10.59987/ads/2013.1.161-169
The aim of this work was to present data from a large sample of patients with Temporo-Mandibular Disorders(TMD) in order to clarify some aspects of the development of pathological conditions that affect large parts ofthe population. This preliminary work put in relation, through an epidemiological evaluation, an amnestic and clinical datacollected from a sample of 2375 patients affected by TMD. Personal data were provided by questionnaire (age, sex, status, etc.), while clinical data were collected following a specific medical chart compiled in accordance with international criteria for TMD. An analysis of these data clearly showed that there were large quantities of variables involved in these disorders and which occur with a wide variety possible of clinical signs. This complexity, in accordance with the current knowledge that it is not able to clarify the etiology of these disorders, makes intricate both diagnostic then therapeutic aspects. You would find in front of a multi-factorial systemic disease that, interfering with the individual bioavailability, exposes him to the possibility of perceiving noxious stimuli which other wise would not able to reach the pain threshold. To support this hypothesis is the data founded in this report that showed how many patients suffered, at the same time, by muscle and spinal pain associated to headache, pain that occur with high frequency from the same side. The presence of these painful conditions tends to underes-timate the dysfunctional problems even if they occur with greater clinical prevalence. Further research should be carried out to clarify these controversial issues.
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Annali di stomatologia
epidemiology
Epidemiological analysis on 2375 patients with TMJ disorders: basic statistical aspects
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Original Article
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Ann Stomatol (Roma)
G. Iannetti 
2013
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Epidemiological analysis on 2375 patients with TMJ disorders: basic statistical aspects
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                                                                                                       Original article


Epidemiological analysis on 2375 patients with
TMJ disorders: basic statistical aspects




                                                                                              li
                                                                                           na
Carlo Di Paolo, MD1                                          not able to reach the pain threshold. To support this hy-
G. Damiana Costanzo, MD2                                     pothesis is the data founded in this report that showed
                                                             how many patients suffered, at the same time, by mus-




                                                                                        io
Fabrizio Panti, MD1
Alessandro Rampello, MD1                                     cle and spinal pain associated to headache, pain that
Giovanni Falisi, MD1                                         occur with high frequency from the same side. The
Andrea Pilloni, MD1                                          presence of these painful conditions tends to underes-




                                                                                     az
Piero Cascone, MD3                                           timate the dysfunctional problems even if they occur
Giorgio Iannetti, MD3                                        with greater clinical prevalence. Further research
                                                             should be carried out to clarify these controversial is-
                                                             sues.




                                                                      n
1
    Department of Oral and Maxillofacial Sciences,
                                                             Key words: temporo-mandibular disorders, statistical
    “Sapienza” University of Rome, Italy




                                                                   er
                                                             analysis, epidemiology.
    Clinical Gnathology Unit
2
    Department of Economic, Statistical and Financial
    Sciences, University of Calabria, Italy
                                                             Introduction
3


    “Sapienza” University of Rome, Italy
    Maxillofacial Surgery Unit               nt
    Department of Oral and Maxillofacial Sciences,

                                                             The Temporo-Mandibular Disorders (TMD) are a set of
                                                             dysfunctional patterns concerning the temporo-mandibu-
                                           iI
                                                             lar joints (TMJ) and the masticatory muscles with frequent
Corresponding author:                                        involvement of other structures of various body districts
Fabrizio Panti, MD                                           with the result of making complicated the classification
                                         on

Department of Oral and Maxillofacial Sciences,               and the diagnostic processes (1-4).
“Sapienza” University of Rome,                               This complexity has led, in recent years, to consider the
Clinical Gnathology Unit                                     origin of the TMD as multifactorial both for the undoubted
Viale Regina Elena, 287/A                                    frequent association of several factors in causing the dis-
                                i


00161 Roma, Italy                                            ease then for the current inability of the researchers to
                             iz


Phone: +39 3358372914                                        recognize the real factors causing the dysfunction (5-
E-mail: fabrizio.panti@fastwebnet.it                         10). In this context it might be useful to have clinical data
                                                             emerging from epidemiological studies of large numbers
              Ed




                                                             of patients to better understand the various and complex
Summary                                                      symptomatology and to try to framing the patient need of
The aim of this work was to present data from a large        care in particular to be able to set an early diagnosis and
sample of patients with Temporo-Mandibular Disorders         to apply prevention therapies (11-12).
(TMD) in order to clarify some aspects of the develop-       The data analyzed in this work are the outcomes of the
ment of pathological conditions that affect large parts of   patients who spontaneously arrived requiring a specialist
 IC




the population.                                              visit at the Gnathological Service of the Oral and Maxillo-
This preliminary work put in relation, through an epi-       Facial Department of University “Sapienza” of Rome dur-
demiological evaluation, anamnestic and clinical data        ing the period from July 1983 to July 2006.
collected from a sample of 2375 patients affected by         Taking into account as diagnostic reference the
C




TMD. Personal data were provided by questionnaire
                                                             RDC/TMD, our researches are related exclusively to the
(age, sex, status, etc.), while clinical data were col-
                                                             Axis 1 clinical aspects, complemented by other possible
lected following a specific medical chart compiled in ac-
                                                             variations in the clinical section of muscle disorders.
cordance with international criteria for TMD. An analy-
                                                             All data were analyzed with statistical evaluation tech-
©




sis of these data clearly showed that there were large
quantities of variables involved in these disorders and      niques and, in view of the amount and complexity of the
which occur with a wide variety possible of clinical         results, they were divided into two papers. In this early
signs. This complexity, in accordance with the current       work the authors have been illustrated and described
knowledge that it is not able to clarify the etiology of     the epidemiological basic characteristics of the sample
these disorders, makes intricate both diagnostic then        with the aid of elementary statistical techniques and tools.
therapeutic aspects. You would find in front of a multi-     This preliminary phase was necessary to carry out further
factorial systemic disease that, interfering with the in-    analysis aimed for identifying most sophisticated and sig-
dividual bioavailability, exposes him to the possibility     nificant links between the different dysfunctional frames.
of perceiving noxious stimuli which otherwise would          In order to give a logical and statistically useful to the large

