**5. Management of sialorrhea**

The management of sialorrhea continues to be a challenge in spite of various effective treatment strategies to diminish saliva production. The flow of saliva from the oral cavity to the esophagus depends on numerous factors, such as cognitive and mental abilities, intact swallowing, oral sensibility, lip closure, and ability to keep the head upright [1].

Treatment of sialorrhea is best accomplished with a multidisciplinary team approach. The complete history and physical examination of the patient, the assessment of the impact of drooling on quality of life, and the potential for improvement can be undertaken by the primary care physicians. Speech pathologists and occupational therapists provide education for swallowing mechanics to the patients and support their posture with devices such as the head back wheelchair. Dentists and orthodontists identify and correct dental and oral diseases and malocclusion. Otolaryngologists diagnose and treat causes of aerodigestive obstruction like macroglossia and adenotonsillar hypertrophy that contribute to drooling. Neurologists assess the severity and prognosis of neurologic conditions that result in drooling [3].

**5.1. Pharmacological therapy**

Oral therapy for sialorrhea encompasses the use of anticholinergic agents such as glycopyrrolate, benztropine, scopolamine, and tropicamide. Anticholinergic agents work by downregulating acetylcholine and ultimately decreasing saliva secretion through the parasympathetic autonomic nervous system. Glycopyrrolate oral solution is an anticholinergic agent that was the first drug approved in the United States for drooling in children with neurologic conditions and is generally well tolerated. However, anticholinergic agents are poorly tolerated by elderly patients. Glycopyrrolate actually has lower risk of central side effects, owing to its quaternary ammonium structure, that makes it impossible to pass the blood–brain barrier in large amounts. It is effective and safe at 1 mg, 3 times a day [2]. Studies have shown 70–90% response rates, but approximately 30–35% of patients discontinue the drug due to side effects such as excessive dry mouth, urinary retention, decreased sweating, skin flushing, irritability, and behavior changes [10]. Other undesirable adverse effects observed with such treatment include constipation, urinary retention, tiredness, and drowsiness [11]. Anticholinergics are contraindicated in patients with glaucoma, obstructive uropathy, gastrointestinal motility disorders, and myasthenia gravis. Intraoral tropicamide films provide short-term relief of sialorrhea. One study provided evidence that 1 mg of tropicamide resulted in significant visual analog scale score decrease and reduction in saliva volume in nondemented PD patients [2]. Transdermal scopolamine, applied as a patch behind the ear, was well tolerated in short-term studies, but its use was

Sialorrhea: A Guide to Etiology, Assessment, and Management

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43

A comprehensive systematic review of the use of anticholinergics in children concluded that benztropine, given 3–3.8 mg per day, could be effective. A significant decrease in the mean score for drooling was reported with benzhexol hydrochloride (2 × 2 up to 2 × 3 mg daily). There was also some evidence for a marked decrease in drooling with glycopyrrolate [13]. Benztropine was also reported to show a significant reduction in the total salivation scores compared to botulinum toxins A and B in a study of mixed treatment network meta-analysis of randomized controlled trials on pharmacological interventions for treating sialorrhea asso-

Antireflux medication has also been suggested for use in drooling; however, there are no

The injection of botulinum toxin (BT) to the major salivary glands has grown in popularity because of its limited invasiveness and demonstrated effectiveness in many patients. It has been shown to improve quality of life of patients effectively with a low profile of side effects. However, it is important to take into account that the duration of the therapeutic effect is

The effect of BT in sialorrhea was first reported in PD patients [15]. This toxin is a potent neurotoxin that blocks the release of acetylcholine and a number of other neurotransmitters from synaptic vesicles; hence, it shows its effect by blocking cholinergic postganglionic para-

double-blind studies in the literature to offer evidence for this recommendation [2].

limited by side effects of urinary retention and blurred vision [3].

ciated with neurological disorders [14].

sympathetic fibers in sialorrhea [2].

limited in time, generally lasting a few months [11].

**5.2. Botulinum toxin**

The goal of the treatment of drooling is a reduction in excessive salivary flow, while maintaining a moist and healthy oral cavity. Avoidance of xerostomia (dry mouth) is essential. The two main approaches are:


Generally, no single approach is adequately effective, and usually, a combination of therapies is used. Primarily, reversible causes of drooling should be treated. Less invasive and reversible methods are preferred before surgery is undertaken [10]. Behavioral approaches and therapies employed by speech pathologists are rarely curative, while systemic medications and surgical approaches may have severe and long-term adverse effects [1].

