Craniosynostosis

non syndromic craniosynostosis

1. C raniosynostosis DR JAMEEL KIFAYATULLAH LECTURER

2. CRANIOSYNOSTOSIS Craniosynostosis is the premature closure of one or more cranial vault or cranial base sutures .

3. Effects/results The prematurely closed suture imposes restrictions to the growth of underlying brain, resulting in compensatory growth and expansion of less restricted areas.

4. OCCURENCE Craniosynostosis has been estimated to occur in 1:2000 to 1:2500 births .

5. Distribution The distribution between the different synostosis are as follows : Sagittal synostosis :40 – 55 % Coronal synostosis : 20 – 25 % Metopic synostosis :5 - 15 % Lambdoid synostosis : 0 – 5 % Multiple suture synostosis 5 – 15 %, mainly as a part of a syndrome.

6. Causes for premature fusion of cranial sutures Factors associated with nonsyndromic premature fusion of cranial sutures are as follows : Environmental factors Multiple gestation ( eg . twins, triplets) Large infant size Abnormal infant position Uterine abnormalities Head constraint Drugs ( eg . Nitrofurantoin , Warfarin ,) Endocrine abnormalities

7. Functional issues During the first year of life the brain will triple in size, followed by slower growth until it reaches its full size in the teen age years. Restrictions of this growth may have functional consequences. The most typical ones are listed below . Elevated intracranial pressure (>15-17mm Hg) occurs in approximately 47% of patients with multiple, and in 14% of patients with single suture fusion

8. Functional issues Blindness: optic nerve atrophy, corneal exposure Hydrocephalus (mainly for Syndromic patients) Developmental delay Abnormalities of speech and hearing Abnormalities of the ocular axis and adnexa Abnormalities of the airway Malocclusion (Angle class III )

9. Functional issues The x-ray on the left show the appearance of the "Beaten Copper Cranium" pattern found in a patient with elevated intracranial pressure

10. Functional issues The appearance of the "Beaten Copper Cranium" pattern in a CT-scan of a patient with a clover leaf skull deformity .

11. Patient examination The diagnosis of craniosynostosis is made by physical examination and radiographic analysis. History of risk factors during pregnancy Multiple gestation ( eg . twins, triplets) Large infant size Abnormal infant position Uterine abnormalities Head constraint Maternal smoking Caucasian maternal race Advanced maternal age High altitude Maternal use of nitrofurantoin Paternal occupation (agriculture, forestry) Fertility treatments Endocrine abnormalities Warfarin ingestion

12. Family history A positive family history may be found in up to: 2 % of patients with nonsyndromic sagittal suture closure 10 % of patients with nonsyndromic coronal suture closure 10 % of patients with nonsyndromic metopic suture closure 50 % of patients with a syndromic craniosynostosis

13. Elevated ICP Elevated ICP occurs in approximately 47% of patients with multiple, and in 14% of patients with single suture fusion. ICP can be recognized clinically by the finding of papilledema on fundoscopic examination and, in later stages, "thumb printing" or the "beaten copper" appearance on plain radiographs of the skull. Headaches, irritability, developmental delays, and sophisticated eye evaluation (visual evoked potentials, colour analysis) may suggest increased ICP.

14. Respiratory problems Patients with significant midface retrusion should be evaluated for the presence of sleep apnea and airway compromise. Syndromic patients may also have intrinsic airway anomalies such as tracheal sleeve and laryngomalacia .

15. Physical examination Physical examination Physical examination should include evluation of: suture ridging sutural patency by manual palpation skull and facial configuration fullness and patency of both the anterior and posterior fontanels the presence of exophthalmos or orbital dystopia eyelid ptosis and strabismus occlusal relationships and dental development the presence of diplopia and papilledema the intracranial pressure

16. Radiographic assessment Although plain film radiographs ( anteroposterior and lateral skull) may be useful, the gold standard radiographic method is 2D- and 3D-CT-scans

17. Sagittal synostosis ( Scaphocephaly ) Premature closure of the sagittal suture leads to scaphocephaly which has the following characteristics: Elongated skull in the sagittal plane Frontal and occipital prominence Bi-parietal and bi-temporal narrowing Palpable sagittal ridge Variations in the deformity may exist, likely depending upon whether the closure started posteriorly or anteriorly and at what age. Consequently the occiput may be more affected than the frontal region, or vice versa .

