Study Evaluates Oral Health Among Children With ADHD

A new study has found that children with attention-deficit/hyperactivity disorder (ADHD) showed substantially poorer oral-health indicators than age-matched children without the diagnosis, including more dental caries, fractured teeth, gingival abnormalities, malocclusion and dental crowding. The findings, published in Child Psychiatry & Human Development, suggest that dental care may need to be integrated more deliberately into the broader health monitoring of children with ADHD. In the study, the average DMFT index—a standard measure of decayed, missing and filled permanent teeth—was 2.82 among children with ADHD, compared with 1.10 in healthy controls. The difference was statistically significant, with a probability of less than one in 1,000 that it arose by chance under the study’s statistical model. The researchers stress, however, that the results show an association rather than proof that ADHD itself directly causes dental disease. The sample was relatively small and selected according to predefined oral-hygiene, dietary and dental-attendance criteria, meaning the results may not represent every child with ADHD.

The investigation included 100 children between 10 and 18 years old: 50 diagnosed with ADHD and 50 healthy controls matched for age. ADHD diagnoses were established by a child and adolescent psychiatry specialist using the criteria of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-5, and were supported by neuropsychological assessments. The comparison group did not have an ADHD diagnosis. All participants underwent standardized dental examinations conducted by a single examiner who was blinded to whether each child belonged to the ADHD or control group. Blinding is important because it reduces the risk that expectations about a participant’s diagnosis could influence clinical judgments, particularly when assessments involve visible signs such as gingival inflammation or tooth damage. The dental evaluation included DMFT scoring, clinical examination of the gums, analysis of bite alignment, assessment of dental crowding and panoramic radiography, which provides a two-dimensional overview of the teeth, jawbones and surrounding structures.

The most direct signal was the difference in caries experience. The DMFT index combines the number of permanent teeth that are decayed, missing because of decay or filled, producing a cumulative measure of a person’s history of dental disease. A higher score does not necessarily mean that all problems are active at the time of examination, because filled teeth remain part of the index. Nevertheless, the contrast between 2.82 ± 1.38 in the ADHD group and 1.10 ± 1.02 in controls indicates a considerably greater burden of dental treatment or untreated disease among the children with ADHD. Dental caries develops when acid-producing bacteria in dental plaque metabolize fermentable carbohydrates, lowering the pH at the tooth surface and gradually dissolving mineral from enamel and dentine. Saliva normally buffers these acids and helps restore minerals, but repeated acid exposure, inadequate plaque removal and delayed treatment can shift the balance toward progressive decay. The study did not establish which biological or behavioral pathway accounted for the higher DMFT scores.

Tooth fractures also appeared markedly more common among the children with ADHD. A fractured tooth was recorded in 36 percent of the ADHD group, compared with 10 percent of controls. The researchers calculated an unadjusted odds ratio of 5.06, with a 95 percent confidence interval from 1.70 to 15.05. In practical terms, the odds of observing a fractured tooth were higher in the ADHD group, although the wide interval reflects uncertainty caused partly by the modest sample size. Several mechanisms could plausibly contribute to this pattern without implying a single cause. Symptoms associated with impulsivity, risk-taking or reduced attention may increase exposure to falls, collisions or other injuries. Difficulties sustaining attention during routine activities could also affect the consistency of protective behaviors. Bruxism, or repetitive clenching and grinding, may place additional mechanical stress on teeth, although this study’s abstract does not report a direct bruxism measurement. The findings therefore point to a clinically relevant pattern but cannot distinguish accidental trauma from other possible contributors.

Gingival abnormalities showed the largest relative difference between the groups. Any abnormal gingival finding was present in 60 percent of children with ADHD but only 12 percent of controls, corresponding to an unadjusted odds ratio of 11.00 and a 95 percent confidence interval of 3.95 to 30.61. The gums respond to bacterial biofilm accumulating along the margin where tooth meets tissue. When plaque is not removed effectively, the local immune response can produce redness, swelling, bleeding and other signs of gingival inflammation. Persistent inflammation can alter the tissue environment and, in more advanced disease, contribute to damage of the structures supporting the teeth. The study did not specify in the abstract which individual gingival abnormalities were counted or whether participants had established periodontal disease, so the results should not be interpreted as evidence that ADHD causes severe gum disease. They do indicate that visible gingival problems were much more frequent in this selected group and may warrant closer preventive surveillance.

The researchers also identified differences in the physical arrangement of the teeth and jaws. Malocclusion—an abnormal relationship between the upper and lower teeth or jaws—was found in 64 percent of children with ADHD, compared with 24 percent of controls. Dental crowding affected 70 percent of the ADHD group and 44 percent of controls. Malocclusion can arise from differences in jaw growth, tooth size, eruption patterns, oral habits and inherited craniofacial traits. Crowded teeth may create areas that are difficult to reach with a toothbrush or interdental cleaner, allowing plaque to persist and potentially increasing the risk of caries and gingival inflammation. Conversely, existing oral discomfort or an altered bite can affect eating, sleep or willingness to undergo dental procedures. Because the study was cross-sectional—meaning exposures and outcomes were assessed at one point in time—it cannot determine whether malocclusion preceded the dental-health differences, contributed to them or simply occurred alongside them. Radiographic examinations added structural information, but the reported results do not demonstrate a developmental pathway linking ADHD to altered tooth alignment.

The authors propose that the findings could support tailored preventive monitoring and closer collaboration between dental and mental-health professionals. Such cooperation could help clinicians account for attention, impulsivity, behavioral regulation and treatment anxiety when designing dental visits, while avoiding assumptions that every child with ADHD will experience oral-health problems. Preventive care might be adapted through shorter or more structured appointments, repeated explanations, visual cues and coordinated communication with caregivers, although the study itself did not test any intervention. Medication may also be relevant in some children, because certain drugs can affect salivary flow or oral dryness, but the present report does not provide medication-specific results and cannot attribute the observed differences to treatment. Similarly, the investigators selected participants using oral-hygiene, dietary and dental-attendance criteria, which may have reduced the influence of some common confounders but also limits generalization. Factors such as socioeconomic conditions, caregiver support, access to specialized dental services, co-occurring neurodevelopmental conditions and the duration or severity of ADHD could all shape oral-health outcomes.

The new results add to a wider body of research reporting connections between ADHD symptoms and dental caries or malocclusion, but they do not settle the question of causation. Earlier studies have produced mixed findings, and differences in diagnostic methods, age groups, dental scoring systems, medication exposure and access to care make direct comparisons difficult. The authors acknowledge that larger and more diverse cohorts are needed to determine whether the associations persist across populations. Future research could follow children over time, measure plaque accumulation and brushing routines directly, record dietary patterns and dental attendance in detail, examine salivary flow and composition, and separate the effects of ADHD symptoms from those of medication, sleep-related bruxism, dental fear and socioeconomic circumstances. Longitudinal studies would be especially valuable because they could reveal whether oral-health differences emerge before or after ADHD diagnosis and whether targeted preventive programs reduce them. For now, the study’s central message is not that ADHD inevitably damages children’s teeth, but that oral health may be an overlooked part of comprehensive care for some young people with the condition.