Art-2-Slavicek

OCCLUSION AND TMJ                                                                                                                                       www.stomaeduj.com




ON THE TRACK OF BRUXISM: QUANTITATIVE,




                                                                                                                                                      Original Articles
QUALITATIVE AND INTRAINDIVIDUAL ANALYSES
OF THE BRUXCHECKER® IN DAILY CLINICAL ROUTINE
                   1,2,a*                         1,3                             1,4,b                        1,2,c
Gregor Slavicek              , David Grimmer            , Anastasia Novitskaya            , Florian Slavicek

¹Steinbeis Transfer Institute Biomedical Interdisciplinary Dentistry, Steinbeis University Berlin, DE-12489 Berlin, Germany
²Orehab Minds GmbH, DE-70567 Stuttgart, Germany
³Zahntechnik Baltz GbR, DE-73728 Esslingen am Neckar, Germany
⁴Dental Clinic Smiletime, RU-14106 Podolsk, Podolsky District, Russia
a
  MD, DDS, MSc, Director and Head, CEO and Head; e-mail: g.slavicek@orehab-minds.com; ORCIDiD: https://orcid.org/0000-0003-2454-4048
b
  DDS; e-mail: anastasia.novitskaya@gmail.com; ORCIDiD: https://orcid.org/0000-0003-3446-3866
c
 BSc ; e-mail: f.slavicek@orehab-minds.com; ORCIDiD: https://orcid.org/0000-0003-4245-7829
ABSTRACT                                                                            https://doi.org/10.25241/stomaeduj.2020.8(3).art.2

Introduction Bruxism is a relevant topic in daily dental routine. Bruxism has to be confirmed by instrumental
procedures. The BruxChecker® (BC) is an inexpensive instrument that does not affect the stomatognathic
system while used and is suitable for routine use in diagnostics and follow-ups. A novel digital approach for
analyzing BC is described, based on first standard values.
Material and Method Within this pilot study, 30 participants (15 males, 15 females) used an upper BC for
one night and a lower BC during another night. A standardized digitalization process and a unique software
application measured all Tooth Contact Areas (TCAs) on the BC: number and size of each TCAs for each
occlusal segment.
Results The mean number of TCAs on upper BC is 28.17 (sd +/-7.84), for lower BC 27.70 (sd +/-7.41). The
mean size (mm2) of TCAs on upper BC is 71.81 (sd +/-51.27), for lower BC 68.11 (sd +/-42.64). There are only
minor, not significant, gender differences regarding the number and size of TCAs. The transversal right-left
TCAs distribution is almost symmetrical; a slightly increased difference can be observed for the size of TCAs
right and left. The sagittal distribution of the TCAs shows the dominance of the posterior contacts, while the
intermediate segments are least involved.
Conclusion Within the limits of this pilot study and based on the digital analyses of TCAs on BC, the paper
presents first standard values and a two-step systematic individual BC analysis.
KEYWORDS
Bruxism; Occlusal Functions; Oral Rehabilitation; Parafunction; Tooth Contact Areas.
1. INTRODUCTION                                                                  But the majority of clinicians focus primarily on
                                                                                 the possible negative consequences of bruxism:
BC visualizes the contacts between teeth that occur                              chipping, occlusal trauma, tooth migration, temporo-
during unconscious teeth grinding or clenching                                   mandibular disorder [2]. The issue of the significance
during awake and sleep bruxism. The BC is fabricated                             of teeth grinding in humans is controversially
for the individual patient using the pressure molding                            discussed in medicine. Is it an abnormal function,
technique. Comparing the actual bruxing scheme on                                a movement disorder [3]? Or, in contrast, can SB
the BC with a so-called optimal centric and eccentric                            be assessed as a relevant physiological occlusal
occlusal situation is one suggested possibility to                               function [4]? If one takes this view, then parafunction
analyze the BC. However, understanding the optimal                               represents a secondary function beside primary
occlusion does not make it easier to work with the                               occlusal functions. The increasing acceptance of
suggested classification scheme. In any case, the                                considering SB as a physiologic function modifies
BC analyses must consider the laterotrusive and the                              the fundamental methodical approach. Today
mediotrusive side contacts during bruxing [1].                                   SB is graduated in possible (based on patient's
A paradigm shift in the assessment of sleep bruxism                              self-reports), probable (determined by clinical
(SB) took place in recent years. SB is no longer                                 inspection), and definite (verified by an instrumental
understood solely as a harmful movement disorder.                                analysis) [5].
             OPEN ACCESS This is an Open Access article under the CC BY-NC 4.0 license.
             Peer-Reviewed Article
  Citation: Slavicek G, Grimmer D, Novitskaya A, Slavicek F. On the track of bruxism: quantitative, qualitative and intraindividual analyses of the
  BruxChecker® in daily clinical routine. Stoma Edu J. 2021;8(3):163-171.
  Received: August 11, 2021; Revised: August 23, 2021; Accepted: August 31, 2021; Published: September 03, 2021
  *Corresponding author: Dr. Gregor Slavicek; Zettachring 2, DE-70567 Stuttgart, Germany;
  Tel./Fax: +49-7307-24922-11;
  e-mail: g.slavicek@orehab-minds.com
  Copyright: © 2021 the Editorial Council for the Stomatology Edu Journal.