18. Sagittal synostosis Posterior reshaping Main indications Limited posterior skull deformity. Further indication When both the anterior and the posterior skull need reshaping, this can be done as a single stage or two separate stages Advantage Single stage restoration of cranial form and increase cranial volume Disadvantage Risk of intracranial injury and significant blood loss

19. Sagittal synostosis Anterior reshaping with widening Main indications Anterior skull deformity with narrowing. Further indication When both the anterior and the posterior skull need reshaping, this can be done as a single stage or two separate stages Advantage Single stage restoration of cranial form and increase cranial volume Disadvantages Risk of intracranial and ocular injury Risk of nerve injury ( ptosis , strabismus)

20. Early surgical treatment Main indications Sagittal craniosynostosis detected early. This is a minimally invasive treatment of sagittal synostosis . Note: If the diagnosis is made within the first weeks or first months of life, less invasive methods of treatment are gaining popularity. These include endoscopically assisted strip craniectomies with molding helmets, and spring assisted craniectomies . These are best performed by 6-12 weeks of age for the endoscopic approach and 3-6 months of age when springs are utilized.

21. Early Surgical treatment Advantage Minimally invasive procedure with less morbidity and shorter hospitalization Disadvantage May not correct the deformity as well as an open approach

22. Total vault reshaping Main indications Significant skull deformities, with or without increased intracranial pressure. Further indication When both the anterior and the posterior skull need reshaping, this can be done as a single stage or two separate stages. Advantage Single stage correction of a combined anterior posterior skull deformity Disadvantages Intracranial injury, blood loss Patient positioning makes it difficult to address the most anterior and most posterior aspects simultaneously

23. Total cranial vault reshaping in sagittal synostosis Premature closure of the sagittal suture results in scaphocephaly ( dolichocephaly ) or a boat shaped head. There may be a great deal of variability in the head shape, depending upon whether the closure started posteriorly or anteriorly and at what age. Consequently the occiput may be more affected than the frontal region, or vice versa. Commonly both are affected. The general goal of surgery is to shorten the skull in a sagittal plane and widen it in a coronal plane.

24. Total Vault Reshaping When the occipital region is significantly affected and the anterior is not, posterior vault reshaping alone may be all that is required. Similarly if the deformity is mostly frontal, correction may be performed here only. Most often both the anterior and the posterior skull need reshaping, and this can be done as a single stage or two separate stages.

25. Total Vault Reshaping Single stage total calvarial reshaping is usually confined to younger patients with less severe deformities. When the deformity is more severe and one has to access the orbits anteriorly or the base of the occiput posteriorly , staged procedures are preferred.

26. Positioning and approach With the patient in the sphinx or "sniffing" position anterior and posterior exposure of the total calvarial vault is made via a  coronal incision .

27. Total Cranial Vault Reshaping Osteotomies After dissecting as far posteriorly as possible and into the superior orbits anteriorly , the skull is systematically disassembled through a series of craniotomies. Barrel-stave or similar osteotomies are performed laterally and the bone flaps are bent shaped and replaced to give shortening in a sagittal plane and widening in the coronal plane. The supraorbital bandeau might also be widened.

28. Total cranial Vault reshaping

29. Total cranial vault reshaping

30. Bilateral coronal synostosis ( Brachycephaly ) Premature closure of both coronal sutures leads to brachycephaly which has the following characteristics: Shortening of the head in the anterior-posterior dimension. Transverse widening of the head Vertical elongation of the head Shortening of the anterior cranial base Retrusive orbital rims Protuberance of the superior frontal and squamous temporal bones Occiput usually flattened

31. Bilateral coronal synostosis Bilateral orbital advancement Main indications Cranial vault deformity, increased intracranial pressure, or eye protection. Further indications Appearance abnormalities (these abnormalities will typically worsen as the child grows older) Increased intracranial pressure caused by restricted growth of the brain Eye protection

32. Bilateral orbital advancement for Cranial Synostosis Advantage Single stage restoration of cranial form and increase cranial volume Disadvantages Risk of intracranial and ocular injury Risk of nerve injury ( ptosis , strabismus)

33. Bilateral orbital advancement The standard treatment is bilateral supraorbital bar advancement and reshaping within the first year of life.

34. Bilateral Orbital Advancement Approach For this procedure the  coronal approach  is used .

35. Bilateral Orbital Advancement Osteotomy After the exposure of the forehead and the orbits via a coronal approach, a bifrontal craniotomy beginning 1 cm superior to the superior orbital rim and extending to behind the coronal sutures is outlined. Burr holes are first placed at the vertex, avoiding the sagittal sinus, and nasal frontal region as well as temporally. An epidural dissection between these points is made. The neurosurgeon then completes the osteotomies using a craniotome .

36. Bilateral Orbital Advancement Osteotomy After the bone flap is removed, the dura is freed from the anterior and middle fossae in the epidural plane. The dura is protected with neurosurgical cottonoids .

