UNIVERSIDADE ESTADUAL PAULISTA
“JÚLIO DE MESQUITA FILHO”
Instituto de Ciência e Tecnologia
Campus de São José dos Campos
ORIGINAL ARTICLE DOI: https://doi.org/10.4322/bds.2025.e4521
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
This is an Open Access article distributed under the terms of the Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/), which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
Alívio dos sinais e sintomas em pacientes com disfunção temporomandibular utilizando placas oclusais estabilizadoras
ajustadas com T-scan versus papel carbono: um ensaio clínico randomizado
Sara Eman Abdelsalam1 , Ashraf Emil ESKANDAR1 , Ramy Maher GHALY2 , Mohamed Amr Mohamed EL KHASHAB1
1 - Cairo University, Faculty of Dentistry. Cairo, Egypt.
2 - Ain Shams University, Faculty of Dentistry. Cairo, Egypt.
How to cite: Abdelsalam SE, Eskandar AE, Ghaly RM, El Khashab MAM. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial. Braz Dent Sci.
2025;28(2):e4521. https://doi.org/10.4322/bds.2025.e4521
ABSTRACT
Objective: To evaluate the relief of signs and symptoms of temporomandibular disorders (TMDs) after splint
equilibration via two methods: articulating foil and T-scan. Material and Methods: Twenty-eight patients with
myofascial TMD were selected and divided into two groups. Each group were treated with additive CAD/CAM
stabilization splints equilibrated using either articulating foil or T-scan. Pain reduction percentage, improvement
in jaw function and pain free range of movements were assessed after 1 and 3 months. The data were analyzed
by the repeated measures one-way ANOVA test followed by the Tukey’s post hoc test and the independent
t- test. Results: There was a signicant reduction in pain improvement in jaw function and pain free maximum
opening within each group, without statistically signicant differences (p>0.05) between both groups after
1 and 3 months. Conclusion: T-scan and articulating foil are both effective in stabilization splint equilibration.
KEYWORDS
Articulating foil; Occlusal splint; Pain; TMD; T-scan.
RESUMO
Objetivo: Avaliar o alívio dos sinais e sintomas das disfunções temporomandibulares (DTMs) após o ajuste
de placas por dois métodos: papel carbono e T-scan. Material e Métodos: Vinte e oito pacientes com DTM
miofascial foram selecionados e divididos em dois grupos. Cada grupo foi tratado com placas estabilizadoras
CAD/CAM do tipo aditiva, ajustadas com papel carbono ou T-scan. A porcentagem de redução da dor, a melhora
da função mandibular e a amplitude de movimentos sem dor foram avaliadas após 1 e 3 meses. Os dados foram
analisados por meio do teste ANOVA de uma via para medidas repetidas, seguido do teste post hoc de Tukey e
do teste t independente. Resultados: Houve redução signicativa da dor, melhora da função mandibular e da
abertura máxima sem dor dentro de cada grupo, sem diferenças estatisticamente signicativas (p > 0,05) entre os
grupos após 1 e 3 meses. Conclusão: O T-scan e o papel carbono são ecazes no ajuste de placas estabilizadoras.
PALAVRAS-CHAVE
Papel carbono; Placa oclusal; Dor; DTM; T-scan.
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
INTRODUCTION
Temporomandibular disorders (TMDs) are
general terms that include various disorders
that involve the temporomandibular joint, the
masticatory muscles and associated structures. TMDs
have become one of the most prevalent disorders
that influence patient’s quality-of-life and daily
functional activities in current populations [1,2].
Patients experiencing TMD typically present with a
range of symptoms, including pain during opening
and closing, crepitus, limited mouth opening and
morning stagnation [3].
Controversial opinions have dominated the
literature concerning the etiology, diagnosis,
and treatment of TMD. Given the challenge
of pinpointing a single primary cause for
these symptoms, the etiology of this disorder
is considered multifactorial. However, the
relationship between dental occlusion and TMD
remains a topic of debate among researchers [4].
The effectiveness of pain reduction through
splint therapy is well-documented in the
literature. Numerous studies have reported the
resolution of symptoms following the insertion
of occlusal splints (OS) [5-7]. The stabilization
splint, with its characteristic occlusion scheme,
is among the most commonly used occlusal
splints for managing symptoms of TMD [8]. To
attain the desired occlusal scheme objectives, the
occlusal splint should be adjusted using occlusal
detection methods.
