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
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