The extent of the psychological impairment of prosthodontic outpatients at a German University Hospital.

ral
ssBioMed CentHead & Face Medicine
Open AcceResearch
The extent of the psychological impairment of prosthodontic
outpatients at a German University Hospital
Michelle A Ommerborn1, Alfons Hugger2, Johannes Kruse3,
Jörg GK Handschel4, Rita A Depprich*4, Ulrich Stüttgen2, Stefan Zimmer5
and Wolfgang HM Raab1
Address: 1Department of Operative and Preventive Dentistry and Endodontics, Heinrich-Heine-University Düsseldorf, Moorenstr. 5, 40225
Düsseldorf, Germany, 2Department of Prosthodontics, Heinrich-Heine-University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany,
3Clinical Institute of Psychosomatic Medicine and Psychotherapy, Heinrich-Heine-University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf,
Germany, 4Department of Cranio- and Maxillofacial Surgery, Heinrich-Heine-University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany
and 5Department of Operative and Preventive Dentistry, University of Witten/Herdecke, Alfred-Herrhausen-Str. 50, 58448 Witten, Germany
Email: Michelle A Ommerborn - ommerborn@med.uni-duesseldorf.de; Alfons Hugger - hugger@uni-duesseldorf.de;
Johannes Kruse - kruse@uni-duesseldorf.de; Jörg GK Handschel - handschel@med.uni-duesseldorf.de; Rita A Depprich* - depprich@med.uni-
duesseldorf.de; Ulrich Stüttgen - stuettgen@med.uni-duesseldorf.de; Stefan Zimmer - Stefan.Zimmer@uni-wh.de;
Wolfgang HM Raab - raab@med.uni-duesseldorf.de
* Corresponding author
Abstract
Background: Psychological factors are not only important in patients with temporomandibular disorders
(TMDs), but also in patients suffering from tooth loss and/or in those awaiting prosthodontic care with fixed or
removable dentures as several authors emphasize. The purpose of the present prospective observational study
was to compare prosthodontic outpatients of the Department of Prosthodontics at the University of Duesseldorf
and patients seeking care at the TMD/Orofacial Pain Outpatient Clinic (TMD/OFPOC) at the same university with
respect to sociodemographic data, self-reported somatic complaints, and psychological impairment.
Methods: A total of 234 patients received two self-administered questionnaires including the Symptom-Check-
List. Complete data have been obtained from 65 prosthodontic outpatients and 60 patients of the TMD/OFPOC.
Results: Results indicated statistically significant group differences regarding sociodemographic data and somatic
complaints. Concerning the latter, in 11 of the 21 items, groups differed significantly and confirmed the absence
of any mixing between the two outpatient clinics. Although the evaluation of psychological impairment revealed
no significant group differences, in 21.9% of the prosthodontic outpatients and in 22.0% of the patients from the
TMD/OFPOC, the extent of the determined psychological impairment was similar to that of psychotherapeutic
outpatients; in 9.4% and 8.5% it was similar to that of psychotherapeutic inpatients, respectively.
Conclusion: Within the limitations of this study, in approximately one third of the evaluated patients of both the
prosthodontic outpatient clinic and the TMD/OFPOC the psychological impairment reached values comparable
to those of psychotherapeutic outpatients and psychotherapeutic inpatients. Therefore, the present findings
emphasize the need to intensify the integration of psychosomatic aspects into dentistry and, in particular, to add
psychological considerations to future German education plans.
Published: 23 October 2008
Head & Face Medicine 2008, 4:23 doi:10.1186/1746-160X-4-23
Received: 26 September 2007
Accepted: 23 October 2008
This article is available from: http://www.head-face-med.com/content/4/1/23
© 2008 Ommerborn et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Page 1 of 8
(page number not for citation purposes)

Head & Face Medicine 2008, 4:23 http://www.head-face-med.com/content/4/1/23
Background
While the prosthodontic management of patients with
fixed partial dentures, removable partial dentures, and
complete dentures represents a routine situation in daily
dental practice, a lot of patients have difficulties adapting
to the sensation of a foreign body [1]. This may be due to
the fact that the oral environment is an extremely sensitive
region [2] which can be affected by both physical and psy-
chological stressors [1]. To give an example for physical
impairment as a result of prosthodontic management:
wearing removable partial or complete dentures often
impairs masticatory function and speech transiently [2,3].
