The use of hydroxyapatite cement in secondary craniofacial reconstruction

Sixty-one patients underwent secondary craniofacial reconstruction for contour defects using hydroxyapatite cement over a 3-year period (20-month mean follow-up). There were 56 children, aged 2.2 to 18 years (mean, 10.7 years), 21 boys and 35 girls. This is the first series of pediatric patients in whom the use of hydroxyapatite cement has been reported. There were five adults aged 21 to 46 years (mean, 32 years), 3 men and 2 women. Thirty-one patients underwent reconstruction for secondary orbitocranial defects after surgery for synostosis, 7 after surgery for hypertelorism, 10 for posttraumatic skull defects, and 13 for a variety of other facial skeletal defects. There were seven complications (11 percent), ranging from a retained drain to postoperative seromas, all of which required reoperation without loss of the contour correction. All of the complications occurred in the first 18 months of our study. There has been excellent retention of implant volume with no recurrence of contour defects to date. We have not found any visible evidence of interference with craniofacial growth over the study period. We conclude that hydroxyapatite cement is a versatile and safe biomaterial when used for the correction of secondary craniofacial contour defects in children and adults. The coupling of antibiotics with this biomaterial may have applications in the treatment of osteomyelitis.

Quantitative assessment of osseous, ocular, and periocular changes after hypertelorism surgery

The purpose of this study was to develop a methodology to quantify osseous, ocular, and periocular fat changes caused by correction of orbital hypertelorism to test the hypothesis that there is a quantitatively predictable relationship between the movement of the osseous orbit and that of the ocular globe. A retrospective review was performed of 10 patients who were status post unilateral or bilateral transcranial medial orbital translocation, for whom there were archival digital data for preoperative and postoperative (mean interval = 30 months) three-dimensional computed tomographic (CT) scans. In addition to standard demographic and surgical data, the clinical preoperative and postoperative interpupillary and intermedial canthal distances were recorded. By using a computer graphics workstation, the CT digital data were registered to four surgically unaltered anatomic fiducial points to allow longitudinal quantitative comparisons. The following three-dimensional measurements were made for each patient preoperatively and postoperatively: interdacryon and interocular centroid distances, and on a standard series of three horizontal and two vertical planes, the position of the medial and lateral orbital walls, and the thickness of the medial and lateral periorbital fat (20 orbits). CT digital distances were compared with similar clinical distances when possible. The age at operation ranged from 4.0 to 12.5 years (mean, 6.6 years). The reduction in interdacryon distance exceeded the reduction in intercentroid distance (mean interdacryon change = -5.3 mm versus mean intercentroid change = -2.7 mm). Although there was a strong correlation between the amount of reduction of the lateral orbital wall and intercentroid distances, there was only a moderate correlation between the reduction in the intercentroid distance and that of the medial orbital wall. Similarly, there was a moderate correlation between the decrease in thickness of the lateral periorbital fat and the reduction of intercentroid distance but not of the medial orbital fat. In conclusion, medial translocation of the orbit does not produce equivalent movement of the ocular globe; neither the intermedial canthal nor the interdacryon distance is a useful predictor of ocular centroid position; and if the goal of hypertelorism operation is reduction of interocular distance, then CT measurement of globe intercentroid distance is essential for outcome assessment.

Management of frontoethmoidal (sincipital) encephalocele

Frontoethmoidal encephaloceles are congenital malformations that cause complex deformities in the frontal, orbital, and nasal regions. As the term implies, with frontoethmoidal encephaloceles, intracranial material has herniated through the dural and skull defect. In this report, 21 patients with frontoethmoidal encephalocele operated by a craniofacial team are presented, and accompanying anomalies, results, and complications are discussed.

Orbital and globe rotation: the role of the periorbita

We hypothesize that excyclorotation of the globe and extraocular muscle cone associated with external orbital rotation around each orbital axis in craniofacial conditions could be at least partially corrected by leaving the anterior periorbita (periosteum lining the orbit) attached to the surgically rotated portion of the orbit. This hypothesis was tested by comparing the degree of rotation of the globe in response to internal rotation of the anterior orbit, leaving the periorbita attached to the rotated portion of the orbit on one (study) side, and stripping the periorbita on the opposite (control) side, in nine fresh cadavers. There was a highly significant difference (P < 0.0001) between the study and control sides. The possible extrapolations of this finding to the clinical situation are discussed.

