10.59987/ads/2017.2.79-88
Aim. Continuous technological innovation has provided the clinicians to access to a computerized device that can analyse the different characteristics of occlusal contacts. The purpose of this research was to use this device to study the occlusal forces comparing healthy subjects and TMD patients.
Materials and methods. The study was conducted by following specific criteria to select participants; the sample was divided into two homogeneous groups: control group (CG) comprising healthy subjects, and dysfunctional group (DG) comprising TMD patients. The occlusal force analysis was performed using the computerized system T-Scan III V 5.20 T. The data were analysed with statistical methods.
Results. The most significant differences emerged between the groups in the average occlusal load distribution and in the location of the centre of occlusal forces (COF). In particular, compared with the CG and the functional standard, reductions in the molar field forces on the second and first molars of 27% and 6.9%, respectively, were observed in the DG. The COF was located in the most forward position in TMD patients compared with healthy subjects.
Conclusions. Although the differences in the distribution of the occlusal forces and the location of the occlusal centre of gravity were significant, the relationship between occlusal contacts and TMD remains to be fully clarified. Further research is needed to investigate whether studying occlusal force distributions in both healthy subjects and TMD patients.
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Annali di stomatologia
occlusal contacts
Digital evaluation of occlusal forces: comparison between healthy subjects and TMD patients
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Original Article
2022-08-10
2022-08-10
2017-06-01
2023-12-04
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Digital evaluation of occlusal forces: comparison between healthy subjects and TMD patients
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                                                                                                 Original article


    Digital evaluation of occlusal forces: comparison
    between healthy subjects and TMD patients




                                                                                              li
                                                                                            na
    Giacomo Ferrato DDS                                    remains to be fully clarified. Further research is
    Giovanni Falisi MD, DDS                                needed to investigate whether studying occlusal
    Gaetano Ierardo DDS, PhD                               force distributions in both healthy subjects and




                                                                                          io
    Antonella Polimeni MD, DDS                             TMD patients.
    Carlo Di Paolo MD, DDS
                                                           Key words: T-Scan III, occlusogram, occlusal forces,




                                                                     az
    Department of Oral and Maxillofacial Sciences,
                                                           TMD, occlusal contacts.

    “Sapienza” University of Rome, Italy
                                                           Introduction

                                                           Years of scientific research investigating the patho-




                                                                   rn
    Giacomo Ferrato                                        genetic factors of temporomandibular disorders
    Corresponding author:

    Department of Oral and Maxillofacial Sciences,         (TMDs) have typically been focused on different as-
    “Sapienza” University of Rome                          pects, such as the occlusion, which is one of the most




                                                       te
    Via Caserta 6                                          controversial and debated aspects (1, 2).
    00195 Roma, Italy                                      The current reference patterns for functionally evalu-
    E-mail: ferrato62@gmail.com                            ating the occlusion refer to simple and generic
                                                           schemes proposed over 50 years ago. One present-
                                                     In
                                                           ed by Beyron has been recently quoted because it is
                                                           regarded as the most reliable basis for a therapeutic
                                                           occlusal scheme design in prosthetics, both for natu-
    Summary
                                                           ral teeth and dental implants. This scheme provides
                                ni

                                                           the opportunity for the dental contact to be evenly
    Aim. Continuous technological innovation has
                                                           distributed in a centric occlusion with a greater load in
    provided the clinicians to access to a computer-
                                                           the posterior lateral areas, the absence of interfer-
    ized device that can analyse the different charac-
                              io


                                                           ence, and a stable occlusal relationship in a relaxed
    teristics of occlusal contacts. The purpose of this
                                                           closure such that the occlusal model is convenient
    research was to use this device to study the oc-
                                                           and does not disturb stomatognathic functions (3, 4).
    clusal forces comparing healthy subjects and
                                                           Many researchers have studied occlusal contacts and
                            iz



