Table 1 Summary of study characteristics and outcomes [5, 12,13,14,15,16,17,18,19,20,21,22,23,24,25]

Wang et al., [15]

RCT

18

China

Age range (18–44)

The test group consisted of digital splints that were planned and manufactured using computer-aided design and computer-aided manufacturing (CAD/CAM) techniques. In contrast, the control group consisted of rigid splints constructed using transparent acrylic resin.

Compared with the control group, the manual time spent in the test group was significantly less. No statistically significant differences were observed across the groups across the VAS retention scores. However, the test group exhibited significantly higher scores regarding wearing comfort. The test group showed significantly lower levels of both maximum depth loss and volumetric loss compared to the control group.

Compared to conventional rigid splints, the digitally generated splints were associated with better comfort and time efficiency. The new milling material (PEEK) also offers superior wear resistance to acrylic resins.

Karakis et al., [30]

RCT

12

Turkey

Students with Age range (18 to 27)

Rigid stabilization splints fabricated from auto-polymerizing acrylic resin. v/s Bruxogard-soft splints are prepared easily without impression.

Using rigid stabilization splints yielded no statistically significant alterations in occlusal force. The Bruxogard-soft splint demonstrated a statistically significant reduction in occlusal force. A statistically significant improvement was observed in the individuals' CMI value in both groups utilizing splints.

Participants' utilization of a Bruxogard-soft splint resulted in a reduction in occlusal force. Utilizing both splints resulted in a notable decrease in the clinical manifestations.

Harada et al., [31]

RCT

16

Japan

Not reported

Stabilization splint (SS) v/s palatal splint (PS). Both are rigid splints made of heat-cured hard acrylic with a wax-up method.

Both splints demonstrated a considerable decrease in SB immediately upon device insertion; however, no further reduction was observed. No statistically significant difference was observed in the impact on SB between the SS and PS conditions.

Both splints demonstrated a reduction in masseter electromyography (EMG) activity that was related to sleep bruxism (SB); however, it should be noted that this impact was temporary.

Dalewski et al., [32]

RCT

30

Poland

mean age 24.8

Okeson's Stabilization Splint is mainly made for the upper arch to position the mandible (lower jaw) in a stable musculoskeletal position. v/s Bimaxillary Involves both the upper and lower arches.

It positions the mandible in a stable musculoskeletal position.

In both groups, pain was significantly reduced.

Both splint designs can effectively alter the pressure pain threshold in patients with diagnosed bruxism.

Dubé et al., [33]

RCT

9

Canada

5 Females

4 Males

(mean age = 23.7)

Hard Acrylic Occlusal Splint- made of hard acrylic material and has a U-shaped design.

It is designed to be worn on the maxillary (upper) arch and adjusted to the patient's centric tooth relation—v/s Palatal Control Device –inserted on the maxillary arch and modified for maximum tooth intercuspation.

The two devices demonstrated a statistically significant decrease in the frequency of SB episodes per hour and SB bursts per hour. Both oral devices showed a reduction of 50% in the occurrence of grinding noise episodes. There was no discernible distinction noticed between the devices. Both devices demonstrated a decrease in muscle activity related to sedentary behavior.

Oral devices minimize SB promotor episodes and tooth-grinding in SB patients.

Okeson, [34]

Intraparticipant design

10

Not reported

Females = 5; males = 5. Mean Age = 27.4 years

Hard Acrylic Occlusal Splint- Covers all maxillary teeth.

It is adjusted for even and simultaneous contacts of mandibular buccal cusps and incisal edges in centric relation. v/s Soft Vinyl Occlusal Splint—Made from thick, soft vinyl sheets adapted to the maxillary cast. Adjusted to achieve even contact of mandibular teeth during light closure.

The rigid occlusal splint significantly reduced muscular activity among 80% of the individuals (8 out of 10). Utilizing the soft occlusal splint resulted in a notable decrease in muscle activity in one person while inducing a statistically significant elevation in muscle activity in five out of the ten participants.

