What internal structure a scan reveals that an external view hides, how the septum is assessed for quantity and quality in advance, and what the scan does not decide.
A photograph records the outside of a nose. It records it well — the line of the bridge, the position of the tip, the width of the base, the asymmetries — and for a great deal of planning that is what is needed.
What it cannot record is the structure underneath. And since surgery works on that structure rather than on the surface, a plan built from photographs alone is a plan built on an inference about what is inside.
At Edition, 3D CT imaging (HDX WILL) is part of the assessment before nose surgery. This page sets out what is read from it that an external view hides, how the septum is assessed before an incision is made, why a plan made without that information is more likely to change during the operation, and — equally important — the decisions the scan does not make. Imaging in a revision setting is a different subject, because the questions asked of it are different, and it has its own page.
A 3D CT scan shows the bone and cartilage the surgery will actually work on: the shape and thickness of the nasal bones, the position and extent of any septal deviation, the condition of the airway, and — most consequentially for planning — how much usable cartilage the septum is likely to yield as graft material. That last figure governs what a plan can promise, because septal cartilage is the first-choice material for building tip support and refining a bridge. What the scan does not do is decide the operation. It describes what is there; the plan remains a clinical judgment made with the patient's aims alongside it.
On this page
- Why an external view is not enough
- What the scan shows
- The septum: quantity and quality assessed in advance
- Why a plan made without it changes more often
- What the scan does not decide
- How the scan is used in the consultation itself
- Practical questions about the scan
- Questions patients ask
Why an external view is not enough
The visible nose is a covering over a framework. Skin and soft tissue of varying thickness sit over bone at the top, cartilage below it, and the partition running through the middle.
Because the covering varies, the outside and the inside do not correspond reliably. Two noses that look similar in profile can have quite different frameworks beneath, and the operation that produces a given change in one is not the operation that produces it in the other.
Three specific mismatches recur.
A bridge that looks low may not be low. The apparent height of a bridge is the height of the bone and cartilage plus whatever covers it. Where the covering is thin, a reasonably positioned framework can read as low. The plan for those two situations is not the same — one calls for adding height, the other does not.
A nose that looks straight may not be. A deviation sitting high or far back can be substantial without showing externally, particularly where soft tissue has settled around it in a way that disguises the asymmetry.
A nose that looks crooked may be crooked for more than one reason. Bone, cartilage, and the septum can each contribute, and they do not always lean the same way. Separating those contributions from the outside is guesswork; separating them on a scan is reading.
What the scan shows
Four categories of information are read from the imaging, and each changes a different part of the plan.
The nasal bones. Their width, thickness, and length, and the shape of the transition where they meet the cartilage below. Where a prominence is to be reduced, this determines how much of it is bone and how much cartilage — a distinction that governs the technique. Where the bones are to be narrowed, their thickness bears on how they are approached.
The cartilage framework. The size and position of the cartilages forming the tip, and how much support they currently provide. A tip that appears round from the outside may be round because the cartilages are broad, because they sit at a particular angle, or because the covering over them is heavy — three different findings with three different answers, and only the third of them is visible from outside.
The septum. Its position, the extent and location of any deviation, whether the bony portion behind is involved, and whether there is a projecting ridge pressing into a passage. Its second role, as a graft source, is discussed in the next section.
The airway. The width of each passage at several points, the condition of the turbinates on the side walls, and whether the two sides are meaningfully unequal. This matters even for a patient with no breathing complaint, because a plan that narrows a nose narrows the passages inside it.
The septum: quantity and quality assessed in advance
This is the single most consequential thing the scan contributes to a first rhinoplasty, and it is the one patients hear least about.
Septal cartilage is the preferred grafting material. It is straight, appropriately firm, the right thickness for building tip support, and it is reached through the same incision the surgery is already using — no second site, no separate scar, no added recovery. Where a plan calls for supporting a tip, lengthening a nose, or refining a line, septal cartilage is generally the first material considered.
