Smile please!

INTRODUCTION
Smile is the most recognizable signal in the world; it is one of the most effective means of conveying your emotions. We all can do a magnificent job of making teeth look great and giving people a healthy and beautiful smile. This concept of framing the smile properly is essential in order to perform a complete smile analysis and any associated aesthetic treatment.
Aesthetic dentistry has been an absolute boom over the last 30 years when it comes to such innovative techniques as teeth whitening and minimally invasive veneers.
However we, as dentists, have become so tooth-centric that we forget that it is very important for the peri-oral areas to look as good as the teeth.
How many times have you seen an aesthetic dental case involving beautifully restored teeth that are left surrounded by wrinkled and thin lips, and deep nasolabial folds? Perhaps the patient has been given beautiful teeth but not a complete and beautiful smile
.
A beautiful smile would be ideally a perfect set of teeth along with pleasing peri-oralfacial esthetics. Peri-oral esthetics looked upon by dentists are lips, gums, chin, marionette lines, nasolabial folds and labiomental folds.
Relationships between three components of teeth, lip framework, and the gingival scaffold determine the esthetic appearance of smile.  One of the most common reasons for seeking orthodontic treatment is excessive display of gingival tissue on smiling, usually referred to as a gummy smile, which is often esthetically displeasing. When an excess of gingiva superior to the maxillary anterior teeth is displayed upon full smile, it is termed a gingival smile. The gingival smile is known by a variety of terms including gummy smile, high lip line, short upper lip, and full denture smile. Perhaps this variety in terms is indicative of the many different causes of a gummy smile. The best orthodontically treated subjects may not be satisfied by the treatment, if soft tissue problem is not corrected. Botox is indicated when the gummy smile is due to hyper functional upper lip elevator muscles (muscular capacity to raise the upper lip is higher than average).  In order for us to understand how to incorpo­rate this extremely valuable treatment modality in our clinical practice we must first explore the basic principles of functional smile musculo-dy namics.

Rubin (1974, 1999) described three types of functional smiles in his studies.
(i) Mona Lisa Smile (approximately 67% of patients studied) -
Characterized by a sharp elevation of the corners of the mouth and a mild elevation of the central upper lip. This resultant smile will typically expose approximately 80% of the upper central incisors and canines and often all of the lateral incisors. In such cases the dominant muscles are zygo¬maticus major and to a lesser extent zygomaticus minor.
(ii) Canine smile or Cuspid smile (31- 35% of patients studied) -
In such patients a high central elevation of the upper lip occurs initially before the corners of the lip are elevated. The dominant muscles here are the levator labii superoris and levator labii superious alaeque nasi and to a lesser ex¬tent depressor septi nasi. If excessive activity of these centre lip elevators occurs during the smile dynamics then an excessive gingival display is likely as well as well pronounced nasio-labial furrows. This smile is also known as Commissure smile.
(iii) Full denture smile/ Complex smile (ap¬proximately 2% of patients studied) – This is characterized by all the upper and lower lip retractors contracting simultaneously to reveal a large percentage of the upper and lower dentition. Hence a comprehensive assessment of the patient must be made prior to treatment to es¬tablish the musculodynamics of the smile and themselves the relative position of the free gingival margins of the upper and lower incisors.

Mona lisa smile	Cuspid smile	Complex smile

CAUSES OF A GUMMY SMILE
1. Pre-Treatment
• Sex Predilection
• Musculature and Lip Incompetence
• Altered Passive Eruption
• Skeletal Disharmonies
2. Possible Causes of Gummy Smile Development During Orthodontic Treatment
• Extrusive Forces
• Anterior-Posterior
• Position of the Maxilla
• Unexpressed Vertical Growth
The appearance of lip framework is determined by activity of various muscles involved in facial expression: Levator labii superioris (LLS), Levator labii superioris alaeque nasi (LLSAN), zygomaticus minormajor (ZMi, ZMj). LLS, LLSANZMi determine the amount of lip elevation during smiling.
What is BOTOX?
Botulinum is derived from the Latin word botulus, meaning sausage, and botulism was originally called sausage poisoning because it occurred after ingestion of poorly prepared blood sausage.
Justinus Kerner (1786-1862) was the first to describe the features of botulism.
Botulinum toxin is synthesized by C. botulinum, C. butyricum, and C. baratii, all of which areanaerobic spore forming bacilli. The spores areheat resistant, and they can germinate to producetoxin in the appropriate environment of anaerobicconditions, low acidity, and liquid medium, asfound in some foods. The toxin is ingested andabsorbed through the gastrointestinal tract into thesystemic circulation.

How botox works?
The medical term for the action of Botox is selective muscle denervation. Normally, to make a muscle contract, a nerve sends a signal to the muscle. The point where the nerve and the muscle meet is called the neuromuscular junction. When the signal gets to the neuromuscular junction a chemical called acetylcholine is released from the nerve side of the junction and binds to the muscle side of the junction causing more chemical reactions that make the muscle contract.
Botox works by blocking the acetylcholine receptors on the muscle side of the junction. Then when the nerve sends a signal to the muscle to contract, acetylcholine is released as before, but it can't bind anywhere on the muscle. The muscle has no idea it is supposed to contract. It is essentially paralyzed, but not because it or the nerve have been damaged.
This acetylcholine blockade is not reversible and begins within 48 hours. The clinical effects of a Botox injection become noticeable between 5-10 days.