[Syndromes 7. Hypertelorism (Greig syndrome)]

Hypertelorism is an increased distance between the orbits. Most evident symptom is the increased intercanthal distance. It can be caused by congenital deformities (facial clefts, encephaloceles, enlarged ethmoïds) and by trauma. Three degrees are differentiated. Grade one and two can be corrected with a small risk for complications. If there is vertical orbital dystopia it has to be corrected by a transcranial procedure, as is necessary in grade 3.

The value of stereolithographic models for preoperative diagnosis of craniofacial deformities and planning of surgical corrections

The purpose of this study was to assess the importance of stereolithographic models (SLMs) for preoperative diagnosis and planning in craniofacial surgery and to examine whether these models offer valuable additional information as compared to normal CT scans and 3D CT images. Craniofacial SLMs of 20 patients with craniomaxillofacial pathology were made. A helical volume CT scan of the anatomic area involved delivered the necessary data for their construction. These were built with an SLA 250 stereolithography apparatus (3D-Systems, Valencia, CA, USA), steered by FORM-IT/DCS software (University of Zurich, Switzerland). The stereolithography models were classified according to pathology, type of surgery and their relevance for surgical planning. Though not objectively measurable, it was beyond doubt that relevant additional information for the surgeon was obtained in cases of hypertelorism, severe asymmetries of the neuro- and viscerocranium, complex cranial synostoses and large skull defects. The value of these models as realistic "duplicates" of complex or rare dysmorphic craniofacial pathology for the purpose of creating a didactic collection should also be emphasized. The models proved to be less useful in cases of consolidated fractures of the periorbital and naso-ethmoidal complex, except where there was major dislocation.

[Results of surgical therapy of orbital abnormalities]

Dystopies of the bony orbit are caused mainly by craniosynostosis, facial clefts and encephaloceles. This article presents the results of the surgical correction of orbital hypertelorism in 24 patients. Using this operation technique, the bony interorbital distance was decreased from an average of 47.6 mm to 22.8 mm. However, the distance between the soft tissues was not reduced by the same amount as the distance between the bony orbits. The intercanthal distance decreased from an average of 58.5 mm to 44.5 mm, whereby an additional refixation of the medial palpebral ligament resulted in a reduction of the intercanthal distance to 40.8 mm. A strabismus divergens was seen preoperatively in 18 patients, postoperatively only in 8 patients. Four of the latter had to undergo operative correction of the diplopia. We conclude that the operative technique is not reserved only for complex cases of hypertelorism because it shows satisfactory functional and aesthetic results with a low complication rate.

[Median craniofacial clefts. Therapy recommendations and late outcome]

Median craniofacial clefts are classified as median facian cleft deformities and are characterized by clefts of the nose involving the skull base. They can be accompanied by hypertelorism and/or encephaloceles. From a total of 22 of our patients with median deformities, three encephaloceles and two severe median nasal clefts with hypertelorism were considered in 2- to-8-year-olds. Two children with severe brain deformities died before the commencement of therapy. The remaining median deformities were corrected as soon as possible, whereby exclusively soft-tissue surgery was performed during the first year of life and in no case later than school admittance. Final corrections on the nasal skeleton were made after the age of 12. No growth disturbances of the middle face or jaw occurred subsequent to craniotomies and corrections of hypertelorism. Plate osteosynthesis has proven to be the most reliable method of stabilization; we removed the osteosynthetic material in all cases. The multiplicity of possible deformities requires that procedures be tailored to the individual case.

[Bone substitute with growth factor. Preliminary clinical cases for cranio- and maxillo-facial indications]

Several biological materials have been analyzed in combination with osteo-inductive growths factors to determine whether such a system can replace bone grafting in surgical practice. Efforts have been aimed at the discovery of the best carriers and delivery systems. We present the results of the surgical treatment of 11 cranio-maxillo-facial defects in 9 patients using a combination of natural coral skeleton (NCS in blocks or granules), human fibrin glue and transforming growth factor beta-1 (TGF-beta 1) as a composite bone substitute. Three patients were initially excluded because of early extrusion of the materials due to a technical error. Clinical and radiological evaluation was performed in all cases, with the patient acting as his own control. Clinical firmness and radiological mineralization occurred in three quarters of cases. New bone formation was confirmed histologically in two of these patients. Clinically the initial results remained stable over a three years follow-up with staged surgical procedures performed on a number of patients. None of the patients suffered any detrimental effect from implantation of the bone substitute. Although the numbers in these series are limited, the association of TGF-beta 1, human fibrin glue and NCS represented an interesting step, although the clinical results could be improved. Important factors in the success of this technique appeared to be stabilisation of the biological materials, quality and asepsis of the surrounding tissue and the dose of growth factor.

