Biomechanical Considerations for Distraction of the Monobloc, Le Fort III, and Le Fort I Segments:

Three-dimensional assessment of outcomes of surgical midface advancement in syndromic craniosynostosis: A systematic review

Le Fort III surgical procedures are used for midface advancement in patients with syndromic craniosynostosis. Three-dimensional (3D) computed tomography (CT) offers significant advantages in planning and evaluating surgical outcomes. It aids in determining the appropriate surgical procedure and assessing the desired and achieved degree of advancement before and after surgery with greater detail. However, to date, systematic reviews have assessed the outcome of midface advancement surgeries using traditional investigation methods such as two-dimensional radiographs. The current systematic review uses 3D assessments to assess post-surgical outcomes after midface advancement with Le Fort III surgeries. Six databases were electronically searched from their initiation through January 2024. Two reviewers performed study selection, risk of bias assessment, and data extraction. After a comprehensive electronic search, ten publications were selected for this review including seven case series and three cohort studies. Overall, the findings suggested that 3D assessment evaluates the segment movement in all dimensions and provides a detailed description of asymmetrical movements. Greater advancement was achieved with the distraction osteogenesis procedures and these movements were found to be stable. Long-term follow-up with 3D measurements is required to determine the stability of the midface advancement after surgery and further growth.

Intraoperative Skull Fracture During Halo Application in Subcranial Le Fort III: Strategies for Managing a Rare Complication

External rigid distraction is an established method for achieving subcranial Le Fort III advancement in severe syndromic craniosynostosis. Craniofacial surgeons commonly use halo-type devices for these corrections, as they allow for multiple vectors of pull and facilitate larger midfacial advancements. Although most complications related to their use involve pin displacement or infection, rare complications such as skull fractures have been reported. At 3 months of age, a patient with Apert Syndrome underwent endoscopic-assisted craniectomies for bilateral coronal craniosynostosis. After a year of helmet therapy, he developed pansynostosis and required fronto-orbital advancement. Later at the age of 6, a Le Fort III distraction using a RED II rigid external distractor was performed to address his midfacial hypoplasia, exorbitism, and severe obstructive sleep apnea. While placing the RED II distractor, a shift in the device was noted upon pin fixation, raising suspicion for a unilateral depressed skull fracture. Although computed tomography imaging revealed pin displacement, there was no clinical indication for immediate repair. Given the surgical and psychological burden this could have on the patient, the decision was made to leave the RED II device in place and proceed with the distraction. After distraction and an 8-week latency period for complete consolidation of the facial bony architecture, the RED II device was removed, and the skull fracture was repaired. In patients with multi-operated skulls and residual cranial defects, halo-type devices may present an increased risk of skull fractures. This report discusses alternatives in the literature and presents an example of a rare complication successfully managed with delayed repair.

Comparative Study of Internal Device versus External Device in Le Fort III Distraction for Syndromic Craniosynostosis

BACKGROUND

Le Fort III distraction for syndromic craniosynostosis is performed using internal or external devices. The authors compared the results of both devices.

METHODS

The authors retrospectively evaluated 60 patients with syndromic craniosynostosis treated with Le Fort III distraction (internal or external device) between 2001 and 2021. The authors verified demographic data, surgery-related data, and complications using medical records. For each of the 2 devices, they compared the various factors associated with the device to each other.

RESULTS

For the external device, 32 patients with syndromic craniosynostosis were included. The mean age at surgery was 11.7 years, and the mean elongation length was 20.0 mm. Class III occlusion reoccurred in 11 patients and was significantly associated with age at surgery. Seven complications (device problems and others) were noted. Cranial pin slippage was significantly related to the elongation length. For the internal device, 28 patients with syndromic craniosynostosis were included. The mean age at surgery was 10.4 years, and the mean elongation length was 18.7 mm. There were 15 complications, including device problems, zygomaticomaxillary fractures, and infections. Elongation length was significantly related to these complications. Class III occlusion reoccurred in 9 patients and was significantly related to age at surgery.

CONCLUSIONS

This study found that complications are significantly more likely to occur in internal devices than in external devices, especially device infection. The authors' findings identified several factors that may assist surgeons in selecting between external and internal devices. The relationship between the amount of extension and device-related problems found in this study will be beneficial for solving these problems.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Practical Considerations in Computerized Surgical Planning for Frontofacial Surgery

The field of frontofacial surgery has advanced considerably, building on the pioneering techniques of Paul Tessier, with computerized surgical planning (CSP) emerging as a critical component. CSP has enhanced the precision and efficiency of surgeries for craniofacial dysostoses and hypertelorism, resulting in improved outcomes. This review delves into the importance of understanding orbital anatomy and the crucial bony and soft tissue landmarks essential to the application of CSP in frontofacial procedures, encompassing Le Fort III and monobloc advancements, as well as the correction of hypertelorism.

