Abstract
Cerebral palsy (CP) is the most common permanent motor disorder in childhood and can affect patient’s daily activities. CP is often associated with epilepsy, mental retardation, sight and hearing impairment and persistent primitive reflexes. Aetiology is multifactorial, including pre-, peri-, and postnatal causes. CP itself does not cause oral health problems, but dental caries, periodontal disease, sialorrhea, dental trauma and malocclusion are more common or more severe in CP patients than in the general population. Lack of correct oral hygiene due to severe motor incoordination, soft diet and sweetened medication are a few of the most frequent causes of these oral health problems.
Dental management of CP patients is a challenge and should be based upon good collaboration between dental practitioner, family and physician. Setting up a Dental Home early in CP patients’ life can help establish a good relationship with the dental team, oral issues can be intercepted early and as a result treatment needs shall be less complex and therefore more likely to be delivered under common circumstances. Dental treatment in office should be adapted in accordance with the patient’s possibility of collaboration and general health conditions. For completely uncooperative patients or when complex treatment is required, sedation or general anaesthesia can be a solution.
Prevention is the key in the dental management of patients with CP. Early and correct information of caregivers, application of personalised preventive means and regular dental check-ups can most efficiently be carried out within the Dental Home concept.
Keywords: cerebral palsy, oral health, prevention
Introduction
Cerebral palsy (CP) is a chronic neuromuscular condition characterised by motor abnormalities and functional impairments [1]. It is the most common severe motor disability in children and affects 2 to 2.5 per 1000 new-borns [2]. Premature children have 10 times higher risk, while underweight children have 25 times higher risk of developing CP [3]. CP is usually diagnosed at birth [4]. Spastic tetraparesis is the most severe form of CP [3], while dyskinetic, hypotonic and mixed forms are milder types of CP [5].
Lesions of the central nervous system before, during or shortly after birth can cause CP. Prenatal risk factors include hypoxia, genetic disorders, metabolic disorders, multiple pregnancies, intrauterine infections, thrombophilic disorders, teratogenic exposure, maternal fever and brain malformations [2]. Perinatal factors can be asphyxia, premature birth, infection, abnormal foetal presentation, blood incompatibility and instrumental delivery. Sepsis, meningitis, respiratory distress syndrome, hyperbilirubinemia and head injury can contribute to postnatal installation of CP [2]. Risk factors are preventable in 30% of the cases [3].
CP is related to loss of muscle tone and rigidity [6]. Patients with CP also have muscular spasticity and involuntary movements. Other symptoms are represented by difficulties of the gross and fine motor skills like walking, running and writing [5]. This motor disorder can coexist with seizures (epilepsy), uncontrolled movements, balanced-related abnormalities, sensory dysfunction (visual/hearing impairment) and intellectual disability [1]. Severity of symptoms varies from mild (merely clumsy/awkward movements) to severe forms that require lifelong assistance and use of a wheelchair [1].
Oral features
Oral health problems are frequent in patients with CP. These problems are not specific, but some of them can be more common or more severe in CP patients than in healthy general population [3]. Impaired motor function, with or without intellectual disability lead to inability in maintaining proper oral hygiene, therefore daily home oral care depends on caregivers [4,7]. Risk of developing dental caries is increased and enhanced by other factors such as soft diet, high-sugar dietary habits, food pouching, mouth breathing, enamel defects, malocclusion (increased overjet and overbite). Effects of medication (either sugary or not) for the various associated medical conditions may affect saliva consistency and composition and may count as predisposing factors to oral diseases in CP children [2,8]. Gingival hyperplasia and bleeding occur more frequently in people with CP than in general population. Antiepileptic drugs like phenytoin, improper oral hygiene followed by plaque accumulation, intraoral sensitivity and oro-facial motor dysfunction are some of the contributing factors [7].
A high percentage, about 30%, of children with CP can be undernourished, with subsequent low calcium intake and vitamin D deficiency [7].
Malocclusion’s prevalence in children with CP varies from 59-92% and the most common types are represented by Angle’s Class II with increased overjet and overbite and anterior open bite [2]. Mouth breathing, lip incompetence and long face can be regarded as risk factors for malocclusion [2]. Pseudobulbar palsy and hypotonia of orofacial muscles associated with anterior tongue position and poor swallow reflex may also contribute [2,5,7]. Tongue thrusting and drooling, commonly associated with CP patients [1], round this vicious cause-effect-consequences circle.