37. Bilateral orbital advancement Supraorbital bar osteotomy Malleable retractors are used intracranially to retract and protect the dura and intraorbitally to protect the orbital contents when performing the osteotomies .

38. Bilateral Orbital Advancement The supraorbital bar is then osteotomized . A vertical osteotomy near the pterion (1) is followed by a horizontal osteotomy to the lateral orbital rim (2). An oblique osteotomy is then made through the orbital rim (3) and a transverse osteotomy is completed at the nasal frontal junction (4).

39. Bilateral Orbital Advancement Alternatively, a tongue-in-groove a) or a step osteotomy b) can be used in the temporal region as shown.

40. Bilateral Orbital Advancement Orbital roof osteotomy With the brain carefully retracted, a right angle saw is then turned intracranially and the orbital roof is osteotomized beginning at pterion laterally and ending at the nasal frontal osteotomy medially, joining the osteotomy made extra cranially across the nasal frontal region.

41. Bilateral Orbital Advancement Mobilization of the supraorbital bar An osteotome is then inserted at the pterion and the lateral orbital wall osteotomy completed on both sides, releasing the supraorbital bar.

42. Bilateral Orbital Advancement Positioning of the supraorbital bar The supraorbital bar is then advanced 10-15 mm. In infants a maximal advancement is usually chosen. In adults who have finished craniofacial growth, advancement is done so that the superior orbital rim is approximately 12 mm anterior to the cornea.

43. Bilateral Orbital Advancement Fixation of the supraorbital bar The advanced bar is then stabilized. A wire or suture is placed between the stable lateral orbital rim and the supraorbital bar.

44. Bilateral Orbital Advancement Positioning and Fixation Pearl: To improve the stability of the advanced segment, a cranial bone graft may also be wedged and placed in the orbital roof between the stable posterior segment and the advanced anterior segment.

45. Bilateral orbital advancement Grafting of temporal bone gap Bone graft harvested from the frontal bone flap is then inserted in the temporal gap and held in position with a resorbable plate (infants and children) or metallic plate (adults).

46. Bilateral orbital advancement If metallic or resorbable plate fixation is unavailable, self-retaining osteotomies may be designed and utilized in conjunction with wire or suture fixation.

47. Bilateral orbital advancement Replacement and fixation of the frontal bone flap The frontal bone flap is then replaced in the desired position. If the frontal bone flap is irregular, it can be rotated, bent and/or reshaped to get the best possible fit and contour before replacement using: A bone bending forceps (children). Partial osteotomies and plate fixation (adults)

48. Bilateral orbital advncement The bone flap is then affixed to the supraorbital bar with resorbable plates or resorbable sutures (infants), or titanium plates (adults).

49. Bilateral Orbital Advancement Grafting of coronal bone gap The coronal bone gap created from the advancement and harvesting of bone is then filled with particulate bone shavings harvested with a manual hand-held burr-hole instrument or commercial harvester ( eg , Safe scraper) from the frontal bone flap or the posterior skull.

50. Bilateral orbital advancement Positioning and Fixation This picture demonstrates the large volume of particulate bone that can be harvested from the inner surface of a bone flap using a hand-held burr-hole instrument.

51. Aftercare following transcranial and Le Fort III procedures in infants and children Intraoperatively Most surgeons favors placement of a bulb suction drain under the scalp for 3-5 days. Resorbable skin sutures are often used. Postoperatively A circumferential head dressing is utilized for 48 hours. The neurosurgeon may request placement of a lumbar drain if significant dural tears have occurred during surgery. Patients should spend at least 1-2 days in an intensive care unit for neurological monitoring. Postoperative positioning Keeping the patient’s head in an upright position postoperatively may significantly improve periorbital edema and pain. Some surgeons use injectable corticosteroids during surgery to reduce periorbital swelling.

52. Aftercare following transcranial and Le Fort III procedures in infants and children Nose-blowing To prevent orbital emphysema, nose-blowing should be avoided for at least 10 days.

53. Aftercare following transcranial and Le Fort III procedures in infants and children Medication The following perioperative medications are controversial. There is little evidence to make strong recommendations for postoperative care. Avoidance of aspirin or nonsteroidal antiinflammatory drugs (NSAIDs) for 7 days. Analgesia as necessary. Antibiotics (many surgeons use perioperative antibiotics. There is no clear advantage of any one antibiotic, and the recommended duration of treatment is debatable.). Nasal decongestant may be helpful for symptomatic improvement in some patients. Steroids may help with postoperative edema. Some surgeons have noted increased complications with perioperative steroids. Ophthalmic ointment should follow local and approved hospital protocol. This is not generally required in case of periorbital edema. Some surgeons prefer it. Some ointments have been found to cause significant conjunctival irritation. Regular perioral and oral wound care has to include disinfectant mouth rinse, lip care if intraoral incision has been used.