Further physical problems such as soreness of denture-
supporting tissues, tooth movement, carious lesions at the
abutment teeth [4], and temporomandibular disorders
[1,5] have been documented. Apart from these physical
reasons that may potentially cause problems following
prosthodontic management, several authors also under-
line the role of psychological factors in the process of
accepting removable dentures and adapting to them [3,5-
7].
In general, psychological response to tooth loss and den-
ture wearing may be influenced by the patient's personal-
ity and, thus, may sometimes depend less on the technical
quality of the dentures [3]. For instance, one investigator
found somatization to be a factor in general dental prac-
tice per se [8], whereas some researchers assumed subjec-
tive body complaints to be an indicator of somatization
particularly in elderly patients [9]. Hence, a clear associa-
tion between age and irreversible complications during
prosthetic rehabilitation has been found [10] and, eventu-
ally, many of these patients are referred to specialized den-
tal clinics, such as prosthodontic outpatient clinics at
university hospitals.
Another group of patients that is typically referred to spe-
cial university-based care clinics consists of patients suffer-
ing from temporomandibular disorders (TMDs).
Although various factors, such as anatomy, trauma,
pathophysiology, and psychology have been suggested to
be involved in the development of TMD, the etiology has
not definitely been clarified so far [11-14]. According to
the literature, psychosocial factors have become a field of
increasing interest. For instance, several studies have
clearly indicated that compared to matched controls TMD
patients had higher levels of psychological distress,
including anxiety, somatization, and depression [15-17].
Considering this and the fact that typically both prostho-
dontic outpatient clinics and TMD/orofacial pain outpa-
tient clinics are university-based care centers, patients in
these institutions were not really found to be representa-
psychological impairment of patients seeking care at a
prosthodontic outpatient clinic (POC) was regarded to be
more obvious than in those patients that usually turn to
their general dental practitioner. Hence, a comparison of
patients of two different outpatient clinics appears to be
more appropriate for the evaluation. Moreover, given the
fact that these outpatient clinics take part in university
education programs, potentially beneficial insights result-
ing from such observational investigation might have a
favorable effect on future education plans. Therefore, the
purpose of the present prospective observational study
was to compare patients of a POC of the Department of
Prosthodontics at the University of Duesseldorf with
patients seeking care at the TMD/Orofacial Pain Outpa-
tient Clinic (TMD/OFPOC) at the same university. We
examined sociodemographic data, self-reported somatic
complaints, and psychological impairment. The hypothe-
sis used in this investigation was that groups differ signif-
icantly regarding their sociodemographic data and self-
reported somatic complaints. Conversely, it was expected
that there is no difference between both groups regarding
the extent of psychological impairment.
Methods
Sample
Following written informed consent obtained by each
patient, a total of 234 subjects, 148 females and 86 males,
with a mean age of 49.24 ± 15.73 years (range 15 to 89
years), participated in this investigation. One hundred
patients who sought care at the POC of the Department of
Prosthodontics at the University of Duesseldorf were con-
tinuously recruited. This group of patients consulted the
POC predominantly for detailed advice and/or treatment
planning of a new prosthodontic restoration or concern-
ing the repair of a damaged or insufficient prosthodontic
restoration, and the presence of dental pain.
