From Volume 52, Issue 4, April 2025 | Pages 253-262
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by a spectrum of symptoms of inattention, hyperactivity and/or impulsivity. Children with ADHD present with a number of behavioural challenges which can potentially increase caries risk, dental trauma incidence and non-compliance in the dental setting.
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by symptoms of inattention, hyperactivity and/or impulsivity.1 Children with ADHD may experience difficulties with listening, compliance and socialising. Neurodiverse behaviour becomes apparent from an early age and persists into adolescence and adulthood.2
As it is one of the most common psychiatric childhood disorders, dental practitioners are likely to come across ADHD patients in their practices. Reasonable adjustments and adaptation of strategies are required for successful patient management.
The global prevalence of ADHD in children is estimated to be around 5%.3
ADHD incidence rates are significantly higher in men than in women with a prevalence ratio of 4.3:1.4 There are increasing discussions regarding underdiagnosis of ADHD in females because they are more likely to mask and internalize ADHD symptoms. Women tend to predominate in the inattention type of ADHD, while men are more likely to demonstrate the hyperactivity-impulsivity type of ADHD.
It is more likely for the hyperactivity-impulsivity type of ADHD to be recognized earlier and referred for assessment.
ADHD is phenotypically heterogenous and is classified in three clinical presentations: the predominantly hyperactive-impulsive type (15%); the predominantly inattentive type (20–30%); and the combined type (50–75%).5
Inattention manifests behaviourally as difficulty in sustaining focus, disorganization and lacking persistence. Hyperactivity relates to excessive motor activity, often in situations when it is deemed inappropriate. Impulsivity refers to an immediate response to a stimulus without consideration of the potential risks and consequences.
ADHD symptoms and manifestations of inattention and hyperactivity-impulsivity characteristics vary between individuals and can change over the course of development. As such, similar to autism, it is considered a spectrum in its unique presentation for each individual.
Despite the chronic nature of ADHD, longitudinal studies suggest the possibility of developmental trajectories: early onset (pre-school ADHD: aged 3–5 years); middle childhood (aged 6–14 years) onset with a persistent course; middle childhood onset with adolescent cessation; and adolescent or adult onset (aged ≥16 years). Treatment is typically provided across these trajectories.6
ADHD often coexists with other developmental conditions, including autism spectrum disorder, tic disorders, learning disabilities and specific learning difficulties. The symptoms of other psychiatric disorders may override those of ADHD, making diagnosing ADHD more challenging.
ADHD diagnosis is made based on a persistent pattern of inattention and/or hyperactivity-impulsivity that is outside the normal variation expected for age and level of intellectual development.
For a valid diagnosis, symptoms of inattention or hyperactivity-impulsivity or both should meet at least six (or at least five in adults) diagnostic criteria as per the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) (Table 1).7 The World Health Organization's International Classification of Diseases 11th Revision has a similar diagnostic formulation, although it does not specify the precise age of onset, duration or number of symptoms.8 These symptoms also need to have caused psychological, social and/or educational or occupational impairment and be pervasive (e.g. occur for at least 6 months).
| ADHD type | Description | Symptoms |
|---|---|---|
| Inattentive | Six symptoms of inattention for children aged ≤16 years, or five for adolescents aged ≥17 years and adults; inattention symptoms have been present for at least 6 months, and are inappropriate for developmental level | Often fails to pay close attention to details or makes carless mistakes in schoolwork, at work or with other activities |
| Often has trouble holding attention on tasks or play activities | ||
| Often does not seem to listen when spoken to directly | ||
| Often does not follow through on instructions and fails to finish schoolwork, chores or duties in the workplace | ||
| Often has trouble organizing tasks and activities | ||
| Often avoids, dislikes or is reluctant to do tasks that require mental effort over a long period of time (such as homework or schoolwork) | ||
| Often loses things necessary for tasks and activities (e.g. school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones) | ||
| Is often easily distracted | ||
| Is often forgetful in daily activities | ||
| Hyperactive/impulsive | Six symptoms of inattention for children aged ≤16 years, or five for adolescents aged ≥17 years and adults; hyperactivity-impulsivity symptoms have been present for at least 6 months, and are inappropriate for developmental level | Often fidgets with or taps hands or feet, or squirms in seats |
| Often leaves seat in situations when remaining seated is expected | ||
| Often runs about or climbs in situations where it is not appropriate (adolescents or adults may be limited to feeling restless). Often unable to play or take part in leisure activities quietly | ||
| Is often ‘on the go’ acting as if ‘driven by a motor’ | ||
| Often talks excessively | ||
| Often blurts out an answer before a question has been completed | ||
| Often has trouble waiting his/her turn | ||
| Often interrupts or intrudes on others (e.g. butts into conversations or games) |
ADHD symptoms are commonly identified at school, where onward referral to the school's special educational needs coordinator is a known pathway for diagnosis. Referral to secondary care differs depending local care pathways and regional funding.