54. Aftercare Ophthalmological examination Postoperative examination by an ophthalmologist may be requested, although severe periorbital edema may prevent useful assessment. The following signs and symptoms are usually evaluated: Vision Extraocular motion Diplopia Globe position Lid position

55. Aftercare Postoperative imaging Postoperative imaging has to be performed within the first days after surgery to verify accuracy of surgery. 3-D imaging (CT, cone beam) is recommended.

56. Aftercare Wound care Remove sutures from skin after approximately 7-10 days if nonresorbable sutures have been used. Apply ice packs for the first 12 postoperative hours as able although infants and young children do not tolerate this well (may be effective in a short term to minimize edema). Avoid sun exposure and tanning to skin incisions for several months.

57. Aftercare Soft diet can be taken as tolerated until there has been adequate healing of any maxillary vestibular incision. In children and infants age appropriate diets are then prescribed. Patients in MMF will remain on a liquid diet until such time the MMF is released.

58. Aftercare Clinical follow-up Clinical follow-up depends on the complexity of the surgery, and whether the patient has any postoperative problems. Most patients are discharged at postoperative day 3-5 and seen again in 2-3 weeks. In patients undergoing monoblock or Le Fort III distraction, distraction typically begins at day five at 1 mm/day and is assessed weekly with plane radiographs and clinical examination until the desired position is reached. After advancement a period of consolidation of 1-3 months is recommended before the retractors are removed.

59. Aftercare Clinical Follow up In patients undergoing conventional advancement with intermaxillary fixation, MMF is kept in place for 4-6 weeks. Routine oral hygiene is prescribed. Patients with arch bars and/or intraoral incisions and/or wounds must be instructed in appropriate oral hygiene procedures. The presence of the arch bars or elastics makes this a more difficult procedure. A soft toothbrush (dipped in warm water to make it softer) should be used to clean the surfaces of the teeth and arch bars. Elastics are removed for oral hygiene procedures. Chlorhexidine oral rinses should be prescribed and used at least 3 times a day to help sanitize the mouth.

60. After care Clinical Follow up For larger debris, a 1:1 mixture of hydrogen peroxide/ chlorhexidine can be used. The bubbling action of the hydrogen peroxide helps remove debris. A Waterpik ® is a very useful tool to help remove debris from the wires. If a Waterpik is used, care should be taken not to direct the jet stream directly over intraoral incisions as this may lead to wound dehiscence.

61. Aftercare Follow-up The patient needs to be examined and reassessed regularly and often. Additionally, ophthalmological, ENT, and neurological/neurosurgical examination may be necessary. If any clinical signs for meningitis or mental disturbances develop, professional help has to be sought. Due to the young age of many patients, routing CT-scans are performed only if clinically indicated to avoid excessive radiation exposure.

62. Unilateral coronal synostosis (Anterior plagiocephaly ) Premature closure of the coronal suture leads to anterior plagiocephaly which has the following characteristics: Ipsilateral Retruded forehead Retruded supraorbital rim Elevated brow Widened palpebral fissure Radix deviates to affected side Contralateral forehead bossing

63. Unilateral coronal synostosis The standard treatment is either bilateral or unilateral orbital advancement, and bone reshaping within the first year of life. The unilateral advancement is used less frequently and mainly when the deformity is less severe and does not extend across the midline.

64. Unilateral Coronal synostosis Premature closure of the coronal suture leads to anterior plagiocephaly (oblique head) which has the following characteristics: Ipsilateral Retruded forehead Retruded supraorbital rim Elevated brow Widened palpebral fissure Radix deviates to affected side Contralateral forehead bossing

65. Unilateral coronal synostosis Unilateral orbital advancement Main indications Cranial vault deformity, increased intracranial pressure, or eye protection. Further indications Appearance abnormalities (these abnormalities will typically worsen as the child grows older) Increased intracranial pressure caused by restricted growth of the brain Eye protection Advantage Single stage restoration of cranial form and increase cranial volume Disadvantages Risk of intracranial and ocular injury Risk of nerve injury ( ptosis , strabismus)

66. Unilateral orbital advancement for unilateral coronal synostosis The standard treatment is either bilateral or unilateral orbital rim advancement, and bone reshaping within the first year of life. The unilateral advancement is used less frequently and mainly when the deformity is less severe and not extending across the midline.

