STOMATOLOGY EDU JOURNAL 2017, Volume 4, Issue 3 SEJ_3-2017_Online - Page 54

Effective applications of botulinum toxin in dentistry and in head and neck surgery 204 Figure 4. Gummy smile before Tx. Figure 5. Gummy smile after Tx. prolonged muscular hypertension. The application into the Pterygoideus lateral does not cause the symptom of the “frozen smile” that can emerge after the diffusion of botulinum toxin into the superficial facial muscles (Fig. 3). To avoid the symptom of the “frozen smile” authors personally have successfully proven the ultrasound navigation of the needle application which significantly minimizes the risk of side effects. 4.1.5. Trigeminal neuralgy The botulinum toxin is used as a supportive therapy to medication before neurosurgical treatment starts or eventually as the main therapy if surgery is contra- indicated. The mechanism is not clear - blockage of proprioceptive sensation probably plays a role. The effect of the botulinum toxin is analgesic, but it never acts as a monotherapy without neurological medications. 20 4.1.6. Sialorrhoea The botulinum toxin is frequently used in the treatment of akinetic diseases typically in parkinsonism and the compensation of stroke side effects. It is applied (sometimes under control of sonography) in parotid and submandibular salivary glands. This procedure ensures reduced salivation for 6-9 months. The same protocol can be successfully used for sialoadenitis and salivary fistula. 21 It is important to give sufficient, i.e. very high doses of botulinum toxin, even higher when compared to the application to the Masseter muscle. 4.1.7. Tinnitus This multifactorial and not fully understood disease can be decreased in intensity with the botulinum toxin if the myoclonus of the soft palate is present, which causes the pathology status in the smallest muscle in the body the stapedius. The application of the botulinum toxin into the soft palate is ideal for the control of EMG. The indications must be given by a neurologist; the application is frequently made by an ENT specialist or maxillofacial surgeon. 22 4.2. Esthetic indications 4.2.1. Decreased or increased position of the upper lip One of the most popular procedures in aesthetic medicine and aesthetic dentistry is the reshaping of the upper lip to achieve the desired size, shape and position. As we get older, the dorsal maxilla retreats. Consequently, natural abrasion (shortening) of the front teeth and (lip) thinning lead to a syndrome of "long lip”. We often see, as a "popular solution", a completely unnatural "inflated" lip red boosted by a variety of injectable filler materials based on hyaluronic acid, whereas the upper lip often exceeds the size of the bottom lip, which is unacceptable. Furthermore, this approach fails to camouflage the so-called "invisible teeth”. On the contrary, it further deepens the problem. The solution has to be interdisciplinary. In rare cases, the mesial orthognathic replacement of the upper jaw is fixed by surgery together with orthodontic pretreatment, or we can shorten a lip by plastic surgery. However, those treatment protocols are very complicated, with significant risk of complications, and we have to reserve them for most demanding cases. Another common solution is to extend the clinical crowns of the anterior teeth with veneers or crowns with the overall increase of the patient's intermaxillary distance. Even this complex procedure has its limits and possible side effects. The new alternative is the weakening of the lower lip depressants and the Orbicularis oris muscle with the botulinum toxin. This treatment improves the display of labial teeth surfaces without interfering to the dental tissues. Unfortunately, even if it is easy and safe, currently it is not a common solution how to hide the unpopular high exposed gums so-called "Gummy smile" via the reduction of the upper lip position 23,24 due to relaxation of the lip levators (Figs. 4, 5). Some dentists still address this problem by difficult and potentially devastating procedures involving the shortening of alveolar bone with subsequent reduction of the gingiva with a final "extension" of the teeth. It is much easier to apply the botulinum toxin to an area where there is an intersection of three upper lip levators, in the latero-caudal way from the nasal wing insertions (Fig. 6). We can also add additional applications, centrally in the subnasal way. This Stoma Edu J. 2017;4(3): 200-207