Management of Midface Deficiency in Syndromic Craniosynostosis with Lefort III Distraction Osteogenesis, Outcomes, and Pitfalls

Abstract

Background

Syndromic craniosynostosis is characterized by premature fusion of cranial sutures resulting in midface deficiency. Lefort III Distraction Osteogenesis (DO) has emerged as an effective surgical intervention for addressing this complex condition. This case series outlines the outcomes, encountered difficulties, and insights gained through the utilization of Lefort III Distraction Osteogenesis (DO). Six patients (age range: 8–18 years) diagnosed with syndromic craniosynostosis underwent Lefort III DO for midface deficiency correction.

Methods

Comprehensive preoperative orthodontic preparation and meticulous surgical planning were executed. The present paper highlighted the promising outcomes with Lefort III DO, such as significant advancements in midface projection, enhanced posterior pharyngeal space, improved ocular position, and the establishment of functional occlusion.

Results

However, some complications such as CSF blepharocele, pin-tract infection, cranial pin perforation, and loosening of the halo frame were encountered. These challenges were addressed with prompt intervention and close postoperative monitoring. Lefort III DO emerges as a valuable approach in effectively addressing midface deficiency in syndromic craniosynostosis patients. While yielding favorable outcomes in terms of facial aesthetics and function, it requires meticulous surgical technique and vigilant postoperative care to address potential complications.

Conclusion

This paper contributes insights into the effective management and potential challenges associated with Lefort III DO in treating midface deficiency in syndromic craniosynostosis patients.

Introduction

The growth and development of the midface is significantly affected in patients with syndromic craniosynostosis resulting in total midface deficiency [1]. The presence of midface retrusion often leads to a constriction of the nasopharyngeal airway, resulting in respiratory compromise. Obstructive sleep apnea (OSA) is a severe manifestation of progressive midface retrusion that necessitates the use of supplemental oxygen or bilevel-positive airway pressure while sleeping. Others may develop severe airway obstruction necessitating tracheostomy [2]. The severe retrusion of the midface can also impede nasal respiration and result in chronic nasal obstruction. Apart from generalized maxillary hypoplasia, severe occlusal discrepancies are present in the form of class III malocclusion, and transverse deficiency of the maxilla leading to crossbite and apertognathia [3]. These occlusal discrepancies lead to impairment of speech articulation and mastication. Additionally, premature fusion of lesser sutures of cranial base sutures leads to abnormal ophthalmologic findings, such as exotropia, exorbitism, orbital dystopia, proptosis, and ptosis, due to lack of orbital depth and diameter [4]. Exorbitism and proptosis subsequently results in corneal exposure which is prone to frequent abrasions or ulcerations. Untreated craniosynostosis with elevated ICP (intracranial pressure) may result in papilledema and eventual atrophy of the optic nerve, leading to partial or complete blindness. Herniation of the globe may occur if the orbits are very shallow, necessitating tarsorrhaphies or urgent orbital decompression [5, 6].

The immediate treatment objectives are to relieve airway obstruction, to prevent brain and optic nerve compression and corneal injury. Long-term objectives are to promote normal development of craniofacial structures such as the brain, cranium, facial bones, and muscles, and minimizing craniofacial deformities [7].

Among all the techniques employed in craniofacial synostosis patients, subcranial Lefort III distraction osteogenesis (DO) is a well-established technique for the correction of midfacial hypoplasia that results in significant enhancement of posterior pharyngeal space, ocular protection, midface retrusion and to achieve functional occlusion. The purpose of this article is to present our experience in managing six patients with syndromic craniosynostosis using Lefort III DO.

Distraction Protocol

Distraction was initiated after a latency period of 5 days. The distraction process was carried out at a rate of 1 mm per day with a rhythm of twice daily (0.5 mm per turn). After achieving the optimal projection of the midface, i.e., an overjet of 2–4 mm, a 20–30% overcorrection was applied in anticipation of relapse. Subsequently, a consolidation period of 12–16 weeks was implemented.