For minimal problems, in children younger than 4 years of age or in adults with unstable neurologic function, observation may be the convenient choice. Minimal issues can be handled with a feeding program aimed at improving oral-motor control as well; nevertheless, this can rarely be helpful. Anatomical problems should be identified and treated, and adenotonsillectomy should be undertaken, if necessary. Dental malocclusion and caries should be corrected. Patients should be fitted with appropriate wheelchairs and braces, when required. A number of orthodontic appliances may be used, such as customized plates that fit the palate for improving lip closure or movable beads placed on the upper plate that stimulate tongue movement, thus helping to deflect saliva toward the pharynx [3].

Other conservative therapeutic options include positioning techniques, oral-motor, and speech therapies given by speech therapists, which improve oral awareness and motor control. Biofeedback and automatic cueing techniques may be utilized in patients with mild neurologic dysfunction and drooling. These devices are used to associate a behavior with a cue, such as swallowing or wiping the face with a beep sound. Reinforcement methods, which are suggested behaviors such as encouraging patients for swallowing and wiping their faces and discouraging open mouth, can be used as an adjunct in moderate sialorrhea [3, 10].

Whenever sialorrhea continues to affect the patient's health and quality of life in spite of these conservative measures, pharmacological therapy and other invasive therapies should be considered.

#### **5.1. Pharmacological therapy**

Treatment of sialorrhea is best accomplished with a multidisciplinary team approach. The complete history and physical examination of the patient, the assessment of the impact of drooling on quality of life, and the potential for improvement can be undertaken by the primary care physicians. Speech pathologists and occupational therapists provide education for swallowing mechanics to the patients and support their posture with devices such as the head back wheelchair. Dentists and orthodontists identify and correct dental and oral diseases and malocclusion. Otolaryngologists diagnose and treat causes of aerodigestive obstruction like macroglossia and adenotonsillar hypertrophy that contribute to drooling. Neurologists assess

The goal of the treatment of drooling is a reduction in excessive salivary flow, while maintaining a moist and healthy oral cavity. Avoidance of xerostomia (dry mouth) is essential. The two

**1.** Noninvasive modalities including positioning, improving eating and drinking skills, oral facial facilitation, speech therapy, biofeedback, positive and negative reinforcement, oral

Generally, no single approach is adequately effective, and usually, a combination of therapies is used. Primarily, reversible causes of drooling should be treated. Less invasive and reversible methods are preferred before surgery is undertaken [10]. Behavioral approaches and therapies employed by speech pathologists are rarely curative, while systemic medications

For minimal problems, in children younger than 4 years of age or in adults with unstable neurologic function, observation may be the convenient choice. Minimal issues can be handled with a feeding program aimed at improving oral-motor control as well; nevertheless, this can rarely be helpful. Anatomical problems should be identified and treated, and adenotonsillectomy should be undertaken, if necessary. Dental malocclusion and caries should be corrected. Patients should be fitted with appropriate wheelchairs and braces, when required. A number of orthodontic appliances may be used, such as customized plates that fit the palate for improving lip closure or movable beads placed on the upper plate that stimulate tongue

Other conservative therapeutic options include positioning techniques, oral-motor, and speech therapies given by speech therapists, which improve oral awareness and motor control. Biofeedback and automatic cueing techniques may be utilized in patients with mild neurologic dysfunction and drooling. These devices are used to associate a behavior with a cue, such as swallowing or wiping the face with a beep sound. Reinforcement methods, which are suggested behaviors such as encouraging patients for swallowing and wiping their faces and

Whenever sialorrhea continues to affect the patient's health and quality of life in spite of these conservative measures, pharmacological therapy and other invasive therapies should

discouraging open mouth, can be used as an adjunct in moderate sialorrhea [3, 10].

the severity and prognosis of neurologic conditions that result in drooling [3].

prosthetic devices, pharmacological therapy, and botulinum toxin

and surgical approaches may have severe and long-term adverse effects [1].

movement, thus helping to deflect saliva toward the pharynx [3].

**2.** Invasive modalities including surgery and radiotherapy

42 Salivary Glands - New Approaches in Diagnostics and Treatment

main approaches are:

be considered.

