Cerebral Palsy (CP) describes a group of permanent disorders in the development of movement and posture that cause activity limitation, which is associated with non-progressive disorders that occur in the developing fetal or infant brain. CP motor disorders are often followed by impaired sensation, perception, cognition, communication, behavior, epilepsy, and secondary musculoskeletal problems. According to Basic Health Research (Riskesdas) 2018, the prevalence among children ages 24-59 months with CP in Indonesia is 0.16% (0.09-0.28), where tooth decay, periodontal disease, and malocclusion cases are higher compared to the general population. Oral treatment in patients with CP requires modification and different approaches due to their disability. Permanent disorder in motor skills causes muscle weakness, muscle stiffness, paralysis, and uncoordinated movements that require assistance from others to maintain their oral health.
Factors that cause the high prevalence of dental and oral health problems in CP children are the consistency of the food consumed, the carbohydrates intake in teeth per day, difficulty chewing and swallowing food or drink due to oral motor dysfunction, difficulty in cleaning the oral cavity due to the biting reflex, long-term use of drugs with potential for decreased salivary secretion (xerostomia) and problems associated with dental management. The most recent study mentioned that saliva, being the biological matrix, can be used as a biomarker to prevent and diagnose diseases. Specifically, protein and peptides in the saliva play an important role in balancing the demineralization and remineralization of enamel in the oral cavity which causes teeth decay and other oral diseases.
Protein total and α-amylase are used as the biomarkers for prevention and diagnosing oral cavity diseases (Caries Risk Assessment). The decreased salivary flow rate, increased osmolality, and total protein concentration in CP patients which caused by hypohydration. Hypohydration in CP children due to lack of water intake caused by CP children is very dependent on the initiative of caregivers or parents to provide water, as well as reduced swallowing ability due to oral motor dysfunction. In addition, the hypohydration condition in CP children, due to body water deficit, was caused by the parents’ or caregiver’s initiatives to give them water and the motor dysfunction to swallow. Besides, hypohydration in CP children was also caused by disorders of the hypothalamus that result in an electrolyte imbalance in the body and reduce their sensitivity to thirst.
Salivary proline-rich protein is the first line of defense against oxidative stress (OE), Reactive Oxygen Species (ROS), and free radicals which have an antimicrobial activity to prevent infection with their viscoelastic character, especially salivary mucin which contains complex carbohydrates and disrupt the microorganism adhesion to the mucosa. Besides, it functions as a permeability barrier to tissue damage, lubrication or lubrication of oral mucosal surface, concentrating antimicrobial molecules on the surface of the oral mucosa and modulating the colonization of bacteria, fungi, and viruses.
The increasing salivary total protein was caused by permanent damage to the central neuron system (CNS) in children with CP which impact the Autonomic Nervous System (ANS) and Peripheral Neuro System (PNS). Thus, it affects the work of the sympathetic and parasympathetic nervous systems and disrupts motor, sensory functions, and salivary flow rate. The decreased saliva flow rate in children with CP results in the electrolyte level of salivary gland acinar cells in the process of primary salivary secretion, thereby interfering with the reabsorption of Na+, Cl- and affecting the quality of the saliva secreted in the oral cavity. This causes a decrease in the viscoelastic protein and an increase in the total salivary protein.
The α-amylase is one of the major salivary proteins that appear as a total isoenzyme, with 10-20% of the protein total, it is common to find in the saliva as it becomes the innate defense system of the oral mucosa and antimicrobial properties that prevent the adhesion of bacteria to the teeth and mucosa. The specific bond is the attraction with microorganisms (cariogenic and periodontal pathogenic) to form agglomerates that are easily soluble by saliva when swallowing which causes an acidic atmosphere in the stomach and can affect the balance of demineralization-remineralization of tooth enamel.
The decreased α-amylase is affected by the salivary flow rate and secretions from the parotid gland under the β-adrenergic stimulation. Human studies have shown that the autonomic nervous system (ANS) plays an important role in the secretion of α-amylase and involves both α and β-Adrenergic mechanisms. ANS disorders in children with CP cause damage to the parasympathetic sympathetic nerves which will disrupt the release of Norepinephrine (NE) at the nerve endings of the salivary glands, so that the concentration of norepinephrine decreases. This causes β-adrenoreceptors in salivary glands, glandular ducts, and vascular beds unable to bind to NE, thus affecting the secretion of α-amylase to decrease. A decrease in α-amylase results in a decrease in its function as an antimicrobial enzyme and interferes with the glucokinase process, resulting in an imbalance of demineralization-remineralization in the long term which will increase the incidence of dental caries and periodontal disease. Decreased α-amylase was caused by limited physical activity, as a study mentioned that levels of α-amylase increase in response to physical stressors or physical activity.
Research in molecular biology states that α-amylase is also used as a biomarker to identify several diseases in the oral cavity, including Recurrent Aphthous stomatitis (RAS) and Burning mouth syndrome (Glossodynia). From these data, it can be correlated that a decrease in α-amylase salivary affects the incidence and prevalence of caries and diseases in the oral cavity of children with CP. It is corroborated by several studies which state that the prevalence of dental caries and periodontal disease in children with CP is higher than in normal children.
Recent studies have shown that children with CP have more acidic saliva compared to normal children, supported by the research result which mention that the deft score and DMFT of children with CP are significantly higher compared to the normal children, whereas the correlation between pH saliva and tooth decay in the primary teeth of children with cerebral palsy was found. This is supported by a recent study that states that variations in the salivary electrolyte concentration of children with cerebral palsy can be a factor causing an increased risk of developing tooth decay and having a negative impact on their quality of life. So this is in accordance with the hypothesis that there is a relationship between total protein and salivary α-amylase on the incidence of caries.
Author: Mega Moeharyono Puteri
Lecturer staf Departement of Pediatric Dentistry, Airlangga University-Surabaya- Indonesia