Case Report 1

A 16-year-old female, a known case of Crouzon syndrome, presented with exophthalmos, strabismus and midface hypoplasia (Fig. 1A, B). She had previously undergone fronto-orbital advancement at the age of 4 years. Following preoperative orthodontic preparation (Fig. 1G, H) and fabrication of an occlusal splint, she underwent subcranial Lefort III osteotomy and midface distraction by a rigid external distraction (RED) device. After a 12-week consolidation period, the distraction device was removed. Postoperative orthodontics resulted in the resolution of any remaining arch discrepancies (Fig. 1I, J). A one-year postoperative clinical assessment revealed substantial midface advancement, improvement in facial profile, successful correction of exophthalmos, and the attainment of functional occlusion (Fig. 1D, E). Comparison of preoperative and postoperative lateral cephalogram at one-year follow-up showed significant midface advancement (Fig. 1C, F). RED assembly used in all of our cases with various components and intraoral acrylic splint with anchorage hooks are shown in Fig. 1K, L respectively.

Fig. 1.

A, B Preoperative frontal and lateral profile photographs showing midface deficiency and proptosis. D, E Postoperative frontal and lateral profile photographs showing significant midface advancement and correction in proptosis. C Preoperative lateral cephalograms showing midface retrusion. F Postoperative lateral cephalograms showing increased airway and midface advancement. G, H Pre-distraction occlusion after orthodontic alignment. I, J Postoperative occlusion after orthodontic treatment. K RED assembly with various components labeled a—Halo frame, b—Carbon rod, c—Cranial pins or fixation screws, d—First and second horizontal cross-bar, e—Adjustment screwdriver, f—Patient screwdriver. L Tooth-borne intraoral acrylic splint with anchorage hooks

Case Report 2

A 18-year-old male, a known case of Crouzon syndrome, exhibited bilateral proptosis, hypertelorism, severe obstructive sleep apnea, midface hypoplasia and mandibular retrognathia planned for staged treatment (Fig. 2A, B). He had undergone frontal-orbital advancement and correction of oxycephaly ten years back. Due to difficulty in breathing and recurrent respiratory infections, tracheostomy was performed two years before. Preoperative orthodontic preparation was done, and the occlusal split was fabricated by the orthodontic team. For the treatment of midface hypoplasia and for the improvement in airway space, he underwent midfacial distraction at Lefort III level by RED device (Fig. 2C, D). Skeletal anchorage was obtained from bone plates at intraoral-rim region. Distraction was initiated after a latency period of 5 days. The distraction process was carried out at a rate of 1 mm per day with a rhythm of twice daily (0.5 mm per turn). After achieving the optimal projection of the midface with 20–30%, overcorrection was done in anticipation of relapse. Subsequently, a consolidation period of 12–16 weeks was implemented. Post-surgery, there was noticeable improvement in both respiratory conditions and facial appearance. Following one year of orthodontic alignment for both arches, mandibular advancement with bilateral sagittal split osteotomy (BSSO) was planned. He underwent mandibular advancement followed by advancement genioplasty of 10 mm. Neck liposuction was also done to remove excessive submental fat. After a period of 1 month, patient was decannulated. One-year postoperative follow-up showed the significant advancement of midface, correction of proptosis and mandibular advancement (Fig. 2E, F). Comparison of lateral cephalograms at preoperative, post-orthodontic alignment, post- Lefort III DO and post-mandibular advancement after final occlusion stabilization showed significant advancement of midface, mandible and posterior pharyngeal airway. Assessment of preoperative, post-Lefort III DO and post-mandibular advancement posterior pharyngeal airway space was performed with Dolphin software which showed a notable increase in pharyngeal airway volume (Fig. 2H).

Fig. 2.