Various occlusal indicators, including Mylar
paper strips, polyether rubber impression bites,
wax, articulation foil, occlusal sprays, foils,
occlusal sonography, and T-Scan are employed
in clinical practice [9]. Among these, articulating
foil is the most commonly used indicator in dental
practice. Previous studies were mainly concerned
with analyzing its physical properties, such as
thickness, composition, ink and substrate, as well
as plastic deformation. However, clinical studies
analyzing the size and characteristics of the foil
marks have shown no correlation between the
size of articulating foil markings and the applied
occlusal force [10].
On the other hand, the T-Scan occlusal
analysis system is a Microsoft system that has
dominated researches once it evolved. It is capable
of recording occlusal contacts within 0.01-s
increments. The T-Scan system is composed of a
recording handle which houses an autoclavable
sensor support and a disposable Mylar-encased
100 µm sensor that registers occlusal contact
at 5-10 µm. It is regarded as the most accurate
occlusal detection method regarding quantity
and timing of occlusal contacts in the literature
which remain unaffected by changing the sensor
or repeating the measurements, as well as the
presence of saliva [11-13].
Although marked occlusal load imbalance
was found in conventionally adjusted stabilization
splints when tested with the T-Scan, no therapeutic
effects of the conventionally adjusted and T-Scan
adjusted splints were studied in spite of its
importance for clarifying the effectiveness of a
well-balanced stabilization splint in symptom
resolutions [14].
Therefore, the objective of the present study
was to evaluate the relief of signs and symptoms
of TMD after using occlusal stabilization splints
equilibrated using T-scan versus articulating foil.
Despite the documented accuracy of the T-scan in
comparison to articulating foil, it is hypothesized
that there will be no difference between them
regarding the relief of TMD signs and symptoms.
MATERIAL AND METHODS
A randomized clinical trial with a
preoperatively dened treatment protocol was
conducted on twenty-eight patients with TMDs.
The research proposal was reviewed and approved
by the research ethics committee and the study
protocol was registered on ClinicalTrials.gov
(NCT04661670).
Sample size calculation was performed by
comparing the reduction in pain score that denotes
relief of symptoms and signs in TMD patients.
As reported in a previous publication [15], the
mean ± SD pain score reduction in the conventional
group was approximately 91.9 ± 21%, and it was
assumed that the new intervention would achieve
at least 25% improvement in pain reduction [14].
Accordingly, we calculated that the minimum
proper sample size was 14 patients in each group
to be able to reject the null hypothesis with 80%
power at α = 0.05 level using the Student’s t- test
for independent samples. Sample size calculations
were performed using PS Power and Sample
Size Calculations software, version 3.0.11 for MS
Windows (William D. DuPont and Walton D.,
Vanderbilt University, Nashville, Tennessee, USA).
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
The patient selection process adhered to
predetermined inclusion and exclusion criteria.
All enrolled patients met the following criteria:
fully or partially dentate male and female
compliant adult patients with no more than
one missing tooth per quadrant (excluding
third molars) and who experienced signs and
symptoms of TMD (diffuse pain in the head
and neck, headache, pain exaggeration by jaw
movements and restricted jaw movements),
which was confirmed using the diagnostic
criteria for temporomandibular disorders
(DC/TMD) Axis I. Patients who were diagnosed
with other TMD disorders such as degenerative
diseases were excluded from the study. All
participants were informed of the nature of
the research study and were allowed to sign an
informed consent form.
The base line pain scale score and range of pain
free jaw movements (mm) were recorded before
starting the treatment. Patients were randomly
divided into two parallel groups at a 1:1 ratio after
diagnosis. Each group was composed of 14 patients;
Group A received occlusal stabilization splints
equilibrated using articulating foil, while Group B
received occlusal stabilization splints equilibrated
using T-scan (Figure 1).
Two computer-generated column tables
of random numbers were established using
www.random.org to produce the random
allocation sequence of the participants. Every
participant grasped an opaque sealed envelope
from a box. Being sealed and opaque ensured
allocation concealment. Blinding of the patients
and the care provider regarding the interventions
was not feasible; however, the outcome assessor
and statistician were blinded.