A rigorous diagnosing process is required, which involves assessment of suspected subjects in multiple situations or settings; hence a diagnosis of ADHD should be made only by a specialist psychiatrist, paediatrician or other healthcare professional with appropriate training and expertise in diagnosing ADHD.
Although the exact disease pathophysiology is unknown, there is no single known causative factor that contributes to the aetiology of ADHD.
ADHD symptoms demonstrate strong genetic influences and are often described as an interplay of both genetic and non-inherited factors. Twin studies show that approximately 75% of ADHD symptoms are invariably inherited, with ADHD hereditability estimated to be 70–80%.9
Multiple genetic risk loci were identified in a genome-wide study.10 Several of these variants are located in or near the genes that implicate neurodevelopmental processes including FOXP2, SORCS3 and SUDP6. While no single genes have been directly correlated to the psychopathology of ADHD, several genetic variants contribute to smaller ADHD effects.
Many environmental influences have been associated with ADHD. These environmental influences can broadly be categorized into biological factors, dietary factors and psychosocial factors.
A range of biological factors, including maternal smoking, alcohol or drug misuse, low birthweight, premature birth and foetal hypoxia, adversely affecting brain development, are associated with an increased risk of ADHD.11,12
Well-known dietary risk factors for ADHD include food additives, sugar, colourings and other E-numbered food additives.13
There is evidence to suggest psychosocial adversity such as a deprived, institutional care and disrupted and discordant family relationships are linked with ADHD, although the exact mechanisms are not known.14,15
When considering the practicalities for treatment planning for people diagnosed with ADHD, psychological, behavioural, occupational and educational needs, which vary according to developmental stages, need to be taken into consideration.
Treatment modalities are likely to evolve as a person matures and regular reassessment of a patient's ability to cope with various medical treatments needs to be considered.
The impacts of ADHD may vary by extent and in different domains, such as the ability to complete school or work tasks, avoiding common hazards and developing interpersonal relationships. The National Institute for Health and Care Excellence (NICE) sets out five domains of performance when assessing the effectiveness of treatment modalities, namely: social skills with peers; problem-solving; self-control; active listening; and dealing with and expressing feelings.16
Non-pharmacological treatment modalities are part of the multi-modal approach and are especially important for children aged <5 years where medication is not recommended, or in instances where there is a reluctance to use medications by either parents or clinicians.
For this group of children, the NICE guideline recommends offering an ADHD-focused group parent-training programme to parents or carers. These sessions should include education on the condition and advice on parenting strategies.
For children aged >5 years, environmental adjustments can be incorporated following liaison with schools, such as changes to seating arrangements, lighting and noise, reduction of distractions, adaptation of shorter periods of focus with breaks as well as appropriate use of teaching assistants.
Cognitive behavioural therapy is sometimes considered an adjunct to medication should a child still demonstrate significant impairment in one of the five domains.
A healthy, balanced diet is advisable and, although evidence of diet modifications in the management of ADHD is inconclusive, advice against certain foods or drinks that appear to lead to hyperactive behaviour may be given to parents or carers.
Medications may be offered if ADHD symptoms persist despite employment of non-pharmacological strategies.
The NICE guideline recommends methylphenidate as the first line of medication for children and adolescents aged >5 years. Methylphenidate is a psychostimulant that blocks presynaptic dopamine and norepinephrine transporters, thereby increasing catecholamine transmission. Methylphenidate, on balance, has good short-term efficacy and superior acceptability and tolerability as compared to other medications.17 Methylphenidate products that can be prescribed in the UK are shown in Table 2.
| Affenid XL tablets |
| Concerta XL tablets |
| Delmosart tablets |
| Equasym XL capsules |
| Matoride XL tablets |
| Medikinet XL capsules |
| Meflynate XL capsules |
| Metyrol XL capsules |
| Xaggitin XL tablets |
| Xenidate XL tablets |
Alternative psychostimulant medications that may be prescribed are lisadexamfetamine and dexamphetamine. Stimulant medications have similar side-effect profiles, including appetite suppression, insomnia, dry mouth and nausea.
Non-responders to psychostimulants or those intolerance to psychostimulants' side effects may be prescribed non-stimulant drugs such as atomoxetine or guanfacine, which have lower responses and effect sizes.
