Multiple sclerosis is a chronic demyelinating disorder that primarily affects the myeline covering of neurons of the central nervous system.
1. Role of Dentist in Multiple Sclerosis
The role of a dentist in the management of MS starts with the identification of MS in an undiagnosed case. The identification is generally based on history and clinical examination. Typical presentation includes a facial pain of unknown origin, tingling or numbness of the extremities, disturbances in vision, and muscle weakness. The above symptoms seen in a young female with a progressive nature of symptoms forms the ground for further investigation into MS. Hence, proper identification and later referral to a specialist for confirmation of diagnosis and management is the primary role of a dentist 
2. Dental Treatment Considerations
Maintaining oral health and providing dental treatment poses a challenge in patients with MS. Firstly, the daily oral hygiene is compromised due to muscle weakness and pain. In addition to that, long periods of fatigue and mobility impairment imposes a barrier for MS patients to travel to receive dental treatment. Also, a lack of knowledge among dentists to manage this group of patients contributes to the situation 
Delivery of dental treatment depends primarily on three factors, namely, current phase of disease, degree of motor impairment, and level of fatigue. Elective dental treatment is not advisable during the relapse phase of the disease, whereas the ideal time to provide treatment is during the remission phase. The emergency treatment must be performed with caution as the medications prescribed for MS can have dental implications 
. Anticholinergic and tricyclic antidepressants cause dryness of mouth, resulting in a burning sensation. In extreme cases, salivary substitutes or pilocarpine can be prescribed for relief 
Patients with stable disease symptoms and reduced muscle spasm can be good candidates for dental treatment. However, patients exhibiting advance stages of MS with pronounced muscle spasm pose difficulties, including the need of support while sitting and rising from the dental chair, being non-ideal subjects for prosthetic and reconstructive treatment, and difficulty in maintaining daily oral hygiene 
. MS patients typically experience maximum fatigue in the afternoon, so it is advisable to arrange short morning appointments.
The use of local anesthesia with a vasoconstrictor does not impose any additional threat; however, the use of nitrous oxide is controversial, as it may cause demyelination 
. Generally, MS patients might be undergoing long-term corticosteroid therapy, hence alteration/supplementation of corticosteroids should be considered before stressful dental procedures. Implementation of stress reduction protocol will be beneficial for MS patients 
According to the literature, periodontal diseases are more prevalent in MS patients, and in many cases, this might be the presenting complaint for the dentist. Gingival inflammation and eventual progression of periodontal diseases will compromise the quality of life. Timely assessment of periodontal health through clinical and biochemical means and intervention is of utmost importance. Depending on the severity of the case and medical status of the patient, the treatment plan should be tailored for every patient. To begin with non-surgical periodontal therapy along with a prescription of herbal or CHX mouthwash is practiced 
. Only after the resolution of the disease and inflammation is the sub-gingival therapy instituted. A strict follow-up is key to successful management.
3. Oral Manifestations
The first signs and symptoms of MS may be initially seen in the orofacial area, including dysarthria, Lhermitte’s sign (electrical sensation down the spine on neck flexion), visual disturbances, facial numbness or pain, and facial palsy or spasm. Additionally, trigeminal neuralgia, glossopharyngeal neuralgia, neuropathy, burning, tingling, and reduced sensation in the affected regions are also seen as initial or presenting complaints 
In a large sample of MS patients (500 patients), 88.6% of the patients had orofacial clinical manifestations that included visual disorders (80.4%), TMJ disorders (58.2%), dysarthria (42.1%), dysphagia (26.6%), facial palsy (19%), and trigeminal neuralgia (7.9%) 
. A brief list of studies that reported oral manifestations are mentioned in Table 1
Table 1. Search strategy used for different databases.
||“Multiple Sclerosis” [Mesh] OR “Demyelinating Autoimmune Diseases, CNS” [Mesh] OR “relapsing–remitting” [tw] AND “Oral Manifestations” [Mesh] OR “Oral Health” [Mesh] OR Mouth [tw] OR “oral health care” [tw] OR “oral mucous irritation” [tw]
||(TITLE-ABS-KEY (multiple AND sclerosis) AND TITLE-ABS-KEY (oral AND mucous AND irritation) OR TITLE-ABS-KEY (trismus) OR TITLE-ABS-KEY (xerostomia) OR TITLE-ABS-KEY (gingivitis))
||multiple sclerosis in Title Abstract Keyword AND trismus in Title Abstract Keyword OR oral mucosal irritation in Title Abstract Keyword OR gingivitis in Title Abstract Keyword OR xerostomia in Title Abstract Keyword—(Word variations have been searched)
There are several oral manifestations seen in MS, which can be either as a result of the disease or can be due to the effect of medications taken for the treatment of MS. The most common oral symptoms include trigeminal neuralgia (TN), oral and perioral paresthesia, and dysarthria. TN is seen to be 400 times more likely to occur in MS patients, and is managed with carbamazepine, clonazepam, gabapentin, or a surgical approach in recalcitrant cases 
According to a few reported cases, TMJ disorders are also seen in MS, in addition to other types of orofacial pain, such as TN. Patients with TMJ disorder generally present with pain originating around the TMJ, such as in the pre- or post-auricle area, and is transferred onto the orofacial and neck region, including temporal, occipital, malar, and cervical regions. The pain can involve either side or bilateral with varying severity 
. Dysarthria is another common manifestation in MS. It includes scanning type of speech and difficulty while eating, swallowing, and speech 
Other oral manifestations include periodontal disease, including gingival inflammation. Furthermore, increased prevalence of dental caries, possibly due to xerostomia, are also prevalent oral findings among this group of patients 
. Additionally, inability to maintain oral hygiene might also be the possible reason for higher prevalence of dental caries and periodontal diseases.
MS patients also exhibit xerostomia due to the disease process and prescribed medications, including tricyclic antidepressants, anticonvulsants, and proton pump inhibitors. This leads to high caries rates, which become evident with high DMFT, halitosis, and functional difficulties