In addition, 134 patients seeking care at the TMD/OFPOC
at the same university for the management of TMD were
also included. As derived from the individual index cards,
at the first appointment each patient was previously sub-
jected to a detailed dental functional examination of the
masticatory system which had been performed by one
trained dentist. According to the Research Diagnostic Cri-
teria for Temporomandibular Disorders (RDC/TMD)
[18], the most frequently determined diagnoses were:
myofascial pain, anterior disc displacement, arthralgia,
osteoarthritis, and osteoarthrosis. Additionally, signs of
bruxism have been documented using the clinical criteria
of the American Academy of Sleep Medicine for the diag-
nosis of sleep bruxism [19].
With respect to the observational character of the presentPage 2 of 8
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tive and thus cannot easily be compared with patients
from a general dental practice. In particular, the extent of
investigation no specific inclusion or exclusion criteria
were determined. Regarding the application of psycho-

Head & Face Medicine 2008, 4:23 http://www.head-face-med.com/content/4/1/23
metric instruments, the only limitation for a participation
in this study was that each participant was required to
have good German language skills.
Design and instruments
At the visit of either the TMD/OFPOC or the POC of the
Department of Prosthodontics subjects completed two
questionnaires. In total, the hand out of the question-
naires took place over a time period of seven months.
Additionally, further descriptive data have been derived
from their index cards. To assess sociodemographic and
descriptive data (Table 1), a form had been prepared and
was given to each subject.
For the assessment of individual somatic complaints each
participant received a self-administered questionnaire to
be completed by each individual. As shown in Table 2, it
consists of 21 items assessing temporomandibular symp-
toms, dental complaints and details which have been fre-
quently reported by patients from the TMD/OFPOC.
The Revised Symptom Checklist (SCL-90-R) is a world-
wide used psychometric instrument with a high internal
consistency and test-retest reliability [20-22] and in the
present study it was applied in its standardized German
version [23,24]. It consists of 90 items and determines the
subjectively rated psychological distress that has been
obtained during the past seven days. Respondents rated
each item on a 5-point Likert scale (from "not at all" = 0
to "extremely" = 4). These 90 items were summarized to
nine subscales which measure different psychological
symptoms (somatization, obsessive-compulsive, interper-
sonal sensitivity, depression, anxiety, hostility, phobic
anxiety, paranoid ideation, and psychoticism). As a total
score of psychological impairment, the Global Severity
Index (GSI) was also applied.
In addition, to estimate the clinical relevance of the
obtained results, the distribution of the GSI values of both
patients from the POC and patients from the TMD/
OFPOC were compared with the previously determined
and published GSI values of a normative sample, a sample
of psychotherapeutic outpatients, and a sample of psycho-
therapeutic inpatients. The estimation of these reference
values has been described in detail elsewhere [25]. Briefly,
if the GSI values collected these three samples have been
graphed, at a GSI value of 0.65 the distributional curve of
the psychotherapeutic outpatient sample exceeded the
curve of the normative sample. At a GSI value of 1.35 the
distributional curve of the inpatient psychotherapeutic
Table 1: Comparison of patients from the POC vs. patients from the TMD/OFPOC regarding sociodemographic and descriptive data
(percentages shown in parentheses)
Patients from the POC (n = 65) Patients from the TMD/OFPOC (n = 60) p
Age (years) 53.03 ± 14.09 43.45 ± 14.01 ***a
Range (years) 26 to 81 17 to 75
Gender 31 F; 34 M 49 F; 11 M ***b
Number of children 1.22 ± 1.08 1.02 ± 1.08 n. s.c
Education (%) n. s.b
10 years of school 48 (73.8) 38 (63.3)
12 years of school 7 (10.8) 9 (15.0)
13 years of school 10 (15.4) 12 (20.0)
No graduation 0 (0) 1 (1.7)
Marital status n. s.b