For many years, the literature on dental caries prevalence in ADHD people had been inconclusive. A recent meta-analysis reported that children with ADHD are more susceptible to developing dental caries than those without the condition.18
Staberg et al found that parents and caregivers of ADHD children reported difficulties in implementing effective toothbrushing.19 In the same study, parents and caregivers also reported difficulty in controlling ADHD children's dietary habits, resulting in high cariogenic foods and drinks.
Hidas et al found that ADHD children had higher dental plaque scores, suggesting inadequate toothbrushing and oral hygiene behaviours.19
Children and adolescents with ADHD may be at an increased risk of traumatic dental injuries, possibly due to the hyperactivity nature of ADHD, relationship problems with peers, physical abuse and motor coordination issues.20,21,22,23
Meta-analyses results have shown that the odds ratios of dental trauma in children and adolescents with ADHD were 1.5 and 1.8 respectively in comparison to non-ADHD cohorts.24,25
The current evidence, however, is weak and contains a high risk of bias owing to subject selection and lack of control groups. This has undoubtably led to variations in odds ratios, prevalence rates and mean number of teeth affected.
In 2013, an international consensus defined bruxism as ‘a repetitive masticatory muscle activity that is characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible’.
Bruxism is specified as either sleep bruxism, characterized by ‘rhythmic or non-rhythmic masticatory muscle activity’, or awake bruxism, characterized by ‘repetitive or sustained tooth contact and/or by bracing or thrusting of the mandible’.26
In one systematic review, Souta-Souza et al found the combined prevalence of sleep and awake bruxism was 31% among children and adolescents with ADHD.27 Similarly, Kammer et al's systematic review of tooth grinding in children with neurodevelopmental disorders showed the prevalence of sleep tooth grinding and/or clenching to be 39.8%. It is worth noting that, in the same systematic review, the pooled prevalence of tooth grinding and/or clenching reported by the study participants was much higher, at 58%.28
A potential limitation of the above systematic reviews was that all included cross-sectional studies, making it difficult to predict the causal relationship between ADHD and bruxism.
In addition, the majority of studies evaluated the rate of bruxism via self-reported and parent-reported questionnaires rather than a comprehensive clinical examination. This could have been done by oral examination or through the use of polysonmnography, an instrumental approach to the assessment of sleep/awake bruxism recommended by international consensus in 2018.29
Despite extensive reports on the prevalence of bruxism in patients with ADHD, only two studies are available to date that measure tooth wear.30,31 Further research into tooth surface loss and ADHD would be welcome in light of the recent increase in ADHD diagnosis.
The mean difference in gingival bleeding index (percentage of bleeding sites) between ADHD children and adolescents and their non-ADHD peers has been estimated to be 11.25%.32 No significant differences have been found in other periodontal markers such as calculus level, sulcus bleeding index and probing pocket depth.33,34
Hasan and Ciancio revealed 30% higher levels of gingival inflammation and gingival enlargement in ADHD children medicated with amphetamine, but no significant difference in plaque levels between groups.35 This suggests the potential association between the introduction of ADHD medication and periodontal disease.
The findings in primary studies of periodontal disease in ADHD children should be appraised with caution owing to the lack of control groups and potential confounding factors leading to high levels of bias.36
Adverse effects of psychostimulant drugs are mostly mild or moderate in severity and occur in the first few months of drug treatment.37
A systematic review by Wolff et al reported xerostomia induced by psychostimulant medications.38 The xerostomic effect appeared to be more frequent in children having combined psychostimulant and antidepressant medications.39 However, there were no differences in saliva pH, viscosity and buffering capacity between medicated and non-medicated children.19,40
Based on the current evidence, the xerostomic effect of psychostimulant medications and higher level of plaque in ADHD children may contribute as risk factors for dental caries.
Results are conflicting regarding the relationship between psychostimulant medications and bruxism. Malki et al suggested the prevalence of bruxism is higher in medicated ADHD children than in those who are not medicated.31
However, the relationship between psychostimulants and bruxism remains unclear.41 Ertugrul et al found no significant difference in sleep bruxism between medicated and non-medicated ADHD groups of children, which is suggestive of the neuropsychiatric nature of the disease, rather than the medication side effects.40
Barriers to dental care operate at multiple levels, including around individual characteristics, access to dental care and the skills and knowledge of dental professionals.
Children with ADHD can display cognitive, physical and behavioural difficulties, which affect their ability to undertake daily oral care and cope with dental visits. These behaviours may be explained by differences in executive functioning and sensory processing.