Annali di Stomatologia 2013; IV (1): 161-169                                                                            161
C. Di Paolo et al.


amount of clinical variables describing the population af-     to introduce a severity code of each case. The last part
fected by temporo-mandibular disorders (TMD), it was           has been left to the spaces specially dedicated to the de-
necessary to encode the different aspects studied in this      scription of the working diagnosis and the subsequent
work in an analytical way. The mat and met paragraph ex-       treatment plan, and finally an adequate space for describ-
plained the details of the type of coding adopted for the      ing the evolution of symptoms during treatment controls




                                                                                               li
symptomatic variables considered and highlighted the           was added. The final version of the medical records used
motivations that have addressed these scientific choices.      for TMD patients was put into current use in the mid-




                                                                                            na
Following the same codifications we were described and         nineties, this explains the choice of the period under re-
analyzed the results and through their analysis the sub-       view.
sequent concluding remarks.                                    Based on the semeiotics suggested by the structure of
                                                               medical proceedings it was therefore possible to identify




                                                                                         io
                                                               four groups of variables, for a total of 33 characteristics
Materials and methods                                          that clearly define a TMJ disorders:
                                                               1. General features and age;
1.1 Selection of sample                                        2. Biomechanical characteristics, which include data re-




                                                                                      az
                                                                    lating to the symptoms of functions and dysfunctions
As mentioned above, patients were selected retrospec-               and occlusal characteristics;
tively from the medical records registered at the Clinical     3. Muscle characteristics, including data related to the
Gnathology Service of the Oral and MaxilloFacial Sci-               presence/absence of the different type of neuromus-




                                                                       n
ences Department of Sapienza University of Rome. The                cular pain;
Service was created at the chair of Maxillofacial Sur-         4. Data describing the treatments and their outcome.




                                                                    er
gery, then it was transferred under the direction of the
Periodontal chair and finally it became special unit, dur-     In the first section were enclosed the variables described
ing the entire period the division has always been             below:


                                           nt
managed by the same calibrated team. The patients
considered in the study were selected with two inclu-
sion/exclusion criteria, the only inclusion criterion
adopted was to have a diagnosis of TMJ disorders, the
                                                               - Sex: several studies have to give particular important
                                                                    to this issue not only because it is well know the high
                                                                    percentages of women compared to men involved in
                                                                    the temporo-mandibular disorders.
                                         iI
only one for exclusion was not having the medical              - Age: to analyze this variable was deemed appropri-
records duly completed. The authors were considered                 ate to adopt, in the following analysis, a division into
those who have made a specific treatment and those                  different classes of age: 0-15 years (children), 16-25
                                       on

who were only observed and recorded because these                   years, 26-40 years, 41-50 years, 51-60 years, 61-70
data could be useful for epidemiological and statistical            years, more than 70 years.
considerations. The period from 1983 to 2006 was the           - Civil status: Although not known for many of the pa-
time interval considered, during that time patients come            tients examined, in our view, it is an aspect to be con-
                               i


to clinical attention were over 8000. The lack of informa-          sidered in order to evaluate the emotional impact of
                            iz


tion founded in medical records present in the chart                private life context (separation, divorce, bereave-
compiled during the first years, however, has required              ment).
the authors to take into account only the data related to      - Occupation: the occupation and the type of activity
             Ed




the patients who have come for a visit during the decade            performed by any subject may be determinant to
1996-2006, this examination has involved 3087 pa-                   evaluate certain attitudes, postural factors and the so-
tients. In the light of the application of above mentioned          cial stress. Furthermore this variable was again di-
selection criteria the study sample has been composed               vided by grouping different professions in the nine cat-
of 2375 patients.                                                   egories proposed by Istat Classification of
                                                                    Occupations: intellectual professions and scientific,
 IC




                                                                    technical and specialized, used, non-specialized in
2.2 Description and coding of variables:                            commercial, craft, industrial and services; house-
from the medical records to statistical data                        wives, students, pensioners, unemployed; more.
                                                               - Existence of a history of trauma: this file is clinically
C




The medical chart which were originally used at the De-             considered as a factor that most often lead to TMJ
partment was formed by 2 front pages. Later also to ob-             (temporo-mandibular joint) functional alterations with
serve the international criteria for the diagnosis of TMD           related pain, neck pain and or other type of pain.
the medical records has been changed to 4 pages, in            - Presence of a previous treatment: this element has
©




which were sequentially well-ordered: the patient’s per-            been recorded in order to assess if the visited patients
sonal data, history, subjective pain symptoms, symptoms             have previously undergone to some therapies in one
and objective by masticatory muscles and articular joint            or more of the stomatognathic components. These
functionality other articular features, occlusal and struc-         variables have been codify for type of therapy
tural examination, symptoms of other districts. This chart          (gnathologic, orthodontic or prosthetic) and for num-
was subsequently update to improve and complete the                 bers of treatments one, two or more.
medical records introducing specific area regarding the in-    - Presence of a disease (different from TMD): it was de-
tra-and extra oral inspection, the presence of structural or        cided to organize, the corresponding variable col-
systemic diseases, to describe the results of the imaging,          lected by the questionnaire, into four major groups:

162                                                                              Annali di Stomatologia 2013; IV (1): 161-169
Epidemiological analysis on 2375 patients with TMJ disorders: basic statistical aspects


     absence of pathology, presence of systemic diseases,       Another cluster of variables considered were the one re-
     presence stomatognathic diseases or both.                  lated to the masticatory muscles disorders. In this group,
The information collected in the “biomechanical charac-         the following variables were embraced:
teristics” section, were combined in the following vari-        - Masticatory muscles pain: we was detected only the
ables:                                                               presence / absence not considering the size and




                                                                                                li
- Presence of tmj pain on the right side and presence                soreness;
     of pain on the left side: for these two variables other    - Headache: this pain condition was considered without




                                                                                             na
     than the presence/absence of pain it was also quan-             classifying, evaluating only the side of onset when its
     tified the pain intensity using the Visual Analogic             referred. For these two characteristics it was used as
     Scale (VAS). To both variables were assigned the fol-           a method of evaluation based on the VAS scale work-
     lowing classes of values: 0 (no pain joints), 0-20 (mild        ing with the same classes of encoding methods uti-




                                                                                          io
     pain), 20-50 (moderate pain), 50-80 (severe pain), 80-          lized for the TMJ pain: 0 (no headache), 0-20 (mild
     100 (severe pain).                                              headache), 20-50 (moderate headache), 50-80 (se-
- Presence of joint noise both left and right side: the              vere headache), 80-100 (very severe headache).
     sounds considered were: click, crepitus, noise of dif-     - Spinal pain: there have been recorded the presence




                                                                                       az
     ferent nature and not attributable to the two previous          / absence regardless of the location (cervical, lumbar
     types called unclassifiable. If the same structure had          or sacral). The presences of these symptoms were an
     multiple symptoms, we have based the classification             important aspect to be investigated because, in the lit-
     on the severity of the disease considering as princi-           erature, several studies agree in highlighting a possi-




                                                                        n
     pal noise the presence of crepitus. The categories of           ble correlation or comorbidity with TMD;
     the variables considered were: No noise, Click, Crepi-     - Emotional factors: state of anxiety or generic stress




                                                                     er
     tus, Other.                                                     that could help to promote the onset of dysfunction,
- Value of the maximum opening of the mouth: this                    were evaluated by clinical method and deducted by
     feature was expressed in mm and divided into the fol-           the anamnestic records.


                                             nt
     lowing classes of values: 0-20 mm, 21-30 mm, 31-40
     mm, 41-45 mm, 46-50 mm and more than 50 mm.
- Missing teeth in the left and/or right dental arch: the
     corresponding variables were coded by defining the
                                                                - Parafunctions: these parameters were divided into
                                                                     two different comportments “bruxism” and “clenching“,
                                                                     they were assessed from the clinic analysis of the
                                                                     masticatory muscles and from the evaluation of the
                                           iI
     following classes of modes: 0 (presence of all dental           teeth status.
     elements in the right or left arch), 1-2, 3-4, 5-8 (num-   The last parameters that we have been evaluated from
     ber of missing teeth in the posterior area).               the comparison of the above variables were the therapies
                                         on

- Missing teeth in anterior area (upper an lower arch in-       performed and its results. Under the wording therapies the
     cluding): for this area we had considered the same pa-     authors have included the main type of conservative
     rameter explained above: 0 (presence of all dental el-     treatment used in different and custom combinations to
     ements), 1-2, 3-6, more than 6 (number of missing          solve a TMD: plates, physiotherapy and pills.
                                i


     teeth in the anterior area).                               Outcome of the therapy: the results of the treatments were
                             iz


- Molar Occlusal Classes (right and left): whereas that         classified in 4 possible outcomes: healed, improved, sta-
     for many occlusal situations the occlusal class it often   ble, worsened. This evaluation has been assumed from
     was not attributable, we were considered four modes:       the pre and post treatment comparison of the semeiolog-
              Ed




     occlusal Class I, occlusal Class II, occlusal Class III,   ical data of each patient. The development of any other
     occlusal Class not definable;                              new symptoms or the aggravation of the previous indi-
- Limitation of maximum opening of the mouth: we                cated a worsening condition. The presence of the same
     have considered only the presence/absence                  symptoms showed a stable condition, the only improve-
- Laxity of ligaments: we have considered only the              ment without a complete resolution of the symptoms
     presence/absence.                                          showed an improved situation, the stable absence of any
 IC




Other variables of which have been calculated only the          symptoms indicated a condition of healing. The authors
presence/absence were the following:                            included in this analysis only the treated patients with a
- TMJ Subluxation: discriminating only the sides (right,        long distance assessments.
     left or both);
C




- Mandibular Dislocation discriminating only the sides
     (right, left or both);                                     2.3 Statistical analisys
- Asymmetry of the mandible: comparing the right with
     the left side with clinical approach and following the     In this work, the statistical analysis of the data obtained
©




     cephalometric procedures proposed by Habets;               from medical questionnaire and medical charts were pri-
- Steep Incisal guidance: it was considered to be ver-          marily used to characterize the basic epidemiological as-
     tical when the cephalometric measure of the angle          pects of the 2375 dysfunctional patients. For this purpose
     formed by long axis of central upper incisor and           descriptive statistical tools, as frequency distributions
     Frankfurt plan is less or equal to 100°;                   and percentages, graphical representations and - ac-
- Decrease of posterior vertical dimension of occlu-            cording to levels of data measurement - various measures
     sion: this parameter was inferred from a clinical and      of central tendency (including mean, median and mode)
     radiological evaluations without specific measure-         and variability (i.e. standard deviation and variance), were
     ment;                                                      essentially used.

Annali di Stomatologia 2013; IV (1): 161-169                                                                             163
C. Di Paolo et al.