A simple procedure for aesthetic correction of the medial epicanthal fold

The author presents a surgical procedure for aesthetic correction of the medial epicanthal fold. The procedure consists of an asymmetrical Z-plasty of the epicanthal fold where a flap is formed from the posterior surface of the epicanthal fold itself. This procedure does not require geometric planning and produces excellent anatomical and functional results, with inconspicuous scars.

A delayed complication with steel wire osteosynthesis

We treated a 6-year-old child for hyperteleorbitism. We performed a facial bipartition steel wire osteosynthesis of the frontal bone. After 7 years we observed two episodes of pneumococcal meningitis, which were treated with intravenous antibiotic, resulting in a prompt recovery. The computed tomographic scan and nuclear magnetic resonance image showed the steel wire included in the frontal sinus and in contact with the dura mater. Removal of the wire and suture of the dura allowed prompt recovery.

Titanium mesh and bone dust calvarial patch during cranioplasty

A technique of filling calvarial defects using bone dust reinforced with titanium Micro Mesh (Leibinger) was investigated using plain x-ray films and computed tomography (CT) in seven consecutive patients (age range, 7-21 years). The aim of our study was to assess whether, in the presence of the titanium, bone dust harvested with a power burr promotes persistent ossification that is comparable with adjacent bone. The mesh was localized by standard skull plain x-ray films, and orthogonal CT scans were obtained at between 9 and 18 months post-operatively. An ultrahigh-resolution algorithm was used to detect neoossification on either side of the Micro Mesh (1-mm collimation, 330-mA and 120 KV(p) at the center of 400 HU, and window width of 2000 Hu). The mesh induced minimal streak artifact. Virtually no new bone formation was seen. It appears that bone dust was completely reabsorbed in this patient group even in the presence of semi-rigid fixation.

Surgical planning and correction of medial craniofacial cleft

In the framework of malformations that concerns the craniofacial area, the orbit is often involved because it represents the border structure between the neurocranium and the splanchnocranium. In these malformations it is very easy to find hypertelorism. Tessier classified clefts rising from the anterior skullbase and involving the maxilla and the alveolar process, as medial or 0 = 14 clefts. We report on a 2-year-old patient, treated with cranial decompression at an early age, suffering from this kind of malformation. To correct it, the surgical technique of facial bipartition was used. This technique, used for the first time by Tessier and then modified by Stricker and colleagues, allows the simultaneous correction of the orbits and maxilla. It is very important to make a correct diagnosis, to plan for surgery carefully for patients suffering from this kind of pathology, and to prescribe the most effective therapy. A computerized analysis system, based on the study of teleradiographic images and on three-dimensional computed tomography, to quantify the extent of the malformation and to define surgical planning was developed.

Craniofrontonasal dysplasia

A series of 10 patients with craniofrontonasal dysplasia presenting to the Oxford Craniofacial Unit since 1983 is presented. In addition to the well-described combination of coronal synostosis and frontonasal dysplasia, 9 patients had very characteristic dry, curly or frizzy hair. All the patients were female. Recognition of the syndrome is important for genetic counselling, although the precise mode of genetic transmission is unclear with females predominating and males being less severely affected. Surgical correction was in two stages: early frontal advancement followed by correction of hypertelorism when the child became aware of the deformity. Four patients had their craniosynostosis treated in the Oxford Craniofacial Unit. Three patients had previously had frontal remodelling elsewhere. Nine patients had surgery for hypertelorism. The preferred technique for hypertelorism correction was facial bipartition. Following hypertelorism correction, the excess skin was allowed to redrape and subsequently dealt with by medial canthoplasties, thus avoiding a midline scar. Careful attention to the primary frontal advancement procedure is important to avoid complications following difficult dissection of the frontal bone flap at the time of hypertelorism correction.