Primary impressions were made using
irreversible hydrocolloid impression material
(Zhermac Hydrogum 5), and the obtained study
casts were used for the mounting procedures and
nal occlusal adjustments of the occlusal splints.
A maxillary face-bow transfer was mounted on a
semi-adjustable articulator (A7-Plus Bio Art semi-
adjustable articulator), followed by a jaw relation
record using Futar D, Ultra Rigid, Kettenbach LP
in the centric relation after deprogramming the
muscles using leaf gauges. A protrusive record
was made at 6 mm mandibular protrusion to
set the horizontal condylar guidance, while the
lateral condylar guidance was adjusted at a xed
value of 15 degrees. The centric relation record
was verified by comparing the first point of
contact intraorally and the rst point of contact
on the articulator after mounting.
The mounted casts were scanned using an
extraoral scanner (DOF Freedom UHD Desktop)
to produce virtual 3D models on which occlusal
splints were designed. Occlusal appliances
were fabricated on mandibular arches for all
patients with the aid of a specialized computer
aided designing software (Exocad-Dental CAD
software). Firstly, virtual surveying was carried
out to detect the teeth height of contour. The
extension of the occlusal splint was determined
at a slightly occlusal level to the height of the
contour buccally while 1-2 mm beyond the
gingival margin lingually. A complete arch
coverage design was performed and shaped to
be at occlusally. Aided by the virtual articular
which was adjusted based on the previously
adjusted angles and color-coding feature in
the software, balanced anterior and posterior
bilateral contacts with posterior disocclusion on
excursive movements was achieved (Figure 2).
Figure 1 - Patients enrollment and distribution.
Figure 2 - Stabilization splint design.
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
The STL les of the nished CAD splints were
subsequently transferred to a 3D slicing software
(Chitubox 1.9.3) to produce twenty-eight occlusal
splints using an occlusal splint resin material
(Harz Labs Dental Splint, Russia) and a DLP, LCD
printer (AnyCubic Photon s, ANYCUBIC, China).
The files were sliced at a zero-degree print
orientation with a 0.05 mm layer height, bottom
layer count of 8, 1.7s exposure time, 1.7 mm/s
lift speed, and a 1s wait before printing .
After completion of the printing procedure,
all the splints were cleaned for 3 minutes in
96% reusable ethanol solution followed by
an additional 2 minutes in 96% fresh ethanol
solution. The cleaned splints were then sprayed
with ethanol and scrubbed with a brush soaked
in ethanol to rinse off any remaining residual
resin. The study samples were then prepared for
post curing by removing the support structures
using a side cutter. The splints were checked for
t and then subjected to a post-curing process
of 80 °C in an oven for 30 minutes followed by
3-5 minutes of 405 nm UV light in a light curing
box (AnyCubic Wash& Cure 2.0 Curing Box,
ANYCUBIC, China) (Figure 3).
Occlusal refinement of the constructed
splints was carried out on the previously mounted
articulator using 20 µm thick articulating foil
(AccuFilm, Parkell, USA) (Figure 4). At the next
clinical visit, all splints were inserted and checked
for stability and comfort before initiating the
intraoral occlusal adjustment.
For Group A; the nal occlusal correction
was performed while the patient was in the
supine position using 20 µm thickness articulating
foil and 8 µm thickness shim stock (DENU Shim
Stock, HDI Inc.) The patient was asked to tap
3 times on the articulating foil and occlusal
correction was performed using a carbide
laboratory bur and rubber cone until a uniform
contact on all teeth was achieved in centric
relation. This was illustrated on the splint by a
series of uniformly appearing articulating foil
marks. The patient was subsequently asked to
perform protrusive, right and left excursions to
ensure smooth anterior guidance and posterior
disocclusion (Figure 5).
For Group B; occlusal equilibration was
performed using the T-Scan III (software
version 8.0) computerized occlusal analysis;
where the same adjustment sequence was used
as in Group A. The T- Scan dental arch size was
adjusted to t the patient’s arch by measuring the
width of the central incisor using a periodontal
probe. A centric occlusion scan in turbo mode
(0.003 second incremental scanning) was
selected. The sensor was placed intraorally so
that the midline ‘V’ of its support contacts the
midline of the central incisors, followed by a
Figure 3 - 3D printed stabilization splint.