Stoma Edu J. 2021;8(3): 163-171                                                                        pISSN 2360-2406; eISSN 2502-0285                163
                    Slavicek G, et al.
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                    Dentists are interested in the best possible care for      clinics. If, however, the use of instruments in bruxing
Original Articles
                    their (bruxing) patients. All diagnostics have impacts     subjects primarily refers to polysomnography [4],
                    on the therapeutic decisions. Expert opinions              the immediate practical implementation is limited
                    regarding the best therapeutic concepts of SB differ       by apparent obstacles. Mobile devices that measure
                    substantially. Instead of the term "therapy" the phrase    the muscle activity of selected masticatory muscles
                    "management" is often utilized [6]; however, both          or record the forces on sensors in occlusal devices
                    terms exclusively refer to the negative consequences       are available but elude clinical applicability due
                    of teeth grinding. Based on today's knowledge, there       to missing cut-off values [15]. Devices measuring
                    is no indication to treat a most probably physiological    tooth contacts in centric and eccentric mandibular
                    oral function. Management recommendations inclu-           positions are available and successfully used in
                    de, among others, behavioral advice, medication,           restorative dentistry. But such approaches are
                    physiotherapy, or physical intervention [7]. The           suitable only to a minimal extent for verifying
                    therapeutic goal of "stop bruxing" can never be            awake or sleep bruxism, as the measurement takes
                    achieved [8]. Such therapeutic concepts must be            place in a completely different setting: awake
                    regarded as meaningless [9]. Dentists find themselves      patients, sitting upright in a dental chair, with an
                    constricted between these points of view: is a             invasive measuring instrument placed intraorally,
                    management strategy necessary? Or are occlusal             performing artificial mandibular movements trying
                    measures to influence/stop bruxism? Are occlusal           to simulate unconscious bruxing. The execution of
                    therapeutic changes indicated or contraindicated in        so-called bruxing movements is very different from
                    bruxing patients? It must be understood that awake         those performed in various sleeping postures with
                    and sleep bruxism will still be executed after occlusal    changing head positions. The BC is a device for such
                    therapy, but maybe with less muscular strength             minimally invasive investigation of unconscious
                    and minor eccentric mandibular movements. The              tooth contacts during sleep. A classifying evaluation
                    ability and the necessity to influence bruxism by          of the BC enables an initial assessment [16]. But
                    occlusal parameters is still a matter of controversy.      occlusion and occlusal structures are core elements
                    Occlusal factors such as the inclination of occlusal
                                                                               in dentistry, and this can be rated as unique
                    guiding structures in the anterior and posterior
                                                                               proposition of dental clinics. Occlusal Rehabilitation
                    occlusal segments seem to play an important role
                                                                               aims to maintain and re-establish oral function such
                    in muscle recruitment during bruxism [10]. In silico
                                                                               as chewing and bruxing [17].
                    simulation demonstrated that both the direction
                                                                               The BC visualizes functional TCAs. But the
                    and the size of the bruxing force vectors adapt and
                                                                               interpretation of the BC remains challenging, and
                    change due to the position and the inclination of
                                                                               many dentists left the use of BC again after their
                    occlusal guiding structures [10]. Grinding areas and
                                                                               initial enthusiasm. For this reason, the authors of this
                    occlusal parameters such as anterior occlusal plane
                                                                               article suggest a different, systematic approach for
                    and overbite are closely related [11]. The need of an
                                                                               the BC analysis based on numerical data. This pilot
                    oral Rehabilitation of bruxing patients is a common
                    situation in daily dentistry. Patients present with        study aims to determine quantitative and qualitative
                    impaired chewing surface morphology, the risk of           data of occlusal contacts areas on BruxCheckers for
                    increased mechanical and technical complications           sleep bruxism.
                    in prosthodontic Rehabilitation rises. Prosthetic
                    intervention in a patient with (heavy) bruxism             2. MATERIAL AND METHOD
                    without taking into consideration heavy occlusal
                    loading on materials and constructions will end            60 already used BC from 30 subjects served as the
                    in a breakdown. "Failure to do so may indicate             data source in this exploratory study. Females
                    earlier failure than is the norm." [12]. Successful oral   and males participated in the study. The exclusion
                    Rehabilitation in patients with severely worn teeth        criteria comprise persons younger than 16 years and
                    seems to be independent of the materials of choice.        older than 35 years, participants with two or more
                    Direct or indirect materials may be feasible options       missing teeth, removable (partial and total) and/or
                    to restore severely worn teeth [13].                       extensive fixed prosthodontic Rehabilitation. This
                    From a clinician's point of view, more clinical studies    manuscript did not require ethical approval. Each
                    are required, with a clear focus on the clinical impact    subject signed an informed consent after being
                    on oral structures of bruxism. The decision-making         informed about the study in detail. The use of the
                    process for successful interventions in bruxing            BC followed the guidelines and recommendations of
                    patients requires more detailed and focused studies        the manufacturer (Scheu Dental, Iserlohn, Germany).
                    [14]. As soon as patients recognize symptoms,              The data analysis uses the BC used by the participants
                    they demand clarification. A link to awake or sleep        for one night; clinical intervention did not take place.
                    bruxism is often not reported by the patient in this       Each participant used two BC for one night, but
                    stage. The clarification of bruxism using instruments      not simultaneously. Only sleep bruxism TCAs were
                    is required to confirm the subjective report of the        analyzed in this pilot study. Before evaluation, white
                    patient [4]. The various uses of instrumental analysis     silicon reinforced the contrast of the TCAs against
                    are known in dentistry and are routine in many dental      the red color of the BC.