    TMD patients.
                                                           their possible relationship with TMDs (5, 6).
    Materials and methods. The study was conducted
    by following specific criteria to select partici-      Some Authors (7-9) have significantly associated an
                                                           asymmetric occlusal contact distribution with TMDs.
            Ed




    pants; the sample was divided into two homoge-
    neous groups: control group (CG) comprising            No study has been able to clarify whether changes in
    healthy subjects, and dysfunctional group (DG)         the distribution of occlusal contacts occurred before
    comprising TMD patients. The occlusal force            or after the onset of TMD or their role.
    analysis was performed using the computerized          The continuous development of biomedical technolo-
    system T-Scan III V 5.20 T. The data were anal-        gies has provided researchers with tools to quantita-
                                                           tively and qualitatively analyse occlusal contact
 IC




                                                           forces. With the advent of digitalization, Maness et al.
    ysed with statistical methods.

                                                           (10) developed a high-precision, easy-to-use comput-
    Results. The most significant differences

                                                           erized system called T-Scan (produced by Tek-Scan,
    emerged between the groups in the average oc-

                                                           Boston USA). T-scan has been constantly improved
    clusal load distribution and in the location of the
C




                                                           in both its sensitivity and software (6); the latest evo-
    centre of occlusal forces (COF). In particular,

                                                           lution, the T-Scan III, is now available in its ninth ver-
    compared with the CG and the functional stan-

                                                           sion (T-Scan Novus). The system uses a sensor that
    dard, reductions in the molar field forces on the

                                                           is interposed between the arches to transform the da-
    second and first molars of 27% and 6.9%, respec-
©




                                                           ta from the occlusal contact into a numeric value ex-
    tively, were observed in the DG. The COF was lo-

                                                           pressed as a percentage (1, 11, 12). In this way,
    cated in the most forward position in TMD pa-

                                                           each tooth can be assigned its own percentage of
    tients compared with healthy subjects.

                                                           strength, reconstructing a model of the distribution
    Conclusions. Although the differences in the dis-

                                                           and intensity of the occlusal contact loads (13-15).
    tribution of the occlusal forces and the location of

                                                           The model of distribution of the occlusal forces pro-
    the occlusal centre of gravity were significant, the
    relationship between occlusal contacts and TMD

    Annali di Stomatologia 2017;VIII (2):79-88                                                                    79
    G. Ferrato et al.


    posed by Maness, expected a greater load on the                   ical guidelines of the 1975 Helsinki Declaration were
    first upper molars which thus represented the “center             followed, the research was approved by the Depart-
    of thrust” of occlusion (20).                                     ment and Ethics Committee: Department of Oral and
    After Maness, one of the first Authors to use this digi-          Maxillofacial Sciences, Sapienza University of Rome.
    talized occlusal contacts analysis method to recon-
    struct a distribution pattern of the occlusal forces was
    Garcia Cartagena et al., in 1997 (13). His study used             Members of the DG: were selected between Septem-




                                                                                                             li
                                                                      Selection of the two groups

    the T-Scan II and showed that the maximum load was                ber 2014 and February 2015 from among those who
    located on the second lower molars, decreasing to-                spontaneously came for a first specialist visit at the




                                                                                                           na
    wards the incisors, and that the average occlusal load            Gnathology Service Clinic Head and Neck Depart-
    was greater on the left side. More recently, two initial          ment of the Policlinico Umberto I “Sapienza” Universi-
    studies of the pattern of occlusal forces in healthy              ty of Rome. The number of patients admitted during
    subjects and TMD patients were conducted by the                   this period was 152; subjects were selected from this




                                                                                                         io
    Authors of this work in 2010 and 2011 (15, 16). The               group according to specific inclusion and exclusion
    results showed that the maximum load fell in the area             criteria listed in Table 1. In all, 35 patients (28 fe-
    of the first upper molars at the mesial-palatal cusp,             males and 7 males) with an average age of 39.8