But the same sheet is a structural strut. A supporting frame along its top and front edges has to remain in place, or the nose loses its support — a bridge can settle, a tip can lose position, and in the worst case the middle of the nose collapses inward. Only what lies behind and below that frame is available to be harvested.
How much that leaves varies considerably from patient to patient. And that variation is a planning problem rather than a surgical detail, because the amount of available cartilage sets a ceiling on what the operation can build.
Reading it in advance changes three things.
- What the plan promises. A plan requiring more graft material than the septum can supply is a plan that will have to change. Knowing the constraint before the consultation ends means the conversation is about what is achievable rather than about what was hoped for.
- Whether another material is needed. Where the septum cannot supply enough, ear cartilage, rib cartilage, or dermis may be brought in. Each carries its own considerations, set out in the page on choosing among three autologous materials — and a patient facing a rib harvest, which involves an incision of around 2 cm at a second site, should know that before the day rather than on it.
- Whether an implant belongs in the plan. The realistic alternatives are weighed with the actual supply in view rather than an assumed one.
Quality matters alongside quantity. A septum can be thin, previously injured, partly ossified, or bent in a way that means a nominally adequate area yields few straight, usable pieces. Imaging gives an indication of this; the final judgment is made when the cartilage is exposed.
Why a plan made without it changes more often
Surgery contains a certain amount of judgment made in the moment regardless of how thorough the preparation was. Tissue is not always exactly what imaging suggested, and no scan removes that entirely.
What preparation does is shift decisions from the operating room to the consultation room, and the difference matters because of who is present. In the consultation, the patient is there. Options can be described, alternatives weighed, and consent given for a specific plan including its fallbacks. In the operating room the patient is asleep, and a surgeon who encounters an unexpected finding is choosing between courses of action the patient has not been consulted about.
Three findings account for most of these surprises, and all three are visible in advance on imaging.
- Less usable septal cartilage than expected, which changes what can be built or requires a second harvest site.
- A deviation more extensive than the external view suggested, which changes both the sequence and the duration of the operation.
- A prominence that is more bone than cartilage, or the reverse, which changes the technique of the reduction.
None of these is catastrophic when it is discovered mid-operation. All of them are better handled as a decision the patient took part in.
There is a related benefit that has nothing to do with technique. A patient who has been told in advance what the fallback is — that if the septum yields less than expected, the plan moves to a named alternative — is not surprised afterwards by a description of surgery that does not match the one they agreed to. Consent given to a plan with its contingencies attached is a different thing from consent given to a plan that assumed everything would go as drawn.
What the scan does not decide
It is worth being explicit here, because imaging is easily presented as though it settled matters that it does not.
It does not decide whether to operate. A scan showing a deviation in a patient who breathes comfortably and is content with their nose is a finding, not an indication. A good many people have some degree of septal deviation and no reason to do anything about it.
It does not decide the shape. Height, projection, and rotation are decided against the proportions of the whole face and against what the patient is asking for. Neither of those is visible on a scan.
It does not measure the covering usefully enough to replace examination. Skin thickness and mobility are judged by hand, and they are among the findings that most affect what a plan can deliver — thick skin absorbs definition, thin skin reveals everything built beneath it, and neither fact comes off a scan.
It does not predict healing. How a particular patient's tissue behaves over the following months is not readable in advance.
The scan describes the material the surgery will work on. The plan remains a judgment, and the judgment belongs to the consultation — which is the subject of the page on how a first consultation is actually run.
How the scan is used in the consultation itself
The imaging is not filed away and referred to later. It is looked at with the patient during the consultation, and that changes the character of the conversation.
A patient who has seen where their own deviation sits, or how much their two passages differ, is in a different position from one who has been told about it. Explanations that stay abstract in words become concrete on a screen, and the questions that follow tend to be better ones.
