What to Look for When Treating the Lips

The lips have been ornamented in diverse ways throughout history. The common reasons of ornamenting the lips include aesthetics and beauty, social status, cultural beliefs and courtship. The ideal lip aesthetics vary greatly among different time periods and culture. According to historical studies on female model profiles from the twentieth century, it was fashionable to have full lips that are anteriorly-positioned. Having analyzed pictures from major fashion magazines from 1930 to 1995, Nguyen and Turley found that the ideal lip aesthetics for males has evolved dramatically over the years, 1 of the observations being an increase in lip curl and protrusion. Plus, they have noticed an increase in the vermilion display.

Medical advancement has made cosmetic procedures, such as lip augmentation, increasingly popular and accessible. The expectations of the patients often reflect the cultural trends in beauty and youth. Since modern lip fillers were introduced, lip augmentation has become 1 of the most requested and popular cosmetic procedures.

Apart from being 1 of the main facial features, lips also play an important role in swallowing and phonation. It is essential to achieve successful lip treatments, as a failed procedure can have disastrous consequences (both aesthetically and functionally). In this article, we will discuss about the current trend of lip treatments, and the techniques of conducting clinical evaluation.

The ideal lip

Aesthetic standards and beauty ideals vary greatly across cultures and eras. In general, well-defined and plump lips are preferred in Western culture. Despite cultural preferences for voluptuous and plump lips, there were no guidelines on lip enhancement and assessment in the early days of medical aesthetics. Current research suggests that the ideal lips should have a well-defined vermilion border, a right balance between the lower upper and lips and adequate volume and fullness. Regardless, the lips should be harmonious with other features on the face. For example, it will not be aesthetically pleasing to have full, enlarged lips on a small face. Always consider the proportion when performing lip augmentation. Men in general have a larger lip volume, total lip height, philtrum width, and mouth width in comparison to women. When augmenting lips, the practitioners should be aware of sexual dimorphism. Thanks to the innovations and advances in biotechnology, techniques of lip enhancement and augmentation have evolved greatly. There are many types of implants and fillers available on the market. Some of them are permanent, while others are semi-permanent or temporary. To ensure correct product usage (and hence, optimal treatment outcome), it is important to have a good understanding on the lips terminology, aesthetics and assessment. In addition, the practitioners should be familiar with the anatomy of the lips. Some of the common anatomical structures of the lips are upper incisor teeth, oral commissures, cutaneous upper lip, upper lip tubercle, philtrum, vermillion border, white roll, cupid’s bow and philtrum columns.

Assessment

Sit the patients up before examination the lips. Make sure that they sit in an upright position (which is standardized and reproducible). The lips should be examined when they are relaxed and while moving. This allows the doctors to assess the symmetry of muscle movements (and to identify any asymmetry). At the same time, the doctor should examine the hyperactivity of muscle groups and the natural position of the lips. While its position is closely related to the alveolar processes and the teeth, the lips is not the sole determinant of smile attractiveness. Dental professionals should assess other factors that affect the smile aesthetics. This includes gingival margin, open gingival embrasure, prominence of nose and chin gingiva-to-lip distance, incisal plane, midline, crown width, morphology of lips and soft tissues incisor crown angulation and crown length. Apart from that, the relative position of skeletal components (e.g. maxilla to mandible) could also affect the aesthetics of smile and lower face.

Evaluation

To gain a better understanding of lips aesthetics (and to ensure successful treatments), it is essential to perform a systematic clinical evaluation. There are several parameters that need to be taken into account. This includes lip thickness, lip height, lip inclination, lip contour, lip posture, lip inclination, lip function and activity and lip prominence. In terms of lip height, consider the chin/lower lip height, lower/upper lip vermilion height and the lower/upper lip height. Additionally, the interlabial gap (i.e. the gap between the lips when they are at rest) and the ratio of upper lip to chin/lower lip height should be carefully examined.

The inclination, curl and curvature can be assessed in both profile and frontal views. The strength and position of dentoskeletal support for the lips can result in either a decreased or an excessive curl. For instance, the retrusion of maxillary dentoalveolar may lead to flat lips.

Directly affecting the prominence of the lips, lip thickness is a key factor that should be carefully considered. The thickness of the lips can vary depending on ethnic background. In contrast to thicker lips, thin lips readily follow the movements of the jaw and teeth. Therefore, in patients who have thin lips, the aesthetics effects of teeth loss/movement will be more prominent.

The lip seal and posture should be assessed in natural head position when the patient is relaxed (and when the muscle tone is normal). During the assessment, there should not be too much muscle contraction. The lip posture (i.e. orolabial soft tissue posture) is unique for each patient. Adaptive postures should be used if the lip seal is not observed in resting position. This indicates that the patient has an unremitting contraction of the circumoral musculature.

Lip inclination often indicates the prominence of the dentoalveolar, which provides support to the lips. A protruded or retruded lower and upper incisors will directly affect the lips, resulting in either retrusion or protrusion of the lips. Eversion of the lower lip may occur if the upper incisor teeth impinges on the lower teeth.

Patients should be screened for hypotonic or hypertonic lips. Hypotonic lips are characterized by underactivity and a low muscle tone, while hypertonic lips are overactive or hyperactive. Hypotonic lower or upper lips may have a flaccid appearance, which could overstretch the lips. This is especially common in patients with an elevated lower face height. A hypertonic muscle of the upper lip levator may lead to a gummy smile.

The lip prominence can be compared to that of the chin and nose in profile views. A number of skeletal factors, dentoalveolar factors (e.g. position of the incisor teeth) and soft tissue factors (e.g. lip thickness) can affect lip prominence.

Conclusion

This article provides insight on the main parameters that should be considered in a lip treatment. Doctors should have a good understanding on the anatomy of the perioral area and the aging process of the lips. To ensure successful rejuvenation (and hence, keep the patients happy), practitioners must know when, where, and how to treat the lips.