                                                                                 az
    and these data were partially confirmed by Ma et al.              years were included.
    in 2013 (17). In 2012, Qadeer et al. stated that the              Members of the CG: were selected from among stu-
    digital T-Scan III technology could effectively aid (18)          dents of the Degree Course in Dentistry of the
    the analysis of occlusal contacts as an alternative to            “Sapienza” University of Rome according to the same
    the use of conventional, non-digital indicators (19).             inclusion / exclusion criteria (Tab. 1). The CG com-




                                                                               rn
    The aim of this study was to use the T-Scan III to                prised 28 subjects (16 females and 12 males) with an
    analyse and compare the distribution patterns of oc-              average age of 26.3 years.
    clusal forces in healthy and TMD patients.




                                                             te
                                                                      Instrument and method used to analyse the oc-

                                                                      The digital occlusion analysis was performed using
                                                                      clusal forces in the two groups

                                                                      the T-Scan III v. 5.20 T. All examinations were per-
    Materials and methods
                                                           In
    The study included two groups of subjects: the dys-               formed by the same dentist, who specialised in the
    functional group (DG), comprising patients diagnosed              use of the system. The resulting data were evaluated
    with TMD according to the Diagnostic Criteria for                 by a second person with the same characteristics
    TMD, and the control group (CG), comprising healthy               who knew neither the patients nor the subjects of the
                               ni

    subjects. A questionnaire regarding privacy laws al-              CG. The computerized occlusion T-Scan III analysis
    lowing the use of sensitive data for research purpos-             was performed in maximum intercuspation in accor-
    es and an informed consent form to participate in                 dance with the following protocol:
                             io


    clinical research were given to each participant. The             1. Patient remains in the sitting position without sup-
    study also statistically examined the data obtained                   port head gear but with the support of the sensor
    from the two groups. In all stage of the study, the eth-              parallel to the floor.
                           iz



    Table 1. Inclusion and exclusion criteria adopted for the selection of the two groups.
           Ed
 IC
C
©




    80                                                                                       Annali di Stomatologia 2017;VIII (2):79-88
    Digital evaluation of occlusal forces: comparison between healthy subjects and TMD patients


    2. Filling in the patient’s medical records as required       tre of occlusal forces (COF). According to the produc-
         by the software, including data concerning sex,          er of the T-Scan, the COF represents the centre of
         age, upper central incisor size, lack of dental ele-     gravity of the occlusion, i.e., the balance point of the
         ments, and the presence of prosthetic crowns.            occlusal forces obtained by summing the moments of
    3. Choosing a small or large sensor for a proper fit          the forces pressing on individual occlusal contacts.
         in relation to arch size.                                This assessment is only graphical-positional, is pro-
    4. Setting the size of the central incisor support, allow-    cessed directly by the software within a predefined




                                                                                                       li
         ing the software to calculate the size of the arch to    area, and was not considered sufficiently reliable by
         report the dental contacts of individual teeth.




                                                                                                     na
                                                                  the Authors; therefore, to obtain a more accurate as-
    5. Informing the patient of the nature of the test and        sessment of the COF, a different methodology was
         performing preliminary motions.                          developed. The graphical representation of the oc-
    6. Carrying out the examination first without activat-        clusal provided by the software was divided into sec-
         ing the recording but with the sensor inserted in        tors by building a grid with eight straight lines, four




                                                                                                   io
         the mouth.                                               each parallel to the MOL and to the interincisive line.
    7. Checking whether the sensitivity setting is set cor-       These straight lines are perpendicular to each other
         rectly; if on maximum strength, 4 or 5 columns ap-       and are traced by considering some easily detectable




                                                                             az
         pear at maximum intensity.                               points on the chart provided by the programme. The
    8. Asking the patient to bite the sensor firmly after
                                                                  straight lines parallel to the MOL are determined by
         recording activation and to keep teeth clenched in
                                                                  the union of the emerging central points from the
         the intercuspal position for a few seconds.
                                                                  meeting point of the midline of the occlusal forces
    9. Visually assessing the video and processing the