It also makes disagreement possible in a useful way. A patient asking for height that the framework and the proportions of the face will not support can be shown the reason rather than simply told the answer. That is a more honest exchange than a refusal, and it usually leads somewhere — most often to establishing what the patient was actually after, which frequently turns out to be achievable by a different route.
One caution belongs here. Seeing your own structure on a screen is informative, and it is also easy to over-read. A deviation looks dramatic in cross-section that is contributing very little to how you look or how you breathe. Which findings matter for your particular aims is the surgeon's reading of the scan, not the scan itself.
Practical questions about the scan
A few practical matters come up often enough to answer directly.
The scan is taken at the clinic as part of the assessment before nose surgery, and it is quick. It is a CT, which means it uses X-rays; the dose for a scan of this type is small, but it is a reasonable thing to ask about, and you should say if you are or may be pregnant.
Patients travelling from abroad sometimes ask whether imaging from their own country can be used instead. It can be useful as background, particularly where it documents a prior injury or an earlier operation, and it is worth bringing. But a scan taken elsewhere is not always in a form that can be read the same way, and the assessment is conducted on imaging taken at the clinic. This is worth raising during a remote consultation rather than discovering on arrival, because it affects how the first day in Korea is scheduled.
Questions patients ask
Do I need a CT if I only want a small change?
The size of the intended change does not tell you what is underneath it. A small change to a bridge can still be a change to bone rather than cartilage, and a modest request can still require graft material. The assessment establishes what the change involves.
Can you plan my surgery from photographs I send before I travel?
Photographs support a useful preliminary discussion about aims and about what is broadly realistic. They do not support a final plan, because the structure the surgery works on is not visible in them. What a remote consultation can and cannot settle is covered separately.
Will the scan tell me exactly what my nose will look like?
No. It shows the structure that will be worked on. It does not simulate an outcome, and no imaging predicts how a particular patient's tissue will settle over the months that follow.
What if the scan shows something unexpected?
That is the point of taking it beforehand. An unexpected finding discussed in the consultation is a decision you take part in; the same finding encountered during surgery is one you do not.
Does a deviation on the scan mean I need septal surgery?
Not by itself. It depends on whether the deviation obstructs your breathing, whether it contributes to the appearance you want changed, and whether the shape plan requires the septum to be straightened. A deviation with none of those attached is a finding to note rather than to act on.
Is the scan repeated later?
Not routinely after a first rhinoplasty. Follow-up is by examination at day 1, day 5, two weeks, one month, three months and six months. Imaging is repeated where a specific question arises that requires it.
About the author
Dae-hee Han, MD — Board-Certified Plastic Surgeon (specialist certificate No. 2045, issued 3 March 2014; medical licence 00394, issued 26 February 2009). Master’s degree, Ajou University School of Medicine. Training at the Craniofacial Center, Chang Gung Memorial Hospital, Taiwan (2013), and the IFAAS Mini Fellowship, University of Florida, USA (2016). Three rhinoplasty papers published in SCIE-indexed international journals. More than 4,500 nose surgeries — Dr. Han’s career total from 2017 to 2025, counted from medical records. Eighteen years in practice since medical licensure in 2009; thirteen years as a board-certified plastic surgeon. He carries out consultation, surgery and follow-up personally; fee guidance is given by the clinic’s consultation manager.
Last reviewed: 2026-08-15
Clinic information
Edition Plastic Surgery Clinic & Dermatology
6F, OPUS 407, 407 Gangnam-daero, Seocho-gu, Seoul 06614, Republic of Korea
One minute on foot from Gangnam Station Exit 10
Tel +82-2-591-0100 · editionprs@gmail.com
Consultation hours: Monday to Friday 10:00–19:00 · Saturday 10:00–17:00 · closed Sundays and public holidays
Disclaimer
Individual results may vary. Bleeding, infection, swelling, asymmetry, and scarring can occur. Please decide after a full consultation with a board-certified specialist.
This page is general medical information. It is not a diagnosis, and it does not promise a particular outcome. Surgical fees are given after an in-person consultation.