 164                Stoma Edu J. 2021;8(3):163-171                                            pISSN 2360-2406; eISSN 2502-0285
  A systematic approach to understand BruxChecker®
                                                                                                                                                                  www.stomaeduj.com



A validated procedure was applied to digitize the BC.                            comparison (e.g., between lateral or sagittal




                                                                                                                                                                Original Articles
Reproducibility tests demonstrated the soundness of                              distribution) could recognize an effect size of 0.2
the digitizing process a priori - a series of 7 recordings                       with the same group size (paired t-test) [18].
of 16 BCs (8 upper and 8 lower BC) were included for                             After the study, all participants received a detailed
that test. A password-protected zip folder guarded                               report on their BC findings.
the data. Finally, the data set listed the automatically
measured key figures number and area of TCAs for                                 3. RESULTS
each BC. The calculation of the maximal differences
and the standard deviations for the differences                                  The mean age of all participants was 27 years (sd
followed. The formula [means +/-(sd*1.96)] sets                                  +/- 4.98 years). The female participants had an
an upper and lower tolerance limit. Bland-Altman                                 average age of 26 years with a sd of 5.3 years, the
Diagrams visualized the results. If all means of record                          male study participants had an average age of 28
                                                                                 years (sd +/- 4.4 years). All participants had a natural
1 to record 7 for all BC were within the upper and
                                                                                 occlusion with only minor restorations. 27 (80%) had
lower tolerance limits, adequate reproducibility can
                                                                                 full dental arches, not considering wisdom teeth.
be derived (Fig. 1a,1b). For anonymization, a 7-digit
                                                                                 In comparison, 14 (47%) presented one or more of
unique identifier tags each BC. A short anonymous                                the following findings: lingual retainer of front teeth
questionnaire collected information on gender,                                   [4 (13%) upper and 8 (26%) lower]; missing teeth [3
age, and subjective symptoms, possibly related to                                (10%) participant, one missing tooth 14, one missing
grinding and clenching. Table 1 presents the personal                            tooth 37 and one missing tooth 47].
functional status of the study participants. In an                               Table 1 presents the subjective functional status of
automatic evaluation process, using a calibrated                                 the study participants (personal self-assessment
software (Orehab Minds GmbH, Germany), the                                       via VAS). The symptom pain for different locations
number and size of each TCAs were determined                                     appears with a minimum of 1 and a maximum of 4
and assigned to a specific segment of the occlusion                              on the VAS. The different localizations of the pain
(right-anterior, left-anterior, right-intermediate,                              showed no noticeable deviations. However, the
left-intermediate, right-posterior, left-posterior).                             intensity of the pain, including its impact on activities
For the statistical analysis, IBM SPSS Statistics 25 was                         of daily life (AoDL), individual stress levels, and the
used. The outcome measures are continuous data;                                  reported quality of sleep, are widely spread. Although
                                                                                 this pilot study aimed not to identify associations
a pretest served to estimate the expected standard
                                                                                 between TCAs and symptoms, the collected data
deviation. The sample size for this pilot study (n=30
                                                                                 will serve as a basis for further studies to determine
participants, n=60 BC) was set on 20% of the sample
                                                                                 whether TCAs' number, size, or distribution are
size calculation for a planned clinical trial with                               equally related to patients' symptoms.
relevant subgroups (e.g., dental status, gender, age,                            All 60 BC (30 upper and 30 lower) from 30 individuals
comorbidity, occlusal characteristics). One hundred                              are analyzed. The mean value of the number of TCAs
fifty participants would still be sufficient to assign                           for the upper occlusion is n = 28.2 (sd +/- 7.8) with a
minor standardized differences in occlusal contact                               minimum number of 11 and a maximum number of
areas with a power of 80% for two-sided errors of                                39 TCAs (Fig. 2a). The mean value of the number of
type 1 (alpha) (two-sample t-test). Intra-individual                             TCAs for the lower occlusion is 27.7 (sd +/- 7.4), with




