Orbital hypertelorism is an abnormal increase in the distance between the orbits. It can be caused by various craniofacial conditions and occurs when the orbits fail to move medially during development. Evaluation involves imaging and examination to plan surgery. The goals of surgery are to narrow the interorbital distance and nasal bones. Approaches include box osteotomy, which mobilizes the orbits medially, and facial bipartition, which separates the midface. Careful planning and postoperative monitoring are needed to address this complex deformity and achieve the best outcomes.

1. Orbital Hypertelorism
January 22nd,2015

2. Introduction
• Abnormal increase in the
interorbital distance (between
the bony orbits at fronto-
lacrimal junction)
• Avg ICD 25mm in women
28mm in men
• Symmetrical or asymmetrical
• Unilateral or bilateral
• Asso. with various conditions
like craniofacial dysplasia,
encephaloceles, dermoid
cysts, glial tumors and
craniosynostosis syndromes
like Apert syndrome
Mulliken – defines ORH as
ICD & OCD > 2 SD from age- and
gender- matched means

4. Embryology & Pathology
• ORH is not a disease in itself but the manifestation of a craniofacial
deformity that may be present in a variety of craniofacial conditions
• Probably gets established at about 28 mm embryo stage -
defective development of the nasal capsule leads to freezing of the
future frontonaso-orbito-ethmoid complex
frontonasal prominence remains in its embryonic position, the
optic placodes cannot move towards the midline resulting in ORH
• Early ossification of the lesser wings of sphemoids leads to arrest of
orbits in the foetal position (Mann)
Deficient latero-medial movement of the orbit

5. Skeletal pathology –
• Increased ICD with broad nose
• Overexpanded ethmoid sinuses
• Maxillary anomalies,mainly insufficient anterior growth in the
upper maxilla resulting in maxillary retrusion & malocclusions
In severe cases –
• Inferior displacement of cribriform plate
• Temporal displacement of orbits
• Decreased A-P dimension of lateral orbital wall
In unilateral cases –
• Inferior and lateral displacement of orbits
• Orbital dystopia
Optic foramina are usually spared - allows orbital movement
without damaging to optic nerve

7. Tessier Classification – 1st degree 30 – 34 mm ICD
(For adults) 2nd degree 35 – 40 mm ICD
3rd degree > 40 mm ICD
For children,
• Farkas et al: Mean ICD @ 1st yr of age 25-27 mm
by 5 yrs of age 27-30 mm
> 20 yrs of age 31-33 mm
• Munro : CT scan based grading
Type I - parallel medial orbital walls more commom
Type II - wedge shaped posteriorly
Type III - oval widest dimension
Type IV - wedge shaped anteriorly post to globe ;
difficuct to correct

8. Munro : CT scan based grading

9. Preoperative evaluation & planning
• Ophthalmologic evaluation - document visual status,
presence or absence of amblyopia and extraocular
dysfunction
• 3D CT face
• P-A cephalogram
• Planning team should involve neurosurgeon and orthodontist

10. Aims of surgery :
- Bring to orbits closer together
- Correct orbital dystopia, if present
- Narrow the nasal dorsum and create normal nose with adequate projection
Timing of surgery :
- If asso. with faciocraniosynostosis - craniosynostosis has to be corrected
independently before 1 year of age
- If asso. with encephalocele – should be operated as early as possible
- If no neurosurgical emergency or craniosynostosis – surgery after age 4 and
preferably before age 8 (at completion of cerebral growth and before frontal
sinus growth)
- Secondary procedures like revision rhinoplasty and orthognathic surgery at
skeletal maturity

11. Approaches
Box Osteotomy
• Tessier et al.(1967) – Combined craniofacial route for an en bloc
mobilization of the orbits medially after resection of midline
structures including cribriform plate (negative impact on
olfactation)
In Tessier’s protocol, especially in adults, a supraorbital bar is kept
in place in order to ensure stability of the mobilized orbits
• Converse et al – Combined cranifacial route with preservation of
cribriform plate & removal of paramedian segments, thus
preserving nasofrontal junction as base for bone grafting in nasal
reconstrucion
Bipartition technique
• van der Meulen – mobilization of the two hemifaces
Instead of infraorbital rim osteotomy, the osteotomies pass
through the zygomatic arch, the pterygomaxillary junction with
midline palatal split

12. Patient selection
Orbital shift or bipartition?
• The maxillary arch:
If the maxillary arch is narrow and inverted with the incisors being
higher than the molars – Facial bipartition
If the maxillary arch and occlusion are normal – Box osteotomy
• The axis of the orbits:
If the axis is normal - a horizontal mobilization by box osteotomy
If the orbits are laterally and downwardly oblique - facial bipartition
• The nasal fossae:
If narrow - Bipartition, improves the airways by enlarging the lower part of face
• Extent of the hypertelorism:
If severe cases – Bipartition
Mild to moderate cases – box osteotomy