Results                                                                   In conclusion with respect to age and gender variables it
                                                                          was established that, the patient type that addressed to
Considering the high number of variables that have been                   the Dental Clinic Department of Sapienza University of
submitted to statistical analysis, in this section will be pre-           Rome during the years 1996-2006 asking a gnathologic
sented and discussed only the most significant results. In                visit was mostly a women, aged between 26 and 40




                                                                                                          li
order to make more clear the subsequent illustration of the               years.
general characteristics of our dataset, the most important                The medical records about the civil state of patients were




                                                                                                       na
descriptive statistics of the quantitative variables are pre-             known only in 16.2% of cases, (statistically insignificant),
sented in Table 1.                                                        while their “profession” was widely known (75 7%). An in-
                                                                          spection on such the data indicated that students, house-
                                                                          wives and employees were the “working” categories that




                                                                                                    io
3.1 Defining general aspects                                              characterize mostly our sample data. We found a very rel-
                                                                          evant percentage of subjects belonging to the intellectual
Firstly, we considered composition of our sample by gen-                  and scientific professions, as well to the so called un-
der and age. About gender, we observed a strong preva-                    skilled workers.




                                                                                                 az
lence of women over men, with a percentage respectively                   Concerning the “trauma” variable, 79.2% of the patients
of 79.5% for women and of 20.5% for men. These results                    didn’t told a history of trauma previous their dysfunction.
confirmed the 8/3 - 8/1 ratio already known in the literature.            While, for the “stomathognathic treatments performed
The age of the patients was known for almost all those                    before the onset of the TMD” variable, the descriptive




                                                                                  n
visited (97.1%). The analysis of age data showed an                       analysis showed that only 2.8% of the patients underwent
high percentage of patients belonging to the middle                       to two treatments, 21.7% to one treatment, and the ma-




                                                                               er
compared to the pediatric age (0-15 class of years):                      jority of 75.5%, said that they did not have undergone to
36.8% and 3.6% respectively. The same results were                        any dental treatment.
found for the advanced senile age (70 +), 1.8% of sub-                    We have reported the frequency distribution of the 2375


(Tab. 1).                                       nt
jects. The mean and median matched with the class 26-
40 years, in particular, the mean age was 35.6 years

The high number of students in the sample could explain
                                                                          patients respect to other diseases (systemic and/or
                                                                          stomathognathic) in Table 2. We can observe that that the
                                                                          majority of subjects 84.2%, (2000) had no disease, while
                                                                          the 13.1% (310) had a systemic diseases in their medical
                                              iI
the high presence of patients in the group of 16-25 years.                history.
Since the lowest frequencies were found in the most ex-                   As mentioned earlier, the low frequencies associated
treme age groups, this confirms that young and the eld-                   with the 12 groups of systemic diseases and the 4 groups
                                            on

erly people represent a minority in the sample. Further,                  of stomathognathic diseases originally considered, did not
when we analyzed the gender respect to age, results                       allow to deduce any evident connection between these
showed that mean and median both matched the 26-40                        variables and TMD’s; that is, it was not possible to detect
class years. However, these measures for women (36 and                    any statistically significant association between such vari-
                                  i


33 years respectively) were greater than men (34 and 30                   ables which might substantiate some pathogenic interac-
                               iz


years respectively).                                                      tions.

Table 1. Descriptive statistics of the quantitative variables.
               Ed




Variable                                     Meaw                Median         Standard deviation        Minimum         Maximum

Age                                          35,64               32,00                  15,047                2                86
Riht articular pain*                         22,57                 ,00                  28,891                0               100
Right articular pain**                       49,58               50,00                  22,227                5               100
 IC




Left articular pain*                         21,16                 ,00                  28,838                0               100
Left articular pain**                        50,35               50,00                  22,559                5               100
Maximum mouth opening                        43,58               45,00                   8,911                1                68
C




Maximum mouth opening***                     46,21               46,00                   6,786                1                68
Missing teeth in the arch right               1,08                 ,00                   1,746                0                 8
Missing teeth in the arch left                1,10                 ,00                   1,747                0                 8
Missing teeht in front area                    ,42                 ,00                   1,639                0                12
©




Headache right*                              24,91                 ,00                  32,241                0               100
Headache right**                             58,53               50,00                  21,775               10               100
Headache left*                               24,01                 ,00                  31,939                0               100
Headache left**                              58,60               50,00                  21,504               15               100

* These variables are, in this case, not considered quantitative and ordinal.
** The values of the indices calculated refer to the variable considered in relation to the symptomatic sample.
*** The values of the indices are calculated in relation to the variable “maximum mouth opening”, evaluated by excluding cases with
    the presence of LAB.


164                                                                                         Annali di Stomatologia 2013; IV (1): 161-169
Epidemiological analysis on 2375 patients with TMJ disorders: basic statistical aspects


Table 2. Composition of the sample by type of other diseases.

Pathology                                                    Values of disease                        Percentages

Absence values of disease                                            2000                                 84,2




                                                                                                         li
Systemic disease/stomatognatic                                         2                                   0,1
Systemic disease                                                      310                                 13,1




                                                                                                      na
Stomatognatic pathology                                               63                                   2,7

Total                                                                2375                                 100,0




                                                                                                   io
3.2. The analysis of the bio-mechanical                                   In order to assess the relative meaning of the different
characteristics                                                           degrees of “TMJ pain” (left and right) only in the symp-




                                                                                                az
                                                                          tomatic sample, we excluded all those subjects showing
The statistical analysis of the TMJ pain in the sample                    zero VAS value from the sample. Such new sub sample
showed that the 63% of patients presented articular pain                  was made up of 1081 patients with right “TMJ pain” and
(compared with the 37% asymptomatic); in particular,                      998 patients with left “TMJ pain”; data in Tab. 4 show that