A, B Preoperative frontal and lateral profile photographs showing total midface deficiency, proptosis and retruded mandible C, D Postoperative frontal and lateral profile clinical photographs with RED distractor in situ (during consolidation phase) E, F Postoperative frontal and lateral profile clinical photographs at one-year follow-up showing significant midface advancement, correction of proptosis and mandibular advancement G (i) Preoperative lateral cephalogram showing total midface deficiency. (ii) Post-orthodontic treatment lateral cephalogram. (iii) Lateral cephalogram during consolidation phase showing considerable midface advancement. (iv) Lateral cephalogram after final occlusion stabilization with total facial correction with BSSO and genioplasty. H Comparison of preoperative airway volume (2560 mm³), after midface advancement with Lefort III distraction (7728 mm³) and after mandibular advancement with BSSO and genioplasty (13,866.5 mm.³)

Case Report 3

A 10-year-old female patient with Crouzon syndrome presented with hypertelorism, midface retrusion, exophthalmos and mild obstructive sleep apnea (Fig. 3A, D). She had undergone fronto-orbital advancement at 3 years of age. After completing preoperative orthodontics and fabrication of an occlusal splint. She underwent subcranial Lefort III osteotomy and midface distraction with RED device. Lefort III osteotomy procedure was performed following exposure of the frontotemporal region, lateral orbital region, nasion, zygomatic arch and zygomatic body via bicoronal approach (Fig. 3G i). Osteotomies were carried out at frontozygomatic suture region, nasofrontal suture region (Fig. 3 G ii), medial orbital wall, zygoma followed by pterygomaxillary dysjunction and nasal septum osteotomy. Midfacial segment was mobilized by maxillary disimpaction forceps. Intraoperatively, halo frame was then attached with cranial pins, aligned parallel to Frankfort horizontal plane and with retention plates at bilateral infraorbital rim region (Fig. 3G iii). Distraction was initiated after 1 week of latency period. During the activation period, occlusal splint became loose and was re-cemented immediately. After 8 weeks of consolidation, the distraction device was removed along with the occlusal splint. One-year follow-up showed the optimal correction of proptosis and midface retrusion (Fig. 3B, E). Comparison of preoperative and postoperative lateral cephalogram at one-year follow-up showed significant midface advancement (Fig. 3C, F).

Fig. 3.

A, D Preoperative frontal and lateral profile photographs showing midface deficiency and proptosis. B, E Post-distraction frontal and lateral profile photographs showing significant midface advancement and correction in proptosis. C Preoperative lateral cephalogram showing total midface deficiency. F Postoperative lateral cephalograms showing significant midface advancement. G (i) Intraoperative photograph showing exposure for performing Lefort III osteotomy via bicoronal approach. (ii) Intraoperative photograph showing osteotomy cuts at bilateral frontozygomatic and nasofrontal suture (white arrow). (iii) Intraoperative photograph showing attachment of RED halo frame with cranial pins and bone-borne attachment with retention plates fixed at bilateral infraorbital rim region

Case Report 4

A 17-year-old female with Crouzon syndrome presented with midface deficiency, malar bone depression, exophthalmos, strabismus, antimongoloid slant, and incompetent lips. She underwent monobloc DO at the age of 11 years (Fig. 4 A–G). At the age of 17 years, due to residual midface deficiency (Fig. 4J, K), she underwent subcranial Lefort III and Lefort I osteotomy and followed by midface distraction with the RED device taking anchorage from both zygoma and intraoral tooth-borne occlusal splint (Fig. 4L, M). Following the initiation of distraction (1-week post-surgery), the patient developed significant swelling around right temporal region and upper eye lid with watery discharge from the eye (Fig. 4H). Draining fluid was analyzed for the presence beta-2 transferrin, and the diagnosis CSF blepharocele was made. The CSF blepharocele was treated through conservative measures, which included the application of a closed suction drain for three days, administering antibiotics, implementing bed rest, and elevating the head (Fig. 4I). On subsequent CECT scan, perforation of the inner table of parietal bone by one of the cranial pins on right side was found. Due to considerable CSF leakage, the RED device was removed. Then, 10 days after stoppage of CSF leak, elastic traction was applied with the help of standard face mask (Fig. 4N, O). However, the patient experienced discomfort due to the significant amount of force being concentrated over the forehead and chin regions. To address this issue, our orthodontics team designed and created a custom-made external face mark device. The device is currently in use to apply the elastic traction, effectively promoting the forward movement of the midface (Fig. 4P, Q).

Fig. 4.