Progressive loss of hard dental tissue due to gastroesophageal reflux disease is more common in people with CP. Primary and permanent dentition can be affected, especially upper and lower molars and upper incisors [7].
Bruxism is also more common, especially in severe forms associated with anxiety. Intense and persistent grinding of the teeth can cause severe tooth wear with flat biting surfaces [9]. Finger sucking, biting on objects and tongue thrusting are other examples of oral habits/ para functions in children with CP [2].
High prevalence of enamel defects like hypomineralization and hypoplasia are reported in children with CP who were born prematurely (<37 weeks) [2]. Enamel defects localisation is usually symmetrical affecting the primary incisors and first molars [2,7]. Dental trauma and injury in the mouth are very common in children with CP, with enamel and dentine fractures as the most frequent type of injury [7]. Motor incoordination and epilepsy seizures are some of the general risk factors that predispose to these injuries. Prominent maxillary incisors, enamel defects and lip incompetence can also contribute to an increased risk of dental trauma [5,7].
Dysfunction in the coordination of swallowing mechanisms due to pseudo-bulbar palsy, mouth opening due to lip incompetence and open bite results in excessive and unintentional loss of saliva from mouth affecting physical health and quality of life [1,2]. Increased production of saliva can be associated with the existence of an irritating factor such as infection or presence of dental caries [7]. Antiepileptic medication may cause severe drooling and can be associated with aspiration syndrome, articulation difficulties and skin irritation [7].
Temporomandibular joint (TMJ) disorders are more common in persons with CP. Risk factors for the development of a TMJ disorder are the existence of malocclusion, mouth breathing, mixed dentition and male gender [7]. CP patients usually have hyperactive bite and gag reflex [9].
Dental treatment
Severity, type of CP and the ability of the patient to cooperate are essential factors in choosing the ideal method of dental treatment. Cooperative patients may benefit from dental treatment under common dental office circumstances, with some particularities. For all patients, detailed anamnesis and good collaboration with the physician and caregivers is essential [1]. Early implementation of the Dental Home concept will create familiarity and favour a good relationship between child, family and dental team [10]. Dental management is best done when the dental team is already known to the patient and can be achieved by precise history taking, correct diagnosis and choice of suitable treatment [10].
Dental examination and treatment can be done in the dental chair or even in the patient’s own wheelchair. Travel pillows can be used as a support for the patient’s head. Caregivers can help by holding the child, if possible. Appointments should be short, with frequent breaks and the environment must be calm, helping the patient to relax. Relaxation of the patient won’t stop his movements, but will reduce their intensity or frequency [1,9]. If longer appointments are needed muscle relaxants can be used. Noises, bright lights and sudden moves should be avoided because they may trigger uncontrolled movements [5]. Every dental treatment must be preceded by explanations and demonstrations of instruments and materials that will be used (TELL-SHOW-DO technique).
Patients with gag reflex should be scheduled in the morning and seated upright [9]. Mouth props can be used to avoid involuntary closing of the mouth during examination and treatment. If a patient begins to shake or to move during dental treatment, it is better not to try to stop him/her; instead, a gentle and firm pressure on the arm will help him/her relax. Use of water spray and suction are essential as many patients can’t rinse properly [2]. Dental restorations should be done using encapsulated materials like GIC which are fluoride releasing and very easy and quick to use. GIC cements can be used especially in this category of patients because they can be placed even in conditions of imperfect tooth isolation and because of their cariostatic effect [11].
CP per se is not necessarily an absolute contraindication for providing orthodontic or prosthetic treatment in children/ patients with CP. However, in moderate/severe CP types treatment planning and expectations (both of the doctor’s, patient and his family) must be carefully and realistically adjusted [2]. In any case, the treatment plan should be kept as simple as possible and followed by proper oral hygiene as there is high risk of caries and enamel defects [5].
Another option for dental treatment for CP patients is under conscious sedation using N2O and O2 mixture. Cooperation of the patient is essential to achieve conscious sedation and reduce stress. If the CP is associated with severe intellectual disability, treatment under conscious sedation can be difficult or even impossible as there are chances the mask is not accepted [2]. A significant reduction of involuntary movements during treatment under conscious sedation was reported by Jensen et. al [12]. N2O does not affect hepatic metabolism and represents an option in treating patients with long-term medication [13]. Completely uncooperative patients or patients with complex dental treatments can be treated under general anaesthesia (GA). More radical treatment options (e.g. extractions rather than complex endodontics) are preferred in order to avoid need for retreatment [5,14].
