In short. Proportion to the whole face, the lip at rest and in movement, the border anatomy, and the movement the lip will subject any material to.
Key points
- A record of any previous injectable treatment, with dates and substance classes if you have them.
- A list of medication, including anything that affects clotting.
- Whether you have ever had cold sores.
The lip assessment is not a look at the lips. It is an examination of the mouth in the face, at rest and in movement, and it settles more about the outcome than the choice of material does.
Proportion to the whole face
The vermilion showing at rest, the length of the upper lip from the nose to the border, the height of the lower lip and the position of the chin are considered together, because lip size is read as a ratio rather than as an absolute.
Rest, then movement
The lip is photographed and watched at rest, then on smiling, then while speaking. This part is specific to the lip. Because the lip is deformed by movement many times an hour, the amount of material it tolerates is decided by how it behaves in motion rather than in a still image. A lip that is fine at rest can be visibly over-filled on smiling.
The border and the anatomy beneath it
The roll of the border, the wet-dry line on the inside and the plane of tissue between them are examined closely, because this is where a small error shows earliest. The injector also has to know where the labial arteries run and that their course differs between people and between the two sides of the same lip. That is not visible on the face, and it decides which plane is used and what is kept ready.
What to bring to the assessment
A record of any previous injectable treatment, with dates and substance classes if you have them. A list of medication, including anything that affects clotting. Whether you have ever had cold sores. Any dental treatment planned in the coming weeks. And photographs of your own face from some years ago.
The history that changes the plan
Previous filler matters because a lip is not fully cleared between sessions, so the baseline is the lip you have now. Cold sores matter because an injection reactivates them, and dental infection or recent dental work matters for the timing. A history of delayed reaction to an injected material changes what it is reasonable to offer.
What an assessment should end with
You should leave knowing which change is present in your lip, whether an injection reaches it, which plane would be used and why, how much is planned and what that amount is measured against, and who is reachable if something went wrong. An assessment that ends with an amount and a date has established none of it.
Stop the assessment if
- Nobody can describe what would be done in the first minutes if the tissue changed colour.
- No record is taken of previous filler, cold sores, dental work or medication.
- The lip is measured against somebody else's photograph rather than against your own face.
What the assessment looks for in the lip is described in The Honest Limits of Lip Volume, and what to ask once it is under way is set out in Questions to Ask Before Your Lips Are Injected.
Frequently asked questions
Why does the assessment look at my teeth and chin when I asked about my lips?
Because lip size is read as a proportion of the face. How much lip shows at rest and how the smile reads are decided partly by the teeth and by where the chin sits, and those are the commonest reasons a lip of ordinary volume still looks small. An assessment that looks only at the lip cannot tell the difference.
Why does the injector watch me talk?
Because the lip is deformed by movement many times an hour, and a lip that looks right at rest can look over-filled in speech. The amount of material a lip tolerates is decided by how it behaves in motion, which is why the assessment includes smiling and speaking rather than a single still view.
What should I bring to a lip assessment?
Any record of previous injectable treatment, with dates and substances if you have them. A list of your medication, including anything that affects clotting. Whether you have ever had cold sores. Any dental treatment planned in the coming weeks. And photographs of your own face from some years ago, which are more useful here than most people expect.
Risks & Limitations
- Vascular occlusion is a time-critical emergency, and the lip is a small area whose arteries vary in course between people and between the two sides. Severe pain out of proportion to the injection, or tissue turning white, grey, mottled or dusky, requires immediate assessment.
- Every filler result is temporary, and the lip fades unevenly: the border often loses definition before the body of the lip flattens. Maintenance treatment is required to keep a result continuous.
- The lip tolerates very little added volume before the change reads as treated, and only the reversible class of material can be broken down at all. A stretched vermilion and a border that has been filled across do not revert when the material goes.
- Lumps, nodules, asymmetry and delayed inflammatory reactions can occur, and an injection commonly reactivates cold sores in someone who has had them before. The lip is the most mobile injected site, so material inside it is being deformed continuously.
When to Seek Care
- Any change in vision, including blurring or a patch of lost sight — seek emergency care immediately.
- Severe pain out of proportion to the injection, or pain that is worsening rather than settling.
- Tissue turning white, grey, mottled or dusky anywhere on or around the lip.
- Swelling that is increasing after the third day rather than settling, or fever with spreading redness, warmth or discharge.
References & Further Reading
- American Society of Plastic Surgeons (ASPS) — procedure and safety guidance
- National Institute for Health and Care Excellence (NICE, UK) — relevant guidance
- Cochrane Library — systematic reviews
- Chinese Medical Association Plastic Surgery Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.