Oral therapy for sialorrhea encompasses the use of anticholinergic agents such as glycopyrrolate, benztropine, scopolamine, and tropicamide. Anticholinergic agents work by downregulating acetylcholine and ultimately decreasing saliva secretion through the parasympathetic autonomic nervous system. Glycopyrrolate oral solution is an anticholinergic agent that was the first drug approved in the United States for drooling in children with neurologic conditions and is generally well tolerated. However, anticholinergic agents are poorly tolerated by elderly patients. Glycopyrrolate actually has lower risk of central side effects, owing to its quaternary ammonium structure, that makes it impossible to pass the blood–brain barrier in large amounts. It is effective and safe at 1 mg, 3 times a day [2]. Studies have shown 70–90% response rates, but approximately 30–35% of patients discontinue the drug due to side effects such as excessive dry mouth, urinary retention, decreased sweating, skin flushing, irritability, and behavior changes [10]. Other undesirable adverse effects observed with such treatment include constipation, urinary retention, tiredness, and drowsiness [11]. Anticholinergics are contraindicated in patients with glaucoma, obstructive uropathy, gastrointestinal motility disorders, and myasthenia gravis.

Intraoral tropicamide films provide short-term relief of sialorrhea. One study provided evidence that 1 mg of tropicamide resulted in significant visual analog scale score decrease and reduction in saliva volume in nondemented PD patients [2]. Transdermal scopolamine, applied as a patch behind the ear, was well tolerated in short-term studies, but its use was limited by side effects of urinary retention and blurred vision [3].

A comprehensive systematic review of the use of anticholinergics in children concluded that benztropine, given 3–3.8 mg per day, could be effective. A significant decrease in the mean score for drooling was reported with benzhexol hydrochloride (2 × 2 up to 2 × 3 mg daily). There was also some evidence for a marked decrease in drooling with glycopyrrolate [13]. Benztropine was also reported to show a significant reduction in the total salivation scores compared to botulinum toxins A and B in a study of mixed treatment network meta-analysis of randomized controlled trials on pharmacological interventions for treating sialorrhea associated with neurological disorders [14].

Antireflux medication has also been suggested for use in drooling; however, there are no double-blind studies in the literature to offer evidence for this recommendation [2].

#### **5.2. Botulinum toxin**

The injection of botulinum toxin (BT) to the major salivary glands has grown in popularity because of its limited invasiveness and demonstrated effectiveness in many patients. It has been shown to improve quality of life of patients effectively with a low profile of side effects. However, it is important to take into account that the duration of the therapeutic effect is limited in time, generally lasting a few months [11].

The effect of BT in sialorrhea was first reported in PD patients [15]. This toxin is a potent neurotoxin that blocks the release of acetylcholine and a number of other neurotransmitters from synaptic vesicles; hence, it shows its effect by blocking cholinergic postganglionic parasympathetic fibers in sialorrhea [2].

Currently, three type A and one type B toxin are approved for use in the US. These are OnabotulinumtoxinA (BOTOX®), AbobotulinumtoxinA (Dysport®), IncobotulinumtoxinA (Xeomin®), and RimabotulinumtoxinB (Neurobloc®/myobloc®) [2]. Both A and B types of BT are reported to be effective in treatment of sialorrhea, and both have a low profile of side effects [1].

well to BT injections can be treated more efficiently with surgery rather than receiving multiple injections. On the other hand, patients who do not respond well to BT may be considered as poor candidates for surgical treatment, because failure rates could be much higher owing

Sialorrhea: A Guide to Etiology, Assessment, and Management

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45

Radiation therapy to the salivary glands is a useful treatment option in elderly patients who are not candidates for surgery and cannot tolerate medications. Radiation causes xerostomia that lasts months to years. The dose may be changed to produce the desired effect, and it can be repeated if required. The main problem is that radiation can induce malignancies, but this does not happen until 10–15 years after treatment and therefore are less of a concern in

While many patients are successfully treated with conservative methods and medical therapies, a number of patients are not able to tolerate the side effects of medications. BT treatment is reported to show improvement in drooling, but surgery provides a larger and longer lasting effect. Surgeons should consider more aggressive interventions for patients with chronic sialorrhea secondary to neuromuscular dysfunction with the impairment of swallowing. In these cases, sublingual or submandibular gland excision, submandibular duct ligation, parotid duct ligation, submandibular or parotid duct rerouting, or any combination of the above procedures result in higher rates of success, both short term and long term, and they may be cost-effective compared to BT injections requiring multiple visits [18]. Nevertheless, it is important to mention that surgery has a risk of permanent consequences (especially xerostomia), and that it should be preferred only in severe cases who are not responsive to nonsurgical therapies and in whom sialorrhea has great impact on the health and quality of