67. Unilateral orbital advancement Approach For this procedure the  coronal approach  is used.

68. Unilateral Orbital advancement Craniotomy After the exposure of the forehead and the orbit via a coronal approach, a craniotomy beginning 1 cm superior to the superior orbital rim at the midline and extending to behind the coronal suture is outlined. Burr holes are first placed at the vertex, avoiding the sagittal sinus, and nasal frontal region as well as temporally. An epidural dissection between these points is made. The neurosurgeon then completes the osteotomies using a craniotome .

69. Unilateral Orbital advancement OSTEOTOMY After the bone flap is removed, the dura is freed from the anterior and middle fossae in the epidural plane. The dura is protected with neurosurgical cottonoids .

70. UNILATERAL ORBITAL ADVANCEMENT Supraorbital bar osteotomy Malleable retractors are used intracranially to retract and protect the dura and intraorbitally to protect the orbital contents when performing the osteotomies .

71. Unilateral orbital advancement The supraorbital bar is then osteotomized . A vertical osteotomy near the pterion (1) on the affected side is followed by a horizontal osteotomy to the lateral orbital rim (2). An oblique osteotomy is then made through the orbital rim (3) and a vertical osteotomy is made medially near the midline (4).

72. Orbital advancement Osteotomy Alternatively, a tongue-in-groove or step osteotomy can be used in the temporal region as shown.

73. Unilateral Orbital Advancement With the brain carefully retracted, a right angle saw is then turned intracranially and the orbital roof is osteotomized beginning at pterion laterally and ending at the nasal frontal region medially, joining the osteotomy made extra-cranially.

74. Unilateral Orbital Advancement Mobilization of the supraorbital bar An osteotome is then inserted at the pterion and the lateral orbital wall osteotomy completed, releasing the bar.

75. Unilateral Orbital Advancement Reshaping of the supraorbital bar The bandeau will typically need to be reshaped by making a closing wedge ostectomy either in the middle segment of the superior orbital rim or at the junction of the superior orbital rim and the temporal bone, or both. The sites of the osteotomies are chosen in order to get symmetric reshaping of the supraorbital bar.

76. Unilateral Orbital Advancement These are stabilized with sutures, wires, or resorbable plates (preferably), which can be placed intracranially or extra-cranially. In adults extracranial titanium fixation is an alternative.

77. Unilateral Orbital Advancement Positioning of the supraorbital bar The supraorbital bar is then advanced 10-15 mm, hinging at the midline. In infants an overcorrected advancement is usually made, as there will be some recurrence of the deformity with growth. In adults who have finished craniofacial growth, advancement is done so that the superior orbital rim is approximately 12 mm anterior to the cornea, and equal or symmetric with the uninvolved opposite side. The key is to try to straighten the bandeau so that both sides are equal and symmetric, employing osteotomies and fixation wherever required to make this possible.

78. Unilateral Orbital Advancement Fixation of the supraorbital bar The advanced bar is then stabilized with a wire or suture placed between the stable lateral orbital rim and the bandeau. The bar is further stabilized with a resorbable plate, wire or suture at the midline and in the temporal region.

79. Unilateral Orbital Advancement Pearl: To improve the stability of the advanced segment, a cranial bone graft may also be wedged and placed in the orbital roof between the stable posterior segment and the advanced anterior segment. Grafting 

80. Unilateral Orbital Advancement Grafting of temporal bone gap Bone graft harvested from the frontal bone flap is then inserted in the temporal gap and held in position with a resorbable plate (infants and children) or metallic plate (adults).

81. Unilateral orbital advancement Self retaining osteotomies If metallic or resorbable plate fixation is unavailable, self-retaining osteotomies may be designed and utilized in conjunction with wire or suture fixation.

82. Unilateral Orbital Advancement Replacement and fixation of the frontal bone flap The frontal bone flap is then replaced in the desired position. If the frontal bone flap is irregular, it can be rotated, bent and/or reshaped before replacement using: A bone bending forceps (children). Partial osteotomies and plate fixation (adults).

83. Unilateral Orbital Advancement The bone flap is then affixed to the supraorbital bar with resorbable plates or resorbable sutures (infants) or titanium plates (adults).

84. Unilateral Orbital Advancement Grafting of coronal bone gap The coronal bone gap created from the advancement and harvesting of bone is then filled with particulate bone shavings harvested with a manual hand-held burr-hole instrument or commercial harvester ( eg , Safe scraper) from the frontal bone flap or the posterior skull.