Late results of hypertelorism correction

The late results of patients who were operated on for the correction of hypertelorism were evaluated. Follow-up ranged between 1 and 11 years (mean, 4.3 years). The mean interorbital distance was 32.9 mm preoperatively and 26.7 mm postoperatively. The significant decrease in the interorbital distance and the absence of serious postoperative complications revealed that craniofacial surgery for the correction of hypertelorism was an effective and reliable procedure.

Early and late surgical treatment of orbital dystopia in craniofacial malformation

Orbital dystopia is one of the most frequent clinical signs of craniofacial malformation. The term dystopia indicates the mono- and bilateral asymmetry of the orbits at least in one of the three-dimensional planes. The diagnosis is based on the clinical test of the patient with the support of diagnostic instruments such as teleradiography in both standard projections, axial computed tomographic (CT) scans at a rate of 1:1 through the neuro-orbital plan, and the three-dimensional CT. Good results of the surgical treatment depend on the patient's age and on adequate programming, which should consider the anomalies in the three spatial planes. The VTO is obtained through a protocol of analysis on cephalometric graphics of the teleradiographics on the CT at a rate of 1:1. The surgical treatment of orbital dystopia is different depending on the age of the patient and the cause of the orbital anomaly. In the case of growing patients, it is preferable to use the fronto-orbital bandeau technique so as not to damage the dental buds, whereas in grown patients Tessier's orbital quadrant technique is used. Even the fixation is quite different between patients who are growing and those who are already grown. In still-growing patients, rigid internal fixation is used only in some cases to avoid the interference with the growth mechanisms.

Maxillary growth in children after early facial bipartition

Facial osteotomies performed in young children are frequently associated with growth deficiencies, especially at the middle third of the face. This problem may be more severe when the initial deformity is associated with alveolar and palatal clefts. Orbital hypertelorism is a major congenital malformation requiring early correction. The resection of the ethmoid tissues located between the orbit and the medialization of the orbital skeleton through the intracranial approach modifies the exaggerated interorbital distance but does not correct the vertical shortness at the midline of the face. Also this procedure interferes with the sagittal growth of the maxilla possibly resulting from the horizontal osteotomy across the maxillae. The medial rotation of the two halves of the face performed by the intracranial approach or the subcranial approach simultaneously corrects the orbital hypertelorism and elongates the nose and the central segment of the face. Our experience with this procedure in infants and young children is analyzed. A series of nine patients with orbital hypertelorism associated with median and paramedian clefts underwent correction by hemifacial rotation. All patients were monitored from 6 to 10 years (mean, 7 years) and demonstrated normal sagittal growth of the maxillae.

Monobloc and facial bipartition osteotomies for reconstruction of craniofacial malformations: a study of extradural dead space and morbidity

This study evaluated the presence of extradural dead space following a monobloc or facial bipartition osteotomy and examined its natural history and relationship to postoperative infection and the presence of a ventriculoperitoneal shunt at the time of osteotomy in a consecutive series of patients with craniofacial dysostosis, frontonasal dysplasia, midline cranio-orbital clefts, and orbital hypertelorism. Only patients followed for at least 1 year were included in the study (range 1.3 to 5.5 years). The 23 patients studied were divided into three groups: 10 patients (mean age 9 years) underwent a monobloc osteotomy with advancement, 7 (mean age 8 years) a facial bipartition osteotomy with advancement, and 6 (mean age 7 years) a facial bipartition osteotomy without advancement. Standard craniofacial computed tomographic (CT) scans were obtained for each patient early after surgery (within 2 weeks in 13 patients and at 6 to 8 weeks in 10 patients) and again 1 year after surgery in every case. The extradural dead space was measured from a reproducible axial CT scan slice for each patient at each postoperative interval. An initial dead space was documented in the retrofrontal region of the anterior cranial fossa when the reconstruction incorporated forward projection of the osteotomy parts. This space was found to be obliterated by the expanded brain by 6 to 8 weeks in the patients examined by CT scan slice for each patient at each postoperative in all patients. Perioperative complications also were documented. The presence of a ventriculoperitoneal shunt at the time of osteotomy (7 of 23 patients) did not increase the risk of complications or alter the pattern of dead space closure after operation. Two patients developed infectious complications that were managed without long-term consequences.

Study and planning of the surgical procedure for the orbital district in patients affected by craniofacial malformations

Orbital surgery is of critical importance within the framework of craniofacial surgery. The conical conformation of orbits requires analysis and surgical procedure planning methods involving all three dimensions. We present our protocol for the analysis and our three-dimensional surgical procedure plan to treat orbital malformations using teleradiography and two- and three-dimensional computed tomographic imaging. A number of clinical cases treated according to this approach are also presented.