                                                                                  n
24.6% of them had bilateral pain, while about 38% of them                 the moderate degree of articular pain was the most fre-
showed pain to one of the temporo-mandibular joints.                      quently occurring in about half of the cases, followed by




                                                                               er
The analysis of the symptom “TMJ pain” have been                          mild and strong; pain assessed as serious showed a
carried out considering separately the two joints. Table                  very low frequency in both joints, 2.3% and 2.8% respec-
3 presents the frequency distribution of “TMJ pain” in                    tively.
the form of class VAS intervals. The frequencies in                       Further, for both joints we investigated the relation be-


                                               nt
such table show that more than a half of the subjects
(54.5% and 58% respectively) had no pain in both
joints. In both right and left “TMJ pain”, the means fall
                                                                          tween pain and age: analysis showed an high frequency
                                                                          of subjects falling in the middle-class (20-50 class of
                                                                          years), but the media was closer to the class endpoint of
                                             iI
in the 20-50 class with a very close value to the low of                  50 years of age.
20, which indicates a moderate degree of pain (the me-                    The analysis of noisy symptoms led to the following re-
dians both coincide to “0”, that is no right and left                     sults: 53.2% of the patients had joint noises, 35.2% of
                                           on

pain); dispersion measures were almost similar in both                    them had noises at one joint, 18% of them had noisy
situations.                                                               symptoms at both joints (TMJ).


Table 3. Frequency distribution right and left articular pain (VAS scale class intervals).
                                  i
                               iz


Classes VAS                                    Right TMJ pain                                       Left TMJ pain

                                Absolute value                Percentages              Absolute value             Percentages
               Ed




             0                        1294                         54,5                      1377                       58,0
          1-20                         275                         11,6                       243                       10,2
         20-50                         515                         21,7                       469                       19,7
         50-80                         266                         11,2                       258                       10,9
 IC




        80-100                          25                          1,1                        28                        1,2

         Total                        2375                        100,0                      2375                     100,0
C




Table 4. Frequency distribution of right and left "TMJ pain" in symptomatic sub sample.

Classes VAS                                    Right TMJ pain                                       Left TMJ pain
©




                                Absolute value                Percentages              Absolute value             Percentages

          1-20                         275                         25,4                      243                       24,3
         20-50                         515                         47,6                      469                       47,0
         50-80                         266                         24,6                      258                       25,9
        80-100                          25                          2,3                       28                        2,8

         Total                        1081                       100,0                       998                      100,0


Annali di Stomatologia 2013; IV (1): 161-169                                                                                     165
C. Di Paolo et al.


Also for the noisy symptoms we considered separately the              mouth” variable, all the patients who have some difficul-
right and left temporo-mandibular joints. The basic statis-           ties in performing the mandibular opening movement (the
tical data showed that: the 35.3% of the subjects had                 dimension of resulting new sample was 1522 subjects).
noises at the right tmj, 21.1% of them had noise identified           In this last case we found that, for both women and men,
as “clicking”, 5.5% diagnosed as “crepitus“ and a share of            the mean and median were increased compared to the




                                                                                                      li
8,7% have noisy symptoms unidentifiable in the two pre-               whole sample and falling in the class opening 46-50 mm.
vious categories. About the left side, the 36% of the sam-            If now consider the gender of such 1522 subjects, despite




                                                                                                   na
ple had noises in the left TMJ, the 21.7% of them had di-             the average and the median value increased both for
agnosis of noise identified as clicking, 9.7% as                      women then for men, we found that female gender
non-specific and only a portion 4.4% showed a noises                  showed lower values than male one. Therefore, these re-
classified as crepitus. Also in this case to evaluate the rel-        sults confirm the quantitative difference in the maximum




                                                                                                io
ative importance of the three types of the TMJ noises, the            opening of the mouth in favors of men than women, and
authors have been considered only the symptomatic                     also confirm that female gender has been shown to be
sample excluding from the statistical calculation the sub-            more sensitive to the TMJ internal disorders.
jects who did not show any articular noises, this has                 Dislocation of the jaw was analyzed by considering the two




                                                                                             az
been done both to total count then for each of left and right         joints in the right and left sides separately. This dysfunc-
joint sides. The results showed that the symptomatic                  tional alteration occurred at the right TMJ in 3.6% of the
sample respectively consists of 838 and 852 patients. In              subjects and at the left side in 3.8% of the subjects. Also
both cases it was found that the clicking sounds were the             about the condylar subluxation, the authors carried out an




                                                                               n
kind of articular noises that occur more frequently having            analysis by right and left side separately. Frequency distri-
a high relative statistical weight, followed by the not iden-         bution showed that 1.6% of the sample suffered of this func-




                                                                            er
tifiable noises and finally the crepitus, both as a much              tional characteristic at the right TMJ, while 1.5% of the sub-
more reduced percentage.                                              jects suffered at left side. TMJ laxity of ligaments was
Considering the “limitation of mouth opening“ variable,               found to be present in 14.1% of the sample.


                                              nt
data showed a significant percentage of the sample,
78.7% with “no limitation of mouth opening” and, then only
the 21.3% of the subjects was found affected by this
symptom.
                                                                      These elements see med to question on the possibility
                                                                      that, a ligamentous laxity and/or a joint hypermobility fo-
                                                                      cused to the TMJ, had a possible role in the determinism
                                                                      of internal disorders of this articulation.
                                            iI
Consider now the “maximum opening of the mouth” vari-                 The evaluation of the absence of teeth examined in the
able, evaluated in millimeters; we had data for such vari-            patients had led to the following results, the 42.9% of the
able in the 83.7% of the medical records. In analyzing                sample had missing teeth in at least one of the three sec-
                                          on

such data we found that mean, median and mode falling                 tors investigated (posterior right and left dental arches, an-
in the same class 41-45 mm; further, the smallest open-               terior area), these sectors were instead simultaneously in-
ing value was 1 mm while the largest was 68 mm (Tab.                  volved in 9.3% of cases. The frequency distributions in
1). The patients were distributed in a rather uniform way             these three specific areas are reported in Tab. 5. In the
                                 i


starting from 31 mm value until 40 mm value, and only the             right sector we found the 84.7% of subjects having at least
                              iz


