An open-roof deformity refers to a condition where the nasal bones do not come together along the top of the nose. In normal conditions, the cartilage and nasal bones, of the nose form a triangle shape that is the nasal structure we manipulate during a Rhinoplasty or Revision Rhinoplasty. The upper part, of this, is made up of the nasal bones, the lower portion is cartilage and finally cartilage makes up the nasal tip.
When to much nasal bone has been removed, during a Rhinoplasty, from the bones section of this structure, a space exits between the right and left nasal bone creating what is called an open roof. The open roof creates a wider appearance to the nose and allows the nasal skin to grow or droop into the space creating vertical lines or depressions in the nasal skin.
The treatment depends on how high or low the nasal bones are at this point. If the nasal bones are to low, creating the customary fractures using osteotomies could create a complete collapse of the nasal bridge because the right and left nasal bones are to short to meet in the midline. In this case, an onlay graft is used to close the gap between the right and left nasal bones. I have found that ear cartilage warps with time, irradiated cartilage dissolves within 15 years as does bone or rib cartilage. Septal cartilage would do well but rarely have I seen septal cartilage long enough to be useful. For this reason, I have always preferred using a silastic straight nasal graft (without the L-section). It's stable and doesn't absorb...however it a man made substance similar to Cheek and Chin Implants.
If, on the other hand, the nasal bones have sufficient height, osteotomies are performed which fractures the nasal bones so they once again meet in the midline.
Without examination by a well experienced plastic and cosmetic surgeon who is well versed in Revision Rhinoplasty, this distinction and therefore surgical plan can not be formulated.