The use of botulinum toxin in head and face medicine: An interdisciplinary field
© Laskawi. 2008
Received: 01 October 2007
Accepted: 10 March 2008
Published: 10 March 2008
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© Laskawi. 2008
Received: 01 October 2007
Accepted: 10 March 2008
Published: 10 March 2008
In this review article different interdisciplinary relevant applications of botulinum toxin type A (BTA) in the head and face region are demonstrated.
Patients with head and face disorders of different etiology often suffer from disorders concerning their musculature (example: synkinesis in mimic muscles) or gland-secretion.
This leads to many problems and reduces their quality of life. The application of BTA can improve movement disorders like blepharospasm, hemifacial spasm, synkinesis following defective healing of the facial nerve, palatal tremor, severe bruxism, oromandibular dystonias hypertrophy of the masseter muscle and disorders of the autonomous nerve system like hypersalivation, hyperlacrimation, pathological sweating and intrinsic rhinitis.
The application of botulinum toxin type A is a helpful and minimally invasive treatment option to improve the quality of life in patients with head and face disorders of different quality and etiology. Side effects are rare.
Justinus Kerner first described the symptoms of botulism in detail . Pierre van Ermengem isolated the microorganism "bacillus botulinus" . In 1979 A.B. Scott first used botulinum toxin (BTA) therapeutically to correct strabism injecting the toxin into external eye muscles .
Diseases treated with botulinum toxin type A in head and face medicine with high interdisciplinary relevance
Disorders of the Autonomous Nerve System
Facial nerve paralysis
Gustatory sweating, Frey's syndrome
Synkinesis following defective healing of the facial nerve
Support in facial wound healing
Facial pain syndromes
Hypertrophy of the masseter muscle
movement disorders of the facial nerve (blepharospasm, hemifacial spasm, facial nerve palsy, synkinesis following defective healing of the facial nerve, aesthetic applications, posttraumatic wound healing preventing excessive scaring)
hypersalivation of different etiologies,
gustatory sweating and
intrinsic or allergic rhinitis.
Facial nerve paralysis, synkinesis following defective healing of the facial nerve, hemifacial spasm, blepharospasm, aesthetic applications, prevention of scar formation
BTA is also helpful in other disorders of the mimic musculature. In some cases a facial nerve paralysis leads to an affection of the cornea with severe problems like a "keratitis e lagophthalmo". In such cases an injection into the levator palpebrae muscle can close the eye for some time to protect the cornea . We use dosages of 5–10 units Botox®, the injection is done subcutaneously in the middle of the upper lid. After about 3–4 months the eye "opens" again and that is usually referring to the regeneration time of the paralysis.
In addition the esthetic outcome of a paralysis of the marginal branch of the facial nerve can be improved by injecting 2.5–5 units Botox® into the depressor labii muscle of the normal side .
Synkinesis are a non-avoidable sequelae following reconstruction of the facial nerve in patients suffering from malignant tumors of the parotid gland. Synkinesis are characterized by synchronous but not intended movements of certain areas of mimic muscles becoming mostly evident during spontaneous movements of the face based on emotional expressions. Mass movements can be reduced using BTA. This options has been described first by our group [7–9].
Another interesting indication is the intraoperative application of BTA during the surgical supply of fresh wounds of the face. It has been demonstrated that weakening of face muscles neighbouring facial wounds leads to a better aesthetic outcome. The reason may be that after the immobilization of the treated muscles the borders of fresh wounds better adapt without muscular tension leading to excellent aesthetic results .
An important, increasing field of application is the use of BTA in different pain syndromes, especially in patients suffering from tension headache, migraine and chronic daily headache (for review see [14, 15]).