Tympanic neurectomy is now regarded as a historical technique used to denervate salivary glands. This technique is performed through the middle ear, where the tympanic plexus and chorda tympani travel before entering the major salivary glands. The procedure is relatively simple and fast, but salivary function returns within 6–18 months, when nerve fibers regener-

Recently, a novel procedure, transoral endoscopic submandibular ganglion neurectomy, was performed in two cases of BT-resistant drooling. Six months follow-up was successful; how-

The most definitive treatment of sialorrhea is to excise the major salivary glands or to ligate or reroute the major salivary ducts. Surgical management can be described by a combination parotid duct ligation or rerouting with either submandibular gland excision or submandibular duct rerouting. Preservation of salivation with decrease in drooling could be accomplished by rerouting of the parotid and submandibular ducts to the posterior oropharynx with the advantage of no external scar. There may be a potential for aspiration after these procedures. Sublingual gland

to the contribution from minor salivary glands to the etiology of sialorrhea [17].

**5.3. Radiation therapy**

**5.4. Surgical treatment**

patients who are elderly and debilitated [3].

life of the individual and caregivers [5].

ever, long-term results are awaiting to be warranted [19].

ate [3, 17].

BT can be injected in parotid and/or submandibular glands. The dose, concentration, and volume of injectate, number of injections, injection site, rate of injection, gauge of needle, and distance of needle tip from the neuromuscular junction are among the factors that can affect the diffusion and spread of BT, thus its efficacy in sialorrhea. A broad dose range of BT has been reported in various studies, specifically from 10 to 100 U of Botox®, from 20 to 300 U of Dysport® per patient, while usually 2500 U of Neurobloc® per patient is reported to be injected. The effect of BT on salivation lasts for 1.5–6 months [11]. Older age is significantly associated with longer benefit duration [16]. Sometimes the reduction in salivary secretion and improvement in drooling may not be correlated, owing to the variability of the factors that influence the severity of drooling and reduction of saliva secretion [2]. Patients with PD showed a more favorable safety-efficacy ratio than did patients with ALS, due to lower adverse events and longer benefit duration [16].

In a recent meta-analysis, eight randomized placebo-controlled trials involving 181 patients were reviewed. The study reported that BT improved drooling severity in patients with sialorrhea significantly in both adult and pediatric populations. Increased saliva thickness (3.9%), dysphagia (3.3%), xerostomia (3.3%), and pneumonia (2.2%) were reported as common side effects [1]. Adverse effects such as chewing difficulties and recurrent mandibular luxation have been reported [11]. BT therapy is reported to have many advantages over other noninvasive and invasive treatments. It is effective and minimally invasive with few side effects and a low risk of aspiration. However, it is expensive and temporary, and the need for repeated sedation can be troublesome with children [2].

Ultrasound guidance for intraglandular injection is preferred by some of the authors. Blind puncture of the superficial lobe of the parotid gland following anatomical landmarks is easier, because the structure is relatively superficial. Since the submandibular glands are normally nonpalpable, infiltration may be more challenging. Ultrasound easily identifies the glandular structures for infiltration, while avoiding accidental damage to other anatomical structures, the facial nerve in the case of injection into the parotid gland, or the facial vessels in the case of the submandibular gland [11].

Jongerius et al. compared the efficacy of BT injections to transdermal scopolamine. They reported that even though both treatments were successful in significantly lowering drooling parameters, patients treated with BT did not experience any side effects, while 40% of patients taking scopolamine reported severe adverse effects. The wide range of side effects and potential drug–drug interactions encountered with scopolamine and glycopyrrolate suggests that BT may be a safer option compared to systemic anticholinergics [13].

BT can also be used for empirical selection of patients who would, in the future, be good candidates for surgical treatment of the major salivary glands. In this way, patients who respond well to BT injections can be treated more efficiently with surgery rather than receiving multiple injections. On the other hand, patients who do not respond well to BT may be considered as poor candidates for surgical treatment, because failure rates could be much higher owing to the contribution from minor salivary glands to the etiology of sialorrhea [17].