  Figure 1a. Bland-Altman-Diagram to demonstrate the reproducibility               Figure 1b. Bland-Altman-Diagram to demonstrate the reproducibility
of the analytic process for BC. Here, the measurement parameter is the           of the analytic process for BC. Here, the measurement parameter is size of
number of TCAs on upper BC. 8 BC were included; digitizing was repeated          TCAs on upper BC. 8 BC were included; digitizing was repeated 7 times per
7 times per BC (56 records in total). The mean difference (1,5) and the          BC (56 records in total). The mean difference (0,6) and the tolerance limits
tolerance limits (upper: 4,46 and lower: -1,46) were calculated. The mean        (upper: 1,03 and lower: 0,168) were calculated. The mean differences per
differences per BC are indicated (•); all are located between the upper and      BC are indicated (•); all are located between the upper and lower limit. No
lower limit. No outliers are detectable; the limits are not exceeded. A slight   outliers are detectable; the limits are not exceeded. A slight dependence
dependence on the number of TCAs may exist.                                      on the number of TCAs may exist.
BC BruxChecker; TCAs Tooth Contact Areas.                                        BC BruxChecker; TCAs Tooth Contact Areas.




Stoma Edu J. 2021;8(3): 163-171                                                                            pISSN 2360-2406; eISSN 2502-0285                      165
                    Slavicek G, et al.
www.stomaeduj.com

Original Articles                Parameter
                                    VAS 0-10
                                                               Mean         sd        min        max

                                tooth_ache*                    3.77        0.68          1         4
                                 headache*                     3.67        0.55          2         4

                                  backpain*                    3.30        0.70          1         4
                                 facialpain*                   3.93        0.37          2         4
                             temporal_pain*                    3.90        0.40          2         4
                              ear_tmj_pain*                    3.77        0.57          2         4
                          pain_mouth_open*                     3.83        0.46          2         4
                           pain_mastication*                   3.87        0.43          2         4
                                                                                                                     Figure 2c. Histogram to show the distribution of the size of TCAs for all
                           AoDL_influenced*                    3.10        1.73          1         8                upper BC, females and males. The mean number of TCAs is 71.81 with a sd
                        overal_pain_intensity*                 3.00        1.64          1         8                of 51.273 and a range of 211 (minimum 13, maximum 224). Based on this
                                                                                                                    sample, a normal distribution cannot be assumed (KS Test, p=0,021).
                              sleep_quality*                   7.00        1.80          4        10                Measurements in mm2.
                              stress_level* 1                  5.80        1.77          2         9                BC BruxChecker; TCAs Tooth Contact Areas; KS test Kolmogorov-Smirnov Test.


                     Table 1. Overview: reported symptoms of the participants. These data
                    were not collected to analyze correlations of TCAs (number and/or size)
                    with subjective complaints but to check the sample for consistency and to
                    support future sample size calculations.
                    TCAs Tooth Contact Areas; sd standard deviation, min minimum; max maximum, AoDL Activities of
                    Daily Living , VAS Visual Analog Scale..




                                                                                                                      Figure 2d. Histogram to show the distribution of the size of TCAs for all
                                                                                                                    lower BC, females and males. The mean number of TCAs is 68.11 with a sd
                                                                                                                    of 42.643 and a range of 183.5 (minimum 11, maximum 194.5). Based on
                                                                                                                    this sample, a normal distribution cannot be assumed (KS Test, p=0.047).
                                                                                                                    Measurements in mm2.
                                                                                                                    BC BruxChecker; TCAs Tooth Contact Areas; KS test Kolmogorov-Smirnov Test.

                                                                                                                    194.5mm2 for the inferior occlusion (Fig. 2c, 2d),
                     Figure 2a. Histogram to show the distribution of the number of TCAs for                        respectively. Table 2a and 2b summarizes these
                    all upper BC, females and males. The mean number of TCAs is 28.17 with a                        results. Kolmogorov-Smirnov Tests (KS test) tested
                    sd of 7.844 and a range of 28 (minimum 11, maximum 39). Based on this
                                                                                                                    the null hypotheses "Within this sample, number and
                    sample, a normal distribution cannot be assumed (KS Test, p=0.019).
                    BC BruxChecker; TCAs Tooth Contact Areas; KS test Kolmogorov-Smirnov Test
                                                                                                                    size of TCAs are normal-distributed." For the upper
                                                                                                                    BC, a normal distribution for both number (KS test,
                                                                                                                    p=0.019) and size (KS test, p=0.021) of TCAs cannot
                                                                                                                    be assumed; for the lower BC, a normal distribution
                                                                                                                    cannot be assumed for size (KS test, p=0.047), but for
                                                                                                                    the number of TCAs (KS test, p=0.2).
                                                                                                                    The comparison between females and males
                                                                                                                    shows only minor, not significant differences for
                                                                                                                    number of TCAs: for the males, an average of 29.13
                                                                                                                    (sd +/- 8.55) TCAs for the upper occlusion; for the
                                                                                                                    females, 27.2 (sd +/- 7.25); for the lower occlusion,
                                                                                                                    an average of 27.13 (sd +/- 6.01) TCAs for males,
                                                                                                                    for the females 28.26 (sd +/- 8.77), respectively.
                                                                                                                    The following data can be described for the size
                      Figure 2b. Histogram to show the distribution of the number of TCAs
                    for all lower BC, females and males. The mean number of TCAs is 27.7 with                       of TCAs: males, upper occlusion: 87.27mm2 (sd +/-
                    a sd of 7.405 and a range of 30 (minimum 13, maximum 43). Based on this                         57.88mm2), females, upper occlusion: 56.35mm2 (sd
                    sample, a normal distribution can be assumed (KS Test, p=0.2).                                  +/- 39.79mm2); males, lower occlusion: 80.38mm2 (sd
                    BC BruxChecker; TCAs Tooth Contact Areas; KS test Kolmogorov-Smirnov Test.                      +/- 46.11mm2), females, lower occlusion: 55.83mm2
                    a minimum number of 13 and a maximum number                                                     (sd +/- 36.29mm2) (Tab. 3). The minimal differences
                    of 43 (Fig. 2b). The mean size of TCAs is 71.8mm2 (sd                                           between women and men related to TCAs also
                                                                                                                    appear in the direct comparison (Fig. 3a, 3b) [Mann-
                    +/- 51.3mm2) for the upper occlusion and 68.1mm2                                                Whitney U test for size of TCAs: upper BC p=0.09;
                    (sd +/- 42.6mm2) for the lower occlusion. The range                                             lower BC p=0.08; Mann-Whitney U test for number
                    of TCAs size for upper occlusion encompasses a                                                  of upper BC: p=0.37; independent samples t-test for
                    span from 13mm2 to 224mm2 or from 11mm2 to                                                      number of lower BC: p=0.6].



