A parent mentions that their child grinds their teeth during sleep. Many sleep consultants hear this and think of it as a dental issue. Something for the dentist to handle. But a 2024 study published in the International Journal of Paediatric Dentistry suggests that tooth grinding in children is tied much more closely to sleep quality and emotional pressure than most professionals realize.
The study, titled “Association between perfectionism, personality traits and probable sleep bruxism in Spanish schoolchildren: A case-control study,” was conducted by Redondo Martínez, Catalá-Pizarro and Rojo Moreno at the University of Valencia. Their findings give sleep consultants a reason to pay close attention when parents bring up nighttime tooth grinding, and to ask questions that reach much further than the teeth.
What the researchers did
The study included 104 children aged 8 to 9 years. Half of them (52) had probable sleep bruxism. The other half (52) did not. All children attended the Paediatric Dentistry Unit at the University of Valencia Dental Clinic.
To be included in the bruxism group, a child had to meet two conditions. First, the parents had to report that their child clenched or ground their teeth during sleep within the previous six months. Second, a clinical dental examination had to confirm abnormal tooth wear. Tooth wear was measured using the Tooth Wear Index, with a score of 2 or higher marking the boundary between normal and pathological wear. A single trained examiner conducted all clinical evaluations.
The children completed two validated questionnaires. One measured personality traits across five dimensions (the BFQ-NA). The other measured perfectionism in children (the Child Perfectionism Inventory, or IPI), which assessed three areas: self-demandingness, self-assessment and external pressure.
Parents filled out three questionnaires. One was a bruxism diagnostic questionnaire based on American Academy of Sleep Medicine (AASM) criteria. It asked about dental grinding, family history of bruxism, nightmares, sleep awakenings, daytime sleepiness, snoring and parafunctional habits such as nail biting. The other two assessed parental personality traits and parental perfectionism.
Restless sleep stood out above everything else
The researchers ran two rounds of statistical analysis, and the difference between them tells the real story.
In the first round (unadjusted binary logistic regression), three variables showed a significant association with probable sleep bruxism. A self-demanding personality raised the odds by 11% per unit increase (OR = 1.11, p = .01). Family history of clenching or grinding teeth tripled the odds (OR = 3.07, p = .0006). Restless sleep, which included nightmares, sleep awakenings and daytime sleepiness, showed the strongest association, with children being more than four times as likely to have probable sleep bruxism (OR = 4.41, p = .004).
Then came the second round. When all three variables were entered together into an adjusted model, only restless sleep remained significant (OR = 3.32, 95% CI 1.13–9.81, p = .03). Self-demanding personality and family history both lost their significance once restless sleep was accounted for.
This is a finding that sleep consultants should sit with for a moment. Of all the factors tested in this study, the quality of a child’s sleep was the single strongest independent predictor of nighttime tooth grinding. Not personality. Not family history. Sleep.
The perfectionism pattern is worth understanding
The perfectionism findings did not survive the adjusted model, but they still tell us something meaningful about these children.
Children with probable sleep bruxism scored higher on self-demandingness and lower on self-assessment compared to controls. This combination is what psychologists call maladaptive perfectionism. The paper explains the difference: adaptive perfectionism is considered positive for achieving goals, but the maladaptive type limits success through an excessive desire to avoid failure.
The authors point out that self-demandingness on its own can actually protect against anxiety and depression. It becomes harmful only when paired with negative self-evaluation. In these children, the two went together. The paper links maladaptive perfectionism to high levels of concern, stress, insomnia and a lack of emotional control.
An interesting detail from the personality data: only 9.6% of children with bruxism scored low on conscientiousness, compared to 26.9% of controls. Children who grind their teeth tended to be more conscientious, more self-disciplined and more meticulous. The authors describe neuroticism and conscientiousness together as forming part of an individual bruxism profile.
No significant differences were found in parental personality or parental perfectionism between the two groups. A trend toward significance was observed for parental emotional instability (p = .087), with parents in the bruxism group described as more anxious, impulsive and irritable, but this did not reach statistical significance.
Why this should change how you talk with parents
Most parents who mention tooth grinding expect to be told it is a dental problem. This study gives sleep consultants the research to reframe that conversation. The authors themselves state that sleep quality should be routinely investigated in children who grind their teeth during sleep.
When a parent reports tooth grinding, the response should not stop at “mention it to your dentist.” Instead, it opens a door to asking about nightmares, how often the child wakes during the night and whether the child seems tired or sleepy during the day. These three signs, which the researchers grouped together as “restless sleep,” were the most reliable indicator of bruxism in this study.
The authors also suggest that sleep bruxism may function as a stress-relieving activity. The restless sleep observed in these children could be a sign of accumulated tension or emotional conflicts.
This does not mean sleep consultants should diagnose perfectionism or treat bruxism. That falls outside the scope of practice. But it does mean that when a family presents with a child who grinds their teeth, wakes frequently and shows signs of daytime sleepiness, the sleep consultant is well placed to address the sleep quality side of the picture and, where appropriate, recommend that the family speak with a psychologist about the emotional component.
Family history is a flag, not a verdict
Family history of bruxism tripled the odds in the initial analysis (OR = 3.07), but this association disappeared once restless sleep was accounted for. The paper does not explain why this happened. What the study did find is that there was no significant difference in parental perfectionism between the two groups, so the familial link does not appear to run through perfectionism directly.
Still, family history remains a useful screening question. A high percentage of children with bruxism had family members who ground their teeth too. Asking about it can prompt a broader conversation about sleep and stress in the household.
How common is this problem?
The paper reports that the prevalence of bruxism in children ranges from 9.8% to 49.6%, affecting boys and girls equally. It tends to decrease with age. Sleep bruxism occurs primarily during non-REM sleep stages. In otherwise healthy children, the authors note, it should be considered a behavior rather than a sleep disorder. But it can be both a risk factor for dental and jaw problems and, at the same time, a signal that the child’s sleep is disturbed.
This is exactly the kind of dual signal that sleep consultants are trained to pick up on. Tooth grinding is not just about teeth. It is about what is happening in the child’s sleep, in their emotional life and in the family environment around them.
Study limitations to keep in mind
This was a single-center study with 104 children from one university clinic in Valencia, Spain. The narrow age range (8 to 9 years) was chosen deliberately, as children at this age can reliably complete personality questionnaires, but it limits how far the findings can be applied to younger or older children. Bruxism was identified through parent report combined with clinical examination, not through polysomnography (which remains the gold standard but is expensive and impractical for routine use). Parents may underreport bruxism if they are unaware of their child’s grinding, which could affect case identification.
Redondo Martínez, I., Catalá-Pizarro, M., & Rojo Moreno, J. (2024). Association between perfectionism, personality traits and probable sleep bruxism in Spanish schoolchildren: A case-control study. International Journal of Paediatric Dentistry, 34(5), 516–523. https://doi.org/10.1111/ipd.13152