What is OBO Surgery? The Basics of Orbital Box Osteotomy
OBO is an acronym for Orbital Box Osteotomy, a specialized surgical procedure used to correct significant abnormalities in the position and shape of the eye sockets (orbits). It is primarily performed to treat craniofacial disorders that affect the midface and skull, leading to deformities such as widely spaced eyes (hypertelorism) or vertically misaligned eye sockets (orbital dystopia). This complex operation requires a high degree of surgical skill and is often performed collaboratively by a craniofacial plastic surgeon and a neurosurgeon.
The procedure is designed to reshape the bony structures that form the orbits, moving them closer together or bringing them into a more level position. The term "box osteotomy" refers to the technique of making precise, box-like cuts around the eye sockets to mobilize and reposition them. The goal is both cosmetic—to improve the patient's facial symmetry—and functional, to protect the eyes from damage and support visual alignment.
Conditions Treated with OBO Surgery
OBO surgery is not a common procedure; rather, it is reserved for specific congenital or developmental conditions. These disorders often involve complex skeletal malformations that cannot be corrected through simpler surgical methods. The most common indications for an Orbital Box Osteotomy include:
- Hypertelorism: This condition involves an abnormally increased distance between the eyes, which can be a feature of several craniofacial syndromes. OBO is used to move the widely spaced eye sockets closer to the midline of the face.
- Orbital Dystopia: This refers to the vertical malposition of one or both orbits, meaning one eye socket is positioned significantly higher or lower than the other. OBO is used to correct the vertical misalignment and level the eye positions.
- Craniofacial Syndromes: Many patients who undergo OBO surgery have underlying genetic conditions that cause complex facial bone anomalies. Examples include Apert syndrome, Crouzon syndrome, cranio-fronto-nasal dysplasia, and hemifacial microsomia.
The Surgical Procedure: A Multi-Specialist Approach
OBO surgery is typically performed on children, often between mid-childhood and early adolescence, to coincide with specific stages of facial development. The operation is conducted under general anesthesia and involves a coordinated effort between a plastic surgeon specializing in craniofacial reconstruction and a neurosurgeon. The steps of the procedure generally involve:
- Incision: A coronal (ear-to-ear) incision is made over the top of the head, and the skin and soft tissues are carefully pulled forward to expose the skull and orbital bones. Additional incisions may be made inside the mouth.
- Access: The neurosurgeon removes the bone over the forehead to allow for protection of the brain and eyes during the subsequent bone cuts.
- Osteotomies (Bone Cuts): Precise, box-like cuts are made around the orbits using specialized instruments. This releases the eye sockets from the surrounding skull and facial bones, allowing them to be freely moved and repositioned. Sometimes, a wedge of bone is removed from the bridge of the nose to accommodate the repositioning.
- Repositioning and Fixation: The eye sockets are carefully moved into their new, corrected position. They are then secured with small, dissolvable plates and screws or strong stitches that hold the bones in place as they heal. Any gaps in the bone are filled with bone grafts, often taken from the patient's own skull bone.
- Closure: The incisions are closed with dissolvable stitches, and a head bandage may be applied to reduce swelling.
Recovery and Post-operative Care
The recovery period following an Orbital Box Osteotomy is intensive and requires careful monitoring. Patients can expect a hospital stay of 10 to 14 days. A dedicated team of nurses, doctors, and specialists provides continuous care during this time.
What to expect during recovery:
- Swelling and Bruising: Significant swelling and bruising of the head and face, particularly around the eyes, is normal and expected. It typically peaks in the first few days and then gradually subsides. Lying in an upright position can help minimize swelling.
- Pain Management: Pain is managed with regular medication, initially administered intravenously and later orally as the patient recovers.
- Antibiotics: To reduce the risk of infection, antibiotics are given intravenously for about seven days post-surgery.
- Diet: Patients are advised to eat soft foods for several weeks as the bones of the midface heal.
- Follow-up: Regular follow-up appointments with the surgical team are essential to monitor healing and the final outcome of the procedure. It is important to remember that OBO primarily changes the skeletal structure and does not improve the functional aspect of the eyes, though it sets the stage for further treatment if needed.
Comparison of Craniofacial Procedures
OBO is one of several techniques used to address complex craniofacial anomalies. The choice of procedure depends on the specific deformity and a patient's underlying condition.
| Feature | Orbital Box Osteotomy (OBO) | LeFort III Distraction | Facial Bipartition | Orbital Decompression |
|---|---|---|---|---|
| Primary Goal | To reposition and reshape the orbital bones (eye sockets). | To advance the cheekbones, orbits, and upper jaw simultaneously. | To reposition the entire face, often used to move the orbits closer together. | To relieve pressure by removing bone or fat from behind the eyes. |
| Conditions Treated | Hypertelorism, orbital dystopia, certain craniofacial syndromes. | Midface hypoplasia, obstructive sleep apnea, exorbitism. | Hypertelorism, Apert syndrome, Crouzon syndrome, craniofrontonasal dysplasia. | Graves' eye disease, proptosis. |
| Involved Structures | Orbits, bridge of the nose, surrounding bone. | Midface, zygomas, maxilla, orbits. | Entire face and orbits. | Orbital walls (medial, inferior, lateral). |
| Key Technique | Box-like cuts to mobilize and shift the orbital bones. | Gradual, controlled bone movement over weeks using distraction devices. | Repositioning of the facial bones along a central line. | Removal of bone or fat to increase volume within the eye socket. |
Conclusion
OBO surgery, or Orbital Box Osteotomy, is a highly specialized and complex reconstructive procedure used to correct severe orbital malformations associated with various craniofacial conditions. By reshaping and repositioning the eye sockets, it can dramatically improve a patient's facial appearance, protect their eyes from damage, and provide a stable foundation for future corrective surgeries. The procedure is a significant undertaking that requires expert, multi-disciplinary care, a period of intensive recovery, and comprehensive post-operative management. While challenging, the results can be life-changing for patients with specific needs, restoring symmetry and improving their quality of life.
For more in-depth information on this procedure and related craniofacial conditions, visit the Great Ormond Street Hospital page on Orbital Box Osteotomy.