                                                                           rn
                                                                  and the line segments bordering the occlusal sur-
         data.
                                                                  faces of premolars and canines. The straight lines
    Of the three tests performed, the occlusal recordings
                                                                  parallel to the interincisive line are traced in the fol-
    in both the CG and DG contained the most informa-
                                                                  lowing manner: first, the two straight lines passing



                                                          te
    tion was considered.
    The analysis of the occlusal forces was performed by          through the points of contact between the median line
    evaluating the data for each dental element and for           of the occlusal forces and the line segments delimit-
    each side (left and right) and sector (back and front),       ing the distal surfaces of the two upper central in-
                                                        In
    following the same procedure for each examined sub-           cisors are drawn; then, the other two straight lines
    ject. The right side was distinct from the left, as indi-     passing them to the identified point are drawn, always
    cated by the interincisive line drawn on the occlusal         on the median line, by calculating half the distance
    axis. The front area was distinct from the back, con-         between the first two lines and the interincisive line.
                                ni

    sidering the maximum occlusal load (MOL) line as the          Compared with the interincisive line, the COF can be
    demarcation limit. This line is defined by the straight       located on the right (D) or left (S). Each side was fur-
    line joining the two mesiopalatal cusps of the first up-      ther divided into three encoded areas: the first area,
                                                                  as indicated by D1 or S1; the second area, as indicat-
                              io


    per molars that represent the major occlusal loading
    area (Fig. 1). In the event that asymmetry prevented          ed by D2 or S2 and corresponding to the second half
    to joining of these cusps with a single line, by con-         of the incisor in question; and the third area, as indi-
    vention it was decided to refer to that passing through       cated by D3 or S3 on the outer remaining portion af-
                            iz



    the mesiopalatal cusp of the first superior molar on          ter the first two (Fig. 2).
    the right.
    Another evaluation parameter examined was the cen-
            Ed
 IC
C
©




                                                                  Figure 2. Graphical representation of the subdivision of the
    Figure 1. Graphical representation of the MOL.                occlusal plane for the graphical-positional evaluation of COF.


    Annali di Stomatologia 2017;VIII (2):79-88                                                                               81
    G. Ferrato et al.


    Three possible variables were obtained with this method        pressed as percentages.
    compared with the MOL: 1. Coincident (C); 2. Rear (P);         In the CG, the greatest occlusal loading was detected
    3. Front (A). In turn, variable A is divided into 4 sectors,   in the area of the first upper molar with an average
    numerically coded and indicated by A1, A2, A3 and A4.          percentage of 14.35% strength. On the second molar,
    The distance of the COF from the MOL and the inter-            the percentage of detected force was 13.6%. On the
    incisive line was used as a parameter for assessing            other elements, proceeding in the posterior-anterior
    its location in both the CG and the DG.                        direction (premolars, canines, incisors), progressively




                                                                                                      li
    The descriptive analysis of the occlusal forces was            inferior values were registered until the incisal area.
    conducted considering the absolute values, averages            There were some differences in the occlusal loads




                                                                                                    na
    and the respective standard deviations.                        detected in the DG compared with the CG. In particu-
                                                                   lar, in the area of the first and second molars, these
                                                                   differences were 13.35 and 9.85%, respectively, cor-
    The basic descriptive statistical evaluation was per-          responding to percentage decreases of 6.97 and 27%
    Statistical analysis




                                                                                                  io
    formed in two stages: 1. Analysis of the occlusal load         in the DG. The percentages of force detected on the
    percentage of any single tooth; 2. Analysis of the             second and first premolars were 6.2 and 6.0%, re-
    arithmetic average of the occlusal load. This last             spectively, with reductions of 10.8 and 1.64%.