Repetitive dystonic contractions of the muscles of the soft palate (palatoglossus and palatopharyngeus muscles, salpingopharyngeus, tensor and levator veli palatini muscles) lead to a rhythmic elevation of the soft palate . This can cause speech and also swallowing disorders due to a velopharyngeal insufficiency. Most patients suffering from palatal tremor complain of "ear clicking". This rhythmic tinnitus is caused by a repetitive opening and closure of the orifice of the Eustachian tube. A particular sequelae of pathological movements of soft palate muscles is the syndrome of a "patulous Eustachian tube" . These patients suffer from "autophonia" caused by an open Eustachian tube due to the increased muscle tension of the paratubal muscles (salpingopharyngeus, tensor and levator veli palatini muscles).
In a first treatment session, the application of five units of Botox® (uni- or bilaterally) into the soft palate is adequate in most cases. If necessary, this can be increased to two times 15 units of Botox®. The application is normally performed transorally (transpalatinal or via postrhinoscopy) under endoscopic control. To optimise the detection of the target muscle, injection under electromyographic control is recommended. To avoid side effects such as iatrogenic velopharyngeal insufficiency the treatment should be started with low doses as described above.
Depending of the kind of movement disorder, botulinun toxin injections into the floor of the mouth, the extrinsic tongue muscles and different jaw muscles have to be done to improve the clinical picture. We avoid injections into intinsic tongue muscles because weakening these muscles may result into relevant side effects like swallowing disorders, speech problems and problems of jawing.
Different approaches for injections are described like the external and internal approach of the pterygoideus medialis muscle as an example.
In the treatment of OMD, we use doses up to 50 units Botox®.
If severe bruxisms does not improve after conventional therapeutic measures, additional injections with botulinum toxin may improve the clinical picture. Injections have to be done into the masseter and temporalis muscles ; doses up to 60 units Botox® per muscle are described. The treatment can be performed using electromyography.
Hypertrophy of the masseter muscle leads to a difference in the symmetry of the face .
The injection can be performed transoral or from outside.
In the literature, injections up to 50 units Botox® into each masseter muscle are recommended.
BTA also is used in patients with a fracture of the jaw for immobilisation of the jaw, in patients with a jaw luxation caused by a hyperactivity of the lateral pterygoid muscle and in patients with a lockjaw.
Based on our expanded experiences literature, we prefer in our patients the ultra-sound-guided injection into the parotid and submandibular gland on each side. We inject into the parotid gland 22.5 units Botox® on each side, distributed on 3 points. The submandibular glands are treated by a ultrasound-guided one or 2-point injection of a total of 15 units Botox® per gland. It has been shown by objective datas in a lot of papers that BTA injections are effective in reducing the saliva flow, accompanied by very few side effects.
Gustatory sweating is a common sequelae following parotid gland surgery [23–28]. The treatment of gustatory sweating with BTA has been described first by our group in 1994 (first treated patient December 1993 [23, 27]) and became the first line treatment option in these patients.
The effectiveness of BTA treatment in patients with gustatory sweating has been confirmed by a lot of other authors. Some patients report a benefit after BTA-injection already at the same day and interestingly, the positive effect remains much longer than in patients with movement disorders . Some patients reach several years of a symptom free interval.
The treatment of hyperhidrosis of the head and/or the face are based on the same principles as described for patients with gustatory sweating. The doses which are reached for each individual patient depend on the size of the sweating area to be treated.
In the last few years, the application of Botulinum toxin type A in patients with intrinsic or allergic rhinitis has been described [32–34]. In experimants the existence of apoptosis of nasal glands has been demonstrated . The main symptom in patients suffering from these diseases is extensive rhinorrhea with secretions dripping from the nose.
For the injection we use 10 units of Botox® for each turbinate (middle and lower nasal turbinates).
With the other technique, the sponges are loaded with a solution containing 40 units of Botox® and one is applied on each side.
Some new developments in the use of BTA in head and face medicine are to mention here (see ). BTA application in patients suffering from tinnitus  or depressions  have been treated with BTA. Further investigations will show whether there is a real hope for clinical use of BTA in these indications.
The application of botulinum toxin type A is a helpful and minimally invasive treatment option in different functional disorders improving the quality of life in patients with head and face disorders of different etiology. Side effects are rare.
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