Preparation, storage, dilutioninjection
Botox® is available in a freeze-dried powder that clumps at the bottom of the vial. During reconstitution, the rubber seal on the vial should be wiped with an alcohol swab before using a 5 ml, 30-guage needle syringe to inject the desired volume of normal preservative-free saline. Rotating the vial during injection also assists a gentle reconstitution. Botox® should be reconstituted after the journey. Agitation during transport may denature the toxin and greatly reduces its duration of action.
The patient should be instructed to avoid taking aspirin or related products, such as ibuprofen or naproxen if possible after the procedure to keep bruising to a minimum.
Reconstitute vacuum-dried BOTOX, with sterile normal saline without a preservative; 0.9% Sodium Chloride Injection is the only recommended diluents. Draw up the proper amount of diluents in the appropriate size syringe, and slowly inject the diluents into the vial. BOTOX should be administered within four hours after reconstitution. During this time period, reconstituted BOTOX should be stored in a refrigerator (2° to 8°C). Reconstituted BOTOX should be clear, colorless and free of particulate matter.
The diluted botox should be used with 4 hours of dilution. Aspiration before botox injection should be done to avoid involuntary deposition into facial arteries.

Diluents added (0.9% Sodium Chloride injection)	Resulting dose Units per 0.1 mL
1.0 mL	10.0 units
2.0 ml	5.0 units
4.0 ml	2.5 units
8.0 ml	1.25 units

Almost all of the injections are intramuscular and not subcutaneous. A safe and reproducible injection point for Botulinum toxin A around the converging area of the three muscles has been proposed and proved effective in clinical applications.
Recently Hwang et al; Yonsei University College of Dentistry, Seoul, Korea have proposed a injection point for botulinum toxin-A, and named it as YONSEI POINT and they recommend a dose of 3U at each Yonsei point.
Yonsei point is located at the centre of the triangle formed by:
1. Levator labii superioris [LLS],
2. Levator labii superioris alaeque nasi [LLSAN], and
3. Zygomaticus minor [Zmi].

Location of Yonsei Point

In cases involving asymmetry caused by muscle contraction, bilateral injection of botulinum toxin is recommended, with a higher dose on the hyperkinetic side. An exception to this recommendation should be made when the asymmetry of the smile is a result of facial paralysis, in which case it is recommended that botulinum toxin is injected only into the hyperkinetic side.
Effect of Botox is seen within 5-10 days and lasts about 6 months, with a range of 4 to 8 months, at which time the patient can return to repeat the process. It is important not to give injections prematurely (before the effects of the treatment have worn off), as this can result in a buildup of antibodies to Botox that would dilute the effect of further treatments.


DRUG INTERACTION
Drugs that may alter the effects of Botulinum toxin include: aminoglycosides (gentamycin), cyclosporine, D-penicillamine, muscle relaxants, aminoquinolones, quinidine, magnesium sulfate, and lincosamide.

CONTRAINDICATIONS
Patients should not be treated or treated with extreme caution who are:

• Psychologically unstable or who have 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 of BTX-A or BTX-B (i.e. BTX, human albumin, saline, lactose and sodium succinate).
• Taking certain medications that can interfere with neuromuscular impulse transmission and potentiate the effects of BTX (e.g. aminoglycosides, penicillamine, quinine, and calcium blockers).
• Pregnant or lactating (BTXs are classified as pregnancy category C drugs).
  
  
  

FACTORS INFLUENCING DOSE OF BOTOX

• Skin
• Ethnicity
• Skin type
• Muscle mass
• Extent of wrinkles
• Previous response to botox

FACTORS AFFECTING POTNECY

• Alcohol on the bottle cap
• Agitation of diluted vial
• Storage of diluted botox for more than 4 hours
• Freezing the reconstituted solution

ADVERSE EFFECTS

• Adverse effects of limited duration that are common, localized and not of a serious nature common with any percutaneous injection
• Mild stinging, burning or pain with injection
• Edema around injection site
• Erythema around injection site
• Mild headache, localized and transient
• Technique dependent
• Ecchymosis lasting 3 to 10 days
• Asymmetry
• Oral incompetence and asymmetric smile
•  Lack of intended cosmetic effect
• Rare and idiosyncratic
• Numbness and paresthesias ( localized and transient)
•  Focal tonic movements (twitching)
•  Mild nausea and occasional vomiting
•  Mild malaise and myalgias (localized and generalized)
• Rare adverse effects of longer duration that can be serious and are not technique dependent
• Immediate hypersentivity reactions
• Urticaria
• Anaphylaxis
• Soft tissue edema
• Dyspnoea

Preoperative	Post operative

Pre operative	Post operative

CONCLUSION
With plastic surgeons, dermatologists, internal medicine physicians, ob­stetricians gynecologists, optha­mologists, podiatrists, nurses, physicians’ assistants, and medical aestheticians (who may not even be medically trained) delivering BOTOX to pa­tients in the oral and maxillofacial areas, it is certainly time to recognize that dentists can be just as proficient in injections than any of these healthcare providers. Dentists also have much expertise in the oral and maxillofacial areas. We are also trained to be experts in the muscles of mastication and the muscles of facial expression which routinely receive these treatments.
Hands-on training is absolutely essential in learning how to provide these procedures and intertwining them with dental treatment plans. With proper training, dentists are usually more proficient than any of these other healthcare professions in providing these treatments to patients, both for dental and cosmetic needs.
It is time to broaden our horizons as a profession and use all of the tools available to us. BOTOX therapy is a conservative, minimally invasive treatment that can expand our therapeutic options for the benefit of our patients and is a natural progression of where we are going in the dental industry.