A, B Preoperative profile frontal and lateral photographs at the age of 11 years showing total midface deficiency and proptosis due to exorbitism. C, D Postoperative frontal and lateral profile clinical photographs with RED distractor in situ (during distraction phase) after monobloc osteotomy which was performed at the age of 11 years. E, F Postoperative frontal and lateral profile clinical photographs after distractor device removal showing improvement in proptosis and frontal prominence at the age of 12 years. G Preoperative intraoral photograph showing constricted maxillary arch. H Swelling and accumulation of CSF in right orbital region (CSF blepharocele) after few days of activation of Lefort III RED device at the age of 17 years and distractor was removed to control the CSF leakage. I Clinical frontal photograph after resolution of swelling. J, K Preoperative frontal and lateral profile photographs at the age of 17 years L, M Postoperative frontal and lateral profile photographs showing with RED device in situ with zygomatic bone and tooth- borne anchorage via occlusal splint. N, O Placement of facemask for elastic traction at zygoma and intraoral anchorage hooks and to prevent the relapse after removal of distractor to control CSF leakage. P, Q Custom-made external face mark device for further elastic traction

Case Report 5

A 10-year-old male patient with Crouzon syndrome exhibited hypertelorism, midface retrusion, exophthalmos and mild obstructive sleep apnea. He had undergone fronto-orbital advancement at 4 years of age. After undergoing preoperative orthodontic preparation and the fabrication of an occlusal splint, he underwent subcranial Le Fort III osteotomy and midface distraction with RED Device. After 8 weeks of consolidation, the distraction device was removed along with the occlusal splint. During the consolidation phase, pin-tract infection occurred which was managed with local dressing and antibiotics. One-year follow-up showed stability of midface advancement and correction of exorbitism.

Case Report 6

A 11-year-old female patient with Apert syndrome presented with hypertelorism, midface deficiency, exophthalmos, and syndactyly. She has undergone cranioplasty and frontal-orbital advancement at 4.5 years of age and surgery of her hands to release web spaces at 9 years of age. After the preoperative orthodontic phase. She underwent subcranial Lefort III osteotomy and midface distraction with RED device. In the activation phase, the halo frame of the RED device got loosened, which was promptly reinforced with two extra cranial pins. After 9 weeks of the consolidation period, the distraction device was removed along with the occlusal splint. One-year follow-up shows the stability of midface movement and correction of exophthalmos and midface retrusion. Table 1 summarizes the demographic details, clinical presentation, surgeries performed, their outcomes, associated complications and their management of all the six patients.

Table 1.

Demographic details of each patient, clinical characteristics, surgeries performed, type of distractor used, outcomes and associated complications

Case	Age	Sex	Diagnosis	Clinical presentation	Previous surgical interventions	Subsequent surgical interventions	Outcome	Preoperative midface deficiency, total distraction achieved and relapse after 1 year	Complications and management
1	16 years	Female	Crouzon syndrome	Proptosis, strabismus midface hypoplasia	Fronto-orbital advancement	Subcranial Lefort III osteotomy and midface distraction	Substantial advancement of the midface, correction of exophthalmos, and functional occlusion	Midface deficiency = 11 mm, Total distraction done = 15 mm, Final advancement after relapse at 1 year = 12 mm	Nil
2	18 years	Male	Crouzon syndrome	Proptosis, hypertelorism, obstructive sleep apnea, midface hypoplasia, mandibular retrognathia	Fronto-orbital advancement and correction of oxycephaly, tracheostomy,	Subcranial Lefort III, mandibular advancement with BSSO, genioplasty, neck liposuction	Improved respiratory conditions, increased pharyngeal airway volume	Midface deficiency = 20 mm, Total distraction done = 26 mm, Final advancement after relapse at 1 year = 21 mm	Nil
3	10 years	Female	Crouzon syndrome	Hypertelorism, midface retrusion, proptosis, mild obstructive sleep apnea	Fronto-orbital advancement	Subcranial Le Fort III osteotomy, midface distraction	Correction of proptosis and significant midface advancement	Midface deficiency = 15 mm, Total distraction done = 22 mm, Final advancement after relapse at 1 year = 20 mm	Dental splint became loose during the activation period and required re-cementation
4	17 years	Female	Crouzon syndrome	Midface deficiency, malar bone depression, proptosis, strabismus,	Monobloc distraction	Subcranial Lefort III and Lefort I osteotomy, midface distraction	Distraction was discontinued, and elastic traction is currently being applied with the help custom made external device	Desired advancement was not achieved due to a failed distraction caused by intracranial complications	CSF blepharocele, cranial pin perforation
5	10 years	Male	Crouzon syndrome	Proptosis, Hypertelorism, midface retrusion, exophthalmos, mild obstructive sleep apnea	Fronto-orbital advancement	Subcranial Le Fort III osteotomy, midface distraction	Correction of proptosis and significant midface advancement	Midface deficiency = 18 mm, Total distraction done = 22 mm, Final advancement after relapse at 1 year = 19 mm	Pin-tract infection managed with local dressing and antibiotics
6	11 years	Female	Apert syndrome	Midface deficiency, Proptosis, syndactyly	Cranioplasty, fronto-orbital advancement, surgery of hands to release web spaces	Subcranial Lefort III osteotomy, midface distraction	Correction of proptosis and significant midface advancement	Midface deficiency = 19 mm, Total distraction done = 23 mm, Final advancement after relapse at 1 year = 20 mm	The halo frame of RED device became loose which was resecured by two additional cranial pins

