Midface Distraction Osteogenesis Research Articles

Midface distraction osteogenesis using a modified external device and 3D virtual simulation: technical note.

Distraction osteogenesis (DO) with an external distraction device such as the rigid external distraction frame has become an established method for treating midface hypoplasia in faciocraniosynostosis. It allows for greater advancement of the midface in comparison with traditional Le Fort III osteotomies, associated or not with fronto-orbital osteotomies (Le Fort IV). However, the forward movement of the bone segments may not always be performed obeying an ideal distraction vector, resulting in asymmetries, anterior open bite, and loosening of screws. In addition, the cost of the distraction devices is significant and may preclude their routine use in developing countries. We present an alternative device and method for craniofacial advancement in a clinical case of Crouzon's syndrome. A 3D virtual simulation of the distraction vector and a modified external device were used in the current case. The alternative external device in this case proved to be safe, effective, and reliable.

Long Term Speech Outcomes Following Midface Advancement in Syndromic Craniosynostosis.

Midface advancement by distraction osteogenesis (DO) is commonly performed in patients with craniosynostosis for indications including midface hypoplasia, exorbitism, obstructive sleep apnea, class III malocclusion, and overall aesthetic facial deficiency. There is evidence to suggest that maxillary LeFort I advancement increases the risk of velopharyngeal dysfunction in the cleft palate population, yet few studies have investigated changes in speech following LeFort III or monobloc midface advancement in patients with syndromic craniosynostosis. The purpose of this study was to examine the effect of midface DO on speech as indicated by the Pittsburgh Weighted Speech Score in patients with Apert, Crouzon, and Pfeiffer Syndrome. Among 73 midface advancement cases performed during the study period, 19 cases met inclusion criteria. Overall, the highest post-advancement Pittsburgh Weighted Speech Score (PWSS) was significantly higher than the pre-advancement PWSS (0.52 versus 2.42, P = 0.01), indicating an acute worsening of VPI post-advancement. Specifically, the PWSS components nasal emission and nasality were significantly higher post-advancement than pre-advancement (nasal emission: 1.16 versus 0.21, P = 0.02) (nasality: 0.68 versus 0.05, P = 0.04). However, there was no significant difference between pre-advancement PWSS and the latest post-advancement PWSS (P = 0.31). Midface distraction is associated with an acute worsening of VPI post-operatively that is followed by improvement, and often resolution over time. Future work with additional patient accrual is needed to determine the effect of different advancement procedures and syndromes on VPI rates and profundity.

An internal distraction device for midface distraction osteogenesis: The NAVID system type Z'gok

Midface advancement with distraction osteogenesis is more routinely used for faciocraniosynostosis. Distraction devices are generally classified into external and internal types. Compared with external distractors, internal distractors are smaller and better tolerated, but their removal is complicated. Here, we introduce a refined internal distraction device and describe its applicability. Unlike the previous anterior fixation plate that utilises screws, the refined internal distraction (type Z'gok) has 3 claws. This anterior point of the distractor is positioned behind the malar eminence, or the lateral orbital wall. Eight patients with syndromic craniosynostosis underwent midface distraction osteogenesis using the type Z'gok between 2016 and 2017 (Z'gok group). Twelve patients were treated using conventional internal distractors (control group). Patient age ranged from 6 to 21 years. Among them, 4 patients underwent Le Fort III distraction osteogenesis, while the others underwent Le Fort IV distraction osteogenesis. The operative time to remove the distractors in the Z'gok group was 65 ± 18min, shorter than 89 ± 12min in the control group. The blood loss per kilogram of body weight in the Z'gok and control groups was 3.6 ± 3.3 mL/kg and 4.7 ± 1.7 mL/kg, respectively. In conclusion, the type Z'gok is a reliable and effective internal distractor for midface distraction osteogenesis.