Monobloc Differential Distraction Osteogenesis

ABSTRACT

Midface advancement at the monobloc level can be the seminal life event for patients with craniofacial dysostosis. Monobloc reconstruction, when planned appropriately, can simultaneously and definitively address multiple functional and aesthetic deficiencies in these patients. The application of distraction has reduced the morbidity experienced with traditional monobloc surgery. The purpose of this study is to report on the outcomes, stability, and growth in younger patients after monobloc advancement in syndromic craniosynostosis patients. The authors report a consecutive series of thirty patients with craniofacial dysostosis treated through monobloc differential distraction osteogenesis. Detailed history, photographic, and long-term radiographic data are reviewed, including a subset of patients who were skeletally immature at the time of their treatment. Differential distraction allows control of midface pitch, roll, and yaw, optimizing functional and aesthetic outcomes. There were no infectious complications requiring reoperation. The average surgical age for all patients was 12.5 years. For the 7 patients age <7 years, average age was 6 years. For all patients, the mean horizontal movement was 12 mm at nasion and 10 mm at A-point. At mean follow-up (4.8 years entire group and 6.2 years age <7 years group) a positive horizontal advancement of 1.1 mm at nasion and 0.8 mm at A-point was observed. More pronounced positive horizontal changes were seen in the age <7 years group. Monobloc differential distraction osteogenesis affords safe and precise repositioning of the midface. The advancement is skeletally stable and young patients show moderate continued growth.

An Unoperated Crouzon Family Treated with Monobloc Distraction: Challenges and Lessons

Crouzon syndrome (CS) is a rare form of craniosynostosis characterized by bicoronal craniosynostosis and facial features including severe midface hypoplasia, exophthalmos, and hypertelorism. Most patients are diagnosed and treated in early childhood; however, there are a few reports of Crouzon patients treated as adults with monobloc facial advancement. To our knowledge, this is the first report of a family affected by CS treated sequentially with monobloc facial advancement using combined internal and external distraction osteogenesis (rigid external distraction).

Craniosynostosis: Monobloc Distraction with Internal Device and Its Variant for Infants with Severe Syndromic Craniosynostosis

The introduction of distraction osteogenesis to frontofacial monobloc advancement has increased the safety of the procedure. One hundred forty-seven patients with syndromic craniosynostosis underwent frontofacial monobloc advancement using 4 internal distractors. Twenty-five were aged 18 months or less. Ten patients presented with a tracheostomy, 5 (50%) were decannulated after surgery, and 3 others (30%) required an additional intervention before decannulation. Six patients required the addition of a transfacial pin and external traction. Very early frontofacial monobloc with 4 internal distractors is a safe and effective treatment to protect the ophthalmic, neurologic, and respiratory functions in infants with severe syndromic craniosynostosis.

Cleft Lip and Palate: LeFort I Distraction with Halo and Hybrid Internal Maxillary Distractors

Distraction osteogenesis is a viable treatment option for patients with a cleft associated with severe maxillary retrusion. A rigid external distraction device and a hybrid internal maxillary distractor have been used to advance the maxilla allowing for predictable and stable results. These techniques can be applied by itself or as an adjunct to traditional orthognathic procedures. The technical aspects are presented. These procedures tend to be simpler and demonstrate great stability compared to traditional surgical methods. The reasons for stability are discussed.

Successful Treatment of Postoperative Mouth Opening Limitation Following Le Fort III Distraction with Bilateral Coronoidectomies

INTRODUCTION

Distraction osteogenesis is a powerful tool in craniomaxillofacial surgery, allowing for large advancements of osteotomized segments in the setting of a restrictive soft tissue envelope. Despite its benefits, distraction can have negative functional consequences. We present a case of a patient with Crouzon syndrome who developed reduced mouth opening capability after a Le Fort III midfacial advancement with rigid external distraction.

TECHNIQUE

Radiographic evaluation revealed that the coronoid process was restricting the normal excursion of the mandible by contacting the posterior zygoma. The patient was subsequently treated with a bilateral coronoidectomy via an intraoral approach, which improved his interincisal opening. Maximum interincisal distance was improved from 18 mm to 33 mm following bilateral cornoid resection.

CONCLUSION

We report coronoid impingement as a potential complication after Le Fort III distraction. Such a finding suggests the need for a detailed vector analysis in cases undergoing midface advancement with distraction. Post-distraction coronoidectomy is a useful surgical procedure to treat mouth opening limitation due to coronoid impingement against the zygoma after midfacial advancement.

Use of distraction osteogenesis in arrhinia

Nasal malformations such as hemiarrhinia and arrhinia have a very low incidence, although many treatment protocols have been described. In this article, we describe 2 surgical techniques to treat arrhinia depending on the age at the beginning of treatment. In our practice, we use Le Fort III osteotomy with distraction osteogenesis as a pillar of the reconstruction because it allows to improve anteroposterior and vertical projections of the midface, giving a proper platform for nasal reconstruction, decreasing the number of interventions. We report a patient with a hemiarrhinia who has completed appropriate reconstruction results and a patient with total arrhinia in whom the distraction was achieved to create a nasal bone support and improve midface projection.

Three-dimensional position changes of the midface following Le Fort III advancement in syndromic craniosynostosis

Little is known about the positional change of the Le Fort III segment following advancement. To study this, pre- and postoperative computed tomography scans of 18 craniosynosthosis patients were analyzed. The Le Fort III segment movement was measured by creating a reference coordinate system and by superpositioning the postoperative over the preoperative scan. On both the pre- and postoperative scans, four anatomical landmarks were marked: the most anterior point of the left and right foramen infraorbitale, the nasion, and the anterior nasal spine. A significant anterior movement of the four reference points was observed. No significant transversal differences were found. A significant difference between the anterior movement of the nasion and anterior nasal spine was found. In vertical dimension, there was a significant cranial movement of nasion in the study group. In addition, from all patients standardized lateral X-rays were viewed to determine the location and direction of force application that were linked to the outcomes of the three-dimensional movement of the nasion and anterior nasal spine (ANS) and the surgical technique. Conclusively, a significant advancement of the midface can be achieved with Le Fort III distraction osteogenesis in this specific patient group. Counterclockwise movement seemed to be the most dominant movement despite different modes of anchorage.