Prevention
Early preventive measures can be applied, ideally, from a very young age through the Dental Home concept. Oral problems can thus be intercepted early and the needed treatments are less complex, with less effort, costs and stress for the patient, family and medical team, and with a good impact upon the patient’s quality of life [10]. Prevention of tooth decay can be achieved by simple and effective ways like personalised daily oral hygiene using toothpaste with adequate fluoride concentration, professional application of fluoride preparations like gels and varnishes and sealants. Caregivers should be informed in due time about the importance of proper daily oral hygiene and helped to adjust techniques of toothbrushing and flossing in a personalised way for each child. Oral care can be simplified if electric toothbrushes or manual toothbrushes with modified handle and floss holders are used [1]. The dental practitioner should demonstrate to the caregiver sitting or standing positions which will facilitate provision of oral hygiene [1]. Use of mouthwashes may be difficult in patients who cannot expectorate and alternatives like chlorhexidine varnishes or gels can be an option [1]. Sugary medication and medication which causes gingival hyperplasia should be replaced if possible. Regular check-ups every 3 months are recommended for all patients with high risk of caries [5].
Case report
T, male, 10 years old has cerebral palsy and generalised hypotrophy. His first dental visit was at age 4 years and 2 months (Fig.1). T’ s level of cooperation was low, with a Frankl score of 2. The initial oral examination revealed multiple untreated dental caries, gingival overgrowth and plaque accumulation (Fig. 2).
Fig. 1. T at his first dental visit 
Fig. 2. Initial oral health situation
Dental treatment was entirely provided under common dental office circumstances despite the patient’s moderate form of CP, with intellectual challenge and lack of adequate cooperation. His mother helped a lot, sitting in the dental chair and holding him, supporting his head and providing both comfort and better control of involuntary movements (Fig. 3). A mouth prop, alternatively controlled by dentist and assistant, was used to avoid closing of the mouth (Fig. 4). Application of anaesthetic gel before professional cleaning reduced discomfort for the inflamed overgrown gingiva. Encapsulated GICs were used for quick and easy restorations.
Fig. 3. Mum holding T and offering help during dental treatment 
Fig. 4. Use of mouth prop during treatment and help from dental assistant
T’s oral health status and collaboration with the dental team improved in time as T regularly visits the dental office (every 3 months) for monitoring and care.
At age 10 y a panoramic radiograph was possible due to improved overall cooperation of the patient (Fig. 5). Congenitally missing 12 and 22 were revealed, explaining over-retention of 52 and 62. The latter were extracted using infiltration anaesthesia to favour mesial movement of 13 and 23 with better prognosis for convenient spontaneous alignment. During anaesthesia, the dental assistant held T’s head for better control of movements (Fig.6). Minimal quantity of anaesthetic was used to avoid subsequent discomfort by funny numbness sensation. Both teeth were extracted during the same visit to avoid excessive stress and risk for numb lip biting.
Fig. 5. Panoramic radiograph at the age of 10 y reveals 12 and 22 anodontia 
Fig. 6. Dental assistant is offering support during infiltration anaesthesia for the extraction of 52 and 62
As T can’t bite on a gauze, he remained in the dental office until full arrest of bleeding (Fig. 7). His mother is informed and instructed to supervise him in order to avoid any attempt of numb lip biting.
T is coming in for regular check-ups every 3 months and although his dental home was set in a less-than-ideal manner, at a later age and already with a lot of dental problems, the concept works nicely for him: home oral hygiene is more efficient, any emerging problems are promptly addressed and solved, his oral health has improved a lot and his dental compliance is much better.
Conclusions
Cerebral palsy is a complex condition which requires adequate care, including oral care. Very early first dental visit (ideally during the first year of life), followed by close professional monitoring (every 3 months), along with efficient, personalised home oral care will minimise caries, periodontal involvement and orthodontic disturbances, with lesser need for complex treatment. Dental compliance of patients with CP already accustomed with the dental office and dental professional since a very young age shall be better, and chances that treatment can be delivered under common dental office circumstances shall be increased.
Targeted preventive strategies for patients with CP and early information of families and caregivers are needed in order to avoid complex, expensive and sometimes unreachable dental treatments. Implementation of the DENTAL HOME concept, even in less-than-ideal circumstances, can have a remarkable positive impact on patients’ oral and general health and also on their quality of life. The digital platform https://oscarpd.eu/ is a step in this direction.
Note: This research is part of 2019-1-RO01-KA202-063820 Erasmus+ Project “Oral Special Care Academic Resources” (OSCAR)
Conflict of interests: None
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