S12-06 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II ERUPTION OF MAXILLARY POSTERIOR PERMANENT MOLARS FOLLOWING EARLY CONVENTIONAL LE FORT III: ADVANCEMENT AND EARLY AND LATE LE FORT III DISTRACTION

Introduction: The purpose of this study was to determine the effect of early conventional Le Fort III advancement and/or distraction on development and eruption of the maxillary posterior permanent molars. Methods: A retrospective review of patients diagnosed with syndromic craniosynostosis, who underwent early Le Fort III or early midface distraction and late surgical intervention, was analyzed. Methods: This single-institution, 33-year (1973 to2006), retrospective study included patients with syndromic craniosynostosis treated with early conventional Le Fort III osteotomy/advancement and Le Fort III distraction. Inclusion criteria consisted of the following: (1) surgical intervention, Le Fort III or midface distraction osteogenesis, befor eage 8 years; (2) two panoramic radiographs, one before surgery and one in adolescence; (3) no apparent abnormalities in the position of permanent tooth buds before surgery; and (4) complete clinical and dental records. Panoramic radiographs taken presurgically (time 1) and at least 1 year post-surgically (time 2) were inspected by a craniofacial orthodontist at two different time points, 1 week apart, to ascertain intrarater reliability. Both the right and left molar tooth buds were classified as being present or displaced and further subdivided into location (tuberosity and sinus), impacted, ankylosed, extracted, or absent and recorded for each time point. Results: In the early conventional Le Fort III surgery group, 93 percent of maxillary second molars and 28 percent of maxillary first molars experienced a disturbance in eruption. In the early distraction group, 82 percent of maxilla in the early conventional Le Fort III surgery group, 93 percent of maxillary second molars and 28 percent of maxillary first molars experienced a disturbance in eruption. In the early distraction group, 82 percent of maxillary second molars and 20 percent of maxillary first molars experienced a disturbance in eruption. In the control group, the late conventional Le Fort III and the late distraction groups, only 26 percent of maxillary second molars and none of maxillary first molars experienced a disturbance in eruption. Conclusion: A common disruption seen postoperatively in the early Le Fort III and distraction groups was displacement of the second molars. The majority of the displaced tooth buds were located in the maxillary sinus. Overall, the early Le Fort III surgery groups experienced more frequent disturbances for both first and second molars, with the common sequela of displacement in the maxillary sinus, leading to the question of whether presurgical planning in cases of early intervention to address midface retrusion should include extraction/enucleation of the second molar tooth buds.

Midface Distraction Osteogenesis Using a Modified External Device With Elastic Distraction for Crouzon Syndrome.

Midface distraction osteogenesis has been popularized for the correction of midface hypoplasia associated with exophthalmos and obstructive sleep apnea in patients with Crouzon syndrome. The purpose of this study was to present the method of utilizing the modified external device with elastic distraction for the midface advancement in Crouzon syndrome, and the clinical outcomes and skeletal changes were analyzed. Five consecutive patients with Crouzon syndrome underwent Le Fort III osteotomy with midface advancement using a modified external device with elastic distraction. The distraction system consists of a rigid external distractor, nickel-titanium shape memory alloy spring, and bone-borne traction hooks. The midface advancement was initiated with the bony anchorage around the nasomaxillary buttress at the level between occlusal plane and infraorbital margin. The device was activated at a rate of 1 to 1.5 mm per day by the length of spring. The skeletal changes were analyzed by cephalometric and computed tomographic measurement. All the patients achieved improvements in midface appearance, obstructive sleep apnea, exophthalmos, and occlusion. No complications occurred during this procedure. After the distraction, 1 patient developed an open bite that was corrected by a definitive orthognathic surgery. Cephalometric and computed tomographic measurement analysis showed a differential advancement of midface with more at the occlusal level than the orbital level. In addition, midface suture and bone remodeling was also observed in growing patient. Our modified external device with elastic distraction offers an alternative method to achieve midface advancement in patients with Crouzon syndrome.

Simultaneous and Differential Fronto-orbital and Midface Distraction Osteogenesis for Syndromic Craniosynostosis Using Rigid External Distractor II

In syndromic craniosynostosis, the relation between the supraorbital area and the frontal bone is not good, and it is not possible to reform this area with 1-block advancement. To avoid this problem, the frontal bone is separated from the fronto-orbital bandeau, each is reshaped and remodeled separately, and then both are reattached. The retrusion of the midface, especially in syndromic craniosynostosis, is usually greater than that of cranial bones, so the technique usually separating the midface from the cranium is Le Fort III osteotomy, which allows differential distraction of each part. In this procedure, the cranial and midfacial bones are advanced simultaneously and differentially, both to the planned extent, in a single-stage operation, using rigid external distractor II, correcting exorbitism, respiratory embarrassment, and cranial structures and avoiding eye complications in the future. This procedure was used, with a follow-up, in 10 patients with syndromic craniosynostosis from 2 to 5 years.

