In short. The lines at rest and in movement, lip volume and border, sun and smoking history, teeth and jaw. What the assessment looks at and why each finding matters.

Key points

  • Bring a photograph from three or five years ago at a similar angle and in similar light.
  • Memory adjusts gradually, so a mouth that has changed slowly looks unchanged in the mirror and obvious in a comparison.
  • It also shows whether the change has been gradual or recent.

An assessment for perioral lines is as much about watching a mouth work as about examining skin. The muscles here are in near-constant use, and the single most informative observation is the difference between the mouth at rest and the mouth in movement.

The lines at rest, then in use

The mouth is watched still, then while speaking, pursing, smiling and drinking. Lines that appear only with movement are produced by the muscle. Lines that remain at rest have something set in the skin or in the tissue beneath it. Most people have both.

Lip volume and the state of the border

How much lip there is compared with earlier photographs, whether the border still has a sharp edge, whether the upper and lower lips are in proportion, and whether the corners have begun to descend. These determine whether the appearance is about lines at all.

The comparison that matters most

Bring a photograph from three or five years ago at a similar angle and in similar light. Memory adjusts gradually, so a mouth that has changed slowly looks unchanged in the mirror and obvious in a comparison. It also shows whether the change has been gradual or recent.

The lip surface itself

The lip is examined as a surface in its own right rather than only as a site of lines. Dryness, cracking, peeling, fissuring at the corners and any lesion are noted, because each of these changes what is appropriate. A mouth with an unhealed sore or inflamed corners is not a mouth to be injected.

Sun and smoking history

Cumulative ultraviolet exposure, outdoor occupation and sport, everyday protection on the lips rather than on the face, and smoking history including duration and whether it continues. These are taken because they change what is worth offering and what to expect.

The teeth, the jaw and how the mouth closes

The position of the front teeth, the height of the bite, whether the mouth is typically held open at rest, and whether there is a habit of mouth breathing. A change in the teeth can change the shape of a mouth without any change in the skin.

What has been done before, and what the goal is

Anything injected into the area and when, and any product or procedure used on the skin. Then what the patient is comparing against, since a mouth judged against a filtered image is being judged against something no treatment reaches.

Findings that end the cosmetic conversation

  • A sore, ulcer or crust that has not healed within a few weeks, or that bleeds.
  • A one-sided change, or numbness or altered sensation in the lip or chin.
  • Sudden deep fissuring with swelling, or a lip that has become and stayed swollen.

The order in which the identified contributors are worth treating is set out in The Treatment Ladder for Lip Lines. What each of those options fails to achieve is stated in What Each Lip-Line Treatment Does Not Achieve.

Related reading

Frequently asked questions

Why does the assessment involve watching me talk?

Because the muscle around the mouth is in constant use and the difference between a movement line and a fixed one is only visible in comparison. Watching the mouth at rest and then in speech, in a purse and in a smile shows which lines vanish and which remain, and that single observation decides more than any measurement taken at rest.

Why would a clinician look at my teeth?

Because the position of the front teeth and the height of the bite change how the lips sit and how much support the mouth has. A mouth whose teeth have been worn, lost or repositioned folds differently, and the lips can appear to have aged faster than they have. It is also one reason a mouth can change shape without any skin change at all.

Do I need to bring photographs?

They help a great deal, because memory is a poor comparison and a mouth changes slowly. Photographs from three and five years ago at a similar angle show whether the mouth projects less, whether the border has blurred, and whether the lines have deepened gradually or changed in the last year. That timing sometimes changes the whole conversation.

Risks & Limitations

  • Perioral lines have several contributors and none of the options erases them. Relaxing the muscle reduces movement, adding volume changes how the mouth folds, and resurfacing softens what is set in the skin. All of it needs maintaining.
  • The lip border is a high-movement area with thin tissue and very little padding beneath it, so material placed there behaves differently from elsewhere in the face and the result depends on technique and on experience rather than on volume.
  • Injectables carry risks that depend on the area treated and on the person placing them, including asymmetry, nodules and, rarely, vascular problems. Resurfacing carries downtime and a risk of pigment change that is greater in deeper skin tones.
  • An active sore, an unhealed lesion, an infection or inflamed cracked corners are reasons to defer treatment, because injecting or resurfacing through them risks a problem being missed or made worse.

When to Seek Care

  • A sore, ulcer or crust on the lip that has not healed within a few weeks, or that bleeds or recurs — have it examined.
  • A change confined to one side of the lip, or numbness or altered sensation in the lip or chin — seek medical assessment first.
  • Sudden deep fissuring with swelling and soreness, or a lip that has become swollen and stayed swollen — seek medical assessment.
  • After any treatment: severe pain, blanching or mottled skin, a spreading dusky discolouration, or worsening swelling — seek urgent care.

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

Medically reviewed by Tongchun Mao, MD (毛彤春), Deputy Director & Head of Aesthetic Surgery. Last reviewed: 19 September 2026.

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.