Figure 4 - Stabilization splint adjusted on the articulator.
Figure 5 - (a) Centric relation contact; (b) Protrusive movement contact; (c) Lateral excursive contact.
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
conditioning process in which the patient was
allowed to strongly bite on the sensor 2-3 times.
At this point it is important to calibrate the
sensitivity level in the software to t the patient’s
biting force. The patient was asked to gently
occlude on the posterior teeth, then clench
rmly for one to three seconds. This procedure
was repeated until 1-3 pink spots were evident
on the T scan graph. Skipping this procedure
will result in a hyper or hypo responsive sensor.
The splint was then inserted intraorally and
the patient was asked to clench to record the
occlusal force. Guided by the articulating foil
marks, areas requiring adjustments were ground
using a carbide laboratory bur until the occlusal
force distribution was bilaterally balanced on the
software and the center of force (COF) icon sits
close to the midline (Figure 6).
Mandibular excursions were then adjusted
in a similar maneuver. The appropriate excursion
scan label was chosen, after which the patient
was asked to clench on their posterior teeth for
one to three seconds, and then move in a lateral
or protrusive excursion to the full extent of
the border movement. Contacts other than the
anterior and canine guidance were eliminated
until achieving anterior guidance and posterior
disocclusion in a time less than 0.5 seconds
(Figures 7 to 9).
Finally, all patients in both groups were
allowed to occlude comfortably in an upright
position to ensure that all teeth were in contact
evenly, with no anterior teeth contacting harder
than the posterior ones. No nishing or polishing
was performed following the final occlusal
adjustments to maintain the achieved rened
occlusal contacts.
All patients were instructed to wear the
occlusal splints during sleep and were initially
scheduled for weekly occlusal refinement
appointments until no longer needed. The
patients were then recalled after 1 (T1) and 3
Figure 6 - Centric relation T-scan record.
Figure 7 - (a) Centric relation contact; (b) Protrusive movement contact; (c) Lateral excursive contact.
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
months (T2) to evaluate the change in TMD pain
symptoms using questionnaires, in addition to the
change in range of pain free jaw movements using
a ruler (Figure 10). Both questionnaires: The
Graded Chronic Pain Scale and Jaw Functional
Limitation Scale questionnaire were used in the
participant’s native language version provided by
the International Network of Orofacial Pain and
Related Disorders methodology website [16].
Statistical methods: Data was analyzed using
the IBM SPSS advanced statistics (Statistical Package
for Social Science), version 20 software (SPSS Inc.,
Chicago, IL, USA). Numerical data was described as
mean and standard deviation or median and range.
Data was explored for normality using the Shapiro
Wilk and Kolmogorov Normality tests. For the
parametric data, the independent t- test was used
for comparison between both groups. Repeated
Measures One-Way ANOVA followed by the Tukey’s
Post Hoc test was used for comparison between
different intervals. A p-value less than or equal to
0.05 was considered statistically signicant. All tests
were two tailed.
Figure 8 - Protrusive movement T-scan record.
Figure 9 - Lateral excursive T-scan record.
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
RESULTS
The normality test revealed that the
signicance level (P-value) was insignicant at
P-value > 0.05, which indicated that the data
originated from a normal distribution (parametric
data) resembling a normal bell curve in both groups
for all parameters. The baseline characteristics of
both groups are shown in Table I.
Pain intensity and percentage of pain
intensity reduction: For both groups, there was
a statistically signicant difference between the
different intervals (P<0.05). The percentage
of pain intensity reduction was calculated and
revealed to be 28% and 39% in the articulating
foil group and T-scan group, respectively. In the
T-scan group, pain intensity was signicantly
greater at baseline and significantly lower,
while T2 revealed an insignificant difference
from the other intervals. On the other hand, in
the articulating foil group, the pain intensity
at baseline and T1 was significantly greater
than that at T2 (P>0.05), while at T2, it was
signicantly lower. A comparison between the
two groups in Table II at different intervals
revealed a statistically insignicant difference
between them regarding baseline, T1 and T2.
Jaw Functional Limitation scale (JFL)
For the T-scan group, there was a statistically
signicant difference between the different intervals
(P<0.05). The JFL score at baseline was signicantly
the highest, while at T1, it was significantly
the lowest, and at T2, revealed a statistically
insignicant difference with the other intervals. For
the articulating foil group, there was an insignicant
difference between different intervals as P>0.05. A
comparison of the two groups in Table III revealed
a statistically insignicant difference between them
regarding baseline, T1 and T2.