Residents' journal review

Residents' journal review

Distraction Osteogenesis of Maxilla and Midface in Postradiotherapy Patients

Although distraction osteogenesis (DO) is widely used, there is minimal information on its use in patients after radiotherapy. The mutilating effects of ablative head and neck surgery, and insufficient development of the craniofacial skeleton after childhood head and neck malignancies, frequently necessitate complex reconstruction techniques. The simultaneous expansion of soft tissue that comes with bony lengthening during DO is a unique phenomenon.1 In selected cases, it causes less morbidity and better esthetic results than any other surgical procedure.

Reactivation of Distraction Length Using External Distractors

Distraction osteogenesis is an established procedure to cope with marked skeletal retrusion or deficiency. A principal theoretical problem with this method is the given length of the distractor unit. Regarding mandibular distraction, some devices allow reactivation of the distractor. For maxillary and midfacial distraction osteogenesis, to date, no report on how to achieve this has been found, creating the rationale for this technical note. Midfacial and maxillary distraction osteogenesis is an accepted therapy for maxillary retrusion and hypoplasia. External, halo-borne devices have been used for more than 15 years as a technical means for that purpose. Under most conditions, a distractor spindle length of over 3 cm will be sufficient for maxillary protraction. Under certain circumstances, however, this length will not be sufficient. A possible reason is subtotal osteotomy, which necessitates higher forces. Therefore forward bending of the extraoral connection rods instead of pure protraction will result, consuming spindle unit length. A further possible reason necessitating resetting is sutural distraction. Within sutural distraction, no osteotomies are perormed and miniplate-based anchoring devices are fixed o the maxilla and inferior zygoma. Because high forces re needed initially, which again lead to an initial bendng of the extraoral rods, the spindle unit length may e exhausted before the desired outcome has been eached.

Dual Midfacial Distraction Osteogenesis for Crouzon Syndrome: Long-Term Follow-Up Study for Relapse and Growth

Rigid external distraction osteogenesis is regarded as a standard treatment for congenital midfacial hypoplasia. However, external distraction for the upper portion of the midface is not as effective and tends to rotate the midfacial segment in a counterclockwise direction. Moreover, patients poorly tolerate it because of the device's bulkiness. To prevent such drawbacks of an external distractor, both external and internal distractors were synchronously applied to patients with Crouzon syndrome. In 6 patients with Crouzon syndrome in whom a dual-distraction technique was applied, distraction of the midfacial region was performed for up to a mean length of 15.3 mm. The external distractor was removed after a 1-month consolidation period, but the internal distractor was maintained for more than 6 months. The degree of advancement of the midface and ossification was measured with lateral cephalometry and 3-dimensional computed tomography imaging, respectively. At long-term follow-up (mean, 4.6 years), the facial contours retained the initial distraction geometry with almost no relapse, showing that the ideal facial contour and occlusion could be obtained. Bone deposition was found to be continually progressing even 6 months postoperatively, and more than 6 months of consolidation was required for complete ossification that mainly occurred in the pterygomaxillary junction and lateral orbital wall. The dual-distraction technique can induce balanced growth without the recurrence of hypoplasia, and it may eventually yield satisfactory outcomes in Crouzon syndrome.

Long-term follow-up of syndromic craniosynostosis after Le Fort III halo distraction: A cephalometric and CT evaluation

Midface distraction osteogenesis (DO) in craniofacial synostosis (CFS) patients has been described by several authors. However, very few cephalometric and computed tomography (CT) long-term follow-up studies are available. A total of 40 consecutive patients affected by CFS subjected to Le Fort III and rigid external distraction (RED) were examined. All patients had pre-DO cephalometric records, immediately post-DO and 6-12 months post-DO. Twenty-seven patients had mid-term records (3 years post-DO) and 20 patients had long-term records (5-10 years post-DO). Fourteen patients had CT data within 1-year of DO, while 10 patients had long-term CT data (range 5-9 years). Excellent post-surgical stability was recorded. Short- and long-term CT data demonstrated excellent ossification at the osteotomy sites post-DO. In the growing patients, surface resorption in the zygomatic-temporal and in the subspinal area (p < 0.05) was observed in the long-term follow-up, as well as a mild increment of the corrected exorbitism (p < 0.05), as only appositional and no sutural growth occurs post Le Fort III, whereby orbital volume does not increase after surgery. Significant advancement of the midface can be achieved and maintained through Le Fort III and RED. In the long term, in growing patients, in general a class III malocclusion does not re-occur, but physiological remodelling processes at the maxillary-zygomatic level, not coupled with sutural growth, tend to mildly re-express the original midfacial phenotype and the exorbitism.

