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Orbital expansion in plagiocephaly
BrifishJournolofPlasficSurgery(1988). 41, 16-19 0 1988The Trusteesof British Association of Plastic Surgeons
Orbital expansion in plagiocephaly I.T. JACKSON,
C. COSTANZO,
W. R. MARSH and M. ADHAM
Section of Plastic and Reconstructive Surgery, Mayo Clinic and Departments of Neurosurgery, Mayo Clinic and Plastic Surgery, University of Oklahoma, USA
Summary-In moderate to severe plagiocephaly, the transverse diameter of the orbit on the affected side is consistently decreased. In these cases, the supraorbital rim has been expanded by the required amount and bone grafted. This makes for greater orbital symmetry and ease in obtaining the correct supraorbital convexity. Ten patients have been handled in this way with satisfactory postoperative results.
Plagiocephaly results from unilateral synostosis of the coronal suture and varying degrees of synostosis of the frontosphenoid, frontoethmoid and lambdoid sutures (Seeger and Gabrielsen, 1971). Since forward growth on the affected side is inhibited, the frontal bone is flattened and the supraorbital rim is retruded. The anterior cranial fossa is shallower than the unaffected side. The orbit is somewhat hypoplastic and is displaced superiorly due to the position of the abnormal sphenoid wing and middle cranial fossa encroachment. This results in a variable degree of proptosis of the globe and constriction of the palpebral fissure. Frequently there may be bossing of the frontal bone on the non-affected side; that is probably compensatory in nature. There have been various suggestions as to why craniosynostosis occurs. Park and Powers (1920) have postulated injury to the blastemal suture anlage, which prevents differentiation of the ectomeninx into a suture and leads to ossification with progressive fusion. Moss (1959), on the other hand, has suggested that the deformity is primarily an abnormality of the cranial base. The premature cranial suture closure, together with prevention of the neurocapsule from responding to the growing brain, results from tension which is transmitted from the deranged basal attachments of the malformed sphenoid wings to the dura. The treatment of unilateral coronal craniosynostosis has varied. Initially neurosurgeons performed strip craniectomy. This progressed to unilateral advancement of the supraorbital margin with lateral canthal advancement (Hoffman and Mohr, 1976) and was followed by unilateral mobilisation of the whole supraorbital rim together with the lateral orbital wall and a portion of the malar and
zygomatic arch with concomitant advancement of the frontal bone on the affected side (Whitaker et al., 1977). This was modified slightly in that the advanced supraorbital rim and frontal bone were remodelled and the temporalis muscle transposed (Stricker et al., 1972). Marchac and Renier (1982) advocated bilateral supraorbital and frontal bone advancement without any posterior attachment, the “front flottant” or “floating forehead”. Jane and Edgerton (1974) and Jane (1975) expanded the dura on the plagiocephalic side by incision and pericranial grafting of the resulting defect with dural plication on the contralateral side. We have found unilateral supraorbital remodelling and advancement, together with rotation of the whole bifrontal craniotomy through 180 degrees, to be a very satisfactory method when combined with the floating forehead technique (Jackson, 1981). If the frontal rotation is not possible, the frontal bone is remodelled by bending or osteotomy. Over the past 2+ years particular attention has been paid to the dimensions of the orbits, both on CT scan and at the time of surgery. It has been noted in moderate to severe cases that there is a decrease in the transverse width on the affected side. This has varied from 5 to 10 mm. Thus at time of surgery, a transverse expansion of the supraorbital rim with bone grafting of the subsequent gap has been performed. Technique The orbits are exposed by the coronal approach and the transverse diameter is measured; the difference between the involved side and the noninvolved side is noted. The plagiocephaly correction proceeds as has been described previously (Jackson, 16
E Gg. 1 Figure l-(A) Right-sided plagiocephaly resulting from unilateral craniosynostosis. Transverse width of left orbit, 30 mm; transverse width of right orbit, 25 mm. (B) Right supraorbital area and lateral orbital wall removed, together with asymmetrical frontal bone. Note mark on flattened right frontal area. (C) Frontal bone rotated 180 degrees. Note position of flattened region and previous mark. (D) Vertical osteotomy through supraorbital rim. (E) Supraorbital rim expanded by 5 mm using cranial bone graft. (F) Refashioned supraorbital rim wired in position. Frontal bone placed in position after 180 degree rotation. Note position of mark.