A soft occlusal splint may not be recommended in individuals exhibiting symptoms linked to heightened muscular activity throughout the night. A rigid occlusal splint seems to be a more probable practical course of therapy.

de Paula Gomes et al., [35]

RCT

60

Brazil

Age range (18–40)

A Michigan-type occlusal splint—molded for each volunteer's upper arch containing canine and protrusive guides and a flat occlusal surface for contact with the teeth. v/s

The silicone occlusal splint- is made by vacuum pressure molding from a 3-mm soft polyvinyl sheet.

Either massage treatment or an occlusal brace did not significantly alter the electromyographic activity of the masseter and anterior temporal muscles.

A multimodal approach may be more effective in managing the complex presentation of TMD and sleep bruxism.

Bergmann et al., [36]

RCT

41

Germany

females = 21; males = 18. Mean Age = 41.3 ± 14.2(control) 37.6 ± 11 (test)

The Adjustable Occlusal Splint (AOS) comprises transparent auto-polymerizing dental acrylic resin. It exhibits a level occlusal surface with consistent contact points in the centric relation and anterior guidance for movements during excursive actions. versus

The Biofeedback Splint (BFB) consisted of soft thermoformed maxillary dental plates that provided a full covering.

The biofeedback group improved the patient's overall well-being, face muscle pain, and decreased burst frequency and length. The average and maximum durations in the biofeedback group were statistically reduced after the therapy was terminated.

Biofeedback splint improves the patient's pain perception and lowers SB. The findings imply that an AOS (adjusted occlusal splint) is not the most effective therapy for discomfort associated with bruxism compared to the biofeedback splint.

Lei et al., [37]

Pre-post Intervention Analysis

16

China

Age Range 20 to 45 yrs

The occlusal splint is composed of a thermoplastic material with a thickness of 1.5 mm. versus. The occlusal splint is composed of a soft thermoplastic material with a thickness of 1.5 mm. A revised anterior splint design, which comprises a thermoplastic partial rigid occlusal splint with a thickness of 1.5 mm, is proposed. This splint is intended to cover the anterior maxillary teeth. A flat bite plate made of self-curing resin is also on the palatal side.

The individuals who used a modified anterior splint had substantially lower EMG data than those who used a hard or soft occlusal splint or did not use a splint. Participants who do not use a splint exhibit the highest biting force and bite area, while participants who utilize a modified anterior splint have the lowest bite force and bite area.

The utilization of a modified anterior splint has been found to exhibit enhanced comfort and efficacy in mitigating occlusion force and electromyographic activity of the anterior temporalis and masseter muscles among individuals with bruxism.

Kolcakoglu et al., [38]

RCT

240

Turkey

children with a Mean Age of 8.6 yrs

Soft Occlusal Splints- made using a 1.5 mm-thick soft thermoplastic material designed to cover all teeth' incisal and occlusal surfaces in a U-shape. v/s

Rigid Occlusal Splints—made using a 1.5 mm-thick thermoplastic hard material and covered all teeth' incisal and occlusal surfaces in a U-shape like the soft splints

Using a soft occlusal splint resulted in a considerable reduction of muscle discomfort during palpation and pain experienced in the dynamic position of the temporomandibular joint (TMJ) pain among patients. The BiteStrip® score for groups I and II showed no statistically significant alteration.

Soft occlusal splints have the potential to alleviate discomfort resulting from nocturnal bruxism, particularly about the muscles and temporomandibular joint (TMJ). No significant correlation exists between treatment outcomes and BiteStrip® ratings among patients using soft or hard occlusal splints.

Ariji et al., [39]

RCT

16

Japan

Men = 11 women = 5; Age

Range 27–53 yrs. Mean Age 35.5 yrs

Soft Splints were customized for each subject and made from 3-mm ethylene–vinyl acetate sheets with a hardness of 7955g. v/s

Rigid Splints were customized for each subject and made from 3-mm polyethylene terephthalate glycol sheets. The splints had a flexural strength of at least 55 MPa and a flexural modulus of around 2000 MPa.