 166                Stoma Edu J. 2021;8(3):163-171                                                                                            pISSN 2360-2406; eISSN 2502-0285
A systematic approach to understand BruxChecker®
                                                                                                                                                                                           www.stomaeduj.com




                                                                                                                                                                                         Original Articles
         Upper                     Number of Tooth                    Size of Tooth                                Females                       Number of Tooth        Size of Tooth
      BruxChecker ®                Contact Areas (n)                  Contact Areas                                                               Contact Areas         Contact Areas
                                                                         (mm2)
                                                                                                           Upper                Mean                 27.2000               56.3533
  N                                            30                              30                       BruxChecker ®
                                                                                                        15 BC analysed            sd                 7.24273              39.79228
  Mean                                     28.1667                           71.81
                                                                                                           Lower                Mean                 28.2667               55.8333
  sd                                       7.84366                        51.27321                      BruxChecker®
                                                                                                        15 BC analysed            sd                 8.76247              36.29183
  Minimum                                    11.00                           13.00
  Maximum                                    39.00                          224.20                    Table 3a. Key figures for number and size of TCAs of upper and lower BC,
                                                                                                     female participants.
  Table 2a. Key figures for number and size of TCAs of upper BC, male and                            TCAs Tooth Contact Areas; BC BruxChecker; sd standard deviation.
female participants.
TCAs Tooth Contact Areas; BC BruxChecker; sd standard deviation.                                                    Males                        Number of Tooth        Size of Tooth
                                                                                                                                                  Contact Areas         Contact Areas
         Lower                     Number of Tooth                    Size of Tooth
      BruxChecker®                 Contact Areas (n)                  Contact Areas                        Upper                Mean                 29.1333               87.2667
                                                                         (mm2)                          BruxChecker ®
                                                                                                        15 BC analysed            sd                 8.54289              57.88172
  N                                            30                              30                          Lower                Mean                 27.1333               80.3800
  Mean                                     27.7000                         68.1067                      BruxChecker®
                                                                                                        15 BC analysed            sd                 6.01031              46.11729
  sd                                       7.40526                        42.64273
  Minimum                                    13.00                           11.00                    Table 3a. Key figures for number and size of TCAs of upper and lower BC,
                                                                                                     male participants.
  Maximum                                    43.00                          194.50                   TCAs Tooth Contact Areas; BC BruxChecker; sd standard deviation.