Fig. 2 Figure Z-(A) Severe right-sided plagiocephaly with protrusion of left forehead. Slight asymmetry of palpebral fissures. (B) Postoperative result. Symmetrical palpebral fissures. Eighteen month follow-up. (C) Severe right-sided plagiocephaly with transverse narrowing of palpebral fissure. (D) Postoperative result. Palpebral fissure width comparable. Seven months follow-up. (E) Severe left-sided plagiocephaly with right-sided frontosupraorbital protrusion. Hypertelorism. (F) Postoperative result with narrowing of glabellar region. Nine month follow-up. Palpebral fissure width satisfactory. Orbital dystopia, left upper eyelid ptosis and left internal strabismus not yet corrected. (G) Moderate left-sided plagiocephaly with protrusion of right frontosupraorbital area. (H) Postoperative result. Transverse width of palpebral fissures equal. (I) Moderate right-sided plagiocephaly with left-sided frontosupraorbital protrusion. Note the decrease in transverse diameter, right palpebral fissure with increase in vertical dimension. (J) Postoperative result with symmetrical palpebral fissures. The preoperative left internal strabismus remains uncorrected. Two and a half years follow-up.
ORBITAL EXPANSION
19
IN PLAGIOCEPHALY
1981) (Fig. 1). The bifrontal bone flap is removed in such a way that it can be rotated 180 degrees to ensure that the flattened area on the plagiocephalic side can be placed within the hairline on the noninvolved side. If this is not possible, it is remodelled as described earlier. The supraorbital rim together with the lateral orbital wall and, if indicated, a portion of the malar depending upon the extent of the retrusion, is removed. The supraorbital rim is cut vertically and a full thickness skull graft is wired between the two segments to obtain the same supraorbital width as the normal orbit. This has two advantages. Firstly, the correct transverse diameter of the orbit is obtained since the supraorbital rim and the lateral orbital wall are moved laterally. Secondly, it makes for a very easy manipulation of the rim to produce a convex shape which is exactly symmetrical with the other side. The supraorbital rim is now fixed to its fellow on the other side and at the lateral orbital margin. There is no posterior orbital fixation. The frontal bone flap is wired to the supraorbital rim, and again there is no posterior fixation. The temporalis muscle is advanced and sutured through drill holes in the lateral orbital rim and the temporalis ridge; the lateral canthus is reattached and the coronal incision is closed in the standard fashion. If possible, this procedure is carried out at the age of 3 months. Discussion During a 12-month period, 10 children with moderate and severe craniosynostosis were found to have a 5 to 10 mm difference between the transverse diameter of the orbit on the affected side compared with the non-affected side. The ages of the children varied from 2 to 9 months. In six patients additional simultaneous procedures were performed. In three children with a degree of bony telecanthus or mild hypertelorism, a segment of bone was removed from the glabellar area to approximate the supraorbital rims and so give a better appearance to the root of the nose. In two patients there was unsightly bulging of the middle cranial fossa in the temporal area, and this segment of bone was removed and turned over so that the convexity was placed towards the temporal lobe and the concavity faced outwards to the temporal fossa. In one of these patients and one other there was a cleft of the secondary palate. This was repaired at the same time. All 10 patients had an extensive release of the sphenozygomatic suture area.