                                                                             az
    point has been evaluated both for side (left and right)        In the area of the front group, an average load of
    and for sector (anterior and posterior). All evaluations       4.3% was detected on the canines. On the lateral and
    were performed in the same process for the two                 central incisors, average loads of 1.9 and 4.05% were
    groups of patients also considering the standard devi-         detected, with increases of 59.25, 192.30 and
                                                                   143.24%, respectively, compared with the CG.




                                                                           rn
    ation.
    All data were sent for statistical processing to a spe-        To obtain a full view of the occlusal force distribution
    cialist for determining the significance of the data ob-       pattern, the Authors added the recorded average da-
    tained using a significance level of P<0.05 and the            ta for single teeth to a Cartesian axis system, produc-




                                                            te
    student t-test, which is a parametric test, to verify that     ing a graph defined as an occlusogram for each
    significant differences between the two groups were            group (Charts 1, 2).
    not due to chance but instead to an actual difference          Standard deviation was assessed by analysing the
                                                                   deviations of single teeth in the two groups (Tab. 3).
                                                          In
    between the averages of the two populations from
    which the samples were derived.                                Evaluated in the two groups showed significant differ-
                                                                   ences. These differences are expressed as percent-
                                                                   ages and reached a maximum of 193.54% on the up-
                              ni
    Results

    As stated above, the analysis of the forces was con-
    ducted for individual dental elements, per side and
                            io


    per sector. A separate analysis was performed for
    evaluating the COF.
                          iz



    Analysis of the occlusal forces for single dental

    Force values expressed as a percentage for individu-
    elements
           Ed




    al teeth in members of the CG and DG were consid-
    ered for this assessment. The arithmetic averages
    and the respective standard deviations were deter-
    mined. Table 2 shows the average values detected
    for single dental elements in the two groups ex-               Chart 1. Occlusogram in the CG.
 IC




    Table 2. Average measured force per tooth element in the two groups.
C
©




    82                                                                                Annali di Stomatologia 2017;VIII (2):79-88
    Digital evaluation of occlusal forces: comparison between healthy subjects and TMD patients


                                                                  per central incisors. This finding is represented in the
                                                                  Table referring to all the teeth analysed.
                                                                  In the following Charts (Charts 3), the average oc-
                                                                  clusal force in the two groups is represented by verti-
                                                                  cal column histograms that represent individual teeth
                                                                  show the respective standard deviations.
                                                                  The detected data were analysed using the student t-




                                                                                                      li
                                                                  test and are presented in Table 4. This Table shows




                                                                                                    na
                                                                  the average forces recorded for each dental element
                                                                  as percentages with the relative levels of P-values
                                                                  significance.
                                                                  The statistical analysis revealed significant results for
                                                                  elements 17, 13 and 11, which show greater variation




                                                                                                  io
    Chart 2. Occlusogram in the DG.                               between the two groups.




                                                                            az
    Table 3. Standard deviation values in the two groups.




                                                                          rn
                                                              te
                                                            In
                                ni
                              io
                            iz
            Ed
 IC
C
©




    Chart 3. Comparison of standard deviations occlusal forces between CG and DG.


    Annali di Stomatologia 2017;VIII (2):79-88                                                                          83
    G. Ferrato et al.


    Table 4. Average measured force for each dental element in the two groups with the relative levels of significance, with a
    threshold of P<0.05.




                                                                                                        li
                                                                                                      na
                                                                                                    io
                                                                              az
                                                                   The analysis of the side forces also highlighted that in
    The assessment of the occlusal forces on the right             these groups, on average, the left side has a greater
    Analysis of the occlusal forces per side

    and left sides was performed considering the average           load percentage than the right side.