8.1% of patients fallen in a mouth opening class “less than           1 or 2 missing teeth. The mean fells in “1-2” class, while
30 mm“. Considering the gender of such subjects, we also              the median coincided with the mode “0”, indicating the
found that mean and median were higher in the group of                presence of all the dental elements; the maximum num-
              Ed




men compared to women, and, in addition, by comparing                 ber of missing teeth in the posterior right arches has
these measures with those calculated for the whole sam-               been equal to eight teeth missing (Tab. 1).
ple, we found that the mouth opening mean and median                  The 84% of the sample showed one or two missing teeth
in women were lower than those ones, while for men the                in the posterior left arch. Also in this case, the average
same values were higher. Further, in order to avoid influ-            value fells in the “1-2” class and the median coincided with
ences by those subjects suffering by a limitation, we ex-             the mode “0”, as well the maximum number of missing
 IC




cluded from the analysis of “maximum opening of the                   teeth was equal to eight (Tab. 1).


Table 5. Frequency distribution of the “missing teeth”.
C




Number           Missing teeth in the right               Missing teeth in the left           Missing teeth in the front side
                  posterior dental arch                    posterior dental arch
©




               Absolute           Percentages         Absolute         Percentages       Number       Absolute        Percentages
                value                value             value                                           value

0                1363                  57,4               1341              56,5             0           2074             87,3
1–2               649                  27,3                654              27,5           1–2            197              8,3
3–4               212                   8,9                235               9,9           3–6             61              2,6
5–8               151                   6,4                145               6,1            6+             43              1,8

Total            2375                100,0                2375            100,0           Total          2375            100,0


166                                                                                     Annali di Stomatologia 2013; IV (1): 161-169
Epidemiological analysis on 2375 patients with TMJ disorders: basic statistical aspects


In the anterior area the 87.3% of the sample has not pre-          be considered a complex patient with concomitant is-
sented missing teeth, the maximum number of missing                sues that often lead to problems both in diagnosis than in
teeth founded was “12 “teeth (Tab. 1).                             therapeutic approach.
These data seem to give particular importance to the               The impact of emotional factors such as stress and anx-
absence of teeth, especially in the posterior region. On the       iety was 8.9%.




                                                                                                    li
basis of this significance, although preliminary, the authors      The parafunction “bruxism” was highlighted in 9.3% of
hypothesized that the loss of teeth could be a very impor-         cases, while the “clenching” was positive in 28.5% of




                                                                                                 na
tant factor in the determination of TMJ dysfunction. This          subjects analyzed; such last parafunction seems to be the
finding should also be considered in the prevention phase          most widespread and the most potentially harmful for
although out of line with the data present in the current lit-     the individuals who are affected.
erature.                                                           About the “headache” almost half of the sample ana-




                                                                                              io
The evaluation of dental classes was separately con-               lyzed, 46.8%, presented this symptom, the most of the
ducted for the right and the left sides. Concerning the right      sample showed, according to VAS scale, an average
side we found that the 44.5% of the sample had a class             level of pain (20-50). This data confirms the high co-mor-
I, the 25.5% a class II and the 10% a class III; in the 20%        bidity of this disease with the TMD’s; the data was in




                                                                                           az
of cases was not possible to ascertain the class due to            agreement with the findings emerging from the literature.
particular dental situations that made it impossible to def-       The data led the authors to state the hypothesis that po-
inite it. On the left side the 42.6% of the sample presented       tentially, at least for the group of patients analyzed in this
a class I, followed by a 26.4% who had a class II and by           study, a patient with headache could be considered at risk




                                                                            n
10.8% of a class III. This finding according to what               for dysfunction and vice versa. The frequency distribution
emerged from the literature has demonstrated the lack of           by site of headache is reported in Tab. 6.




                                                                         er
reliability of the relationship between occlusal classifica-       To assess the relative impact of different degrees of
tions and TMJ disorders.                                           cephalic pain in the sample, it was necessary to exclude
Two other data relating to the occlusion were particularly         from analysis all those who were free from this symptom


                                             nt
significant, the first was the steep of incisal guidance
(vertical incisal guide) which was detected in the 26.1%
of the sample, the second was the loss of posterior ver-
tical dimension which was detected in the 27.3% of cases.
                                                                   (Tab. 7). In that way it was possible to detected how the
                                                                   moderate degree of headaches, followed by high-grade
                                                                   headaches, were the most commons among those who
                                                                   were suffering.
                                           iI
These variables, which were positive in previous epi-              It was also possible to observe that the majority of patients
demiological studies, may deserve closer attention in the          revealed a medium or high intensity head pain, this has
evaluation of occlusal pathogenic factors for TMJ disor-           led us to reflect on the capacity of the dysfunctional pa-
                                         on

ders.                                                              tients to underestimate the headache until it reaches high
With regard to facial asymmetry, this variable was pres-           threshold levels.
ent in 3.8% of cases. This finding seems to confirm a lack         In conclusion to the illustration of the previous results we
of relation, at least in the sample considered in this paper,      now present data on “treatment variable” and its out-
                                i


between the presence of facial asymmetry and TMD.                  comes.
                             iz


                                                                   About treatment the 48.5% of sample was subjected to a
                                                                   conservative treatment (pills, plates and physiotherapy),
3.3. Analysis of muscle characteristics                            the 15.9% of patients was suggested a distance re-
              Ed




                                                                   assessment of the disorders, the remaining part (35.6%)
As concerns this group of variables, we observed that the          of patients were not treated due to one of the following
muscular pain was present in the 30.7% of the cases,               reasons:
while the spinal (postural) pain was present in the 37.7%          - did not require specific treatment;
of the cases analyzed. These so high percentages could             - in need of other therapy than that gnathological;
be related to the presence of a strong comorbidity be-             - needed surgery (Orthognathic or TMJ surgery);
 IC




tween TMD and other pain arising from different areas of           - refused or couldn’t practice, for personal grounds,
the spine. Therefore the dysfunctional patient needed to                the proposed therapeutic plan.
C




Table 6. Frequency distribution of headache symptoms (VAS scale class intervals).