All children left hospital within one week of surgery. The postoperative results on a short followup are satisfactory (Fig. 2). The deformity described may be minor but nonetheless exists, and thus should be corrected at this time. It is simple to do, the harvesting of the cranial bone graft presents no problems and the introduction of this bone graft makes for very efficient remodelling of the supraorbital rim. In this way, anteroposterior and transverse symmetry is achieved. The palpebral fissures compare well in size and shape. This may be significant in the long term and requires further observation. References Hoffman, H. J. and Mohr, G. (1976). Lateral canthal advancement of the supraorbital margin: a new corrective technique in the treatment of coronal synostosis. Journalof Neurosurgery. 45,376. Jackson, I. T. (1981). Aesthetic correction of coronal craniosynostosis. Clinics in Plastic Surgery, 8, 3 17. Jane, J. A. (1975). Radical reconstruction of complex cranioorbito-facial abnormalities. Birth Defects, 11, 341. Jane, J. A. and Edgerton, M. T. (1974). Radical reconstruction ofcomplexcranio-orbito-facial abnormalities. MedicalCollege of Virginia Quarterly, 10, 220. Marchac, D. and Renier, D. (1982). Craniofacial Surgery jbr Craniosynostosis. Boston: Little, Brown and Co. Moss, M. L. (1959). The pathogenesis of premature cranial synostosis in man. Acta Anatomica (Base]), 37, 351. Park, E. A. and Powers, G. F. (1920). Acrocephaly and scaphocephaly with symmetrically distributed malformations of the extremities: A study of the so-called “acrocephalosyndactylism”. American Journalof Diseases of Children, 20,235. Seeger, J. F. and Gabrielsen, T. 0. (1971). Premature closure of the frontosphenoidal suture in synostosisof the coronal suture. Radiology, 101,631. Stricker, M., Montaut, J., Hepner, H. and Flot, F. (1972). Les osteotomies du crane et de la face. Anna/es de Chirurgie Plastique, 17, 233. Whitaker, L. A., Schut, L. and Kerr, L. P. (1977). Early surgery for isolated craniofacial dysostosis : Improvement and possible prevention of increasing deformity. Plastic and Reconstructive Surgery, 60,575.
The Authors Ian T. Jackson, MD, Section of Plastic and Reconstructive Surgery, Mayo Clinic. ChristopberCostanzo, MD, Section of Plastic and Reconstructive Surgery, Mayo Clinic. W. Richard Marsh, MD, Department of Neurosrugery, Mayo Clinic. Mehdi Adham, MD, Department of Plastic Surgery, University of Oklahoma. Requests for reprints to: Dr Ian T. Jackson, Rochester, MN 55905, USA. Paper received 11February Accepted 30 March 1987.
1987
MD, Mayo Clinic,
Orbital expansion in plagiocephaly I.T. JACKSON,
C. COSTANZO,
W. R. MARSH and M. ADHAM
Section of Plastic and Reconstructive Surgery, Mayo Clinic and Departments of Neurosurgery, Mayo Clinic and Plastic Surgery, University of Oklahoma, USA
Summary-In moderate to severe plagiocephaly, the transverse diameter of the orbit on the affected side is consistently decreased. In these cases, the supraorbital rim has been expanded by the required amount and bone grafted. This makes for greater orbital symmetry and ease in obtaining the correct supraorbital convexity. Ten patients have been handled in this way with satisfactory postoperative results.
Plagiocephaly results from unilateral synostosis of the coronal suture and varying degrees of synostosis of the frontosphenoid, frontoethmoid and lambdoid sutures (Seeger and Gabrielsen, 1971). Since forward growth on the affected side is inhibited, the frontal bone is flattened and the supraorbital rim is retruded. The anterior cranial fossa is shallower than the unaffected side. The orbit is somewhat hypoplastic and is displaced superiorly due to the position of the abnormal sphenoid wing and middle cranial fossa encroachment. This results in a variable degree of proptosis of the globe and constriction of the palpebral fissure. Frequently there may be bossing of the frontal bone on the non-affected side; that is probably compensatory in nature. There have been various suggestions as to why craniosynostosis occurs. Park and Powers (1920) have postulated injury to the blastemal suture anlage, which prevents differentiation of the ectomeninx into a suture and leads to ossification with progressive