Range of pain free jaw movements: For both
groups, there was a statistically insignificant
difference between different intervals regarding
protrusion, right and left excursion. Regarding
pain free maximum opening, in the T-scan
group, there was a signicant difference between
baseline and T1 (P=0.01) and an insignicant
difference between T1 and T2. In the articulating
foil group, there was a significant difference
between baseline and T2 (P=0.007), while T1
revealed insignicant differences with the other
intervals. A comparison of the data between
the two groups at different intervals in Table IV
revealed that the differences were not statistically
signicant (P >0.05), and revealed statistically
insignificant differences at all intervals of
opening, protrusion, right or left excursion.
In Table V, a summary with a P value
difference between baseline, T1 and T2 with each
group for each outcome.
Figure 10 - Range of movement assessment: (a) Maximum pain free opening; (b) Lateral excursive movement measurement.
Table I - Baseline characteristics
Characteristics
T-scan
equilibration
group
Conventional
equilibration
group
Age 18-35 years old 17-40 years old
Gender Males 0 2
Females 14 12
Medical
history
Colitis 2 4
Sinusitis 6 3
Sleep
problems 4 6
Neck and
back pain 2 1
Stress 6 7
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
Table II - Pain intensity score at different intervals between both groups and percentage of pain intensity reduction
Study group Control group (Articulating foil group) P value(T-scan group)
Mean Standard Deviation Mean Standard Deviation
Pain intensity score
Baseline 63.00 23.92 53.00 21.66 0.23
T1= 1M 50.57 24.91 47.86 28.66 0.78
T2=3M 52.29 23.89 43.57 24.85 0.33
Percentage of pain intensity
reduction 39 44 28 33
Table III - Jaw Function Limitation Scale at different intervals between both groups
Jaw Function
Limitation Scale
Study group Control group
P value(T-scan) (Articulating foil)
Mean Standard Deviation Mean Standard Deviation
Baseline 32.86 19.00 28.14 22.09 0.53
T1= 1M 18.71 13.44 23.29 16.77 0.41
T2=3M 21.29 12.24 22.86 16.58 0.76
Table IV - Pain free jaw movements (in mm) at different intervals between both groups
Pain free jaw movements
Study group Control group
P value(T-scan) (Articulating foil)
Mean Standard Deviation Mean Standard Deviation
Opening
Baseline 35.71 2.70 34.71 9.01 .580
T1= 1M 40.00 7.17 36.43 8.50 .240
T2=3M 39.86 6.29 37.71 8.50 .455
Protrusion
Baseline 6.86 .66 6.29 1.54 .214
T1= 1M 7.29 .99 6.29 1.54 0.051
T2=3M 7.29 1.20 6.71 1.82 .335
Right excursion
Baseline 7.43 2.59 8.57 2.06 .208
T1= 1M 8.00 2.22 7.57 2.34 .623
T2=3M 7.86 2.25 7.86 1.79 1.000
Left excursion
Baseline 8.43 2.21 7.86 2.80 .554
T1= 1M 8.14 1.79 7.43 2.53 .397
T2=3M 8.43 1.91 7.86 1.88 .432
Table V - P value difference between baseline, T1 and T2 within each group
Control group (Articulating foil) Study group (T-scan) Outcome
0.008* 0.02* Pain intensity score
0.1 0.008* Jaw Functional Limitation Scale
0.007* 0.01* Pain free opening
Pain free jaw movements
in (mm)
0.23 0.34 Protrusion
0.14 0.06 Right excursion
0.31 0.27 Left excursion
* p<0.05 statistically significant
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Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
DISCUSSION
The present study was designed to compare
two methods of stabilization splint equilibration
techniques which were the use of articulating
foil or shim stock versus T-scan regarding pain
intensity reduction, jaw function limitation
and range of pain free mandibular movements.
Based on the results of the present study,
there was a signicant reduction in pain and
improvement in jaw function and pain free
maximum opening within each group, without
statistically significant differences (p>0.05)
between the two groups after 1 and 3 months.