85. Unilateral Orbital advancement This picture demonstrates the large volume of particulate bone that can be harvested from the inner surface of a bone flap using a hand-held burr-hole instrument

86. Bilateral orbital advancement Main indications Cranial vault deformity, increased intracranial pressure, or eye protection. Further indications Appearance abnormalities (these abnormalities will typically worsen as the child grows older) Increased intracranial pressure caused by restricted growth of the brain Eye protection Advantage Single stage restoration of cranial form and increase cranial volume Disadvantages Risk of intracranial and ocular injury Risk of nerve injury ( ptosis , strabismus )

87. Bilateral Orbital advancement

88. Bilateral orbital advancement The standard treatment is either bilateral or unilateral supraorbital bar advancement and reshaping within the first year of life. The bilateral advancement is used more frequently and is the procedure of choice when the deformity is more severe, when it extends across the midline, and there is contralateral frontal bossing .

89. Bilateral orbital advancement Approach For this procedure the  coronal approach  is used.

90. Bilateral orbital advancement Craniotomy After the exposure of the forehead and the orbits, a bifrontal craniotomy is outlined. It starts 1 cm above the superior orbital rim and extends to behind the coronal suture on the affected side and to just behind the lateral orbital rim on the contralateral side (insert) Burr holes are first placed at the vertex avoiding the sagittal sinus and nasal frontal region as well as temporally. An epidural dissection between these points is made. The neurosurgeon then completes the osteotomies using a craniotome .

91. Bilateral orbital advancement After the bone flap is removed, the dura is freed from the anterior and middle fossae in the epidural plane. The dura is protected with neurosurgical cottonoids .

92. Bilateral Orbital Advancement Supraorbital bar osteotomy Malleable retractors are used intracranially to retract and protect the dura and intraorbitally to protect the orbital contents when performing the osteotomies .

93. Bilateral orbital advancement The supraorbital bar is then osteotomized . A vertical osteotomy near the pterion (1) on the affected side is followed by a horizontal osteotomy to the lateral orbital rim (2). An oblique osteotomy is then made through the orbital rim (3) and a transverse osteotomy is completed at the nasal frontal junction (4 ).

94. Bilateral orbital advancement Osteotomy Alternatively , a tongue-in-groove or step osteotomy can be used in the temporal region of the affected side as shown .

95. BILATERAL ORBITAL ADVANCEMENT OSTEOTOMY On the non-affected side, the osteotomy typically begins just behind the lateral orbital rim as a vertical osteotomy and is made similarly through the rim .

96. BILATERAL ORBITAL ADVANCEMENT Orbital roof osteotomy With the brain carefully retracted, a right angle saw is then turned intracranially and the orbital roof is osteotomized beginning at pterion laterally on the affected side and ending at the nasal frontal region medially, joining the osteotomy made extra cranially across the nasal frontal region. On the non-affected side the orbital roof osteotomy begins anterior to the pterion and ends medially as above .

97. BILATERAL ORBITAL OSTEOTOMY Orbital roof osteotomy With the brain carefully retracted, a right angle saw is then turned intracranially and the orbital roof is osteotomized beginning at pterion laterally on the affected side and ending at the nasal frontal region medially, joining the osteotomy made extra cranially across the nasal frontal region. On the non-affected side the orbital roof osteotomy begins anterior to the pterion and ends medially as above .

98. Bilateral orbital advancement Mobilization of the bandeau An osteotome is then inserted at the pterion and the lateral orbital wall osteotomy completed on both sides, releasing the bandeau .

99. Bilateral orbital advancement 4. Reshaping of the bandeau The bandeau will typically need to be reshaped on the affected side by making a closing wedge ostectomy either in the middle segment of the superior orbital rim or at the junction of the superior orbital rim and the temporal bone, or both. The sites of the osteotomies are chosen in order to get symmetric reshaping of the bandeau .

100. Bilateral orbital advancement These are stabilized with sutures, wires, or resorbable plates (preferably), which can be placed intracranially or extra cranially. In adults titanium fixation is an alternative .

101. BILATERAL ORBITAL ADVANCEMENT Positioning of the supraorbital bar The supraorbital bar is then advanced 10-15 mm on the side of the fusion, hinging at the point just behind the orbital rim on the uninvolved side. In infants an overcorrected advancement is usually made, as there will be some recurrence of the deformity with growth. In adults who have finished craniofacial growth, advancement is done so that the superior orbital rim is approximately 12 mm anterior to the cornea, and equal or symmetric with the uninvolved opposite side. The key is to try to straighten the bandeau so that both sides are equal and symmetric, employing osteotomies and fixation wherever required to make this possible .

102. BILATERAL ORBITAL ADVANCEMENT Fixation of the supraorbital bar The advanced bar is then stabilized. A wire or suture is placed between the stable lateral orbital rim and the bandeau .

