Oral splints to help tic control in people with Tourette syndrome: A review of the evidence

Posted on 21 August 2025 by Pippa McClounan

Share

by Eileen Joyce, Emeritus Professor of Neuropsychiatry, UCL Queen Square Institute of Neurology 

In 2010, Sims and Stack described the beneficial effects of an oral splint in patients with Tourette syndrome. They had previously used this technique to treat patients with pain involving the head and face caused by a misaligned lower jaw. They noticed that there was a concomitant improvement in associated behavioural problems including tics. They reported 5 medication-free patients with Tourette syndrome and OCD who they found had an ‘over-closed’ dental bite. For each patient, they fashioned a rigid oral splint which fitted over the lower teeth. This was designed to increase the space between the upper and lower jaw so that the lower jaw was held in a more open position. The height of the vertical space was determined prior to making the splint using 2mm spacers placed between the upper and lower teeth until tics were not evident. They then used this position to create a mould which was used to fabricate a rigid splint. They argued that the vertical height between lower and upper jaw to control tics is unique to each patient. Three months after the splint was fitted, the participants reported that their urge to tic, the tics themselves, and their OCD symptoms were significantly reduced when they wore the splint. This improvement lasted throughout a 6 month follow up period. 

Since then, there have been several case reports describing success in the reduction of tics. Similar, personal splints were fabricated after measuring the vertical height between the upper and lower jaw that was associated with tic suppression (Kwon at al 2018; Murakami et al 2019; Hottel et al. 2019; Stahlke et al 2025; see Appendix for summaries). These studies differed in several ways but the common features included: age below 20 years; the presence of motor and phonic tics; the personalised construction of a splint with a vertical height which opened up the jaw and reduced tics; a positive effect on all types of motor and phonic tics within weeks; effective only while wearing the splint.  

Although several of these studies used objective measures of tic severity, only one has employed a double-blind, randomised, placebo-controlled trial (RCT). This was designed to examine whether positive findings could be directly attributed to the effect of the oral splint or whether there was a more non-specific effect, i.e. a placebo effect (Bennett et al., 2022). They pointed out that patient involvement in determining the appropriate splint vertical height and the multiple, expensive orthodontic visits are potential sources of a placebo effect. They conducted a proof of principle study, i.e. a small, brief study to establish the acceptability of the procedure and whether the vertical height of the orthotic splint determined its effectiveness. 

The study was meticulously planned with each participant being measured for both an ‘active’ splint and a ‘sham’ splint (which was either higher or lower than the height of the active splint; see Figure 1). 13 patients were randomised to wear either the  active (6) or sham (7) splint for 2 weeks. Effectiveness was measured using a tic specific scale (the Yale Gilles de la Tourette Symptom Scale, YGTSS) by an assessor who did not know if the participants were wearing an active or sham splint. After this 2-week ‘double-blind’ phase, there was a significant beneficial effect in the group wearing the active splint compared to the sham splint (p<0.003). The most common side effects were mouth soreness and head and neck pain, but these were mild and diminished over time.

However, there were also some problematic findings. At the end of the 2-week period, the participants were told whether they had been wearing the active splint or the sham splint  and, if they were assigned to a sham splint, they were switched to their own active splint to wear for a further 2 weeks. After these 2 weeks, during which the participants knew which type of splint they were wearing, those continuing to wear the active splint (i.e. for 4 weeks) showed no further improvement although they maintained their initial 2-week improvement. The group which switched from sham to active splint showed no improvement over the following 2-week open phase. All patients were assessed at 8 weeks following the start of the trial and again, there were no significant changes compared to their 4-week assessment. This trial was therefore not definitive in the findings. The demonstration that the ‘blinded’ part of the study did show a significant effect of the splint is encouraging but the lack of improvement when patients were switched from sham to active splints and the low numbers studied suggest that a larger trial is required with sufficient power to test the effect of the splint. To date, there is no indication that such a larger trial is underway (clinicaltrials.gov).   

Figure. A typical oral splint which is individually fitted over the lower teeth to increase the vertical height between upper and lower jaw. Taken from Bennett et al (2022). Child Psychiatry & Human Development (2022) 53:953–963. Shown with kind permission of Dr Bennett.

How might an oral splint work?     

There have been two yet unproven explanations as to how an oral splint might reduce tics.  One was proposed by Sims and Stack (2010) who first described tics being improved by the use of an oral splint. They suggested that in Tourette syndrome, the lower jaw (mandible) is abnormally positioned at the base of the skull causing constant irritation of the trigeminal nerve as it enters the mandible to innervate the teeth, muscles and skin of the lower jaw. This nerve is known to relay sensations from these areas to the brain. Abnormal trigeminal stimulation is thought to be the cause of nerve pain and has also been linked to bruxism (clenching and grinding of the teeth). They argue that in Tourette syndrome, this irritation is below the threshold for conscious pain perception but that constant stimulation could feed into brain sensory systems which can then trigger reflexive involuntary movements. They suggest that the splint relieves this abnormality by repositioning the mandible. Currently, there is no experimental evidence to support this hypothesis.