#### **5.3. Radiation therapy**

Currently, three type A and one type B toxin are approved for use in the US. These are OnabotulinumtoxinA (BOTOX®), AbobotulinumtoxinA (Dysport®), IncobotulinumtoxinA (Xeomin®), and RimabotulinumtoxinB (Neurobloc®/myobloc®) [2]. Both A and B types of BT are reported to be effective in treatment of sialorrhea, and both have a low profile of side

BT can be injected in parotid and/or submandibular glands. The dose, concentration, and volume of injectate, number of injections, injection site, rate of injection, gauge of needle, and distance of needle tip from the neuromuscular junction are among the factors that can affect the diffusion and spread of BT, thus its efficacy in sialorrhea. A broad dose range of BT has been reported in various studies, specifically from 10 to 100 U of Botox®, from 20 to 300 U of Dysport® per patient, while usually 2500 U of Neurobloc® per patient is reported to be injected. The effect of BT on salivation lasts for 1.5–6 months [11]. Older age is significantly associated with longer benefit duration [16]. Sometimes the reduction in salivary secretion and improvement in drooling may not be correlated, owing to the variability of the factors that influence the severity of drooling and reduction of saliva secretion [2]. Patients with PD showed a more favorable safety-efficacy ratio than did patients with ALS, due to lower

In a recent meta-analysis, eight randomized placebo-controlled trials involving 181 patients were reviewed. The study reported that BT improved drooling severity in patients with sialorrhea significantly in both adult and pediatric populations. Increased saliva thickness (3.9%), dysphagia (3.3%), xerostomia (3.3%), and pneumonia (2.2%) were reported as common side effects [1]. Adverse effects such as chewing difficulties and recurrent mandibular luxation have been reported [11]. BT therapy is reported to have many advantages over other noninvasive and invasive treatments. It is effective and minimally invasive with few side effects and a low risk of aspiration. However, it is expensive and temporary, and the need for repeated

Ultrasound guidance for intraglandular injection is preferred by some of the authors. Blind puncture of the superficial lobe of the parotid gland following anatomical landmarks is easier, because the structure is relatively superficial. Since the submandibular glands are normally nonpalpable, infiltration may be more challenging. Ultrasound easily identifies the glandular structures for infiltration, while avoiding accidental damage to other anatomical structures, the facial nerve in the case of injection into the parotid gland, or the facial vessels in the case

Jongerius et al. compared the efficacy of BT injections to transdermal scopolamine. They reported that even though both treatments were successful in significantly lowering drooling parameters, patients treated with BT did not experience any side effects, while 40% of patients taking scopolamine reported severe adverse effects. The wide range of side effects and potential drug–drug interactions encountered with scopolamine and glycopyrrolate suggests that

BT can also be used for empirical selection of patients who would, in the future, be good candidates for surgical treatment of the major salivary glands. In this way, patients who respond

BT may be a safer option compared to systemic anticholinergics [13].

effects [1].

adverse events and longer benefit duration [16].

44 Salivary Glands - New Approaches in Diagnostics and Treatment

sedation can be troublesome with children [2].

of the submandibular gland [11].

Radiation therapy to the salivary glands is a useful treatment option in elderly patients who are not candidates for surgery and cannot tolerate medications. Radiation causes xerostomia that lasts months to years. The dose may be changed to produce the desired effect, and it can be repeated if required. The main problem is that radiation can induce malignancies, but this does not happen until 10–15 years after treatment and therefore are less of a concern in patients who are elderly and debilitated [3].

## **5.4. Surgical treatment**

While many patients are successfully treated with conservative methods and medical therapies, a number of patients are not able to tolerate the side effects of medications. BT treatment is reported to show improvement in drooling, but surgery provides a larger and longer lasting effect. Surgeons should consider more aggressive interventions for patients with chronic sialorrhea secondary to neuromuscular dysfunction with the impairment of swallowing. In these cases, sublingual or submandibular gland excision, submandibular duct ligation, parotid duct ligation, submandibular or parotid duct rerouting, or any combination of the above procedures result in higher rates of success, both short term and long term, and they may be cost-effective compared to BT injections requiring multiple visits [18]. Nevertheless, it is important to mention that surgery has a risk of permanent consequences (especially xerostomia), and that it should be preferred only in severe cases who are not responsive to nonsurgical therapies and in whom sialorrhea has great impact on the health and quality of life of the individual and caregivers [5].

Tympanic neurectomy is now regarded as a historical technique used to denervate salivary glands. This technique is performed through the middle ear, where the tympanic plexus and chorda tympani travel before entering the major salivary glands. The procedure is relatively simple and fast, but salivary function returns within 6–18 months, when nerve fibers regenerate [3, 17].