"Piggyback" osteotomies in craniomaxillofacial surgery

The total correction of severe skeletal dysplasias in patients with craniofacial anomalies can often be limited by the use of standard osteotomy designs. In this report, we emphasize the concept of the "piggyback" osteotomy for the correction of severe skeletal dysplasias. The piggyback approach, which uses the tiering or stacking of one osteotomy segment on another, allows the reconstructive surgical team to address multiple skeletal problems in one operative setting adequately. The use of this approach throughout the entire craniomaxillofacial skeleton is illustrated with several clinical examples. The conceptual importance of the piggyback principal and the rationale behind its application are discussed.

Internal brain herniation in a patient with Apert's syndrome

Patients with Apert's syndrome typically exhibit craniosynostosis, exorbitism, midface hypoplasia, and symmetric syndactyly. There have also been occasional descriptions of the variable dysmorphology of the inner surface of the calvarium. We present a patient with Apert's syndrome who had an intracranial herniation of a portion of the frontal lobe through a ridge of ossified dura. The ridge and the gliotic cortical tissue were removed when the patient underwent repair of the hypertelorism at age six. Bone grafts for this repair were fashioned in part from the resected ridge. We believe this finding may be the result of a small dural tear that occurred during prior surgery.

Monobloc and facial bipartition osteotomies: quantitative assessment of presenting deformity and surgical results based on computed tomography scans

PURPOSE

The results of monobloc (MB) or facial bipartition (FB) osteotomies on 23 consecutive patients operated on between 1987 and 1991 were evaluated.

PATIENTS AND METHODS

A previously described method of clinically relevant linear measurements taken from preoperative and postoperative computed tomographic scans of these patients was used to document their presenting dysmorphology and the results of surgical correction initially and 1 year after operation. These data were compared with control values, and a percentage of normal for each measurement was derived for each patient.

RESULTS

In the patients with craniofacial dysostosis undergoing an MB osteotomy, the initial cranial vault length (87% of normal), medial orbital wall length (87%), zygomatic arch length (84%), and extent of globe protrusion (134%) all indicated horizontal (anterior-posterior) deficiency of the upper and middle face. After surgery, these measurements moved closer to age-matched control values. At the 1-year interval a minor degree of relapse was evident. In the patients with craniofacial dysostosis who were believed to need an FB osteotomy, the globe protrusion (142% of normal), medial orbital wall length (85%), and zygomatic arch lengths (83%) all indicated horizontal (anterior-posterior) deficiency in the upper and middle face. In addition, the anterior interorbital distance (123% of normal), mid-interorbital distance (122%), and intertemporal distance (126%) all indicated upper face hypertelorism. As a result of the FB osteotomy, anterior bony projection was achieved, and the hypertelorism was improved, but fell short of age-matched normal values. In the patients with frontonasal dysplasia, cranio-orbital clefting, and isolated orbital hypertelorism who underwent an FB osteotomy, preoperative measurements showed a distinct widening of the whole upper midface with forward projection of the medial relative to the lateral orbital walls. The orbital measurements revealed a substantially widened anterior interorbital distance (175% of normal), increased mid-interorbital distance (123%), and an increased distance between the lateral orbital walls (106%). After the surgical procedure, these measurements were improved and relatively stable but not completely normalized.

CONCLUSION

The use of quantitative measurements in the initial evaluation, intraoperative skeletal reshaping, and assessment of early and late reconstructive results provides useful benchmarks.

Neurosurgical considerations on the anatomy of the medial canthus in children

Craniofacial surgery and anterior skull base surgical techniques require an intimate knowledge of periorbital structures. The medial orbital anatomy is especially important for midline approaches to nasion encephalocele, midline trauma, surgery for hypertelorism as well as midline approaches to anterior skull base lesions. The medial canthal tendon is of primary importance in anchoring the eyelid medially in a cosmetic and functional fashion. This review will summarize the anatomic features of the medial canthus and its surrounding structures, including vascular and muscular components. The intimate relationship of the three components of the medial canthal tendon to the nasal lacrimal apparatus is emphasized. Techniques to prevent injury as well as to repair abnormalities in this area will be discussed.