Dr Souphiyeh Samizadeh outlines how to create an aesthetically pleasing smile through awareness of perioral ageing and dental structure
When we start our training to become aesthetic practitioners, the first things we learn are to fill the nasolabial folds and marionette lines. But how much do we actually know about perioral ageing? The lips and the perioral soft tissues play a key role in facial attractiveness. Lips have physiological functions (protection, eating, speaking and position of teeth) and are central to non-verbal and psychological communication. Plump and well-defined lips represent youth, attractiveness, sexuality and beauty.1,2 Teeth are an integral part of a beautiful smile, and the dentition and smile are significant features in determining facial attractiveness.3 Healthy and well- aligned teeth have been shown to have a positive effect on an individual’s confidence and psychosocial wellbeing.3,4,5 From my own findings, as well as media reports, ageing of the perioral region (e.g. thin lips, mouth furrows, and downward corners of mouth) seems to be amongst the main reasons people seek surgical or non-surgical aesthetic treatments.6 Understanding the components of facial ageing will result in a better understanding of the patient’s individual needs and therefore better-tailored treatment plans.
The perioral region is defined as the lower third of the face, extending from the subnasale to mentum (Figure 1). The key perioral landmarks are:
Skeletal structure and relationships, soft tissue contours, the dentition and gingival contour, and the lip framework determine a patient’s lower face aesthetic. Skin ageing, subcutaneous fat atrophy and skeletal remodelling are the key factors that contribute to facial ageing. Other factors include smoking, stress, lifestyle, work habits and diet.7,8,9 Treatment and rejuvenation of this region without an in-depth understanding of the anatomy and the ageing process can produce undesirable results.For example, as we age lower facial volume increases, thus, the desired ‘inverted triangle’ facial aesthetic decreases. I also find patients lose fine lip movement and sometimes require additional dental or surgical treatment. Dentition and dental treatment play a significant role in restoring the perioral complex. Conversely, rejuvenation of the perioral complex will further enhance the aesthetic outcome of cosmetic or restorative dentistry. When treating perioral ageing, it is important to bear in mind that facial characteristics are different in men and women. Men have larger philtrum widths, and total lip height, wider mouth width, and their pogonion (the most forward- projecting point on the anterior surface of the chin) is located more inferiorly than in women.10,11,12
Characteristics of ideal lips
When discussing ideal aesthetics and treatment planning for patients, it is important to recognise the differences in races, genders, cultures and aesthetic ideas. The position of lips is affected by the skeletal make up of an individual and the underlying dental support.13,14,15 Abnormal dental-skeletal relationships should be recognised. These patients may need orthognathic surgery or orthodontic treatment, which is beyond the scope of this article. Regardless of cultural and ethnic differences, youthful lips are characterised by fullness and well-defined curvatures.
The position and alignment of the dentition influence position of lips, smile, phonetics and functional balance. The maxillary incisal edge curvature would be parallel to the curvature of the lower lip in an ideal smile arc (Figure 4). At rest, there should be 2-4mm vertical exposure of the maxillary incisors in relation to the upper lip.21,22,23 Evaluation of anterior smile aesthetics must include both static and dynamic evaluations of profile, frontal and 45° views to optimise both dental and facial appearance.23,24 Position of the upper and lower teeth, crowding, lost dentition, discoloured teeth or different coloured restorations and tooth wear, all affect the aesthetic of a smile. During advanced facial and smile analysis, tooth proportions and symmetry, the dental midline, gingival aesthetics, the smile arc, width of the smile, buccal corridors (the negative space between buccal surface of upper first premolars and the commissure of lips when patients smile), contacts, embrasures, and incisal and gingival display should be taken into consideration.21,25
The hard tissue structures that shape the perioral complex include the mandible, the maxillary bone and the dentition. These bony components are central to the overall facial three- dimensional contour of the face and suspension of the soft tissues. The ageing process affects all of these structures. Genetics, occlusal relationship (the relationship between upper and lower teeth), dental integrity, midface development and skeletal maturity are some of the factors that influence skeletal ageing. Therefore, the rate of skeletal ageing varies in different individuals.7,26,27
Studies have shown that ageing results in:
Decrease in the maxillary angle and height may play a role in the malar fat pad moving down and forward. This results in a posterior positioning of the upper lip and deepening of the nasolabial folds.28
The mandible is the structural foundation of the lower face. Any changes in the dimensions of the mandible will affect the overall aesthetic of a patient’s face. Studies have shown that with ageing:9,16,26,29
Chronological tooth wear may result in flattening of the incisal edges, and consequently adversely affect the smile arc. Tooth loss affects the thickness of cortical bone; edentulous patients suffer from significant cortical bone loss and maxillary and mandibular alveolar ridge resorption. This is more pronounced in the mandible than maxilla, and more in women than men, and results in reduced lower face height.30 Tooth loss from the lateral areas of the jaw can result in narrowing of the face and hollowing of the cheeks, whilst loss of anterior teeth will produce a concave profile.31 Severe tooth wear can also reduce the vertical dimension of the lower face. Dentures affect the position of soft tissues and lips, and have a direct effect on the lower face height.27,29
Changes in lip morphology during ageing include the position of the lip lines, a decrease in lip volume and thickness (degeneration of elastic and collagen fibres), lip tonicity, changes in lip length and retraction of the lips. On average, there is 2-4mm increase in upper lip length with age.2 It has been observed that the natural curves of the lips are lost through ageing and lip dryness is shown to be statistically more marked in aged women. The lower lip becomes dominant over the upper lip and is more noticeable in women. Vertical wrinkle lines start to appear during the fourth decade of life but become more visible during the fifth decade (there have been some suggestions that this corresponds to menopause).11 The commissures descend and inter-commissural distance increases with age.11
As a result of ageing:11,32,33
The focus of human communication is the face, thus it is key to social interaction and the perception of attractiveness. The correct soft-hard tissue balance is important for achieving and maintaining a pleasing aesthetic appearance and function.
Better understanding of facial ageing leads us towards a three- fold facial rejuvenation technique: restoring volume (loss of bony volume), lifting and reducing the soft-tissues and skin rejuvenation. Advanced rejuvenation involves multidisciplinary treatment and may necessitate dental restorations or plastic surgery. Overfilling and volumising where there is advanced bone resorption or dental problems may lead to undesirable aesthetic results. Likewise, perioral rejuvenation without midface correction is not recommended as this can result in an unnatural look.
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