Authors : Dr Rabiya a hameed .
 

Introduction:

As society becomes more aesthetically conscious, Aestheticians are more challenged to produce aesthetic smile. Amongst all of the human facial expressions, the smile is the primary facial expression of pleasure, happiness, amusement, or derision and it is likely the most complex in terms of meaning and few needs adjustment to get an immaculate smile which is appealing and dynamic. Every minute detail is becoming more important.

Aesthetically pleasing smile is influenced by three factors: arrangement and proportion of these factors.
 

1. Lips


2. Teeth


3. Gums

Recent studies have indicated that the measure of gingival show on smiling is very important to smile attractiveness. For an alluring smile, upper lip should symmetrically display gums. The ideal gingival display to be 0 mm for males and 2 mm for females range being ( 0 to 3 mm).

While the acceptable scope of gingival exposure has been talked about, it is obvious that an abundance of 4 mm or above of gingival showcase on smiling is concidered as unaesthetic. At the point when an unnecessary measure of gingiva is shown upon smiling, it is termed “gummy smile”.
 

Gummy smile

 

Types of gummy smile

Rosemarie Mazzuco et al., classified gummy smile into 4 based on the excessive contraction of muscles involved.
 

1. Anterior: 3mm of gingival show between canine to canine (Muscle involved Levator labii superioris alaeque nasi)


2. Posterior: more than 3mm of gingival show posterior to canine. (muscle involved zygomaticus muscle)


3. Mixed: Excess gingival show both anterior and posterior.(Multiple muscle involved).


4. Asymmetric: seen on one side because of assymetric contraction of muscle.


5. Goldstein classified according to the degree of exposure of the teeth and gums into 3 types: high, medium, or low.

 

Causes of Gummy Smile

1. Sex Predilection


2. Hyperfunctional Musculature and Lip Incompetence


3. Altered Passive Eruption


4. Skeletal Disharmonies

The appropriate treatment for a gingival smile is determined by the cause. There are number of distinctive treatment modalities described in the literature for the treatment of gummy smile which includes invasive or non invasive. A non-surgical choice for reducing excessive gingival show offer appealing treatment for specific patients. "Botox" have been utilized as a part of solution since the 1970s for treating excessive muscular contraction and in aesthetic medicine for treating facial agony and migraines. Since 1987 its utilization has expanded significantly in correcting facial ageing.
 

Anatomy of lip

 

TREATMENT FOR GUMMY SMILE

Altered passive eruption	Gingivectomy, Crown lengthening
Altered passive eruption	Apical reduction of the entire dentogingival complex with or without osseous reduction
Skeletal Disharmonies	Orthodontic treatment, orthognathic surgery,
Hyperfunctional Musculature and Lip Incompetence	Muscle resection, anterior nasal spine implant and Botulinum toxin

 

Anatomy of the lips

The upper lip consists of three subunits: the central philtrum and the two lateral subunits. The lower lip is a single subunit
 

Lip consist of

1. Bundles of striated muscle called the orbicularis oris,


2. Externally covered by skin


3. Internally lined by pink mucus membrane.


4. Submucosally there is a thin layer of tissue called the submucosa that contains mucous glands.

 

Parts of lip:

1. philtrum is the region in the middle of the upper lip directly beneath the midportion of the nose


2. Vermilion border: it is white roll of lip , a junction between pink mucosa and skin, and this area doesnot contain hair or sweat gland.


3. Cupids bow: small rolled or puckered border in the vermilion.


4. Commisure: Corner of mouth where both lip meets


5. Tubercle of upper lip it is slightly projected area in center of upper lip


6. Central crease of lower lip: vertical crease in midline of lower lip

 

Lip aesthetic
Lip lines	Maxillary incisor exposure at rest 2–4mm. Depends on upper lip length and vertical maxillary incisor position Lower lip should cover incisal third of maxillary incisors.
Lip activity	A strap-like lower lip often retroclines incisors. Flaccid lips are less likely to significantly alter position with anteroposterior dental movement.
Lip morphology	Everted lips may be due to interposed proclined maxillary incisor teeth. Flat or backward sloping lips give an ‘aged’ appearance to facial profile. Full lips are less likely to significantly alter position with anteroposterior dental movement. Thin lips are more likely to ‘flatten’ with incisor retraction. Vermilion show of lower lip slightly more than upper lip (by 2–3 mm).
Lip posture	Lips held together at rest (competent). Lips apart at rest by more than 3–4mm(also termed lip incompetence). Potentially competent (lips are unable to be held together due to interposed incisor teeth).

