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ORIGINAL ARTICLE AESTHETIC

Classification of the Aging Lips: A Foundation for an Integrated

Approach to Perioral Rejuvenation

Vincenzo Penna • G. Bjorn Stark • Matthias Voigt •

Alexander Mehlhorn • Niklas Iblher

Received: 6 August 2014 /Accepted: 3 October 2014

Ó Springer Science+Business Media New York and International Society of Aesthetic Plastic Surgery 2014

Abstract

Background Although perioral aging is highly individual

with several distinct processes taking part simultaneously,

there is scarce systematic information which helps to

indicate the right rejuvenation approach among the multi-

tude of proposed procedures. Existing data about perioral

aging has not yet been transformed into a consistent ther-

apeutic concept. The intention of this study was to provide

a simple, yet reproducible classification and to offer

appropriate rejuvenation approaches.

Methods To identify reliable and constant landmarks of

the ongoing process of perioral aging, 462 perioral photo

documentations were morphometrically analyzed. Based

upon the identified landmarks a two-dimensional classifi-

cation was developed. The classification was validated by

three plastic surgeons. Inter- and intra-rater reliability was

calculated using Cohen’s kappa coefficient.

Results Perioral aging can be broken down into changes

of the lip shape and changes of the lip surface. Both

processes can be classified into three stages each: Lip shape

according to the shape in profile view, the lip length in

relation to the frontal incisors, and the degree of vermilion

inversion. Lip surface according to the presence and degree

of radial wrinkles and the visibility of the structural ele-

ments Cupid’s bow, philtrum, and white roll. Inter-obser-

ver reliability was rated very good (kappa values between

0.819 and 0.963) and perfect for intra-observer reliability

(1.0).

Conclusion A better understanding of perioral aging

leads to a simple classification for the aging lips. Using the

classification helps to tailor an appropriate treatment to the

individual patient and aids to achieve a natural rejuvenation

result.

Level of Evidence IV This journal requires that authors

assign a level of evidence to each article. For a full

description of these Evidence-Based Medicine ratings,

please refer to the Table of Contents or the online

Instructions to Authors www.springer.com/00266.

Keywords Perioral � Aging � Rejuvenation � Lips �

Wrinkles � Classification

Introduction

A broad variety of approaches for upper lip rejuvenation

has been suggested. All of these can be subdivided into 3

categories: Volume augmentation, surface enhancements,

and surgical lip lifting approaches. Although several arti-

cles have been published which shed light on the aging

process of the perioral complex [1–4], these data have not

been transformed into consistent therapeutic concepts.

Despite these findings the large majority of physicians

dealing with perioral rejuvenation have to rely on personal

Part of this manuscript was presented at the Anti-Aging World

Congress in Monaco 2010 and at the Meeting of the German Society

of Plastic Reconstructive and Aesthetic Surgery, September 2010 in

Dresden, Germany.

V. Penna � G. B. Stark

Department of Plastic and Hand Surgery, University of Freiburg

Medical Center, Hugstetterstrasse 55, 79106 Freiburg, Germany

M. Voigt � N. Iblher (&)

Center for Plastic and Aesthetic Surgery of the Face and Nose,

Bismarckallee 17, 79098 Freiburg, Germany

e-mail: dribl@web.de

A. Mehlhorn

Department of Orthopedic and Trauma Surgery, University of

Freiburg Medical Center, Hugstetterstrasse 55, 79106 Freiburg,

Germany

123

Aesth Plast Surg

DOI 10.1007/s00266-014-0415-2

Author's personal copy

experience and often subjective criteria to choose their

procedure of choice. Volume augmentation has been

achieved by a multitude of substances, such as autologous

fat, dermis (autologous or allogenic), SMAS, collagen,

hyaloronic acid, gore-tex, silicone in the form of tubes,

microparticles or gel, polyacrylamid and gelatin, etc. [5–

13]. Resurfacing relies on chemical peels, laser ablation,

dermabrasion, or chemodenervation by botulinum toxin

injections [14–17]. A wide range of surgical approaches

with different excision sites and figures have also been

described [4, 18–25]. Most of these procedures address

certain aspects of the aged lips, if correctly indicated and

performed. However, if applied in an undifferentiated

manner they might lead to suboptimal results.

