Aesth. Plast. Surg. 25:73–84, 2001 DOI: 10.1007/s002660010100 © 2001 Springer-Verlag New York Inc. Botulinum Toxin A and Facial Lines: The Variable Concentration Claude Le Louarn 59 rue Spontini, 75116 Paris, France Abstract. Our improved understanding of the functional Migration Factors anatomy of the face and of the action of the botulinum toxin A leads us to determine a new injection procedure which conse- The main concern with the use of toxin A lies in the risk quently decreases the risk of eyebrow and eyelid ptosis, and of migration. Three injection sites are specifically asso- increases the toxin injection’s possibilities and efficiencies. ciated with the risk [6]. Variable toxin injection concentrations adapted to each injected An injection above the eyebrow into the corrugator area are used. Thanks to the new procedure in the upper face, muscle can cause eyelid ptosis. The migration distance toxin A action is quite close to an endoscopic surgical action. between the injection site and the levator palpebrae In addition, interesting results are achievable on the nose, upper muscle is 2 cm. part of the nasolabial fold, jawline and neck regions. Lastly, a An injection in the lateral part of the orbicularis oculi smoothing effect on the skin is obtained by the anticholinergic muscle, just below the eyebrow, can allow the toxin to action of the toxin A on the dermal receptors. migrate into the levator palpebrae muscle or into the extraocular muscles. Migration distance is 2 cm. Key words: Botulinum toxin A—Variable concentration— Injection in the upper part of the frontalis muscle can Injection technique migrate into the lower part of the frontalis muscle. As described in Fig. 5, lower frontalis muscle paralysis in- duces eyebrow ptosis. Migration distance is 2 cm. Two types of botulinum toxin A are used in this study, The migration is specially due to injection volume, the DYSPORT toxin distributed by BEAUFOUR-IPSEN injection orientation, and injection bleeding. laboratory (Each vial contains 500 Speywood units of toxin A), and the BOTOX toxin distributed by ALLER- Injection Volume GAN laboratory (Each vial contains 100 Allergan units of toxin A). When following the instructions of the Dysport package The toxin equivalence seems to be 3 to 4 Speywood insert, 500 units of Dysport are mixed with 2.5 ml of Allergan unit (Botox) [7]. A Dys- non-preserved saline: 20 units equals a volume of 0.1 ml 1 ס (units (Dysport port vial contains 25% to 40% more usable product than which is frequently larger than the volume of muscle to one Allergan vial. be injected. Obviously, the risk of side effects is high. To correct dystonia and spasm, injections must be re- In order to obtain a more precise effect, the contents of peated at a constant frequency to maintain the desired a vial are diluted in 0.7 ml of saline (nearly a quarter of effect [10]. This seems to be related to the high intensity the recommended quantity) thus the volume to inject will and frequency of nerve stimulation in such disorders. be smaller than the volume of the muscle injected (Fig. In the cosmetic field (facial lines) injection frequency 1). The risk of migration in the periorbital region is thus can be progressively decreased because of 2 factors: a drastically diminished. mild long-term muscle atrophy, and a change in facial For Botox toxin, 100 Allergan units are usually mixed animation patterns with a lower intensity and in the fre- with 4 ml of saline [4]. The proposed dilution is 100 quency muscle nervous stimulation [1,2]. Allergan units mixed with 1 ml of non-preserved saline. The following study describes the new possibilities of It is better to use a 0.5 ml diabetic syringe to inject the botulinum toxin A when using new injection tech- a high concentration solution of toxin A rather than a niques which limit its migration. 1 ml syringe. The 0.5 ml diabetic syringe is twice as 74 Varying Botulinum Toxin A Concentrations Fig. 1. Volume of 15 units of Dysport in case of dilution of the Fig. 2. The 0.5 ml insulin syringe with 50 units. vial with 2.5 ml, 1.25 ml, 0.62 ml of saline. use of the tip of the thumb and not of its base; lastly, the precise as the 1 ml, but also the 0.07 ml loss of solution unit number in each vial of Dysport or of Botox is subject per use between the syringe and the needle doesn’t exist to a variation of 20%. This unavoidable variation results with the smaller syringe. Indeed, the 0.5 ml diabetic sy- from the toxin manufacturing processes. A good injec- ringe has a 29 gauge needle directly inserted in the cavity tion technique limits problems 1 and 2. with no empty space. The performing syringe we found