cosmetic dentistry_ beauty & science

industry report _ new concept of aesthetic restoration I botulinum toxin since the middle of 18th century, when Justin Kerner described it as “sausage poison” because of the effects in patients after eating contaminated sausage. Only in 1949, did Arnold Burgen report the discovery of the blocking action of botulinum toxin on neuro- muscular transmission. Since then, many studies have been conducted onthetherapeuticandcosmeticuses of botulinum toxin. It was first used for therapeutic purposes with the approval of health regulatory agencies in 1989 in ophthalmologytotreatstrabismus,blepharospasm and hemifacial spasms. From 2000, botulinum toxin Type A began to be widely used in muscular and cosmetic therapies but without indication of use, that is off label.1 When it is injected into muscle, botulinum toxin Type A paralyses muscular movement. The mecha- nism of action of botulinum is the inhibition of acetylcholine, the neurotransmitter released by the action of nerve impulses at neuromuscular junctions, thus preventing muscular contraction. Consequently, temporomandibular joint dysfunc- tion syndrome, muscular hypertonia (trismus), mi- graines and gummy smiles, among others, are dysfunctions that may benefit from the use of the toxin (Figs. 1a–3b).2 Botulinum toxin is contra-indicated in lactating and pregnant women, people with autoimmune diseases,neurologicaldiseasesanddiseasesthataf- fect the muscles, people allergic to egg protein and people using medicines derived from aminoglyco- sides. Among the major risks of botulinum toxin is overdosing and application to incorrect regions, which may result in asymmetry. In terms of health, it could affect the movements necessary for good function such as blinking, chewing and swallowing.3 Botulinum toxin has a temporary effect, thus its treatments must be seen as palliative and not de- finitive. For this reason, if treatment is satisfactory, it will have to be repeated to maintain the results. There is not a rule, each person has a singular reac- tion, but the applications are generally done every sixtoeightmonths,alwaysbyaskilledprofessional. The possibility of developing resistance and thus requiring increasingly higher dosages and shorter intervals between treatments is a matter of debate. Some studies show that over time the patient may develop resistance to the toxin, indeed requiring higher dosages in future applications. This dosage excess may cause an insensitivity of the patient to the effects. Other studies however show that over timetheneedforthetoxinisreduced,whichimplies thatlowerdosagesarerequired.Aftersometimethe relaxed muscle shows a decrease of conditioning spontaneousofactivity,asanatrophy,thusexplain- ing the decrease in need of toxin.4, 5 Filling materials are widely used in medicine. In orofacial dentistry, filling materials such as polyamide, hyaluronic acid and hydroxyapatite are employed to fill nasolabial folds, the lips, the bar- code lines of the upper lip and short interdental papillae, also known as black triangles or black spaces, and to sculpt the Cupid’s bow and model thephiltrum,theverticalgrooveinthecenterofthe upper lip. (Figs. 4a–5c).6, 7 Therapeutic procedures to restore function are combined with procedures to restore aesthetics in Figs. 3a & b_Before (a) and one week after treatment (b) of chronic migraine (Case 3) by reduction of tension in the temporal and frontal muscles. Figs. 4a–c_Case 4: Filling of nasolabial folds (arrow), Cupid’s bow (oval) and philtrum (rectangle) with a filling material made of polyamide (Aqualift). I 27cosmeticdentistry 1_2013 Fig. 4a Fig. 4b Fig. 4c Fig. 3a Fig. 3b