Executive functioning refers to a set of high-order cognitive abilities, such as working memory, self-control, problem solving and emotion control, which enable goal-directed behaviours.42 ADHD groups have been shown a varying degree of executive functioning impairments.43
The oral health implications of executive functioning impairment may include making unhealthy lifestyle choices, such as smoking, substance misuse and a cariogenic diet, as well as an inability to undertake oral hygiene and missing dental appointments.44
ADHD should be considered in conjunction with sensory over-responsivity (SOR) in children.45,46 SOR is characterized by faster, longer or enhanced responses to sensory stimuli, such as touch, movements, visual, noises, tastes and/or smell.44
ADHD children with SOR may not be able to perform appropriate oral hygiene as they may struggle with the sensation and/or sounds of toothbrushing and the taste of toothpaste. Their diet may also be restricted owing to their preferences for certain tastes, smells and textures of food and drinks. The dental environment has many potential sensory stimuli, which act as barriers to access for children with SOR.47
There is lack of evidence specifically regarding dental practitioners' skills and attitudes to treating and managing ADHD patients. However, it has been reported that a lack of experience and insufficient undergraduate education and clinical exposure to treat patients with neurodiversity and learning difficulties could act as barrier to dental care.48,49
While some patients have received a diagnosis of ADHD, many are undiagnosed and not aware of their neurodiversity, which could significantly impact access to dental care.3,50
A recent population-based cohort study reported increases in ADHD prevalence and in ADHD medications prescribed between 2000 and 2018.51
Possible explanations of this phenomenon could be a genuine increase in the frequency of the condition, an increasing awareness of the condition among patients, caregivers and medical professionals, changing attitudes towards ADHD, broadened diagnostic criteria, over-/misdiagnosis and the use of medication for cognitive improvement in otherwise healthy individuals.5253,54
Cohort studies have estimated the highest prevalence as 2.3% in boys in 2018 in the UK, which is lower than the community and global prevalence of 5%.55 This highlights a possible underdiagnosis of ADHD in the UK, potentially owing to long waiting lists, a lack of awareness surrounding signs and symptoms or a lack of NHS funding and focus on directing people displaying symptoms to the appropriate medical teams for diagnosis.
The Equality Act 2010 protects those receiving care or education from being treated unfairly because of they have any characteristics that are protected under this legislation.56 It is a legal requirement to make reasonable adjustments to accommodate dental patients with disabilities; disability under the Equality Act is defined as a physical or mental impairment which has a substantial and long-term adverse effect on a person's ability to carry out everyday activities.
Reasonable adjustments can operate at an individual level to meet each patient's need, but they can also be associated with a service-level change. According to the General Dental Council Standards for the Dental Team (standard 1.4), a holistic approach needs be adopted depending on patients' specific needs, preferences and communication methods to support overall wellbeing.57
All dental care must be provided on the basis of a needs assessment, specifically considering patients' executive functioning and sensory processing differences. Treatment plans should, as such, focus on the individual needs of each patient.
Prevention in the form of dietary and lifestyle modifications, as well as clear oral hygiene instruction is vital in preventing oral diseases including dental caries, dental erosion and periodontal disease.
When dental treatment is indicated, treatment modalities including a range of behavioural and pharmacological options may be adopted to improve patient outcome.
A thorough medical history is necessary to establish any comorbidities, medications and their interactions. Psychostimulants used to treat ADHD are shown to cause elevations in systolic and diastolic blood pressure and increased pulse rates. The use of aspirating syringes for local anaesthetic administration can therefore prevent intravascular injections and exacerbation of the effects of psychostimulants.58
Children with ADHD can demonstrate behavioural problems, short attention spans and poor cooperation.59 Consultation with their parents is useful to understand the management strategies being employed by the family at home and in school.
Flexible scheduling of appointments can help to maximize patients' attention spans and medication routines. For medicated ADHD children, scheduling appointments in the morning is beneficial since medication levels are then optimal and children are more attentive, less fatigued and more likely to stay in a dental chair.60
Alternatively, liaising with medical practitioners can be useful to identify medication modifications to enhance and use the benefits of medication induction in the delivery of dental care.
Shorter and more frequent appointments also can avoid draining children's attention and help with acclimatization to the dental setting.
Oral hygiene advice should be broken down into smaller, more manageable steps. Concise, clear and specific instructions need to be given to children without over-burdening their short-term memory.
When delivering oral hygiene advice, eye contact should be maintained with the child and it should be ensured that the child is not distracted by the surrounding environment, such as the dental nurse clearing up instruments.61
A consistent oral hygiene routine integrated into daily routines can provide a predictable and manageable pattern for children to follow. Visual cues or a checklist can help develop consistency.