Maxillary and mandibular occlusal splints have
been shown to be equally effective at relieving
temporomandibular disorder (TMD) signs
and symptoms [8,17,18]. However, in the
current study, the selection of the mandibular
occlusal splint design was based on the authors’
perspective of it being more esthetically
acceptable with less speech disturbance, thus
potentially increasing patient compliance. The
included patients were from both sexes, but the
majority were females due to the greater sex
predilection nature of TMD. Only disorders of
myofascial origin were included in the present
study to avoid the confounding effect of different
diagnoses and variable stages of derangement
on the study outcomes.
The effectiveness of stabilization splints
in reducing pain and improving jaw function
depends on various factors, including the
persistence of multi-systemic etiologies, the
diagnostic origin of TMD, patient compliance
with wearing the appliance, and the method of
appliance fabrication. The benecial effect of
using a stabilization splint in TMD management
has been justified by many theories ranging
from occlusal disengagement, raising of vertical
dimension, improving the condyle-fossa relation,
improving cognitive awareness of harmful
behavior up to reducing the load on masticatory
components or exerting placebo effects [19].
In an attempt to eliminate the covariant
factors in the present study, patient selection
criteria, splint design, duration of wearing
the appliance and fabrication method were
standardized and controlled among both groups.
Additionally, patients were ensured not to use
any complementary pain-relieving factors such
as medications or physiotherapy throughout the
study timeline.
For both groups, occlusal equilibration of the
stabilization splint was performed until bilateral
simultaneous contact was established on all teeth
in the centric relation position, anterior guidance
in protrusive movements and canine guidance
on lateral excursive movements with complete
posterior teeth disocclusion. In the T-scan group,
the disocclusion time reduction of all molars
and premolars was adjusted to be < 0.5 seconds
per lateral excursion. This approach was proven
to reduce muscle hyperactivity levels and their
related myogenous symptoms as indicated by
Poovani and Thumati [20]
Pain reduction and jaw function limitation
were subjectively measured using validated
questionnaires, while the pain-free range of
mandibular movements was objectively evaluated
by a blinded assessor. The assessor took an
average of three measurements for each pain-
free opening, protrusion, left and right lateral
excursions at each time interval. This combination
of subjective and objective outcomes was intended
to ensure that the patient’s responses were not
biased by the effect of using a digital device in
the test group.
Most treatment outcome studies conducted
on temporomandibular disorders (TMDs) have
been based on comparison of the mean values
of different treatment groups. However, it would
be more benecial for clinicians to relate these
mean values to the smallest detectable difference
of an outcome variable. This approach provides
insight into the level of improvement required
for a treatment approach to be considered
therapeutically successful or preferred over
another treatment approach. In the literature,
the reported smallest detectable difference in
actual pain intensity on a 0-100 visual analog
scale is 25 [21]. Accordingly, by comparing the
mean pain intensity reduction percentage in the
T-scan group and articulating foil group (39 and
28, respectively), with the reported smallest
detectable difference in pain intensity, it can be
concluded that both equilibration techniques are
considered equally successful in treating TMD
patients with stabilization splints.
Pain is reected in jaw function and range of
pain free movements. The results of the present
study showed that pain reduction, improvement
in jaw function and maximum pain free opening
were more pronounced at T1 (after 1 month)
than at T2 (after 3 months) in the T-scan group,
10
Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
revealing a statistically significant difference
between baseline and 1 month while there was
no signicant difference between 1 and 3 months.
Conversely, in the articulating foil group, the
maximum improvement in outcomes occurred
at T2, and there was no signicant difference
between baseline and 1 month.
These ndings could be attributed to the
accurate equilibration obtained by the T-scan as
indicated by Kerstein et al. [14], thus resulting in
accelerated improvement occurring at 1 month
compared to that in the other group, which
showed signicant improvement after 3 months.
The insignificant difference between the two
groups after 3 months was possibly due to the
effect of clenching and progressive splint wear.
This nding suggests that any initially unapparent
premature contact present in the articulating foil
group may have self-corrected over time due to
the aging of the splint.
Despite maintaining the occlusal contacts in
the T-scan group, a rebound in pain intensity was
evident after 3 months. Although being statistically
insignificant, this finding is noteworthy as it
supports the notion that TMD is a multifactorial
condition and other contributing factors such as
stress or sleep problems may lead to increase in
pain levels again. This improvement uctuation
within a short period of time is reported in the
literature to be associated with high impact more
than low impact TMD cases [22].
