An unusual appliance: detrimental occlusal consequences of a lack of clinical monitoring

Case report

A 33-year-old male patient was referred by his GDP to the oral and maxillofacial surgery (OMFS) department of a district general hospital with a history of an increasing anterior open bite (AOB) that he had first noticed while looking in the mirror 6 months previously (Figure 1). The patient had a long-standing history of parafunctional habits and resultant TMD. He had been wearing a custom-made occlusal splint (Figure 2) every night for 18 months prior to noticing his altered occlusion. The patient reported the appliance was constructed in the US using impressions taken by his previous GDP. The patient had shown the appliance to his previous GDP and local dental laboratory, to check that it was appropriate and to see whether the lab provided a similar device. He described the device as being a custom-made bite guard with some spiked components in the palatal aspect to encourage him not to close into intercuspal position (Figure 3).

The patient explained that he had requested a referral to the department from his new dentist owing to concerns about the change in his appearance. Prior to this appointment, when his dentist had instructed him to stop wearing the appliance and agreed to refer him, he was wearing it every night as it had been successful in reducing his TMD. On attendance to the department, he admitted that he had continued to wear the appliance two to three times per week, against the advice of his dentist, despite his concerns over his appearance.

He presented with a mild skeletal Class 2 pattern and clinically increased vertical proportions with habitually competent lips. Mild tenderness of the right masseter muscle was detected on palpation with unrestricted mouth opening. Intra-orally, his dentition was unrestored, and the upper and lower second and third molars alone were in occlusion. There was no evidence of acute or chronic trauma to the palatal mucosa.

Initial management of this patient consisted of educating him on the need to completely cease wearing the appliance, and to provide alternative non-invasive self-management strategies for his TMD. Articulated study models (Figure 4) were constructed and mounted to provide a record of his malocclusion on presentation. He was assessed 3 months later to see whether his AOB was spontaneously resolving because he abstained from wearing the appliance. After 3 months of conservative management, full clinical and radiographic review including a lateral cephalogram (Figure 5) indicated that no spontaneous improvement had occurred. The option of orthodontic intrusion of the lower second and third molars was to be considered if the patient wished for his occlusion (Figure 6) to be corrected. If this proved unsuccessful, then further options would be discussed including extractions.

Discussion

This case report illustrates an unusual appliance that, despite full occlusal coverage in the maxilla, allowed differential tooth movement of the mandibular teeth because its components did not occlude against all of the posterior teeth. The spiked aspect of the fit surface to the palatal tissues was presumably incorporated to discourage the patient from clenching on the rigid acrylic wings. Despite a comprehensive review of the literature, no reports of such a device could be found.

The COVID-19 pandemic restrictions drastically limited the number of clinical examinations undertaken by dentists worldwide.⁶ As previously reported, there are a plethora of well-marketed over-the-counter occlusal splints available on the internet;⁷ however, this appliance was custom made for the patient with the assistance of his former dentist. Anecdotally, patients were reported to have experienced more symptoms of TMD and bruxism during the pandemic,⁸ and therefore may have been more likely to seek out occlusal splints. This case, where the device was custom made abroad, but subsequently checked by a GDP, perhaps highlights that unsubstantiated claims from manufacturers can mislead patients, and even trained clinicians.⁹

A Cochrane review concluded that there is insufficient evidence either for or against the use of stabilization splint therapy for the treatment of TMD,⁵ but where these appliances are described in the dental literature, an emphasis is placed on the importance of providing full occlusal coverage, among other features, to prevent unwanted occlusal changes.^10,11 The appliance discussed here had full occlusal coverage of the maxillary teeth, but the bilateral rigid acrylic wings that were present provided occlusal contact to all of the posterior mandibular teeth apart from the second and third molars which supra-erupted. This resulted in a marked AOB.

As well as carefully considering the design of appliances, this case demonstrates that where an appliance is provided for a patient, it is of vital importance that the occlusion is monitored. A simple means by which to do this is to record an occlusal examination, for example via shimstock contacts,¹² photographs or using study models, before a patient embarks on treatment.

Conclusion

This case report demonstrates the negative impact that poorly designed appliances sought for symptoms of TMD and bruxism can have on a patient's occlusion where there has been a lack of consideration for appliance design, or a lack of monitoring of the patient's occlusion. This case is especially relevant at a time where patients may be experiencing higher levels of TMD and bruxism and have reduced access to regular clinical assessment by a dentist.