Planes of the lips: The lips are formed by five planes and it is important for us to understand them to mater lips filler. Three planes form the upper lip, and two planes form the lower lip. Understanding these planes gives the cosmetic augmenter insight into location, direction, and the amount of fill the planes will facilitate. The two upper lateral planes are cone shaped, with the apex at the corners of the mouth and the base abutting the middle plane. The middle plane of the upper lip is semicircular and tapers toward the opening of the mouth. The lower lip is formed by two teardrop shapes that taper toward the corner of the mouth. Lips are as diverse as the human face. While no two sets of lips are exactly the same, all lips have these five structural planes in common. It is the different combinations of these planes that lead to the unique appearance of each individual’s lips. These five planes are created by the joining of the developmental facial processes of the face in utero. Incomplete union of the medial and lateral nasal processes can lead to cleft lip which has a reported prevalence of 1.00 to 1.82 per 1,000 live births. You can see these planes with the naked eye in patients who suffer from this condition as a result of an isolated defect or hereditary syndromes.
Static Vs. Kinetic As dentists we restore to a tooth-to-tooth or a bone-to-bone relationship which is both recordable and repeatable. An example of this is “Centric Relation.” Even in the edentulous patient, we can restore to a certain fixed skeletal relationship.23,24 With the soft tissue of the face, however, we aren’t as fortunate in predicting a repeatable relationship. The oral-facial lines and folds change on a consistent basis. The entire make of the face changes with age, genetics, and environment. The face and, in particular, the lips, can be viewed in either a static or kinetic state. As cosmetic augmenters, understanding the difference between these two states is essential in planning treatment for our patients. During an examination, we must examine our patients in both a kinetic and static position. This can be accomplished by asking the patient to smile and frown. A simple trick to assist you in establishing the relative static position of a patient’s lips is to ask him or her to utter the letter “M.” The position of the lips after this consonant is spoken is considered the static position. Dentists naturally ask patients to smile in an effort to evaluate the dentition. In oral-facial augmentation, it is important to focus your attention on the nasolabial (or mental fold) as the patient smiles. If these areas are augmented, it is imperative to consider how augmentation will affect the kinetic fold of the tissue. Augmenting the lips filler in a static position, without viewing the smile line and incisal appearance, can lead to overfilling of the lips fillers and produce an unpleasant appearance. In addition the evaluation of perioral lines (rhytids) must be evaluated in static and kinetic movements for purposes of botulinum toxin therapy; “Simply Botox.” It’s difficult for one to quantify or qualify the amount of filler needed when evaluating the relationship between kinetic and static tissue. It is in practicing and perfecting the art of the fill that this measurement is incorporated into the augmentation process and becomes easier to determine as your experience grows.
Maxillary Labial Zone A (ZA) extends from and includes the superior aspect of the vermilion border to the lower border of the columella nasi of the nose. This zone is wider due to the philtrum that is, at times, augmented in this zone. Zone B (ZB) is the area midpoint between the inferior border of the vermilion border (ZA) and the superior border of Zone C. Zone C (ZC) is the area from the inferior border of Zone B to the lower transitional zone (wet/dry line) lips filler. Most shaping will be performed in Zone A and volume will be added in Zone B. Zone C is a label in order to complete the mapping of the extra oral presentation of the lips fillers. Under no circumstances do we augment Zone C. Instead Zone C is used for marking pathology, injuries, and describing the relationship of the bottom of
Kinetic Even as the lip and perioral tissue is stretched around the skeletal and dental anatomy, the relationship of the ideal proportions still remains. Overfilling the lips may not present as noticeable in the static position, yet when the patient smiles, the overfill may become more evident as the filler material is displaced over the dental profile. the lip to the dentition. Remember, the zones curve with the lips in a bow shape and end at the commissure of the lips.
Mandibular Labial Zone C extends from the transitional zone (wet/dry line) to the border of Zone B. Zone B extends from the middle of the lip (border of ZB) to the vermilion border of the lower lip. Zone A extends from— and includes—the vermilion border and the cleft superior to the metal protuberance of the chin. Zone A will have fill room, but the majority of fill will be performed in Zone B. Zone C is demarcated for completion of the classification area. There will be no augmentation in Zone C. Since there is no distinct vermilion border of the lower lip like the upper lip, sculpting of Zone A on the lower lip will usually never be performed. Remember that Zone A of the lower lip is a gradual transition from vermilion tissue of the lips to the keratinized epithelium of the oral-facial area.