Recently, a novel procedure, transoral endoscopic submandibular ganglion neurectomy, was performed in two cases of BT-resistant drooling. Six months follow-up was successful; however, long-term results are awaiting to be warranted [19].

The most definitive treatment of sialorrhea is to excise the major salivary glands or to ligate or reroute the major salivary ducts. Surgical management can be described by a combination parotid duct ligation or rerouting with either submandibular gland excision or submandibular duct rerouting. Preservation of salivation with decrease in drooling could be accomplished by rerouting of the parotid and submandibular ducts to the posterior oropharynx with the advantage of no external scar. There may be a potential for aspiration after these procedures. Sublingual gland excision is suggested as well when the submandibular ducts are rerouted to prevent formation of salivary retention cysts. Parotid duct ligation is a simple fast procedure without an external scar, which decreases the stimulated salivary flow. There may be a risk of sialocele development. The most definitive surgical procedure, which includes bilateral parotid duct ligation and submandibular gland excision, is highly successful, with nearly total elimination of sialorrhea, a low incidence of facial weakness, and significant patient and caregiver satisfaction [3].

[5] Young CA, Ellis C, Johnson J, Sathasivam S, Pih N. Treatment for sialorrhea (excessive saliva) in people with motor neuron disease/amyotrophic lateral sclerosis. Cochrane

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[6] Srivanitchapoom P, Pandey S, Hallett M. Drooling in Parkinson's disease: A review.

[7] Thaxter Nesbeth KA, Samuels LA, Nicholson Daley C, Gossell-Williams M, Nesbeth DA. Ptyalism in pregnancy—a review of epidemiology and practices. European Journal

[9] Bird AM, Smith TL, Walton AE. Current treatment strategies for clozapine-induced sial-

[10] Bavikatte G, Sit PL, Hassoon A. Management of drooling of saliva. British Journal of

[11] Fuster Torres MA, Berini Aytés L, Gay Escoda C. Salivary gland application of botulinum toxin for the treatment of sialorrhea. Medicina Oral, Patología Oral y Cirugía Bucal.

[12] Thomas-Stonell N, Greenberg J. Three treatment approaches and clinical factors in the

[13] Jongerius PH, van Tiel P, van Limbeek J, Gabreëls FJ, Rotteveel JJ. A systematic review for evidence of efficacy of anticholinergic drugs to treat drooling. Archives of Disease in

[14] Sridharan K, Sivaramakrishnan G. Pharmacological interventions for treating sialorrhea associated with neurological disorders: A mixed treatment network meta-analysis of

[15] Pal PK, Calne DB, Calne S, Tsui JK. Botulinum toxin A as treatment for drooling saliva in

[16] Petracca M, Guidubaldi A, Ricciardi L, Ialongo T, Del Grande A, Mulas D, et al. Botulinum toxin A and B in sialorrhea: Long-term data and literature overview. Toxicon.

[17] Reed J, Mans CK, Brietzke SE. Surgical management of drooling: A meta-analysis.

[18] Formeister EJ, Dahl JP, Rose AS. Surgical management of chronic sialorrhea in pediatric patients: 10-year experience from one tertiary care institution. International Journal of

[19] Ozturk K, Erdur O, Gul O, Olmez A. Feasibility of endoscopic submandibular ganglion

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The meta-analysis of surgical management using a variety of surgical procedures demonstrates significant subjective relief in 81.6% of pediatric patients with sialorrhea following surgery. Bilateral submandibular gland excision and parotid duct rerouting had the highest reported success rate of 87.8%. However, simple bilateral submandibular duct rerouting and bilateral submandibular duct rerouting with bilateral parotid duct ligation had similar levels of subjective success. Four-duct ligation had the lowest success rate at 64.1%. Although this procedure seems simpler and less invasive compared to other surgeries, it can cause significant pain and swelling, since the ligated glands continue to produce saliva for a period before atrophy occurs. Bilateral submandibular duct rerouting is a procedure that is more complex than a simple submandibular duct ligation. The reported success rates with this procedure are consistently good and similar to procedures involving submandibular gland excision. Limited data suggest that fibrosis of the gland occurs due to obstruction of the rerouted duct, ending up as an actual ligation of the duct, but in most of the patients, function is maintained in at least one gland [17].
