventional), the mean of nasopharyngeal area and Nasopharynx floor length showed a significant increase (P < 0.05) after the surgery, while in Group B (DO), the trend of changes was vice-versa. The changes in SNA, overjet, and soft-tissue convexity were similar in both groups.

CONCLUSION

AMSD can improve facial profile, almost similar to the conventional Le Fort I advancement, while there is a significant decrease in nasopharyngeal; hereby there is no increase in the velopharyngeal sphincter.

Combined orthognathic distraction procedure: Le Fort I maxillary osteotomy and mandibular curvilinear distraction osteogenesis. A new technique for craniofacial management

Dentofacial deformities are traditionally treated by maxillary and mandibular osteotomies conducted separately or simultaneously. Recently, distraction osteogenesis has become an irreplaceable part of the surgical armamentarium, for its ability to induce new bone formation between the surfaces of bone segments that are gradually separated by incremental traction, along with a simultaneous expansion of the surrounding soft-tissue envelope. The aim of this article is to describe a combined surgical technique consisting of simultaneous maxillary Le Fort I advancement and mandibular surgical repositioning by means of bilateral sagittal split osteotomy with a curvilinear distractor based on a preliminary computerized presurgical prediction.

Hyrax application as a tooth-borne distractor for maxillary advancement

Distraction osteogenesis (DO) has become a mainstream surgical technique for patients with jaw deformities. The aim of this study was to report the use of internal DO in the treatment of maxillary hypoplasia in a patient with cleft lip and palate. The case illustrates a 17-year-old boy with class III malocclusion, maxillary deficiency, and cleft lip and palate. Because the patient was experiencing severe hypernasality, it was decided to treat him by DO. The treatment process began by mounting a hyrax in the upper jaw for lateral expansion. A second hyrax was mounted in a way to create anteroposterior expansion. One day after the second hyrax application, the patient underwent a modified Le Fort I osteotomy. He was instructed to turn the screws twice per day for 12 days. The treatment was continued by means of a conventional face mask for 2 months. After 16 months of active treatment, favorable correction of the skeletal problem was observed. The S-N-A angle increased by 5 degrees, and patient's hypernasality was comprehensively improved.

Patient with Pfeiffer's syndrome treated by midfacial distraction and comprehensive orthodontics

Treatment for patients with craniofacial anomalies always presents a great challenge to orthodontists. Treatment usually requires both comprehensive orthodontic treatment and orthognathic surgery. In this article, we report on a patient with Pfeiffer's syndrome treated by midfacial distraction and comprehensive orthodontics.

Stability of orthognathic surgery and distraction osteogenesis: options and alternatives

Relapse in orthognathic surgery is multifactorial and can be attributed to posttreatment growth, condylar changes, lack of rigid fixation, and muscle pull and function. Consideration of these factors can aide the surgeon in the decision-making process with regards to treatment options and alternatives. This article reviews the stability of various orthognathic movements using traditional osteotomies and fixation, and compares them to what is currently in the literature regarding distraction osteogenesis.

Distraction osteogenesis: advancements in the last 10 years

Distraction is still evolving in the management of patients with orthopedic and craniomaxillofacial deformities. The relationship among latency, gap size, rate, rhythm, and duration of fixation is not totally understood for all of the individual patients and variations in their needs seen in a clinical practice. Numerous factors can influence the quality and quantity of bone seen with distraction, including the age and nutritional status of the patient and the type of distractor that is used.

The Use of Internal Maxillary Distraction for Maxillary Hypoplasia: A Preliminary Report

PURPOSE

Distraction osteogenesis is a useful alternative to advance the maxilla in complicated cases of maxillary hypoplasia. The purpose of this article is to review the workup, experience, and preliminary results with the use of internal distraction osteogenesis for maxillary hypoplasia at one teaching institution.

PATIENTS AND MATERIALS

Over a 5-year period, more than 300 patients with craniofacial and dentofacial defects have undergone oral and maxillofacial surgery at our center to correct their skeletal discrepancies. Of these, 10 have had maxillary distraction osteogenesis done with internal distractors. Follow-up of 6 months or more was available for 8 patients. Stereolithographic models were used to bend distractors prior to surgery in 6 patients.

RESULTS

Latency prior to the start of distraction was 3 to 7 days and varied with the age of the patient. Distraction occurred at approximately 1 mm per day with an average distraction length of 8.5 mm (range, 6-10 mm). Excellent occlusal results were obtained in 5 patients. Major complications including nonunion and failure to achieve acceptable occlusal results were observed in 3 patients. Minor complications including pain and loosening of the distracter devices were observed in 2 patients, but did not appear to affect the esthetic and functional results.

CONCLUSIONS

Distraction osteogenesis is a useful alternative to traditional orthognathic surgery to treat maxillary hypoplasia. Internal distractions are attractive to patients, but are more difficult to place and can cause discomfort to patients when trying to achieve an ideal primary vector of distraction. Stereolithographic models can help with placement of the device. Changes in design of distractors may help with patient discomfort.