103. Bilateral orbital advancement Pearl: To improve the stability of the advanced segment, a cranial bone graft may also be wedged and placed in the orbital roof between the stable posterior segment and the advanced anterior segment on the affected side.

104. Bilateral Orbital Advancement Grafting of temporal bone gap Bone graft harvested from the frontal bone flap is then inserted in the temporal gap and held in position with a resorbable plate (infants and children) or metallic plate (adults ).

105. Bilateral Orbital Advancement If metallic or resorbable plate fixation is unavailable, self-retaining osteotomies may be designed and utilized in conjunction with wire or suture fixation .

106. Bilateral orbital advancement Replacement and fixation of the frontal bone flap The frontal bone flap is then typically split down the midline and reshaped with a bone bending forceps (children) or with a partial osteotomies and plate fixation (adults). Usually the right and left flaps are rotated, bent contoured and switched to get the optimal symmetry . The bone flaps are affixed to the supraorbital bar with resorbable plates or resorbable sutures (infants), or titanium plates (adults ).

107. Bilateral Orbital Advancement Grafting of coronal bone gap The coronal bone gap created from the advancement and harvesting of bone is then filled with particulate bone shavings harvested with a manual hand-held burr-hole instrument or commercial harvester ( eg , Safe scraper) from the frontal bone flap or the posterior skull .

108. Bilateral orbital advancement This picture demonstrates the large volume of particulate bone that can be harvested from the inner surface of a bone flap using a hand-held burr-hole instrument .

109. Metopic synostosis ( Trigonocephaly ) Premature closure of the metopic suture leads to trigonocephaly which has the following characteristics:  Keel-shaped forehead (best observed from a coronal view) Bi-temporal narrowing Hypotelorism Palpable midline frontal ridge

110. Bilateral orbital advancement and expansion( metopic synostosis ) Main indications Cranial vault deformity, increased intracranial pressure, or eye protection. Advantage Single stage restoration of cranial form and increase cranial volume Disadvantages Risk of intracranial and ocular injury Risk of nerve injury ( ptosis , strabismus)

111. Bilateral orbital advancement and expansion In metopic synostosis or trigonocephaly there is a prominent keel in the midline with retrusion of the lateral orbit and bitemporal narrowing. The standard treatment is completed within the first year of life and involves not only bilateral advancement of the lateral orbit but transverse expansion of the supraorbital bar as well. The frontal bone needs reshaping to match the reconstructed bandeau .

112. Bilateral orbital advancement and expansion For this procedure the  coronal approach  is used .

113. Bilateral orbital advancement and expansion( Metopic synostosis ) Craniotomy After the exposure of the forehead and the orbits, a bifrontal craniotomy beginning 1 cm superior to the superior orbital rim and extending to behind the coronal sutures is outlined. Burr holes are first placed at the vertex avoiding the sagittal sinus and nasal frontal region as well as temporally. An epidural dissection between these points is made. The neurosurgeon then completes the osteotomies using a craniotome .

114. Bilateral orbital advancement and expansion( Metopic synostosis ) After the bone flap is removed, the dura is freed from the anterior and middle fossae in the epidural plane . The dura is protected with neurosurgical cottonoids .

115. Bilateral orbital advancement and expansion( Metopic synostosis ) Orbital osteotomy Malleable retractors are used intracranially to retract and protect the dura and intraorbitally to protect the orbital contents when performing the osteotomies .

116. Bilateral orbital advancement and expansion( Metopic synostosis ) The supraorbital bar is then osteotomized . A vertical osteotomy near the pterion (1) is followed by a horizontal osteotomy to the lateral orbital rim (2). An oblique osteotomy is then made through the orbital rim (3) and a transverse osteotomy is completed at the nasal frontal junction (4 ).

117. Bilateral orbital advancement and expansion( Metopic synostosis ) Orbital roof osteotomy With the brain carefully retracted, a right angle saw is then turned intracranially and the orbital roof is osteotomized beginning at pterion laterally and ending at the nasal frontal osteotomy medially, joining the osteotomy made extra cranially across the nasal frontal region .

118. Bilateral orbital advancement Mobilization of the supraorbital bar An osteotome is then inserted at the pterion and the lateral orbital wall osteotomy completed on both sides, releasing the supraorbital bar.

119. BILATERAL ORBITAL ADVANCEMENT Reshaping The bar is cut in the midline and a cranial bone graft taken from the frontal bone flap is inserted between the two hemi-orbital segments. This bone graft varies from 10-20 mm depending on the severity of the deformity. It is held in place with a resorbable plate .