Classes VAS                       Right headache                                             Left headache
©




                    Absolute value               Percentages                 Absolute value                  Percentages

0                         1364                        57,4                          1402                         59,0
1–20                       132                         5,6                           119                          5,0
20–50                      454                        19,1                           449                         18,9
50–80                      369                        15,5                           351                         14,8
80–100                      56                         2,4                            54                          2,3

Total                     2375                      100,0                           2375                        100,0


Annali di Stomatologia 2013; IV (1): 161-169                                                                                167
C. Di Paolo et al.


Table 7. Frequency distribution of headache symptoms in the symptomatic sample.

Classes VAS                       Right headache                                           Left headache

                     Absolute value                Percentages             Absolute value                   Percentages




                                                                                                  li
1–20                       132                           13,1                     119                           12,2




                                                                                               na
20–50                      454                           44,9                     449                           46,1
50–80                      369                           36,5                     351                           36,1
80–100                      56                            5,5                      54                            5,5

Total                     1011                          100,0                     973                          100,0




                                                                                            io
It was therefore interesting to evaluate the efficacy of ther-    data collected in this preliminary retrospective study were




                                                                                         az
apy carried out. The results are presented in Tab. 8. The         subjected to a simple statistical analysis to describe the
sample was made up of 649 patients (we excluded those             basic epidemiology aspects of a large sample of patients
patients for which the therapeutic process was still under        with TMJ dysfunctions (2375 patients).
way).                                                              The first data to be collected are related to age and gen-




                                                                          n
For the 649 patients who had finished their course of treat-      der. These variables in the sample, are similar to those in-
ment and had also completed a period of post-treatment            dicated in the literature, in fact, the average age was




                                                                       er
control, and for whom it was possible to make a judgment          35.6%, and the majority of patients are in the group of
about the validity of the therapy it has been claimed that        years ranging from 26 to 40; the gender proportion is gen-
the 37.8 % of patients were recovered and the 46.4%               erally about 8 to 2 in favor of the female. This confirms the
were improved. The 84,1% of patients had a positive or            reliability of the current sample.

                                             nt
very positive post-treatment conclusion. The 14.5% of the
treated sample showed no change in symptom and was
considered stable, while only the 1, 4 % reported a wors-
                                                                  Between the symptoms analyzed, the more detected was
                                                                  the joint pain present in over 60% of the sample exam-
                                                                  ined, with a double prevalence compared to muscle pain,
                                           iI
ening of their initial symptoms.                                  which has proved to be present in just over 30% of pa-
These findings have led us to state that the gnathologic          tients this finding does not agree with the literature
treatments performed can be considered to be particularly         (Kononen et all. 1996, Magnusson et all 2000). The tar-
                                         on

effective in treating temporo-mandibular disorders. Our re-       get of population that has turned in our Service of
sults are consistent with the current literature that indicates   Gnathology seems mainly affected by biomechanical
the individualized management of conservative gnatho-             TMJ dysfunctions and that the masticatory muscle are in-
logic treatment as the most appropriate versus the TMD.           volved secondary to the functional problems. This result
                                i


                                                                  is confirmed by the second prevalent symptom founded
                             iz


                                                                  that was the joint noises, which have been revealed, in
4. Discussion and conclusions                                     clicking form, in the 53.2% of the sample.
                                                                  The postural pains in the spine and especially the
              Ed




The large quantity of data that has been collected from the       headache appear simultaneously present in just under an
examination of thousands of medical records during the            half of the sample (respectively 37% and 46%). These
years 1996-2006 suggested to us to separate the study             data confirm the high relationship, at least of co-morbid-
in two parts, the second, carried out by more refined sta-        ity, present between TMD and the above painful condi-
tistical means, will aim to identify any possible relation and    tions. In the case of headache it could even be argued
significant associations between the symptoms and the             that a TMD patient is potentially at risk for some headache
 IC




different clinical forms of the dysfunctional disorders. The      development forms (probably tensive type) and vice


Table 8. Frequency distribution of outcome treatment.
C




Result                                Absolute values             Percentage valid                  Percentage valid

Cured                                        245                          10,6                               37,8
©




Improved                                     301                          13,0                               46,4
Worse                                          9                           0,4                                1,4
Stable                                        94                           4,1                               14,5

Total                                        649                          28,1                             100,0

Missing                                     1664                          71,9

Total                                       2313                        100,0


168                                                                                 Annali di Stomatologia 2013; IV (1): 161-169
Epidemiological analysis on 2375 patients with TMJ disorders: basic statistical aspects


versa. The clinician who should be confronted with pa-           shades. This complexity is in line with the current knowl-
tients affected by these painful complaints, especially          edge that it not be able to clarify the etiology of these dis-
when they are chronic, should always be suspected in the         orders making intricate both diagnostic and therapeutic
diagnostic phase, the possible presence of the other             aspects. We may be in front of a multi-systemic disease
pathological forms, and also during the therapeutic man-         that it interferes with the bioavailability of the individual,