Single 14 (21.5) 16 (26.7)
Married 40 (61.5) 31 (51.7)
Divorced 5 (7.7) 8 (13.3)
Widowed 4 (6.2) 2 (3.3)
Re-married 2 (3.1) 3 (5.0)
Residence (1 missing) n. s.b
Duesseldorf 39 (60.9) 26 (43.3)
Up to 25 km outside of Duesseldorf 10 (15.6) 8 (13.3)
More than 25 km outside of Duesseldorf 15 (23.4) 26 (43.3)
Duration of complaints (months) (3 missing) 32.81 ± 90.6 43.50 ± 80.41 ***c
Type of referral (8 missing) **b
Referred by general dentist 16 (26.7) 30 (52.6)
Without referral 34 (56.7) 14 (24.6)
Miscellaneous 10 (16.7) 13 (22.8)
n. s. = not significant; * = p < 0.05; ** = p < 0.01; *** = p < 0.001
a Two-sample, two-tailed t test; data are presented as means ± standard deviations (SD)Page 3 of 8
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b Chi-square test
c Mann-Whitney U test; data are presented as means ± standard deviations (SD)

Head & Face Medicine 2008, 4:23 http://www.head-face-med.com/content/4/1/23
sample exceeded the curve of the psychotherapeutic out-
patients. Concluding from these previously performed
clinical group comparisons, in the present study the mag-
nitude of psychological impairment of patients with a GSI
value ≤ 0.65 was assigned to the field of the normative
sample, that of patients with a GSI value ranging >0.65
and <1.35 to the field of psychotherapeutic outpatients,
and that of patients with a GSI value ≥ 1.35 was seen in the
field of psychotherapeutic inpatients, respectively.
Missing data
Generally, subjects that had more than one missing item
in the form collecting sociodemographic and descriptive
data and, additionally, one or more missing item in the
questionnaire to determine individual somatic com-
plaints were excluded. According to these criteria, 109
subjects were not included in the analysis. This drop-out
sample consisted of 68 females and 41 males.
Finally, the remaining 125 subjects included 65 patients
from the POC and 60 patients from the TMD/OFPOC.
Thus, the average response rate amounted to 53.4%. The
data of two participants were not included, because the
amount of missing items in the SCL-90-R compromised
the calculation of the summary score. The maximum crit-
ical values of missing items still allowing the calculation
Statistical analysis
The statistical analysis was performed using the statistical
software "SPSS" Version 14.0. Normal distribution was
tested by using the Kolmogorov-Smirnov-Test along with
an assessment of histograms. The analysis of group differ-
ences between patients from the POC and patients from
the TMD/OFPOC was carried out for most of the predom-
inantly qualitative variables (e.g., gender, education,
items of the somatic questionnaire) by using Chi-square
test. Independent samples t test was only performed for
age which was normally distributed as tested by Kol-
mogorov-Smirnov-Test. For all quantitative variables that
were not normally distributed (e.g., duration of com-
plaints, subscales of the SCL-90-R), differences were eval-
uated by means of the Mann-Whitney U test. When using
the Mann-Whitney U test, the adequate statistical values
are the mean ranks and the sum of ranks. However, to
improve the comparability of the obtained results, data
are presented as means and standard deviations (SD). For
all statistical analyses an α-error probability of p < 0.05
was adopted as the statistically significant level.
Results
As seen in Table 1, the comparison between patients from
the POC and patients from the TMD/OFPOC revealed sta-
tistically significant differences with respect to age, gen-
Table 2: Frequency distribution of several somatic complaints reported by patients from the POC and patients from the TMD/OFPOC
(percentages shown in parentheses)
Patients from the POC (n = 65) Patients from the TMD/OFPOC (n = 60) p
Joint clicking 13 (20.0) 46 (76.7) ***
Other TMJ sounds 3 (4.6) 14 (23.3) **
Impaired mouth opening 8 (12.3) 36 (60.0) ***
Impaired mouth closing 7 (10.8) 13 (21.7) n. s.
Impaired chewing 11 (16.9) 36 (60.0) ***
Masticatory muscle fatigue 5 (7.7) 19 (31.7) **
Masticatory muscle stiffness 4 (6.2) 20 (33.3) ***
Extensive prosthodontic management prior to consultation 48 (73.8) 33 (55.0) *
Extensive orthodontic management prior to consultation 16 (24.6) 20 (33.3) n. s.