The rigid splint resulted in an augmentation of the blood oxygen level-dependent (BOLD) signals inside BA6 and BA20. The blood oxygenation level-dependent signals in the left BA6, the left BA20, 37, and the right BA44, 45 exhibited a statistically significant increase when clenching with a rigid splint compared to natural teeth.

Clenching one's jaw while wearing a rigid splint resulted in neural activation throughout many expansive brain areas, including the specific area connected with the coordination of motor functions.

Lukic et al., [40]

RCT

10

Switzerland

Males = 4 females = 6, Mean Age = 30 ± 6 yrs.)

Michigan Splint: Customized for each participant using (CAD/CAM) and manufactured from methyl Methacrylate, a hard-acrylic resin. v/s

NTI-tss Device -Designed to cover the maxillary incisors and contact only the tips of the lower middle incisors and filled chair-side with auto-polymerizing acrylate to adjust the patient's teeth

The NTI-tss device was associated with a reduction in muscle activation. The Michigan splint was shown to be the favored choice among most patients, primarily because of its superior level of wearing comfort.

NTI-tss devices have shown more efficacy in reducing jaw muscle activation during sleep. One notable benefit of the prefabricated NTI-tss is its immediate accessibility during the acute phase of temporomandibular disorders linked to sleep bruxism. In addition, it is essential to consider subjective preferences, the level of wearing comfort, and the associated expenditures.

Al Quran & Lyons, [41]

Not Clear

10

UK

Young adults (age range 21–34 yrs.)

Rigid Acrylic Resin Splint- Made to a jaw registration with the mandible in the (retruded) returned position, anterior teeth approximately 2 mm apart, and widespread occlusal contacts in the (retruded returned position.

v/s

Soft Acrylic Resin Splint: Vacuum-formed on a cast of the upper teeth with no occlusal adjustment.

The study revealed that using rigid splints reduced electromyographic (EMG) activity compared to the absence of splints during maximal clenching. This effect was seen in both muscles, with a notable drop in the anterior temporalis muscle. The use of soft splints resulted in a modest elevation in the activity of both muscles, with a specific emphasis on the masseter muscle.

The therapeutic impact of both a hard and a soft splint may be attributed, in part, to a reduction in the activity of the temporalis muscles compared to the masseter muscles. However, it is worth noting that this decrease is more pronounced with a rigid splint.

Deregibus, [42]

RCT

40

Italy

13 Males

27 Females

47.2 ± 12.8 yrs.; range, 22 to 56 yrs.)

Upper Michigan OS (Group 1)- in contact with the mandibular supporting cusps and had cuspid guidance that disclosed the supporting cusp contact almost as soon as lateral movements were made.

v/s

Mandibular OS (Group 2)- constructed to allow only posterior contacts (from the second premolar to the second/first permanent molar) without static and dynamic anterior contacts.

The outcome measures tested within both groups showed no statistically significant differences. Nevertheless, it was observed that Group 2 exhibited a notably more excellent range of motion (ROM) in the right lateral mandibular direction at T2 and a substantially higher ROM in the left lateral mandibular direction during T3.

The research findings indicate that an orthodontic splint (OS), regardless of its placement on the upper or lower arch, does not substantially impact pain reduction among patients with temporomandibular disorder (TMD) during six months.

Silva et al., [43]

Not Clear

1

Brazil

Young-adult male patient

Hard v/s soft Occlusal Splint (OS)- A standard OS with a 3 mm thickness, designed for the study subject, was used during image acquisition and later created as a part of the 3D model.

Comparing occlusal splints showed no significant stress intensity or distribution changes in the left or right TMJ discs. It should be observed that the anterior disc was most stressed.

Using rigid acrylic occlusal splints over soft ones is advisable in most situations. It is recommended to prioritize using thinner operating systems, with an anterior thickness ranging from 2 to 3 mm, as opposed to thicker ones measuring 3 to 4 mm. It is advisable to choose lighter contacts over heavy contacts when considering the contact surface area of the second molar to mitigate stress concentrations and minimize the risk of fractures.

TOTAL

529