 

Ideal lip

Beautiful lip and its aesthetic standards vary across eras, cultures and also acording to changing trend in fashion. No actual guidelines exits for assessment for lip aesthesis. Research suggest that ideal lip should have following charecteristics.
 

1. Puffy and volume


2. Balance between upper and lower lip


3. Well defined lip borders


4. Harmonious with other features

 

Botulinum toxin for gummy smile

Fortunately, gummy smile can be essentially and viably remedy by Botulinum toxin injection to diminish the action ofthe muscle the elevate upper lip. Botulinum toxin is associated with excess muscle contraction, and this can be a minimal invasive option for interim change of gummy smiles with minimal risk involved.
 

Preparation And Injection Technique

Botulinum toxin is available in a freeze-dried powder, to be used after dilution by adding 4.0ml of 0.9% normal saline to 100 unit botulinum powder without preservatives as per manufacturers guideline.
 

Diluents added (0.9% Sodium Chloride injection)	Resulting dose Units per 0.1 mL
1ml	10 unit
2ml	5 unit
4ml	2.5 unit
8ml	1.25 unit

 

Yonsei point

 

Injection technique

Injection should be administered intramuscular but not subcutaneous. One ml tuberculin or insulin syringes be used as it gauges the dose accurately in minute quantities. Intramuscular injection for correction of excessive gingival display is given at Yonsei point. This point is loacated at the center of triangle formed by following muscles Levator labii superioris, Levator labii superioris alaeque nasi, and
Zygomaticus minor. The injection sites were determined by muscle action (smiling) and palpation on contraction to ensure precise muscle location before injection.
 

Post op care

• Avoid lying down for the first 4 hours.


• Avoid exercise


• Avoid sun exposure for 24hours


• Avoid skin manipulation


• Avoid alcohol

 

Mode of Action

This toxin acts by preventing the release of acetyl choline from presynaptic vesicles at the neuromuscular junction resulting in an inhibition of muscular contraction. Therapeutic effects of Botulinum toxin, first appear in 1 to 3 days, peak in 1 to 4 weeks, and decline after 3 to 4 months, after which sprouting of new axon terminals results in a return of neuromuscular function. Therefore, Botulinum toxin injections are needed to be administered 2-3 times a year.
 

Contraindication.

• patient with unrealistic expectations.


• Dependent on intact facial movements and expressions for their livelihood (e.g. actors, singers, musicians and other media personalities).


• Afflicted with a neuromuscular disorder (e.g. myasthenia gravis, Eaton-Lambert syndrome).


• Allergic to any of the components.


• drug interaction (e.g. aminoglycosides, penicillamine, quinine, and calcium blockers).
• Pregnant or lactating (category C drugs).

 

Adverse effects

common non serious short term:

• Mild stinging, burning or pain with injection


• Edema


• Erythema


• Mild headache, localized and transient


• Ecchymosis lasting 3 to 10 days


• Asymmetry


• Oral incompetence and asymmetric smile


• Lack of intended cosmetic effect

 

Rare and idiosyncratic

• Numbness and paresthesias


• Focal muscular twitching


• Mild nausea and occasional vomiting


• Mild malaise and myalgias

 

Rare, longer duration that can be serious:

• Immediate hypersensitivity reactions


• Urticaria


• Dyspnea


• Soft tissue edema


• Anaphylaxis

When compared to other surgical procedures Botulinum toxin provides effective, minimally invasive, temporary treatment of gummy smile for patients with hypermobile upper lip, which can be repeated if the patients like the aesthetic improvement achieved.