Cranium and Midface Distraction Osteogenesis

The adaptation of distraction osteogenesis (DO) to the midface and cranium in the 1990s and the advancements that followed at the turn of the century resulted in a shift of paradigm in craniofacial surgery. Because skeletal advancement was not sudden anymore, but incremental, the monobloc advancement became safer to perform. Because bone was generated in the distraction gap, bone grafts were no longer needed, and younger patients could benefit from craniofacial advancement. Today, DO is the most powerful tool to simultaneously correct both exorbitism and the respiratory impairment of the faciocraniosynostosis, but practices vary greatly between teams. Current practices, controversies, and near-term future applications will be outlined and discussed. Our current treatment strategy for faciocraniosynostosis is based on early intervention (<18 months of age) to prevent irreversible brain damage. In the first 6 months of life, infants with faciocraniosynostosis receive posterior vault decompression. We currently use posterior vault distraction, using 2 internal distractors. Around 18 months of age, a frontofacial monobloc advancement with DO is performed. It further decompresses the brain, improves respiratory function, and corrects exorbitism. Because we operate at such an early age, we favor internal over external distractors. In severe faciocraniosynostosis, when midface hypoplasia causes major exorbitism endangering the eye or causes respiratory distress requiring a tracheotomy, we do not hesitate to perform a frontofacial monobloc advancement with DO before the age of 18 months, reinforcing the frontozygomatic junction with a plate and placing a transzygomatic pin. The pin is then connected to a traction rope. We frequently use the external distractors, which allow precise control over the rotation of the maxilla and are well tolerated after 5 years of age. When midface hypoplasia is very severe, we combine external and internal distractors. The ongoing debate between proponents of internal versus external distractors or 1-stage versus 2-stage approach is based mostly on anecdotal data. Multicenter prospective studies are necessary to bring objective data to answer these questions.

Midface Distraction Osteogenesis: patient satisfaction survey, second cohort results

Midface Distraction Osteogenesis: patient satisfaction survey, second cohort results

Management of Exorbitism Using Midface Distraction Osteogenesis

Management of patients with syndromal craniosynostosis is probably one of the greatest challenges. They usually present with variable deformities yet share common characteristics. Patients with Crouzon and Aperts syndrome present with exorbitism and midface hypoplasia. Exorbitism is a protrusion of the eyeball due to a decrease in the capacity of the orbital container, and it may lead to drastic consequences if left untreated. Four cases with exorbitism and midface hypoplasia. Three presented with Aperts syndrome and one with Crouzon syndrome. They all underwent an intraoral modified Le Fort III osteotomy followed by midface distraction osteogenesis. Distraction osteogenesis of the midface is a safe and highly effective method in managing exorbitism associated with midface deficiency.

Application of Orthodontic Mini-Implants and Ligation for Absolute Skeletal Anchorage to the Intraoral Labiolingual Appliance

Patients with cleft and several craniofacial syndromes usually show skeletal class III malocclusion with midface hypoplasia. Although the Rigid External Distraction (RED) System (KLS Martin, LP, Jacksonville, FL) has been used widely, bowing of the external traction hooks (ETHs) and tooth-borne anchorage for the intraoral labiolingual appliance (ILA) can result in inappropriate change of force application level and vector control, eventually improper rotation of the osteotomized bony segment and unwanted dentoalveolar effect. Instead of the ETH and ILA, direct fixation of the skeletal plate on the maxilla can be another option. However, it also has some disadvantages including inflammation, fixation failure, and the need for a second surgery to remove the plates. These phenomena could be minimized by the addition of rigidity to the ETHs and fortification of absolute skeletal anchorage to the ILA. Therefore, the purpose of this article was to introduce application orthodontic mini-implants on the buccal attached gingiva and palate areas and ligation for absolute skeletal anchorage to the ILA in midface distraction osteogenesis cases treated with the RED System. In cases that need a large amount of advancement and bodily translation or clockwise rotation of the midface and that have oligodontia or anchorage problem for the ILA, application of the orthodontic mini-implants and ligation for absolute skeletal anchorage to the ILA can be a highly effective fixation approach to obtain more accurate vector control.