  Table 2b. Key figures for number and size of TCAs of lower BC, male and                            Further attention during the analyses of BC has to
female participants.                                                                                 be paid to the distribution of TCAs right and left, the
TCAs Tooth Contact Areas; BC BruxChecker; sd standard deviation.
                                                                                                     transversal (lateral) distribution. The number of TCAs
                                                                                                     is almost identical on the right and left sides (Fig.
                                                                                                     4a). There are minor differences in the distribution of
                                                                                                     the size of TCAs on the right and left (Fig. 4b). Tab. 4a
                                                                                                     and 4b present these results. The transversal (lateral)
                                                                                                     distribution seems to be regardless of the number
                                                                                                     or the size of TCAs (Fig. 4c, 4d). The evaluation of the
                                                                                                     sagittal distribution weighs three sections: anterior
                                                                                                     (corresponds largely to anterior teeth including
                                                                                                     the canine), intermediate (corresponds largely to
                                                                                                     the premolar region), and posterior (corresponds
                                                                                                     largely to the molar region). The sagittal distribution
  Figure 3a. Comparison of number of TCAs for females and males,                                     of TCAs in the upper jaw is 8.2 (sd +/- 3.3) anterior,
shown for upper and lower BC. Boxes indicate the IQR [Q3-Q1], the lines (-)
                                                                                                     7.5 (sd +/- 2.5) intermediate, and 12.5 (sd +/- 4.8)
indicate the median (Q2). The whiskers are limited by minimum and
maximum. Outliers (о) are identified if the distance to Q1 or Q3 is bigger                           posterior. The sagittal distribution of TCAs in the
than IQR multiplied by 1.5. In such cases, the whiskers are limited by the                           lower jaw is 8.3 (sd +/- 3.1) anterior, 6.6 (sd +/- 2.1)
value that just does not represent an outlier.                                                       intermediate, and 12.8 (sd +/- 4.6) posterior. The
TCAs Tooth Contact Areas; IQR Interquartile Range; Q1 First Quartile, Q2 Second Quartile, Q3 Third
Quartile.
                                                                                                     following values describe the mean size of TCAs:
                                                                                                     for the upper occlusion 28.2mm2 (sd +/- 23.7mm2)
                                                                                                     anterior, 13.9mm2 (sd +/- 10.8mm2) intermediate




  Figure 3b. Comparison of size of TCAs for females and males, shown
for upper and lower BC. Boxes indicates the IQR [Q3-Q1], the lines (-)
indicate the median (Q2). The whiskers are limited by minimum and                                     Figure 4a. Comparison of the transversal (lateral) distribution of number
maximum. Outliers (о) are identified as such if the distance to Q1 or Q3 is                          of TCAs for total vs. right vs. left. Total (□), right (◄), and left (►) TCAs are
bigger than IQR multiplied by 1.5. In such cases, the whiskers are limited by                        shown for upper and lower BC (males and females).
the value that just does not represent an outlier.                                                   TCAs Tooth Contact Areas, BC BruxChecker.
TCAs Tooth Contact Areas; IQR Interquartile Range; Q1 First Quartile, Q2 Second Quartile, Q3 Third
Quartile.




Stoma Edu J. 2021;8(3): 163-171                                                                                                pISSN 2360-2406; eISSN 2502-0285                           167
                    Slavicek G, et all.
www.stomaeduj.com


Original Articles

                     Figure 4b. Comparison of the transversal (lateral) distribution of size of        Figure 5a. Comparison of the sagittal distribution of the number of
                    TCAs for total vs. right vs. left. Total (□), right (◄), and left (►) TCAs are   TCAs for anterior vs. intermediate vs. posterior. Anterior (▲), intermediate
                    shown for upper and lower BC (males and females).                                (●), and posterior (♦) number of TCAs are shown for upper and lower BC
                    TCAs Tooth Contact Areas, BC BruxChecker.                                        (males and females). Posterior sections are dominantly involved, while the
                                                                                                     intermediate sections have the lowest number of TCAs. Similar distri-
                                                                                                     butions are shown for upper and lower BC.
                                                                                                     TCAs Tooth Contact Areas; BC BruxChecker.




                      Figure 4c. Scatter plot for size of right vs. left TCAs for the upper BC         Figure 5b. Comparison of the sagittal distribution of the size of TCAs for
                    (males and females). The R2 value of 0,873 shows a tendency towards a            anterior vs. intermediate vs. posterior. Anterior (▲), intermediate (●), and
                    symmetrical lateral distribution of the number of TCAs.                          posterior (♦) size of TCAs are shown for upper and lower BC (males and
                    TCAs Tooth Contact Areas; BC BruxChecker; R2 coefficient of determination.       females). The dominance of posterior sections can only be seen for lower
                                                                                                     BC, while the anterior and posterior sections of the upper BC are almost
                                                                                                     equally involved. The intermediate sections show the smallest sizes of
                                                                                                     TCAs.
                                                                                                     TCAs Tooth Contact Areas; BC BruxChecker.