120. Bilateral orbital advancement The construct is frequently not stable enough and often a larger bone graft is placed on the endocranial surface spanning the central bone graft and affixed with wires or sutures .

121. Bilateral Orbital advancement Closing wedge osteotomies are then made at the lateral orbit endo cranially and the bar is reshaped. The new shape is maintained with resorbable plates placed intra- or extra-cranially .

122. Bilateral Orbital advancement Positioning The reshaped supraorbital bar is then replaced in the now transversely expanded and laterally advanced position. Frequently there is no bony gap temporally but if the orbit needs more lateral advancement, a cranial bone graft is placed in the temporal gap and stabilized with a resorbable plate (insert ).

123. Bilateral orbital advancement Fixation The advanced bar is then stabilized. A wire or suture is placed between the stable lateral orbital rim and the bar .

124. Bilateral orbital advancement Pearl: To improve the stability of the advanced segment, a cranial bone graft may also be wedged and placed in the orbital roof between the stable posterior segment and the advanced anterior segment .

125. Bilateral orbital advancement Reshaping The frontal bone flap is then cut in two in the midline. The segments are forcefully bent with bone bending forceps to make them malleable and shapeable .

126. Bilateral orbital advancement Replacement and fixation The two frontal bone pieces are then replaced with an inter-positional bone graft harvested from the posterior edge of each flap. The bone flaps are affixed to the supraorbital bar with resorbable sutures or resorbable plates which are also used to span the bone graft and hold it in position between the right and left frontal bone segments .

127. Bilateral orbital advancement Alternatively, the two bone flaps may be joined in the midline without an interposed graft if they match well to the supraorbital bar .

128. Bilateral orbital advancement Grafting of coronal bone gap The coronal bone gap created from the advancement and harvesting of bone is then filled with particulate bone shavings harvested with a manual hand-held burr-hole instrument or commercial harvester ( eg , Safe scraper) from the frontal bone flap or the posterior skull .

129. Bilateral orbital advancement This picture demonstrates the large volume of particulate bone that can be harvested from the inner surface of a bone flap using a hand-held burr-hole instrument

130. Unilateral lambdoid synostosis ( Plagiocephaly ) Premature closure of the lambdoid suture leads to posterior plagiocephaly which has the following characteristics: Ipsilateral occipital flatness Ipsilateral mastoid bulge Posterior/inferior displacement of the ear ipsilateral to the suture Variable ipsilateral frontal bone retrusion

131. Unilateral Lambdoid synostosis Posterior vault reshaping Main indications Cranial vault deformity and increased intracranial pressure. Further indications Appearance abnormalities (these abnormalities will typically worsen as the child grows older) Increased intracranial pressure caused by restricted growth of the brain Advantage Single stage restoration of cranial form and increase cranial volume Disadvantage Risk of intracranial injury and significant blood loss

132. Posterior vault reshaping In lambdoid synostosis there is ipsilateral occipital flattening with a compensatory mastoid bulge, and compensatory vault expansion on the opposite side. The goal of surgery is to release the fused suture, and make the cranial base symmetric. The mastoid bulge cannot be corrected due to its low position .

133. Posterior vault reshaping Positioning With the patient in a prone position with a horseshoe head rest, the exposure of the posterior half of the skull is made via a  coronal incision .

134. Posterior vault reshaping OSTEOTOMIES After exposure of the posterior cranial vault, a craniotomy of the occiput and the parietal regions is outlined. Burr holes are first placed at periphery of the flap. An epidural dissection between these points is made. The neurosurgeon then completes the osteotomies using a craniotome .

135. Posterior vault reshaping Reshaping of the basal occipital bone After the bone flap is removed, the dura is freed from the anterior and middle fossae in the epidural plane. The dura is protected with neurosurgical cottonoids .

136. Posterior vault reshaping Malleable retractors are used to retract and protect the dura when performing the osteotomies . On the involved side barrel-stave osteotomies with out-fracturing are made. The newly positioned barrel-staves may be left to float or are stabilized with a long resorbable plate .

137. Posterior Vault Reshaping Alternatively to barrel-stave osteotomies , an occipital segment can be cut and advanced posteriorly . The segment is secured with resorbable plates .

138. Posterior Vault Reshaping Reshaping of the occipital flap This typically involves splitting the bone longitudinally and bending and shaping the two segments, placing the right piece on the left side and vice versa. However the segments can also be replaced in their original position and rotated. The principle is to make the involved side more rounded and full, slightly overcorrected but generally symmetric with the opposite side .

139. Posterior Vault Reshaping Fixation The segments are secured with resorbable plates and screws, wires, or sutures .