The second explanation is that the splint acts as a ‘sensory trick’ (Murakami et al., 2019). The use of a sensory trick is well described in people with a painful movement disorder known as dystonia who find that touching or pressing a part of the head and neck or adopting a certain head and neck posture brings temporary relief from the uncomfortable neck muscle contractions. They suggest that biting down on the splint similarly modulates sensory signals from the muscles which close the jaw and that these sensory signals are relayed to a brain area shown to be hyperactive in Tourette syndrome, the insular cortex. Although there is no experimental evidence to support this as a mechanism, there are several reports describing various sensory tricks used by Tourette patients in everyday life (Gilbert, 2013; Wojcieszek and Lang, 1995).    

Summary

The beneficial effect of wearing an oral splint for tic control was first described in 2010. Since then, there have been several other positive reports.   Suppression of tics is thought to be due to the splint increasing the vertical height between the upper and lower jaw. Only one study, reported in 2022, used a design which could distinguish between a specific effect of the splint or a more general ‘placebo’ effect.  This was a small study which nevertheless showed a positive effect indicating that the height between the upper and lower jaw created by the splint is critical and is different for each person. However, there were other more complex findings which would need a much bigger study to show sustained improvement of tics. At present, to our knowledge, the use of oral splints is not being actively studied using such a rigorous design.       

The view of Tourettes Action                                                                

Although the results of studies are promising, there is insufficient evidence to recommend an orthodontic intervention. More research is needed to investigate whether oral splints provide a sustained positive effect in large groups of people with Tourette syndrome. In addition, to manufacture the type of oral splint shown to improve tics requires considerable orthodontic expertise and is costly. To our knowledge, there is no standard procedure available in the UK to make such a splint.  For these reasons, we cannot recommend the use of an oral splint uniquely for the relief of tics e.g. when splints are not otherwise needed for other orthodontic reasons.

References 

Bennett SM, Hindin JS, Mohatt J, et al., Proof of concept study of an oral orthotic in reducing tic severity in Tourette syndrome. Child Psychiatry and Human Development. 2022 53 (5): 953–963. Gilbert RW. Tic modulation using sensory tricks. Tremor Other Hyperkinet Mov (N Y). 2013;3:tre-03-115-3129-1. 

Hottel TL, Jack RL, Taynor E, et al. Improved Yale Total Tic Severity Score due to craniofacial manipulation with an oral appliance. Compendium of Continuing Education in Dentistry. 2019 40 (1): e6–e15. 

Kwon OS, Lee SM, Choi KH, et al. Effects of orthopaedic treatment using temporomandibular joint balancing appliance (TBA) at improving the symptoms of tic/Tourette syndrome: Case report. Integrative Medicine Research. 2018 7 (4): 381–386. 

Murakami J, Tachibana YD, Akiyama S, Kato T, Taniguchi A, Nakajima Y, Shimoda M, Wake H, Kano Y, Takada M, Nambu A, Yoshida A. Oral splint ameliorates tic symptoms in patients with Tourette syndrome. Movements Disorders. 2019 34 (10): 1577-1578. 

Sims AB, Stack BC. An intraoral neurocranial vertical distractor appliance provides unique treatment for Tourette’s syndrome and resolves comorbid neurobehavioral problems of obsessive compulsive disorder. Medical Hypotheses. 2010 75:179–184

Stahlke AH, Bonotto D, Bonotto DV, Hilgenberg-Sydney PB. Conservative management of Tourette syndrome tics using intraoral ccclusal devices: Report of two cases. Special Care in Dentistry. 2025 45(2): 1-5.   

Wojcieszek JM, and Lang AE. Gestes Antagonistes in the suppression of tics: “tricks for tics”. Movement Disorders. 1995 10(2): 226-228  Mov Disord. 1995 Mar;10(2):226-8.  

Appendix. Summary of observational studies after the initial report by Sims and Stack (2010). 

Kwon et al (2018) reported 3 cases (8,9 and 15 years) treated with oral splints to correct temporomandibular right-left deviation and supplemented by acupuncture and Chinese herbs. All 3 had motor tics affecting more than one body part, as well as phonic tics. They used 3 assessment measures conducted at intervals during the follow-up period: the Yale Gilles de la Tourette Symptom Scale (YGTSS) completed by parents, a visual analogue scale (VAS) completed by the participant, and videos assessed by the clinicians. The symptoms were reduced by day 30 and remained at a reduced level 240 or 300 days later. Most of tics had disappeared by 240–300 days.  

Murakami et al (2019) examined tic scores in 22 patients with an average age of 17 years using the Tic Symptom Self-Report. The patients had motor tics affecting more than one body part, and phonic tics. The average reduction in tic rates were 30% and 43%, respectively. 72.7% exhibited improvements in both motor and phonic tics. Overall, motor and phonic tic scores were significantly improved and the effects were long lasting (>100 days of treatment). Younger age at onset was associated with a better degree of improvement 

Hottel et al (2019). This is a study described in an abstract without a full paper being available. 58 patients completed a study comparing the Tic Guard appliance and a sham. They showed a statistically significant improvement in the YGTSS with both the sham appliance and the Tic Guard with more robust improvement with the Tic Guard. The sham appliance resulted in a 25% overall reduction in tic severity, while the Tic Guard resulted in a 39% overall reduction in tic severity. It is not clear if the study was an RCT.  

Stahlke et al (2025) published two case studies of patients with Tourette syndrome and bruxism (clenching and grinding of the teeth), aged 10 and 17 years. They were followed for 6 months and reported improvements in tic frequency as well as enhancements in their ability to focus and concentrate on academic activities.

August 2025

Return to news