                                                                                                     Based on this pilot study, the authors recommend a
                                                                                                     two-step procedure for the systematic BC analysis:
                                                                                                     Step 1 - Quantitative analysis; Step 2 - Qualitative
                                                                                                     Analysis. In the future, an option of a third step (intra-
                                                                                                     individual analysis) for individual occlusal planning
                                                                                                     exists.
                                                                                                     Step 1 - Quantitative analysis
                                                                                                     The quantitative analysis of a BC: based on the
                                                                                                     measured critical numbers for number and size; the
                      Figure 4d. Scatter plot for size of right vs. left TCAs for the lower BC
                                                                                                     extent to which the individual uses occlusion when
                    (males and females). The R2 Value of 0,704 shows a tendency towards a
                    symmetrical lateral distribution of the size of TCAs.                            bruxing during sleep, compared to average values
                    TCAs Tooth Contact Areas; BC BruxChecker; R2 coefficient of determination.       (Fig. 6).
                    and 29.7mm2 (sd +/- 24.9 mm2) posterior; for the                                 Step 2 - Qualitative analysis
                    lower occlusion: 23.7mm2 (sd +/- 17.2mm2) anterior,                              Understand the distribution of TCAs on the BC is a
                    12.3mm2 (sd +/- 8.8mm2) intermediate and posterior                               crucial element in occlusal functional analysis. The
                    32.2mm2 (sd +/- 24.5mm2) posterior. The results                                  following assumptions facilitate the qualitative
                    are summarized in Tables 5a and 5b and shown in                                  analysis of a BC: involvement of all occlusal sections;
                    Figures 5a and 5b. A TCAs may exceed the midline                                 symmetric transversal distribution; the sagittal
                    (right-left) or the boundaries between sections                                  distribution shows the dominance of the posterior
                    (anterior-intermediate or intermediate-posterior).                               occlusal segments, both for the number and the
                    In such situations, TCAs are split up and allocated                              size of TCAs, followed by the anterior segments. The
                    proportionally to both sides of the adjacent sections.                           intermediate section shows the least participation
                    The areas are measured per TCAs and summed up                                    (Fig. 7).
                    for each segment. Rounding errors can lead to                                    Typically, the dental focus is on "large" and "eye-
                    minimal inaccuracies in the automatic summation in                               catching" grinding spots. However, such a focus
                    the decimal places.                                                              inhibits a deeper understanding of the involved



 168                Stoma Edu J. 2021;8(3): 163-171                                                                            pISSN 2360-2406; eISSN 2502-0285
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                                                                                                                                            www.stomaeduj.com



occlusion. It is essential to pay attention to those                            This quantitative approach to BC enables the




                                                                                                                                          Original Articles
occlusal sections not used in bruxing. In addition, it                          clinician not only to focus on adverse effects [1,6,8,
might be helpful to superimpose the visible TCAs on                             12,13] but instead on therapeutic aspects – which
the BC and the functional structures of the occlusal                            occlusal parameters to be changed [10,11,17]. It
morphology (Fig. 8).                                                            seems possible to change the muscle recruitment
                                                                                during bruxing activity by modifying occlusal
                                                                                structures [10,11], based on an increased alertness
                                                                                of dentists for TCA´s and their distribution by BC
                                                                                visualization and numerical analyses. In addition,
                                                                                it appears reasonable to alter bruxing patterns by
                                                                                the design of occlusal parameters such as canine
                                                                                guidance concerning the temporomandibular joint
                                                                                movement pattern [17].
 Figure 6. The quantitative analysis of an individual BC based on the           The BC constitutes a clinically suitable instrument
measured key numbers for number and size of TCAs; value table and               for long-time observation and a functional recall
graphical overview.                                                             after Rehabilitation. It is up to the supervising team
TCAs Tooth Contact Areas; BC BruxChecker.
                                                                                whether other diagnostic methods should be used
                                                                                [1,2,4,11].
                                                                                Missing teeth may influence the quantitative
                                                                                analysis of a BC. The number of the OCA´s on the
                                                                                upper BC of participant with missing teeth are close
                                                                                to the sample mean (missing first premolar: 36 TCAs;
 Figure 7. The qualitative analysis of an individual BC based on the bar        missing first lower molar: 29 TCAs; missing second
charts to point out the transversal and sagittal distribution of TCAs.
                                                                                lower molar: 30 TCAs). The size of the OCA´s on the
TCAs Tooth Contact Areas; BC BruxChecker.
                                                                                upper BC of these participant are close to the sample
                                                                                mean (missing first premolar: 96.7mm2 TCAs; missing
                                                                                first lower molar: 69.2mm2 TCAs; missing second
                                                                                lower molar: 80.82mm2 TCAs). The number of the
                                                                                OCA´s on the lower BC of these participant are close
                                                                                to the sample mean (missing first premolar: 36 TCAs;
                                                                                missing first lower molar: 22 TCAs; missing second
                                                                                lower molar: 15 TCAs). The size of the OCA´s on the
                                                                                upper BC of these participant are still high and close
  Figure 8. An additional opportunity to use an individual BC is the
                                                                                to the sample mean (missing first premolar: 92.4mm2
intraindividual occlusal analysis in comparing the distribution of actual and
expected TCAs within the dental arches.                                         TCAs; missing first lower molar: 63.2mm2 TCAs;
TCAs Tooth Contact Areas; BC BruxChecker.                                       missing second lower molar: 38.9mm2 TCAs). Missing
4. DISCUSSION                                                                   teeth have to be considered in the BC analyses.
                                                                                The effect of absent teeth on the key figures of BC
From the authors' point of view, the quantitative                               analysis has to be evaluated in future studies
approach is an advantage to understand the BC,
and thus for tooth grinding pattern of the individual                           5. CONCLUSION
patient. The claim for instrumental confirmation by
the SB is fulfilled [4]. The key figures support the                            • The average size of TCAs in this study population
possibility to compare the individual situation with                            shows a high variance (72mm² +/-51 mm²).
standard values and expectations for optimized                                  • The average number of TCAs in this study population
occlusion [3,16,17,19]. The distribution of TCAs for                            is 28 with a sd of +/-8.
the upper and lower occlusion is symmetric for the                              • There is only a not significant gender-specific
transversal (lateral) distribution and well-adjusted                            difference.
in the sagittal distribution. The following concepts                            • The lateral distribution of TCAs is symmetrical for
may explain the quantitative differences between                                both number and size.
upper and lower BC: a) different nights: bruxing                                • The sagittal distribution shows a dominance of the
activity varies from night to night; b) The lower                               posterior occlusion.
dental arch is smaller than the upper dental arch. c)                           • Based on the quantitative analysis, the clinician has
grinding of teeth has different effects on the upper                            the option to assess occlusion with the number and
and lower teeth, especially on anterior teeth: while                            size of TCAs and thus perform a functional-occlusal
the lower front teeth will contact with a relatively                            analysis: all sections of occlusal seems to be involved
small area during the entire bruxing movement, the                              in bruxing.
upper front teeth will be "used" widely – from centric                          • In the future, dentists’ attention can be focused
occlusion contact points up to the incisal edge. In                             more on the number of TCAs in combination with
the premolar and molar regions, these differences                               the size of TCAs: few but large TCAs should be seen
are less significant.                                                           differently compared to many but small TCAs.