Discussion

The functional impairments and aesthetic stigma associated with craniofacial deformities have consistently presented a challenge to surgeons in managing deficiencies of the middle third of the face. In 1967, Tessier’s pioneering efforts revolutionized the treatment of patients with craniofacial synostosis and he made various modifications concerning the typology of osteotomy [8]. He introduced the concept of safe and consistent mobilization of entire midface via combined intracranial and extracranial approach. Lefort III DO was first described in 1995 [9] and has become a reliable and evidently effective technique for the management of syndromic midface hypoplasia. Lefort III DO allows gradual advancement of craniofacial region in severe syndromic midfacial hypoplasia leading in greater advancements with diminutive relapse rate. The conventional Lefort III osteotomy procedure is considered to be more invasive than Lefort III DO, as it usually necessitates the use of bone grafts and results in greater soft tissue tension and more complications. Mean midfacial advancement that can be achieved with conventional Lefort III osteotomy ranges from 2 to 17 mm [10], whereas advancements of more than 30 mm are possible with Lefort III DO [11]. DO permits greater advancement distances, more stable long-term results [12], smaller bone gaps, and a lower risk of perioperative complications due to progressive soft tissue expansion[13, 14]. Therefore, Lefort III DO has largely replaced the Lefort III osteotomy technique for the management of syndromic craniosynostosis patients [11, 14].

Monobloc advancement which was first introduced by Ortiz-Monasterio et al. in 1978, is another excellent procedure to address both frontal and midface advancements simultaneously [15]. Monobloc technique is recommended for the management of elevated intracranial pressure as well as orbital and maxillary hypoplasia in patients with severe craniofacial synostosis. However, this approach is related with higher mortality and complications such as meningitis, CSF leaks, epidural abscess followed by osteomyelitis due to created dead space in the anterior cranial vault and more reoperations are reported, whereas Lefort III DO allows gradual bone distraction which does not disrupt the dural adhesion to the frontal bone, leaving no frontal dead space resulting in reduced incidence of infection and lower morbidity [16].

Approximately 50% of patients with syndromic craniofacial synostosis develop obstructive sleep apnea [17]. Respiratory obstruction in this patient group stems from a range of factors, including midface retrusion, diminished anterior cranial base, elongated velum, posterior repositioning of the base of the tongue, and enlarged adenoids. These factors collectively contribute to the narrowing of the airway space as soft tissues are pushed posteriorly. In our second case, the patient underwent permanent tracheostomy 2 years back due to severe respiratory difficulty and the development of acute respiratory distress syndrome. Perkins et al. observed a tracheostomy rate of around 15% in syndromic craniosynostosis patients [18]. Although tracheotomy is successful in managing severe cases of obstruction, it is associated with high morbidity and potential social disturbances. Advancing the midface enlarges the velopharyngeal space in both the sagittal and lateral dimensions, thereby obviating the need for tracheostomy [2].