Segments of the Lips (Static) Lips can be divided into six segments, which correspond to the planes that constitute the lips. The upper lip is segmented into three parts which correspond to the planes that make up the upper lip. The three parts are divided between the cone and tapered semi-bucket shape of the philtrum. The lower lips are also segmented into three parts that correspond to the planes that make up the lip. The lower lip is composed of a teardrop shape that has a ball and a tail. The segments are divided at the ball-and-tail junction. In order to define a constant on which the lips are draped, we use the dentition as a reference point. To assess a patient’s segments, you have to have them open their mouths a little to see the maxillary dentition. The segments are simply divided by drawing a line down the lips laterally to the maxillary central incisors (#8, #9). Upper lip and Lower lip: Segment 1 is the area extending from thelateral of #8 to the corner of the mouth. Segment 2 is from the lateral of #8 to the lateral of #9. Segment 3 extends from the distal of #9 to the corner of the mouth. Lower lip: Segment 4 extends from the corner of the mouth to the line drawn down from the lateral of #9. Segment 5 extends from the line drawn down from the distal lateral of #9 to the distal lateral of #8. Segment 6 extends from the line of the distal lateral of #8 to the corner of the mouth.
LARS: Lip Length, Age, Race & Sex As a cosmetic/aesthetic augmenter, you possess the understanding that there are many factors that impact the presentation of the oral-facial area. We can categorize a majority of these into four factors identified by the acronym “LARS”: lip length, age, race and sex.28 Lip Length The length of the upper lip ranges from 10 to 36 mm. The longer the upper lip, the less maxillary dentition is visible and the more mandibular dentition is shown in kinetic movement. Age As we age, the lips are drawn down and out over the skeletal and dental framework. The intrinsic and extrinsic effects of aging are covered in greater detail in the aging section. Race A person’s bony structure varies across all racial identities. The skeletal/dental structure is the scaffolding for the oral-facial region; and with the addition of musculature and overlying skin, we see marked differences in the physical makeup of different races. Facial augmenters must realize these differences and appreciate the harmony that lies between the racial spectrum. Our main focus is to enhance the beauty our patients possess, not alter them to subscribe to intercultural or racial stereotypes. Nevertheless, studies support that there are marked differences between the lips of each race. For example, the lips of African-Americans have a greater incisor inclination and a more protrusive soft tissue profile. A more protrusive profile is more accepted in the African-American population. Sex Usually when we observe an infant, we are unable to identify whether they are male or female. The influence of sex hormones on the contour of bodies, facial features, and lips is no different. The male’s face is more rugged and bolder. The female’s appearance is gentler and rounder. The subtle differences translate to the lips and face and will be explored further later in the book. Generally, males have a longer maxillary lip than females. The average maxillary tooth display is 1.91 mm for men and 3.40 mm for women.28 SEGMENTS OF LIPS (KINETIC) The canine teeth are the cornerstone for the arch form in the maxilla and mandible (Fig. 2). The lip arch form lays itself over the dental arch form. The lip arch form presents as a “U,” “V,” or square shape corresponding to the patient’s dental arch form. The lateral segments (Segs. 1, 3, 4 & 6) on the upper lip and lower lip become wider and elongated as the lips move into a kinetic smile. The central segments flatten and lengthen as the muscles of facial expression contract and pull the lips against the dental arch.
THE DYNAMICS OF KINETIC AND STATIC MOTION IN THE CLASSIFICATION SYSTEM We augment our patients’ lips in the static position. We assess the lips for augmentation in both the static and kinetic positions. The segments and zones we assign in the static state will translate proportionally to the kinetic state (smiling). In other words, if we overfill Segment 2 in the static state, this will result in an overfill in Segment 2 in the kinetic state. Even though we stretch the lips when we smile, the proportional relationship of the lips will still be present in the same segment in the kinetic motion. The borders for the kinetic segments translate to the curvature of the arch, which develops at the canines. In a full smile, Segments 2 and 5 fill the space medial between the canines of the upper and lower dentition.