                                                                            rn
    values and respective standard deviations detected in
    the two groups.
    Even these data were analysed using the student t-             As mentioned above, the anterior region is bordered
                                                                   Analysis of the occlusal forces per sector

    test to verify whether the differences between the av-         from the rear by the MOL. In fact, it is in correspon-
    erages of the two samples were significant; the ob-
    tained values are shown in Table 5.
    There were no significant differences between the
                                                          te       dence to this zone that the MOL is usually located
                                                                   and referred to more generically as the first upper
                                                                   molar. In Table 5 lists the average values per sector
                                                        In
    two groups. However, an increase in the main differ-           (front and back) in the two groups. The standard devi-
    ence in the DG was noted compared with the CG                  ations and the average differences observed between
    (from 0.5 to 5.7), as well as an increase in standard          the two corresponding sectors are also given.
    deviation from 7.7 in the CG to 10.5% in the DG.               These data were also analysed using the student t-
                              ni

    Table 5. Average measured force per side and sector in the two groups with the respective standard deviations, mean dif-
    ferences and level significance.
                            io
                          iz
           Ed
 IC
C
©




    84                                                                                  Annali di Stomatologia 2017;VIII (2):79-88
    Digital evaluation of occlusal forces: comparison between healthy subjects and TMD patients


    test to verify whether the differences between the av-
    erages of the two samples were statistically signifi-
    cant; the values obtained are reported in Table 5.
    The P-values obtained were not significant. However,
    the differences between the two groups seemed to in-
    dicate a recurring tendency, i.e., an increase in the
    percentage of strength in the anterior region in the




                                                                                                      li
    DG compared with the CG.




                                                                                                    na
    Analysis of COF position in the posterior-anterior

    As described above, the assessment of the COF lo-
    direction

    cation in the anteroposterior direction is considered a




                                                                                                  io
    function of its distance from the MOL. The Authors
    identified and marked with numerical code 3 specific
    areas for the evaluation of the COF position with re-         Chart 4. Graphical representation of the COF position in




                                                                            az
    spect to the MOL: 1. coincident (C); 2. posterior (P);        the CG.
    and 3. anterior (A). As area A was larger, it was fur-
    ther divided into 4 numerically encoded sectors: A1,
    the remaining portion of the first molar; A2, at the
    second premolar; and A3 and A4, corresponding to




                                                                          rn
    the first bicuspid and canine areas, respectively.
    Table 6 shows the rates (expressed as percentages)
    at which the centre of gravity was located in different




                                                           te
    areas in the two groups. These data are also repre-
    sented graphically.
    The analysis of the COF position highlighted that in
    the CG, on average, the COF coincided with the MOL
                                                         In
    (or remains in A1), while in the DG, the COF tended
    be positioned more towards the rear (P) or the front
    areas (A2, A3, A4) (Charts 4, 5).
                                ni

    Analysis of COF position in the latero-lateral di-
                                                                  Chart 5. Graphical representation of the COF position in
    To evaluate the COF position in the latero-lateral di-
    rection
                                                                  the DG.
                              io


    rection, its distance from the interincisive line was
    considered, thus identifying three areas (1-3) for both
    the right (D) and the left (S) parts. Table 7 shows the       the S2 and S3 areas more often, showing a greater
    frequencies (expressed as percentages) with which             range of localization (Charts 6, 7).
                            iz



    the COF was localized in the different areas in the
    two groups. These data are also represented graphi-
    cally.
            Ed




    The analysis of the COF position showed that it was
                                                                  Discussion

    more frequently located on the left side in both              The data recorded on the individual teeth of healthy
    groups. In the DG, the COF tended to be located in            subjects indicate that there is a recurring pattern in


    Table 6. Localization of COF detected in the two groups.
 IC
C
©




    Annali di Stomatologia 2017;VIII (2):79-88                                                                         85
    G. Ferrato et al.


    Table 7. Localization of COF detected in the two groups.