fusion. Moss (1959), on the other hand, has suggested that the deformity is primarily an abnormality of the cranial base. The premature cranial suture closure, together with prevention of the neurocapsule from responding to the growing brain, results from tension which is transmitted from the deranged basal attachments of the malformed sphenoid wings to the dura. The treatment of unilateral coronal craniosynostosis has varied. Initially neurosurgeons performed strip craniectomy. This progressed to unilateral advancement of the supraorbital margin with lateral canthal advancement (Hoffman and Mohr, 1976) and was followed by unilateral mobilisation of the whole supraorbital rim together with the lateral orbital wall and a portion of the malar and
zygomatic arch with concomitant advancement of the frontal bone on the affected side (Whitaker et al., 1977). This was modified slightly in that the advanced supraorbital rim and frontal bone were remodelled and the temporalis muscle transposed (Stricker et al., 1972). Marchac and Renier (1982) advocated bilateral supraorbital and frontal bone advancement without any posterior attachment, the “front flottant” or “floating forehead”. Jane and Edgerton (1974) and Jane (1975) expanded the dura on the plagiocephalic side by incision and pericranial grafting of the resulting defect with dural plication on the contralateral side. We have found unilateral supraorbital remodelling and advancement, together with rotation of the whole bifrontal craniotomy through 180 degrees, to be a very satisfactory method when combined with the floating forehead technique (Jackson, 1981). If the frontal rotation is not possible, the frontal bone is remodelled by bending or osteotomy. Over the past 2+ years particular attention has been paid to the dimensions of the orbits, both on CT scan and at the time of surgery. It has been noted in moderate to severe cases that there is a decrease in the transverse width on the affected side. This has varied from 5 to 10 mm. Thus at time of surgery, a transverse expansion of the supraorbital rim with bone grafting of the subsequent gap has been performed. Technique The orbits are exposed by the coronal approach and the transverse diameter is measured; the difference between the involved side and the noninvolved side is noted. The plagiocephaly correction proceeds as has been described previously (Jackson, 16
E Gg. 1 Figure l-(A) Right-sided plagiocephaly resulting from unilateral craniosynostosis. Transverse width of left orbit, 30 mm; transverse width of right orbit, 25 mm. (B) Right supraorbital area and lateral orbital wall removed, together with asymmetrical frontal bone. Note mark on flattened right frontal area. (C) Frontal bone rotated 180 degrees. Note position of flattened region and previous mark. (D) Vertical osteotomy through supraorbital rim. (E) Supraorbital rim expanded by 5 mm using cranial bone graft. (F) Refashioned supraorbital rim wired in position. Frontal bone placed in position after 180 degree rotation. Note position of mark.
Fig. 2 Figure Z-(A) Severe right-sided plagiocephaly with protrusion of left forehead. Slight asymmetry of palpebral fissures. (B) Postoperative result. Symmetrical palpebral fissures. Eighteen month follow-up. (C) Severe right-sided plagiocephaly with transverse narrowing of palpebral fissure. (D) Postoperative result. Palpebral fissure width comparable. Seven months follow-up. (E) Severe left-sided plagiocephaly with right-sided frontosupraorbital protrusion. Hypertelorism. (F) Postoperative result with narrowing of glabellar region. Nine month follow-up. Palpebral fissure width satisfactory. Orbital dystopia, left upper eyelid ptosis and left internal strabismus not yet corrected. (G) Moderate left-sided plagiocephaly with protrusion of right frontosupraorbital area. (H) Postoperative result. Transverse width of palpebral fissures equal. (I) Moderate right-sided plagiocephaly with left-sided frontosupraorbital protrusion. Note the decrease in transverse diameter, right palpebral fissure with increase in vertical dimension. (J) Postoperative result with symmetrical palpebral fissures. The preoperative left internal strabismus remains uncorrected. Two and a half years follow-up.