Therefore, the intention of this study was to provide a

simple yet reproducible classification of the progressive

aging changes of the upper lip and to offer appropriate

rejuvenation approaches. Because perioral rejuvenation is

requested almost exclusively by female patients this study

is based on female subjects.

Materials and Methods

Development of the Classification

The main focus of this investigation was to identify reliable

and constant landmarks in the ongoing process of lip aging.

In an earlier study, over 240 perioral regions of Caucasian

subjects were morphometrically analyzed using patient

photographs or cranial MRI scans [2] and 40 histological

specimens of upper lips were processed and morphomet-

rically analyzed [1]. To gain further information about the

specific patient group undergoing perioral rejuvenation

procedures, 22 patients receiving a lip lift were further

analyzed pre- and post-operative [4]. The proportions of

upper lip prolabium, vermilion height, total lip length as

well as surface structure and appearance in profile view

were observed. An additional 200 adult Caucasian female

patient photographs (age 28–78 years) were analyzed in a

similar manner for this study. For this purpose, patients

were photographed in a standardized manner by a profes-

sional medical photographer. During photography, it is

crucial to tell the patient to have a relaxed facial expression

without smiling and grimacing, maintain a relaxed closed

bite and keep the face straight by aligning the Frankfort

line with the horizontal plane. During clinical examination

of facial plastic surgery patients and the development

process of the classification, it became obvious that besides

regular frontal and lateral views it is necessary to evaluate

the patient with lips slightly parted. The opening of the

mouth has to be the result of slightly lowering the mandible

and is not due to activation of the mimic musculature

(smiling/baring teeth). Without this special view, it is

impossible to reliably determine upper lip elongation,

especially in relation to frontal teeth display (compare

Fig. 2).

Based on previously performed studies [1, 2, 4], the

identified criteria were transformed into a simple classifi-

cation. The classification is designed to provide the fun-

dament of a clear, reproducible therapeutical concept to

assist in choosing the right procedure for an individualized

perioral rejuvenation approach.

Validation of the Classification

To validate the objectivity, inter-observer reliability, and

reproducibility of the proposed classification, the photo-

graphs of 42 female patients (aged 33–79 years) were

presented to three experienced plastic surgeons. After a

short introduction, the surgeons were asked to classify the

Fig. 1 Proposed classification of the aging upper lip. Left row (1–3)

describes changes in length and form. Right row (a–c) describes

surfaces changes

Aesth Plast Surg

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presented pictures according to the proposed classification.

To additionally test the intra-observer reliability, 5 photo-

graphs were included twice in a blinded fashion within the

42 photographs. The inter-rater reliability (Surgeon A/B,

A/C, B/C) and intra-rater reliability were calculated using

Cohen’s kappa coefficient for both dimensions of the

classification in accordance with Landis/Koch and Altman

[26, 27].

Results

The examination of the exact physiological changes reveals

that upper lip aging can be broken down into two pro-

cesses: surface changes and changes of lip shape. There-

fore, the presented classification is designed as a two-

dimensional matrix. Although these two processes are not

entirely independent, they do progress at varying speeds

and one stage of surface change can be accompanied by

several stages of shape change and vice versa. Thus, dif-

ferent aspects of lip aging have to be addressed in varying

extents in each patient.

The following classification is suggested for the

assessment of lip aging (Fig. 1):

The shape change of the aged lip is classified into three

stages based on the frontal and lateral view with slightly

parted lips:

(1) Short concave upper lip with 2–3 mm of upper

incisors visible and prominent everted vermilion

(2) Moderately elongated and straighter upper lip with

upper incisors at the lower border of the upper lip and

mild degree of vermilion inversion

(3) Strongly elongated upper lip which forms a convex

curve around the frontal teeth row. Upper incisors are

not visible and vermilion is inverted.

The surface changes of the lips are also classified into

three stages:

(A) Distinct philtral columns, Cupid’s bow and white roll

without static radial wrinkles, minor dynamic radial

wrinkles

(B) Flattened philtral columns and Cupid’s bow, indis-

tinct white roll, beginning static radial wrinkles,

strong dynamic radial wrinkles

(C) Invisible philtral columns, Cupid’s bow and white

roll, considerable static radial wrinkles

Validation of the Classification

The applicability, objectivity, and reliability of the classi-

fication were tested by three plastic surgeons. All of them

found the classification simple yet helpful to evaluate the

aging changes of the perioral region. Cohen’s kappa

coefficients for inter-rater agreement (Surgeon A/B, A/C,

B/C) were 0.886, 0.855, and 0.963 (mean 0.901) for the

dimension of lip shape change and 0.854, 0.819, and 0.963

(mean 0.879) for surface changes. The mean Cohen’s

kappa coefficient of all inter-observer reliability tests was

0.890. The kappa coefficient for intra-observer reliability

(doubled photographs) was 1.00 for all surgeons and for

both shape and surface changes.