                                                                                                  li
                                                                                                na
                                                                                              io
                                                                         az
                                                                       rn
                                                           te
                                                         In
                              ni

    Chart 6. Graphical representation of the COF position in   Chart 7. Graphical representation of the COF position in
    the CG.                                                    the DG.
                            io


    the distribution of the occlusal forces, which in the      normal occlusion (29 males and 24 females) and
                          iz



    limits of the examined sample, could be referred to as     claimed to have found data supporting a model in
    “normal” or a reference (9, 16-19). This model has         which the MOL was located in an area between the
    been defined as an occlusogram, which showed that          first premolar to the second molar.
           Ed




    the area with the highest load, i.e., the MOL, was lo-     In spite of an incomplete accordance of data in the
    cated at the mesiopalatal cusp of the first upper mo-      literature, the Authors consider the presented model
    lars. Within this area, the occlusal loads tended to       to be valid. This conclusion is supported by other fac-
    steadily decrease in the rear direction, towards the       tors of the clinical examination conducted, such as
    second and third molars, but more so in the anterior       repeatability, sensitivity and simplicity. If carried out
    direction, towards the incisors.                           properly, the digitalized occlusion examination is sim-
 IC




    The identification of the maximum load at the level of     ple, repeatable, and largely operator independent.
    the first upper molars, apart from being in accordance     Moreover, the occlusogram is very sensitive to any
    with the classical gnathology concepts now widely re-      acute modification of the occlusion. The simplicity of
    ported in texts by Authors such as Maness and              the scheme is in line with the most recent statements
C




    Pedoloff (20), Okeson (21), Dawson and Arcan (22),         regarding occlusal models proposed for prosthetics
    and Ciancaglini (9), is also in agreement with the         that reflect the concepts expressed by Beyron (3, 4)
    work of others; in 1996 and 2002, the previously           in the fifties and quoted in a work by Manfredini (24).
    mentioned Ciancaglini performed a study with oc-           Additionally, regarding the COF evaluation, the re-
©




    clusal waxes and obtained similar results (23). When       sults revealed a recurring and statistically prevailing
    analysing occlusal forces with a T-Scan II in 1996,        pattern. On average, it is located in a frontal area im-
    Garcia Cartagena et al. (13) had proposed a slightly       mediately adjacent to the MOL, and the statistical
    different model by singling out the major load on the      analysis of the frequencies of its location in healthy
    second inferior molar. However, in 2013, Ma et al.         subjects showed a Gaussian behaviour, with a maxi-
    (17) used a T-Scan III on 53 healthy subjects with         mum frequency in the A1 area, which decreases in

    86                                                                            Annali di Stomatologia 2017;VIII (2):79-88
    Digital evaluation of occlusal forces: comparison between healthy subjects and TMD patients


    the front and rear directions. The study of the fre-          the COF. It ’should finally point out that the T-Scan III
    quency with which the COF is located in a given area          system does not yet permit any pathogenic interpre-
    was made possible by the specific graphical-position-         tation of the causes of such a behaviour as well as
    al evaluation grid conceived and developed by the             any diagnostic evaluation of temporomandibular joint
    Authors.                                                      dysfunction.
    The use of the map designed by the Authors makes it           Further investigation is still needed to confirm the
    difficult to compare other data from the literature ob-       preliminary hypotheses proposed and to better under-




                                                                                                            li
    tained using different systems or processed by the            stand future potential applications.




                                                                                                          na
    software supplied with the device.
    Regarding the comparison of data from the two
    groups, both the occlusogram and COF analyses                 The Authors have carried out the required revision.
                                                                  Report on the review

    showed statistically significant differences.                 The English translation was made at the American
    Specifically, the occlusogram in the DG showed a re-          Journal Expert (AJE) that has released its editorial




                                                                                                        io
    duced occlusal load in the posterior region and an in-        certification.
    creased load in the frontal area (Charts 1, 2). This re-
    sult, which seems far from those of other Authors,




                                                                              az
    could be a physiological pattern and is repeated even
    with wide individual variations in the DG.
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