                                                                                                   li
agement he shall be prepared to approach these pa-               exposing him to the possibility of suffering noxious stim-
tients with combined multidisciplinary treatments.               uli, which otherwise not could able to achieve the pain




                                                                                                na
The statistics also revealed a direct proportionality be-        threshold. Confirmation of this it has been shown, with a
tween the different levels of pain intensity reported by pa-     high frequency, that many patients contemporary pre-
tients, regardless of location. This may mean that a pa-         sented muscle pain, spinal pain and headache to over-
tient who reports a moderate headache suffered by the            shadow the dysfunctional type problems even if they oc-




                                                                                             io
same grade of pain both joint and masticatory muscle.            cur with a greater clinical prevalence. Finally we have to
Moreover a patient who simultaneously presents noises            mention the good results obtained from the patients un-
and pain, is very likely that he refer this symptoms to the      dergoing to a complete specialist conservative treatments
same joint and at the same side.                                 who are about half of the sample. In fact over 80% of




                                                                                          az
The biomechanical variables analysis led to the following        these patients showed a complete recovery or a signifi-
considerations. The average value of opening of the              cant improvement of the previous state.
mouth of a dysfunctional population was found to be 43.5         Further researches should be carried out to clarify these
mm that is slightly lower than that considered normal (45        controversial aspects.




                                                                          n
mm), with mean values increased by about 3 mm in the
male compared to female. Patients who have skilled a sig-




                                                                       er
nificant limitation of this parameter (less than 30 mm)          Reference
were a minority, the 8.1%, but they still significant in view
of the seriousness of this problem. This information should      1.  Di Paolo C, Cascone P. Patologia dell’articolazione Tempo-
                                                                     romandibolare. UTET 2004.


                                             nt
address the clinical approach in the evaluation of the
opening of the mouth to consider the quantitative value al-
ways in association with the qualitative and with the pain.
The joint hyper mobility was detected in about 15% of the
                                                                 2. Segu M, Sandrini G, Lanfranchi S, Collegano V. La patoge-
                                                                     nesi delle cefalee di tipo tensivo: ruolo dei disordini cranio-
                                                                     cervico-mandibolari. Protocollo di ricerca. Minerva Stoma-
                                           iI
                                                                     tol Jun 1999.
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it calls into question the possible role of ligaments laxity         dren and adolescents: prevalence of pain, gender differ-
as a risk factor for a joint disorders.                              ences, and perceived treatment need. Journal Of Orofacial
                                         on

Several values related to the state of the occlusion merit           Pain Winter 1999.
some reflections.                                                4. Al Ani MZ, Davies SJ, Sloan P, Glenny AM. Stabilization
The first data confirm that the analysis of occlusal classes         splint therapy for TM pain dysfunction syndrome. The
                                                                     Cochrana Database of Systematic Rewiews 2004.
does not represent a substantial interest when analyzing
                                                                 5. Graff-Radford, Newman: The role of temporomandibolar
                                i


patients with TMD in fact, the findings are in line with that
                             iz


                                                                     disorders and cervical dysfunction in tension-type headache.
of the population free from dysfunctions and this is in              Curr Pain Headache Rep Oct 2002.
agreement with the results aroused from the literature.          6. Magnusson T, Syren M. Therapeutic jaw exercises and in-
Between the evaluations of the static occlusion the most             terocclusal appliance therapy. A comparison between two
              Ed




significant data was the steepness of the incisal guidance           common treatments of temporomandibolar disorders. Swed
present in 26.1% of the sample.                                      Dent Jan 1999.
Another indicative value was the absence of the teeth. This      7. Pettengill C. A comparison of headache symptoms between
condition is present in over 40% of the subjects in partic-          two groups: a TMD group and a general dental practise
ular in the posterior dental arches. If we add to this the           group. Cranio Jan 1999.
                                                                 8. Liljestrom, Jamsa, LeBell, Alanen, Anttila, Metsahonkala,
value of the reduction of the posterior vertical height of oc-
 IC




                                                                     Aromaa, Sillanpaa. Signs and symptoms of temporomandi-
clusion, present in 27.3% of the subjects, it becomes pos-           bolar disorders in children with different types of headache.
sible to assume that the loss of dental elements can be a            Acta Odontol Scand Dec 2001.
risk factor for the development and maintenance of a TMJ         9. Freund BJ, Schwartz M. Relief o tension-type headache
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C




rary association of the two factors that lead the mandible           treated with botulinum toxin-A. Headache Nov Dec 2002.
in a posture which would facilitate the development of a         10. Ekberg E, Vallon D, Nilne M. Treatment outcome of
disc dislocation. Another risk factor could be the over-             headache after occlusal appliance therapy in a randomized
loaded caused by the clenching, type of parafunction                 controlled trial among patients with temporomandibular dis-
©




                                                                     order of mainly artrogenous origin. Swed Dent J 2002.
which has present in almost 30% of patients.
                                                                 11. Thilander B, Rubio G, Pena L, de Mayorga C. Prevalence
So we can suggest that these are some of the factors on
                                                                     of Temporomandibular Dysfunction and Its Association With
which it would be appropriate to take action as a preven-            Malocclusion in Children and Adolescents: An Epidemiologic
tive measure in order to ensure that a “healthy” subject             Study Related to Specified Stages of Dental Development.
does not become “dysfunctional” patient.                         12. Pedroni CR, De Oliveira AS†, Guaratini MI. Prevalence
A proper analysis of the full data, clearly shows that there         study of signs and symptoms of temporomandibular disor-
are a large amount of variables involved in these disor-             ders in university students. Journal of Oral Rehabilitation
ders that occurred in a wide range of possible clinical              2003; 30:283-289.



Annali di Stomatologia 2013; IV (1): 161-169                                                                                   169
