Oral manifestations of neurological disorders

Sir, The central nervous system and oral cavity have a close anatomical location. At this time, diseases of central nervous system have been extensively studied in various specialties of biomedical sciences like otology, ophthalmology, neurology, neurosurgery, and dentistry. Identification of orofacial manifestations of central nervous system is usually in a direct relation with the liabilities of a dental surgeon. Preventive dental care for patients with neurological disorders needs a specific approach, because of the fact that these patients belong to the category of patients with special needs; all kind of preventive and rehabilitative treatments necessitates well-planned and specific approaches. [1] Neurological disorders affect the orodental tissues in different ways. As mentioned, the common neurocutaneous (phakomatosis) diseases include Sturge-Weber syndrome, tuberous sclerosis, neurofibromatosis of Von Recklinghausen and incontinentia pigmenti. These diseases frequently remain unnoticeable, but have significant direct relationship to oral cavity and orofacial structures. [2] Oral environment may also be severely altered by neoplasias of orofacial nerves and their sheaths (e.g., neurofibroma, neurolemmoma, traumatic neuroma, malignant schwannoma), cranial nerve tumors with orofacial affections (e.g., trigeminal neurinoma, acoustic neurinoma, and olfactory neuroblastoma), and systemic tumors with significant neural and orofacial symptoms (e.g., Gardner's syndrome and multiple endocrine neoplasia syndromes). [3,4,5,6] Parkinson's disease frequently presents unique challenges in establishing and maintaining an effective and efficient dental management approach. People of nearly all ages with Parkinson's disorder encounter similar challenges; but for those who are older, the dilemmas can be particularly serious. The deleterious symptoms of Parkinson's disease pose challenges both for daily home dental hygiene measures and periodic recall visit intraoral examinations. Some of the key components includes; household oral healthcare programs which necessitate muscle-eye coordination, digital dexterity, and tongue-cheek-lip control. [7] Moreover, presence of tremor militate against effective oral hygiene and plaque control measures. Weakened swallowing capability can augment the risk of aspiration (choking) of sophisticated dental instruments. In addition, people with Parkinson's disease who have been on prescriptions like levodopa for several years may begin to develop dyskinesias, which can affect the jaw (where they are called orobuccal dyskinesia) as well as teeth grinding. Individuals suffering from Parkinson's disease may also experience dry mouth or xerostomia, which may be one of the most important aspects with consequences on the dental status and oral mucosa that frequently lead to the worsening of already existing masticatory difficulties or denture anxiety. As the normal salivary flow helps to maintain the integrity of the oral mucosa, reduction of the salivary flow severely compromises the remineralization process of oral hard tissues and new dental caries possibly will easily appear including root surface caries. [8] Dry mouth condition also lowers the resistance of the oral mucous membrane to foreign body invasion. This is especially true for prosthetic trauma caused by loosening of dentures due to lack of saliva which serves as salivary biofilm and is desirable for the perfect adhesion. Orofacial manifestations of neurological diseases have direct relation with dentistry; therefore, dentists should be familiar with those common diseases that exist between neurology and dentistry. [9] The potential overlap of neurological symptoms over dental ones should be thoroughly explored as recognizing them is very important and unfamiliarity with them may be bothersome. [1,10] As a potent drug side effect, dry mouth has been known to be caused by over a hundred medications which necessitates a comprehensive salivary investigation including quality and quantity of saliva, the salivary pH, bacteriological salivary tests, and mycological salivary tests. Such patients are advised to take antimycotic drugs along with regular antibiotic therapy. Topical application of fluoride to teeth is not enough in case of low salivary pH as the efficiency of the fluorine decreases at a pH of 4.5 (the critical pH). [11] Therefore, the regular contacts of tooth surface with acidic foods and the demineralization is not subdued by active fluoride ions. This leads to the imperative role of patient motivation to stay away from strong acidic food. To counterbalance the effects of acidic pH, it is recommended to periodically moisten the oral mucosa with distilled water instead of artificial saliva (where it is possible). Furthermore, the use of pharmaceuticals based on chlorhexidine mouthwash, gels, and toothpaste with baking soda is advocated as they could increase the overall resistive capacity of the whole saliva. [12,13] For physically or mentally handicapped and pediatric patients, the use of electric or sonic toothbrush is usually advocated as an excellent substitute to the normal manual toothbrush. Oral manifestations of neurological diseases fairly exhibit a coherent and reasonable association of these diseases with dentistry. We believe in personalization of dental care for each patient with a neurological disease. Such act must conform to the recommendations for personal oral hygiene, and the recall for dental hygiene in dental clinics with evaluation of overall dental profile, bacteriological and mycological tests, salivary flow estimation and xerostomia diagnosis. Professional applications of dental pharmaceuticals like pit and fissure sealants could help to check the development of dental caries. Moreover, a close communication between the neurologist and the dentist must be established in order to find the best recommendations for the patient and to increase the quality of life for the patients who suffer from neurological diseases. Therefore, to familiarize dental surgeons with these neurological manifestations, it is important for them to learn better recognition, diagnosis, and make correct decisions when treating the manifestations in such patients.