Oral health adjuncts can be tailored to individual sensory processing needs. For children with hypersensitivity or an aversion to strong or specific taste, differently flavoured, unflavoured or non-foaming (sodium lauryl sulphate-free) toothpastes can be tried. Figures 1 and 2 show examples.
Toothbrushes with extra soft or silicone bristles can be recommended for children with hypersensitivity to touch. Three-sided toothbrushes, such as Dr Barman's toothbrush (Figure 3) have design features that simultaneously mechanically remove plaque from three tooth surfaces.
Electric toothbrushes with built-in timers can help ensure adequate duration of toothbrushing.
Additionally, encouraging the use of communication adjuncts such as storyboards that are used by schools may aid facilitation of toothbrushing.
Among various behaviour management techniques, Fellicetti and Julliard found tell-show-do to be most effective in improving cooperation and focusing children's attention on a procedure.62
Positive reinforcement is a powerful tool to reinforce desired behaviour, including that which would have been expected. Providing breaks, even if they are brief, may help with attention control.63
Accompanying parents could advise on the child's need for breaks, their frequency and duration.64
The British Society of Paediatric Dentistry (BSPD) has provided an updated guideline of non-pharmacological behavioural management.65
Depending on the child's needs and the clinical expertise of the health professional, techniques adopted should be adjusted to optimize paediatric patients' experience and confidence.
The most commonly adopted dental conscious sedation techniques in the UK are titrated intravenous midazolam or titrated inhaled nitrous oxide. These techniques have an excellent safety record and provide an alternative to general anaesthetic to make treatment possible in primary settings.66
For children aged <12 years, inhalation sedation using nitrous oxide and oxygen can be provided in community and primary care. For children and adolescents aged ≥12 years, single-drug technique using midazolam (intravenous, oral or transmucosal) can be provided as an alternative to inhalation sedation.
Nitrous oxide inhalation does not react with ADHD medication and can reduce disruptive behaviour, especially for lengthy, more complex dental treatment. Nitrous oxide acts with minimal alteration to the level of consciousness while maintaining respiratory capacity, and ability to understand physical and verbal commands.
Tell-show-do could be used to introduce the nitrous oxide delivery unit and the nasal hood. When inhalation sedation is being performed, ADHD children should be given short and clear instructions. A clear signalling system and distraction by counting out numbers can empower patients and increase their control; this is the same as for healthy children.67
A recent Cochrane review provides increasing evidence to demonstrate the use of oral midazolam as an effective sedative agent for children.68 The meta-analysis of six, small, clinically heterogenous studies showed that the use of oral midazolam in doses between 0.25 and 1 mg/kg was associated with more cooperative behaviour; however, there was limited evidence relating the use of oral midazolam in ADHD children.
Where dental treatment is not tolerated under local anaesthesia and/or conscious sedation, general anaesthesia could be considered.
The BSPD outlines the management of children referred for dental extractions under general anaesthesia, including the necessary pre-operative discussions and assessment, peri-operative care and post-operative management.69
It should be noted that general anaesthesia does not help ADHD children develop coping mechanisms for future dental treatment. Every effort should be put in place to instil confidence in the dental profession and a create a positive outlook for future dental care.
Table 3 summarizes management strategies for paediatric patients with ADHD.
| Medical history | Take a thorough medical history to establish any comorbidities, medications, and their interactions |
| Work with the child's paediatrician if appropriate | |
| Appointment scheduling | Flexible scheduling of appointments when medications are optimal (usually in the morning) |
| Arrange several shorter appointments to maintain attention span | |
| Treatment considerations | Use of aspirating syringe to avoid intravascular injections and exacerbation of the effects of psychostimulants |
| Incorporate behavioural management such as tell-show-do and distraction | |
| Provide breaks within an appointment | |
| Consider the use of conscious sedation to improve cooperation for treatment | |
| General anaesthesia may be resorted to when treatment is not tolerated with the use of local anaesthesia and/or conscious sedation | |
| Communication | Concise, clear and specific instructions |
| Chunk and check | |
| Maintain eye contact and check on patient engagement | |
| Avoid background distractions when communicating | |
| Prevention | Discuss specific dental needs and risks with patients and parents/carers and provide adequate, tailored support |
| Regular recalls to reinforce preventive messages and ensure diseases are identified and managed early |
While symptoms of ADHD present from an early age, the condition remains largely underdiagnosed in the UK.
Dental professionals should recognize ADHD symptoms as a medical condition under the wider neurodiversity umbrella.
Every effort should be made to understand the impact ADHD has on dental care provision and to provide reasonable adjustments for ADHD children depending on their needs for successful dental care.