13. Surgical Techniques
Box osteotomy
- Permits a translational movement towards midline along the horizontal or
vertical axes as per needs of ORH
- Orbits are sectioned in a 360° fashion,with osteotomies made posterior to
the equator of the globes (“functional orbital volume”)
- The orbits and contained globes are mobilized towards midline as
individual cubes (“box osteotomies”)
- When the interorbital distance is greater than 40 mm, the neurosurgical
approach is critical because it allows access to the orbital roof and the
central ethmoidosphenoidal area
- Extracranial approach alone is only possible if the cribriform plate is very
high and the deformity is minimal

14. Box-shift mobilization of orbits
Before mobilization of the orbits After mobilization of the orbits

15. Technique

19. Facial bipartition
- Technique shares many surgical steps in common with box osteotomy
Differences are :
• V-shape resection of bone at the nose
• Absence of osteotomy in the infraorbital rim, instead the osteotomies pass
through the zygomatic arch, the pterygomaxillary junction
• Palatal bone is split in midline
• Medialization, of orbitomaxillary segment instead of orbits, creates an
opening at the palatal level, corrects narrow palatal arch and also widens
nasal fossae,thus improving breathing
• Results in change of orbital axis
• Occlusal splint is used to ensure maxillary occlusion postoperatively

20. Medialization of the two hemifaces after bipartition
Before medialization After medialization

22. Subcranial or U-shaped osteotomy
• Hypertelorisms < 35 mm ICD - single medial wall mobilization
• In selected cases presenting with mild symmetrical hypertelorism
(35–40 mm) with large frontal sinuses and a high pituitary sella -
supraorbital rim and roof of the orbits are left in place
with mobilization of the other three walls as U- shaped
orbital segments
• Osteotomy is made at level of frontozygomatic suture and carried
through full thickness lateral orbital wall f/b floor and medial wall
osteotomy
• Comined intra- and extra-cranial approach OR only extracranial
approach can be used foe exposure

24. Associated Procedures
• Medial canthopexy : canthal ligaments are fixed with transnasal SS wires
• Nasal reconstruction : cantilever split calvarial bone graft for dorsal
augmentation
• Fronto-galeal flap : described by Jackson et al to interpose b/w nasal cavity
and dura after resection of ethmoid sinuses and nasal septum
• Excess skin : may be treated initially by sagittal resection OR can be
postponed as this tissue may contract over time
Delay in midline skin resection is beneficial as it provides some degree of
skin excess required during secondary rhinoplasty for dorsal nasal bone
grafting

25. Postoperative care
• Close monitoring is best achieved in a specialized pediatric
intensive care unit for at least the first 24 hours
• Prophylactic antibiotic therapy
• Degree of postoperative airway edema may dictate a
prolonged intubation extending up to 3 or 4 days
• The prophylactic preoperative tarsorrhaphy is left in place
until after successful extubation

26. Outcomes, prognosis, and complications
• Excessive bleeding
• Cerebrospinal fluid leakage through the nose, may require lumbar
drainage if persistent after 3 days
• Infection linked to an insufficient cranialization of the frontal sinus -
best prevented by operating early after the age of 4 years, when
the frontal sinus has usually not yet developed
• Ophthalmological complications such as keratitis or chemosis are
best prevented by the initial tarsorrhaphy
Blindness represents an exceptionally rare but dramatic
complication

27. • Postoperative strabismus is common, and care should be
taken to sufficiently medialize the medial orbital walls
posterior to the osteotomies so as to avoid a step-off that may
impinge on the medial rectus muscles
• insufficient correction - most likely to occur not by relapse,
but by soft-tissue relaxation, especially at the medial canthi
• Temporal hollowing

28. Secondary procedures
• Soft-tissue problems are more complex to treat than bony
irregularities
• Temporal hollowness can be addressed by fat grafting
• Secondary rhinoplsaty
• Orthognathic and orthodontic procedures

29. Recurrences of hypertelorism
• Recurrences are not frequent if the repair has been
performed after 4 years of age, at the completion of skull
growth
• Higher recurrence rate if the hypertelorism corrected earlier
age as brain growth might counteract medialization of the
orbits
• Relapse rate are higher for maxillary retrusion if ORH is asso.
with craniosynostosis,because of inherent lack of growth in
craniosynostosis

33. …THANK YOU…