Midface distraction osteogenesis: Internal vs. external devices

This study compares internal and external distraction devices in the treatment of midface retrusion. 20 patients were treated with midface distraction (12 Crouzon, 4 Apert, 4 others); 12 with internal distraction (MID device), 8 with external distraction (Red or Blue device). The two groups were compared regarding operation time, peroperative blood loss and complications. The groups were comparable regarding patient age, sex, weight and diagnosis. In the MID-group, 7 of 12 patients (58%) underwent Le Fort III, 5 underwent 12 monobloc (32%). In the Blue device group, three of eight patients underwent Le Fort II (38%), three of eight underwent Le Fort III (38%), and two of eight underwent monobloc (25%). Operation time was shorter in the Blue device (mean 298 min) than in the MID group (mean 354 min). Peroperative blood loss and complication rates were similar. The internal distraction device is the 'gold standard' for treating midface retrusion. The use of an external distraction device in midface distraction osteogenesis is associated with a shorter operation time; peroperative blood loss and complications were similar. An external device affords better 3-dimensional control during the distraction process, so external distraction is preferable in patients who will tolerate this treatment.

67 A simple technique for the planning and placement of distractor devices in midface distraction osteogenesis

67 A simple technique for the planning and placement of distractor devices in midface distraction osteogenesis

Midface distraction osteogenesis and conventional orthognathic surgery: a comparative study of the patient's perspective

Aims/Method: Using a validated questionnaire 22 midface distraction osteogenesis (DO) patients and 22 conventional orthognathic surgery (CO) patients were surveyed. Key themes explored including reasons for surgery, perioperative experiences, benefits of treatment and information provided.

The Assessment of Midface Distraction Osteogenesis in Treatment of Upper Airway Obstruction

Le Fort III osteotomy with midface distraction osteogenesis (Le Fort III DO) can improve the midface form and change the upper airway space. Some surgeons believe that midface advancement can improve respiratory outcome dramatically, but others think it does not predictably result in the cure of obstructive sleep apnea (OSA). In this study, we evaluated the structural and functional changes of the upper airway before and after Le Fort III DO; we hope these studies can improve future protocols for midface advancement. A retrospective study of 11 patients with severe midface retrusion who underwent Le Fort III osteotomy with midface external distractor system was undertaken. These patients had an average of 5.4 months of follow-up. Three-dimensional volumetric assessment of the upper airway was used before and after surgery. We also evaluated the two-dimensional cross-sectional area of the upper airway to show the changes in different airway levels. Two patients with preoperative evidence of OSA were evaluated both preoperatively and postoperatively by overnight polysomnography. The midface was distracted for an average of 20.27 +/- 8.04 mm. Comparison between preoperative and postoperative three-dimensional computed tomographic data showed an average 64.30% increase in upper airway volume, an improvement of 9.13 +/- 6.94 mL (P < 0.05). The two-dimensional measurement also showed that the cross-sectional area at the posterior nasal spine and uvula airway level increased (P < 0.05), but the cross-sectional area at the epiglottis level and the separation of airway and esophagus level did not increase (P > 0.05). Two patients with preoperative evidence of OSA had both preoperative and postoperative sleeping studies that showed improvement. Le Fort III DO can significantly improve the upper airway space in the cases of syndromic craniosynostosis. The upper airway space above the uvula level was significantly enlarged after Le Fort III DO according to two-dimensional and three-dimensional image measurements, and according to the polysomnography, the OSA was alleviated. Le Fort III DO is a promising procedure in the treatment of severe midface retrusion with OSA in young patients.

O.196 Midface distraction osteogenesis, internal vs external devices

This study compares internal and external distraction devices in the treatment of midface retrusion. 20 patients were treated with midface distraction (12 Crouzon, 4 Apert, 4 others); 12 with internal distraction (MID device), 8 with external distraction (Red or Blue device). The two groups were compared regarding operation time, peroperative blood loss and complications. The groups were comparable regarding patient age, sex, weight and diagnosis. In the MID-group, 7 of 12 patients (58%) underwent Le Fort III, 5 underwent 12 monobloc (32%). In the Blue device group, three of eight patients underwent Le Fort II (38%), three of eight underwent Le Fort III (38%), and two of eight underwent monobloc (25%). Operation time was shorter in the Blue device (mean 298 min) than in the MID group (mean 354 min). Peroperative blood loss and complication rates were similar. The internal distraction device is the 'gold standard' for treating midface retrusion. The use of an external distraction device in midface distraction osteogenesis is associated with a shorter operation time; peroperative blood loss and complications were similar. An external device affords better 3-dimensional control during the distraction process, so external distraction is preferable in patients who will tolerate this treatment.