ORBITAL EXPANSION
19
IN PLAGIOCEPHALY
1981) (Fig. 1). The bifrontal bone flap is removed in such a way that it can be rotated 180 degrees to ensure that the flattened area on the plagiocephalic side can be placed within the hairline on the noninvolved side. If this is not possible, it is remodelled as described earlier. The supraorbital rim together with the lateral orbital wall and, if indicated, a portion of the malar depending upon the extent of the retrusion, is removed. The supraorbital rim is cut vertically and a full thickness skull graft is wired between the two segments to obtain the same supraorbital width as the normal orbit. This has two advantages. Firstly, the correct transverse diameter of the orbit is obtained since the supraorbital rim and the lateral orbital wall are moved laterally. Secondly, it makes for a very easy manipulation of the rim to produce a convex shape which is exactly symmetrical with the other side. The supraorbital rim is now fixed to its fellow on the other side and at the lateral orbital margin. There is no posterior orbital fixation. The frontal bone flap is wired to the supraorbital rim, and again there is no posterior fixation. The temporalis muscle is advanced and sutured through drill holes in the lateral orbital rim and the temporalis ridge; the lateral canthus is reattached and the coronal incision is closed in the standard fashion. If possible, this procedure is carried out at the age of 3 months. Discussion During a 12-month period, 10 children with moderate and severe craniosynostosis were found to have a 5 to 10 mm difference between the transverse diameter of the orbit on the affected side compared with the non-affected side. The ages of the children varied from 2 to 9 months. In six patients additional simultaneous procedures were performed. In three children with a degree of bony telecanthus or mild hypertelorism, a segment of bone was removed from the glabellar area to approximate the supraorbital rims and so give a better appearance to the root of the nose. In two patients there was unsightly bulging of the middle cranial fossa in the temporal area, and this segment of bone was removed and turned over so that the convexity was placed towards the temporal lobe and the concavity faced outwards to the temporal fossa. In one of these patients and one other there was a cleft of the secondary palate. This was repaired at the same time. All 10 patients had an extensive release of the sphenozygomatic suture area.
All children left hospital within one week of surgery. The postoperative results on a short followup are satisfactory (Fig. 2). The deformity described may be minor but nonetheless exists, and thus should be corrected at this time. It is simple to do, the harvesting of the cranial bone graft presents no problems and the introduction of this bone graft makes for very efficient remodelling of the supraorbital rim. In this way, anteroposterior and transverse symmetry is achieved. The palpebral fissures compare well in size and shape. This may be significant in the long term and requires further observation. References Hoffman, H. J. and Mohr, G. (1976). Lateral canthal advancement of the supraorbital margin: a new corrective technique in the treatment of coronal synostosis. Journalof Neurosurgery. 45,376. Jackson, I. T. (1981). Aesthetic correction of coronal craniosynostosis. Clinics in Plastic Surgery, 8, 3 17. Jane, J. A. (1975). Radical reconstruction of complex cranioorbito-facial abnormalities. Birth Defects, 11, 341. Jane, J. A. and Edgerton, M. T. (1974). Radical reconstruction ofcomplexcranio-orbito-facial abnormalities. MedicalCollege of Virginia Quarterly, 10, 220. Marchac, D. and Renier, D. (1982). Craniofacial Surgery jbr Craniosynostosis. Boston: Little, Brown and Co. Moss, M. L. (1959). The pathogenesis of premature cranial synostosis in man. Acta Anatomica (Base]), 37, 351. Park, E. A. and Powers, G. F. (1920). Acrocephaly and scaphocephaly with symmetrically distributed malformations of the extremities: A study of the so-called “acrocephalosyndactylism”. American Journalof Diseases of Children, 20,235. Seeger, J. F. and Gabrielsen, T. 0. (1971). Premature closure of the frontosphenoidal suture in synostosisof the coronal suture. Radiology, 101,631. Stricker, M., Montaut, J., Hepner, H. and Flot, F. (1972). Les osteotomies du crane et de la face. Anna/es de Chirurgie Plastique, 17, 233. Whitaker, L. A., Schut, L. and Kerr, L. P. (1977). Early surgery for isolated craniofacial dysostosis : Improvement and possible prevention of increasing deformity. Plastic and Reconstructive Surgery, 60,575.
The Authors Ian T. Jackson, MD, Section of Plastic and Reconstructive Surgery, Mayo Clinic. ChristopberCostanzo, MD, Section of Plastic and Reconstructive Surgery, Mayo Clinic. W. Richard Marsh, MD, Department of Neurosrugery, Mayo Clinic. Mehdi Adham, MD, Department of Plastic Surgery, University of Oklahoma. Requests for reprints to: Dr Ian T. Jackson, Rochester, MN 55905, USA. Paper received 11February Accepted 30 March 1987.
1987
MD, Mayo Clinic,