One of the mechanisms of action of
stabilization splints is minimizing muscle
hyperactivity and promoting muscle relaxation
which alleviate pain, improve jaw function
and increase pain free movements. The lateral
pterygoid muscle, being a depressor muscle, is
often the most hyperactive muscle in patients with
TMD [23]. This phenomenon could potentially
explain the significant improvement in pain-
free jaw opening observed in the current study
in comparison to the protrusive and lateral
excursion movements which didn’t show any
signicant improvement.
Various studies have sought to provide scientic
evidence on the effect of wearing stabilization
splints on brain cerebral activity using functional
MRI to correlate with the improvement in signs
and symptoms. According to Lotz et al. [24], a well-
adjusted Michigan splint reduced the activation in
primary sensorimotor areas, which was associated
with a decrease in electromyographic activity
in the masticatory muscles. On the other hand,
Otsuka et al. [25], reported that a malfunctioning
splint leads to additional activation in the anterior
cingulate cortex and the amygdala which was
positively associated with scores of discomfort.
Additionally, splint therapy was found to decrease
the activation in the anterior insula cortex; an area
that is highly involved in autonomic reactions,
affective motivational functions, and the association
of emotions with former painful experiences [26].
It is worth mentioning that the reliability of
functional MRI studies is questionable, as they
are subject to an uncontrollable margin of error
due to factors such as thermal noise, system
noise, physiological noise and non-task-related
cognitive processes [27,28]. This suggests that
stimulation of neural activity responsible for
pain, attributed to other factors such as stress,
can counteract the effect of stabilization splints
on neural activity. This may explain the diversity
of results observed in the present study over time.
The limitation of the present study is mainly
represented in the limited number of participants
who are characterized with variable muscle
strength, pain threshold perception, stress levels
and emotional status. All these factors possibly
led to inconsistent pain level improvement and
eventually were reected on their jaw functions
and range of movements. In considering the
feasibility of incorporating the T-scan into daily
clinical practice, it’s important to note that
despite its apparent accuracy in detecting occlusal
discrepancies, patients from both groups exhibited
similar outcomes after 3 months. Furthermore,
the cost of the T-scan device should be taken
into account, along with the fact that multiple
sensors are typically required to complete the
equilibration process for each patient.
CONCLUSION
Within the limitations of the present
study, it can be concluded that both the T-scan
and articulating foil are equally effective in
stabilization splint equilibration, reducing
pain intensity and improving the range of
pain-free mouth opening in patients with
temporomandibular disorders (TMDs).
Clinical implications
Both the T-scan and articulating foil are
regarded as equally effective in guiding the
11
Braz Dent Sci 2025 Apr/Jun;28 (2): e4521
Abdelsalam SE et al.
Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
splint equilibration process. However, the cost
and availability of articulating foil render this
approach more convenient.
Author’s Contributions
SEA: Funding Acquisition, Investigation,
Methodology and Writing – Original Draft
Preparation. AEE: Conceptualization, Data
Curation and Supervision. RMG: Validation.
MAMEK: Formal analysis and Writing – Review
& Editing
Conict of Interest
The authors have no conicts of interest to
declare.
Funding
The present research did not receive any
specic grant from funding agencies in the public,
commercial or not-for-prot sectors.
Regulatory Statement
The present study was conducted in
accordance with all the provisions of the local
human subject oversight committee guidelines
and policies of Cairo University. The present
study protocol was reviewed and approved by
[The Research Ethics Committee, School of
Dentistry, Cairo University], approval number
(NCT04661670).
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Relief of signs and symptoms in patients with tempromandibular disorders using occlusal stabilization splints equilibrated by T-scan versus articulating foil: a randomized clinical trial
Abdelsalam SE et al. Relief of signs and symptoms in patients with tempromandibular
disorders using occlusal stabilization splints equilibrated by T-scan
versus articulating foil: a randomized clinical trial
Date submitted: 2024 Sept 13
Accept submission: 2025 May 10
Sara Eman Abdelsalam
(Corresponding address)
Cairo University, Faculty of Dentistry, Cairo, Egypt.
Email: sara.eman@dentistry.cu.edu.eg
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