Discussion

Esthetic treatments to the lips can be motivated by two

main purposes: Rejuvenation and beautification. In the

past, these two modalities have often been intermixed.

Especially in the age group above 40, these two concepts

become less distinctive and thus suggested treatments have

been used interchangeably. Beautification of the perioral

region is a very complex challenge and to a high degree

dependent on the individual and cultural concept of beauty.

Most proposed treatments rely on volume augmentation

(although sometimes up to bizarre dimensions). A detailed

inquiry into the widely varying cultural and individual

requests for lip beautification and a differentiated treatment

concept is beyond the scope of this article. Perioral reju-

venation, like any other rejuvenation concept, has the goal

of reverting the aging process of this particular esthetic

unit. Although the scientific description of perioral aging

did not go beyond the status of narrative expert opinions

for a long time, recent reports have shed some light and

manage to systematically investigate the underlying phys-

iological changes [1–3]. It was the intention to provide a

classification which defines different stages of this process,

prompting distinct options for rejuvenation.

Medical classifications are often ambiguous and

imprecise, thereby failing to produce consistent classifica-

tion results when applied by different physicians. To avoid

this problem, the proposed classification is designed as a

two-dimensional matrix. Although surface changes and

form changes are not entirely independent processes, the

same stage of one aspect can be accompanied by different

stages of the other aspect. Therefore, a one-dimensional

matrix cannot correctly depict the multiplicity of existing

conditions. The two dimensions trigger different thera-

peutical concepts which are not completely independent of

each other but can be combined in different ways.

The indistinctness of medical classifications is often due

to the difficulty of pressing a constant ongoing biological

process into clear objective stages, which allows different

users to come to the same classification result.

To evaluate the inter-rater reliability of the proposed

classification three different plastic surgeons rated 42

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patient photographs in a blinded fashion. The resulting

Cohen’s kappa values are all well above 0.8, indicating a

very good degree of inter-rater reliability according to

Altman [26] or an almost perfect level of agreement in

accordance to Landis and Koch [27] (compare Table 1).

The intra-rater reliability tested by repeated testing of the

same subject photographs was evaluated with a perfect

kappa score of 1.00 for all three testers. These results can

be judged as extremely satisfying, especially because the

proposed classification is capable of demarcating clear

stages of the continuous and indistinct ongoing aging

processes of the complex anatomical perioral region. These

results also compare favorably to a similar evaluation of an

anatomically related classification to judge lip fullness

[28]. Consequently, the goal to create a classification that

can be used by experienced plastic surgeons reliably and is

simple enough to be of value in daily practice could be

accomplished.

There is no need for any classification if the classifica-

tion result does not trigger specific consequences. And like

in any other area of esthetic rejuvenation, it is essential that

different patients with differently pronounced aspects of

their individual aging process are offered individually tai-

lored therapeutic options. Although this claim is beyond

discussion in almost any field of esthetic surgery, it is our

impression that for perioral rejuvenation a lot of ‘‘one

procedure fits all’’ concepts are still being advocated,

although more and more integrated approaches to perioral

rejuvenation are being presented [29, 30]. This does not

implicate that personal experience and/or prevalence can

be replaced. Yet, only by recommending those procedures

for each stage of the classification which most effectively

address the underlying physiological changes, a causal

treatment concept can be achieved (Table 2). This tool is

also intended to facilitate the objective evaluation of pro-

posed rejuvenation treatment outcomes.