THE LINE BETWEEN THE LIPS (LBL) The line between the lips (LBL) presents in four ways on the human face. Artists use the LBL as an identifying trait on all portraits. The line between the lips has a definite subconscious effect when we perceive a person’s appearance. Because an artist’s job is to facilitate an emotion without overtly exaggerating facial expression, this line is very important on mouth presentation. Leonardo da Vinci’s masterpiece, the “Mona Lisa,” is the gold standard in a study of lips. Examine the subject’s facial expression and the line between her lips. Is she smiling? Is she presenting an aloof attitude of superiority, or communicating a passive state of bliss? We may never know for certain what her smile conveys about her mood, which is why this work of art is timeless, captivates our attention, and inspires us, depending on our personal perception of her mood. The LBL is dictated predominantly by the maxillary lip. It is in the mouth’s relaxed (static position) where we can best evaluate this line. When we augment, we have a significant impact on the existing LBL. Consequently, a thorough understanding of the different expressions of the LBL is needed. The expression of this line is in Zone C in the upper lip. The genetic development of an individual establishes the form of the LBL at lip maturity. An inverse LBL can be viewed as contributing to the aged look of the mouth. This is partly because the inverse smile line corresponds to the aging process of the oral-facial area, which is a downward and outward growth and sagging of the oral-facial tissue. Although an inverse LBL can present as a component of an aged smile, it does not completely imply an aged smile. A lack of fullness in the lips presents more of an aged view of the face. Patients often come in for consultations because of the loss of volume in their lips. The loss of lip volume contributes more to the development of rhytides and deepening of lines around the lips. We know that we very seldom augment in Zone C. Zone C reflects the architecture from Zone A. After filling in the volume of the lip (Zone B), we then evaluate the architecture of Zone A. If needed we then sculpt Zone A. Zone C will then reciprocate the form established by the previous two filling orders of Zone B and A. Think of the vermilion border of the maxillary lip as a curtain rod that is uniform in both length and width. When we bend the curtain rod up and down and hang the fabric on the rod, the bottom edge of the curtain (Zone C) reflects the shape of the bent rod (Zone A). Incompetent Lip (Open Lip) This presentation of the LBL is open when the face is relaxed. There are a myriad of reasons for an incompetent lip, to include VME (vertical maxillary excess), short lip or chronic airway obstruction. Lip incompetence is one situation where cosmetic augmenters may have an opportunity to add to Zone C without violating the dental presentation underneath. Adding volume in Zone C is achieved by inserting the needle into the inferior border of Zone B and letting a limited amount of material flow into Zone C. There is a segment of the population that has incompetent lips, or lips that separate in the static position. This can be attributed to dental and/or skeletal malocclusion. The cause of incompetent lips is usually not associated with lip deficiency. The incompetence of the lips is attributed more to a skeletal malformation. This phenomenon is related to excessive interlabial space. At rest a relatively small amount of separation between the lips is normal. The primary measurement of interlabial distance is defined by stms and stmi: stomion superius and stomion inferius. The measured normal distance ranges from lightly touching to a 3-mm distance between both points.32 Patients with incompetent lips are excellent candidates for augmentation of the lips and or Botox therapy. The jaw rests in a neuromuscular position creating a freeway space. The freeway space is an approximate 2 mm vertical height separation between the upper and lower teeth. In this position, the muscles of the jaws are at their most relaxed position. If we are not talking or eating, we maintain this position during which the lips are naturally closed or competent. However, when this inter lip space is excessive and requires the patient to contract the orbicularis muscle with intention, we classify this as incompetence. This is usually around 4 mm+. Common causes of incompetent lips include Soft tissue – Short philtrum, where the space between subnasale (base of the nose) and the superior border of the vermilion fails to complete a relaxed seal of the lips. As a result of the amount of interlabial space available, we are able to augment more liberally in Zone B, without obscuring needed incisal dental length for aesthetic appearance. If the patient presents with a full upper lip, other alternative therapeutics may be indicated such as Botox therapy. Denervating the levator labii superioris alaeque nasi (LLSAN) muscle may length the upper lip in order for the patient to present with more competent lips. Dental – Excessive dental overjet, where the maxillary teeth protrude over the mandibular jaw, forcing the lips to separate. Skeletal – Relationships attribute to vertical maxillary excess (VME) with and without anterior open bite resulting in down and back rotation of the mandible and excess lower facial height.