Stoma Edu J. 2021;8(3): 163-171                                                                pISSN 2360-2406; eISSN 2502-0285            169
                    Slavicek G, et all.
www.stomaeduj.com



                    • Occlusal segments without any TCAs have to be                          analysis and critically revising the manuscript. AN: contributed
Original Articles   seen as critical as those with huge TCAs                                 to the gathering and analysis, their interpretation and critically
                    • Based on the knowledge of the distribution of                          revising the manuscript. FS: contributed to the data analysis, their
                    number and size of TCAs, a qualitative analysis of                       interpretation and critically revising the manuscript.
                    the BC serves as a valuable element in the functional
                    assessment of the individual occlusion.                                  ACKNOWLEDGMENTS
                                                                                             None.
                    AUTHOR CONTRIBUTIONS
                    GS: contributed to the concept, protocol, data gathering and             CONFLICT OF INTEREST
                    analysis, their interpretation and critically revising the manuscript.   Gregor Slavicek and Florian Slavicek are CEO’s of Orehab Minds
                    DG: contributed to the concept, protocol, data gathering and             GmbH, DE-70567 Stuttgart, Germany.


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                                                                                                                Gregor SLAVICEK
                                                                                                                     MD, DDS, MSc
                                                                                                             CEO, Head & Director
                                                                Steinbeis Transfer Institute Biomedical Interdisciplinary Dentistry
                                                                                                        Steinbeis University Berlin
                                                                                                       DE-12489 Berlin, Germany

                    CV
                    Dr. Slavicek is an MD, specialized in Dentistry. He is currently Director of the Steinbeis Transfer Institute Biomedical Interdisciplinary
                    Dentistry, Steinbeis University Berlin. Since 2019, he has been CEO of Orehab Minds GmbH in Stuttgart, Germany. He graduated
                    from the University Vienna (medicine and dentistry), also specializing in Clinical Research at the same university (Master of
                    Science). He attended additional postgraduate orthodontic training at University Aarhus (Denmark), Prof. B. Melsen, and
                    postgraduate gnathological training at University of Florida (USA), Prof. H. Lundeen and Prof. C. Gibbs. He is an honorary member
                    of the Italian Gnathological Society. He was awarded an honorary professorship by the Ukrainian Dental Society. He was visiting
                    professor at the first medical state University in Moscow Sechenov (2014-2018).



 170                Stoma Edu J. 2021;8(3):163-171                                                              pISSN 2360-2406; eISSN 2502-0285
A systematic approach to understand BruxChecker®
                                                                                                                  www.stomaeduj.com




Questions




                                                                                                                Original Articles
1. How can bruxism be graduated according to the actual international consensus?
qa. Possible, confirmed, severe;
qb. Possible, probable, definite;
qc. Confirmed and not definite;
qd. Possible, harmless, sometimes.

2. Which number of tooth contact areas to expect on an upper BruxCheckers® (males and
females)?
qa. Number: 8 +/-2;
qb. Number: 71 +/-51;
qc. Number: 28 +/-8;
qd. Number: 101 +/-51.

3. Which size of tooth contact areas to expect on an upper BruxCheckers® (males and
females)?
qa. Size: 71mm2 +/-51mm2
qb. Size: 7,1mm2 +/-5,1mm2
qc. Size: 17mm2 +/-15mm2;
qd. Size: 171mm2 +/-151mm2.

4. Which answer is correct?
qa. The lateral distribution of tooth contact areas on BruxCheckers® is almost symmetrical;
qb. The posterior segments are dominant in the sagittal distribution of tooth contact areas on BruxCheckers®;
qc. There are only minor differences between females and males regarding tooth contact areas;
qd. Answers 1-3 are correct.




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Stoma Edu J. 2021;8(3):163-171                                        pISSN 2360-2406; eISSN 2502-0285           171