For lips classified as 1 and/or A no rejuvenation pro-

cedure is necessary (Fig. 2). It should be pointed out that

like in most other areas of facial morphometrics, the per-

ioral aging process is a very individual process with a wide

variance. While one individual may have a very pro-

nounced philtrum and cupid’s bow with prominent white

roll and full, pouting vermilion, another individual might

present with thinner lips and far less prominent structural

components of the upper lip, although being of the same

age. The aging process therefore has to be evaluated

individually for each patient, taking into account the

changes that have occurred in this individual (possibly by

comparing the current situation to older photographs). As

mentioned above, the fact that rejuvenation is not indicated

in 1A lips, does not affect possible beautification possi-

bilities for these patients, yet, like stated above, complex

individual preferences and widely diverging cultural

backgrounds put this topic beyond the scope of this article

[31].

The elongation of class 2 lips is not as pronounced that a

lip shortening procedure is absolutely indicated, but the

option should be discussed with the patient (Fig. 3).

Especially if a structural augmentation is planned in these

patients, the result will be more natural and a ‘‘pumped up’’

look is avoided if the elongation is simultaneously

corrected.

Table 1 Interpretation of Cohen’s kappa values for inter/intra-rater

reliability

Value Definition

according to

Value Definition

according to

Landis and

Koch [27]

Altman [26]

0–0.19 Poor \ 0.20 Poor

0.20–0.39 Fair 0.21–0.40 Fair

0.40–0.59 Moderate 0.41–0.60 Moderate

0.60–0.79 Substantial 0.61–0.80 Good

0.80–1.0 Almost perfect 0.81–1.00 Very good

Table 2 Treatment options for each classificaton category

Category Suggested treatments

Shape change

1 Rejuvenation not necessary

2 Tailor structural and volume augmentation to increased

length—discuss shortening procedure

3 Lip lift—Careful with isolated augmentation

Surface change

A Rejuvenation not necessary

B Evaluate resurfacing with laser or peeling, add definition

to white roll and philtrum with fillers or fat

C Deeper resurfacing, filler/fat for vertical rhytides and

restoration of lip structure

Fig. 2 Frontal and lateral photograph of a type 1 and type A lip in a

34-year-old female. Note the short, ramp shaped, concave prolabium

with everted vermilion (pouting) and visible upper incisors. No

wrinkles are present and the Cupid’s bow, philtrum, and white roll are

well defined

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In class 3 lips (Fig. 4), the elongation is the main aspect

of the aged perioral impression and should be addressed

with a lip lifting procedure. Different techniques have been

described by Rozner, Austin, Guerissimi, and others [18,

21–25]. While we prefer the Austin-type bullhorn excision

at the nasal base and could show that this technique ade-

quately corrects the length increase and inversion [4], other

techniques may be preferred by other surgeons. Solely

relying on injection techniques for volume augmentation in

these lips will most likely lead to unnatural results. It even

is to be stated, that the longer the upper lip becomes the

less augmentation is possible if unnatural results are to be

avoided. It might be beneficial to exclusively address radial

wrinkles, reconstruct the lip structures (philtrum, white

roll), and treat the neighboring esthetic units of the naso-

labial fold and the corner of the mouth.

The surface changes in class B lips (Fig. 5) benefit from

a milder form of resurfacing, such as chemical peels or

superficial laser treatments [16, 17, 32–34]. Although static

superficial radial wrinkles can also be addressed by fillers

or autologous tissue grafting [35–38], these applications

can be intricate, time-consuming, and less efficient than

resurfacing in these patients. Application of fillers or

autologous tissue transplantation might prove more bene-

ficial for deeper perioral wrinkles. Due to the beginning

flattening of the structural elements of the lip, the possi-

bility of structural enhancement of the philtrum, cupid’s

bow, and white roll may prove beneficial and should be

pointed out to the patient. The role of chemodenervation

with botulinum toxin in perioral rejuvenation is still being

discussed. While some authors report favorable results and

even postulate ‘‘pseudo’’ augmentation and lip eversion

[14, 39–42], others point out possible downsides including

asymmetry, functional alterations, difficulties pronouncing

certain sounds, and involuntary biting of tongue, inner lip,

and cheek as a result of overdosing or neighboring muscle

absorption [14, 33, 43–46]. It is generally accepted that

perioral botulinum toxin injections are among the most

difficult to treat facial locations with a narrow margin for

successful treatment. In our opinion, the effects of botu-

linum toxin for the esthetic treatment of static perioral

wrinkles are limited and of short duration due to the fact

that the injection has to be performed very superficially and

with small doses to avoid complications.