Variable Toxin Concentration for this use is the BD 4-100 Insulin microfine 8 mm 0.5 ml with 50 units (Fig. 2). The concentration of a motor end-plate near the injection point depends on each type of muscle. A flat and thin Injection Orientation muscle like the platysma muscle has a medium motor end-plate concentration, and, on the contrary, a short and Not only is the bevelled angle of the needle directed to thick corrugator muscle has a high concentration of mo- the desired target exactly like in Collagen injection tech- tor end-plates near the injection point. On this basis, we niques, but also any dangerous adjacent muscle direction describe 3 different toxin concentrations, high, medium of the injection is to be avoided. and low depending upon the action we look for. In case of corrugator muscle injection, the bevelled angle of the needle is directed opposite to the levator The high toxin concentration. 0.7 ml of saline are used palpebrae muscle. to dilute 500 units of Dysport or 1 ml of saline for 100 units of Botox. The action is strong and precise, on thick Bleeding Induced with Injection muscles of the peri orbital area: the corrugator muscle, the orbicularis oculi muscle pars orbitalis, the depressor A needle injection creates a micro-tissue trauma, micro- supercilii muscle and the lower part of the frontalis bleeding, sometimes an ecchymosis. This ecchymosis muscle. This high concentration diminishes the volume downward migration due to gravity, carries along the of injection and prevents migration. botulinum toxin. This risk is minimized with the help of the following procedure: Any injection on a vascular axis Medium concentration toxin. To obtain a medium con- such as the supraorbital bundle, should be avoided [3]; an centration toxin, two volumes of saline including adrena- appropriate digital pressure is realized when the needle is line is added to the volume of high concentrated toxin removed from the injection site. This action is mainly which is already in the syringe (Fig. 3). important in case of corrugator muscle injection, as well The action is clear and spread over a larger surface as in the case of frontal and orbicularis oculi muscles with the same number of units of toxin. The muscles such as previously described, and in any case of ecchy- concerned are the frontalis, the orbicularis oculi temporal mosis; adrenaline is added to the non-preserved saline and malar pars, the platysma and the chin muscles. with a dilution of 50 ␮ gr/per ml (like xylocaïne 1% The low concentration toxin. 3 volumes of saline includ- adrenaline). ing adrenaline are added to the volume of toxin already in the syringe. The action of the injection is partial and Injection Technique localised. It is useful for injecting spots in the vermillon border of the lip or in the orbicularis oculi pars orbitalis There are three causes of the injection imprecision that in the lower eyelid area. The variable concentration can can explain different results with the same patient and be adapted to each physician’s experience and to each the same technique at different injection sessions: a par- patient’s reaction. A patient with a long duration effect allax error vision due to an axis of vision which is not on the periorbital area and too short an effect on the perpendicular to the axis of the syringe; imprecision in frontal area, will benefit from a higher concentration of the digit pressure on the piston of the syringe due to the toxin injection in the frontal area at a further session. C. Le Louarn 75 Seven to 14 units of Dysport or 3 to 5 units of Botox are injected. The tip of the needle is on the arcus super- ciliaris bone, the bevelled opening oriented to the gla- bella area and not to the levator palpebrae muscle. The bony insertion of the muscle is injected, not its skin insertion. The injection of the medial part of the corru- gator muscle decreases the vertical glabella frown lines. Injection of the lateral part of the corrugator muscle. This injection is realized in case of non-sufficient action of the injection of the medial part of the corrugator muscle to decrease the glabella frown lines, or too low a location of the middle third of the eyebrow. This injec- tion produces the elevation of the middle third of the Fig. 3. The sterile cap of the syringe is filled with the same and eyebrow. The product is injected deeply, near the bone at volume solution of saline, plus adrenaline, used to dilute the the lateral extremity of the corrugator muscle, which toxin. The syringe is filled with the necessary amount and means at the lateral extremity of the bony arcus super- volume of toxin to weaken the target muscles.