In all of our cases, RED device was used for midface distraction. Polley et al. first reported the application of rigid, adjustable external device for the management of severe maxillary deficiency in 1997 [19]. External distractor device allows greater multidirectional vector control resulting in more uniform advancement of midface which can be customized to the skeletal and occlusal requirement of each patient [13, 20], whereas the vector of internal distractor device cannot be modified in the activation phase and are reported to result in clockwise rotation of midface leading to inferior displacement [21]. Challenges associated with external device are increased likelihood of accidental dislodgement of the device, intracranial pin migration, pin loosening, pin-tract infections and require more patient’s compliance [21, 22]. On the other hand, internal distractor devices have less interference on patient’s daily activities and are less likely to dislodge. However, internal distractor device is associated with subcutaneous infection as the external shaft of the device is introduced from outside to inside during advancement and requires more invasive surgery for removal of the device [21, 23, 24]. An alternative system has been devised to address shortcomings in distraction devices through the replacement of metallic fixation plates with biodegradable devices which allow early removal of the distractor screws. Without requiring complete removal, this system will stabilize and protect bony regeneration and distraction [25].

Potential intraoperative complications associated with Lefort III DO are CSF leakage, seizures, massive blood loss, unintentional osteotomy cuts, skull base fractures, transcranial pin migration, and ocular injuries. Postoperatively, complications such as CSF rhinorrhoea and CSF blepharocele might occur, necessitating careful monitoring and timely intervention. Additional challenges include the loosening of the distractor device, failure of the anchorage system, and even the potential failure of the distraction process itself. In our cases, pin-tract infection was effectively addressed through local dressings, regular cleaning of the cranial pins, and antibiotic treatment. The loosening of the halo frame was resolved by affixing two supplementary cranial pins on each side. During the activation period, the occlusal splint of one of our patients became dislodged. However, we promptly addressed this issue by re-cementing the splint in place. Therefore, regular assessments of both bony and dental anchorage are imperative to avert the risk of distraction failure. CSF blepharocele which occurred as a consequence of cranial pin perforation was managed conservatively employing the use of a closed suction drain for three days, administration of antibiotics, bed rest, and head elevation. However, if nonoperative measures prove ineffective in resolving the leakage, the subsequent course in the protocol involves CSF diversion through lumbar drainage [26]. Hence, vigilant preoperative planning, meticulous surgical technique, and thorough postoperative care are essential to mitigate these potential complications and ensure the best possible outcomes for patients undergoing Lefort III DO.

Despite surgical efforts, there are several potential pitfalls associated with Lefort III DO. Proper correction of orbital deformities may not be achieved in some cases even after the procedure. Additionally, nasal deformities can persist, leading to dissatisfaction with the aesthetic outcome. In severe deformity cases, even following the profile correction, patients may require additional camouflage surgery and other adjunctive procedures to enhance their aesthetic outcome.

Orthodontists plays a pivotal role in the comprehensive management of midface deficiency in syndromic craniosynostosis patients [27]. They address crowding of teeth to achieve optimal alignment, correction of crossbite by the expansion of narrow maxillary arch, correction of open-bite and several other arch discrepancies in the perioperative period, to ensure a balanced and functional occlusion, enhancing both aesthetics and proper chewing function. Furthermore, they are instrumental in designing occlusal splint which is essential for providing dental anchorage to the distractor device.

Lefort III DO is now considered as gold standard management of syndromic craniosynostosis. However, specific limitations include the presence of a considerable abnormality in the supraorbital/forehead subunit and a three-dimensional vertical inclination of the facial halves, which necessitate a technique combining both intracranial and extracranial approach, such as monobloc osteotomy or facial bipartition [15].

Conclusion

Le Fort III DO is a reliable extracranial approach which effectively addresses all the functional and aesthetic impairments in syndromic craniofacial synostosis patients. A comprehensive assessment of preoperative CT scans, the surgeon’s expertise, diligent postoperative care, and access to orthodontic resources is essential for ensuring the success of the procedure.

Declarations

Conflict of interest

No any financial assistant and conflict of interest.