Class C (compare Fig. 4) lips benefit from more aggres-

sive resurfacing, for example by dermabrasion or ablative

laser application with the downside of potential hypo/

hyperpigmentation. Alternatively, deep radial wrinkles can

be very well addressed by dermal fillers [38, 47–50] or

autologous material [35–37, 51]. Orbicularis oris myotomy

has been described but has not reached wide spread accep-

tance [37]. To achieve a natural rejuvenation result, the

complete structural loss of the philtrum and Cupid’s bow in

these lips has to be corrected. This is best achieved by linear

introduction of the preferred filler material. We prefer bio-

compatible and resorbablematerials, such as hyaloronic acid

or autologous fat, the latter being somewhat less predictable

due to varying resorption and a higher difficulty to sculpt

precisely, yet offering a longer lasting effect and possible

positive effects on skin micro-structure [52]. Hyaluronic

Fig. 3 Frontal and lateral photograph of a type 2 lip in a 38-year-old

female. Note the moderately elongated upper lip, the straight profile

with loss of concave, forward projection (pouting), and the no longer

visible upper incisors (lower teeth are visible on frontal view)

Fig. 4 Frontal and lateral photograph of a type 3 and a type C lip in a

76-year-old woman. Note the clearly elongated upper lip which forms

a convex curve around the upper teeth and the almost invisible,

inverted vermilion in the lateral view. The surface changes are clearly

classified as type C: White roll, Cupid’s bow, and philtrum are almost

invisible and there is severe radial wrinkling

Fig. 5 Frontal photograph of a type B lip in a 53-year-old woman.

Note the relatively flat Cupid’s bow, the weak philtral columns, and

the moderate static radial wrinkles

Aesth Plast Surg

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acid offers the advantage of being reversible in case of

overcorrection or inhomogeneous results and do not require

the deleterious correction procedures known to have been

required after introduction of materials like silicone or

polymethyl methacrylate [53–56].

Any proposed treatment algorithm will be limited by the

fact that not all influencing factors can be included. This

certainly holds true for the herein proposed classification as

well. Like stated in the introduction, this concept focuses

on the female lip and morphometrical results, which have

been obtained in Caucasian patients. Although male

patients rarely present with rejuvenation requests centering

around the mouth, the existent data suggest that similar

processes take place in the male mouth [2, 3], possibly at a

slower pace and more concealed by facial hair. The lower

lip plays an astonishingly minor role in perioral aging,

although structural enhancements (white roll) and espe-

cially volume introduction should always be matched to the

upper lip. Ethical factors and differences in facial appear-

ance, scars, the influence of the underlying bony structures

with their distinct changes over time and the overall quality

of the skin as well as a wide variance of individual

appearance all influence the evaluation of the perioral

region and have to be taken into account.

Special consideration has to be paid to dentition. It is

obvious that severemalocclusion,malalignment, or deficient

teeth are important to detect as these factors negatively affect

the hard tissue foundation for the lips. It is also well known

that frontal incisor length decreases with increasing age [57],

and consequently one of the used reference points of our

classification is not time-stable by itself.Yet, as in other areas

of facial surgery, the absolute dimension of a certain struc-

ture is not as important as the relative dimension compared to

a neighboring structure (e.g., drooping nasal tip makes a

dorsal hump look bigger). Therefore, if the shortening of the

upper teeth is not corrected by esthetic dentistry, it should

make the observer even more aware of upper lip lengthening

and possible corrective measures.

However, as a rule of thumb, patients should be advised to

correct their dental deficiencies before considering esthetic

treatments of the perioral soft tissues. A stable dental situa-

tion provides a solid fundament for further soft tissue and

will ultimately lead to a better overall rejuvenation result.

We consider the proposed classification a valuable tool

to systematically evaluate the individual stage of perioral

aging and develop a suitable rejuvenation concept for each

patient.

Conclusion

A better understanding of the physiological changes of

perioral aging leads to a clear and simple classification for

the aging upper lip. By using the classification a differen-

tiated rejuvenation approach can be tailored to the indi-

vidual need of each patient. This will help to achieve more

natural and satisfying outcomes.

Acknowledgments The authors would like to thank Saskia Mane-

gold for assistance with graphical illustration. This research received

no specific grant from any funding agency in the public, commercial,

or not-for-profit sectors. The authors declare that they have no con-

flicts of interest to disclose.

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