Extensive surgical management prior to consultation 21 (32.3) 19 (31.7) n. s.
Extensive occlusal adjustment prior to consultation 22 (33.8) 18 (30.0) n. s.
Presence of habits 4 (6.2) 9 (15.0) n. s.
Nail biting 2 (3.1) 1 (1.7) n. s.
Lip biting 2 (3.1) 8 (13.3) *
Smoking 13 (20.0) 10 (16.7) n. s.
Tooth hypersensitivity 23 (35.4) 22 (36.7) n. s.
Disturbance of a single tooth 8 (12.3) 14 (23.3) n. s.
Pain upon wide mouth opening 6 (9.2) 37 (61.7) ***
Mouth dryness/burning mouth 17 (26.2) 21 (35.0) n. s.
Need of a specific position to correctly close the mouth 9 (13.8) 26 (43.3) ***
Self-assessment of treatment need 29 (44.6) 54 (90.0) ***
For group comparisons Chi-square test was applied: n. s. = not significant; * = p < 0.05; ** = p < 0.01; *** = p < 0.001Page 4 of 8
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of the subscales and the summary score, viz, the GSI, have
been published elsewhere [24].
der, the duration of complaints, and the type of referral,
whereas the evaluation of further sociodemographic vari-

Head & Face Medicine 2008, 4:23 http://www.head-face-med.com/content/4/1/23
ables, such as education, marital status, and residence,
showed no significant differences between both groups
(Chi-square; p = n.s. = not significant). Considering the
career, patients from the TMD/OFPOC were significantly
more ambitious than patients from the POC. To specify
only the most relevant groups, 20% of patients from the
POC and 43.3% of patients from the TMD/OFPOC were
employed, 9.2% and 13.3% were in leading positions,
18.5% and 13.3% were housewives, and 30.8% and 8.3%
were pensioners, respectively (Chi-square test; p < 0.05).
In 11 of the 21 items, the analysis of the distribution of
somatic complaints revealed the following statistically sig-
nificant differences (Table 2): patients from the TMD/
OFPOC reported more frequently joint sounds in general,
an impaired mandibular movement or function (such as
opening, yawning, chewing), masticatory muscle discom-
fort, problems to correctly bring maxillary and mandibu-
lar teeth together as well as oral habits like lip biting.
Moreover, these patients stated that, immediately prior to
the consultation, they did not receive as much extensive
prosthodontic rehabilitation as patients from the POC.
Finally, patients from the TMD/OFPOC unambiguously
expressed the necessity of their complaints to be treated.
Considering psychological impairment due to distress
perceived during the past seven days, the comparison of
the two clinical groups did not show any differences
between both groups (Table 3). In neither a subscale nor
in the GSI statistically significant group differences were
obtained. To estimate the clinical relevance of the
recorded data, the above described reference values were
applied (Table 4). In consideration of these reference val-
ues, no group specific differences were observed again.
Even though data failed to reach the level of statistical sig-
nificance, on the basis of the present findings, the GSI val-
ues of 31.3% of patients from the POC and 30.5% of
patients from the TMD/OFPOC were clearly located
above the GSI values that were obtained from a normative
sample. In 21.9% of patients from the POC and in 22.0%
of patients from the TMD/OFPOC, the extent of the deter-
mined psychological impairment reached values that
were in the range of psychotherapeutic outpatients and,
moreover, in 9.4% and in 8.5% values in the range of psy-
chotherapeutic inpatients, respectively (Chi-square; p =
n.s. = not significant).
Discussion
This prospective observational clinical study compared
patients from the POC at the University of Duesseldorf
with patients from the TMD/OFPOC at the same univer-
sity regarding sociodemographic data, self-reported
somatic complaints, and psychological impairment. As a
major finding, the results clearly demonstrated that the
degree of psychological impairment was similarly high in
both groups. Interestingly, in approximately one third of
the evaluated patients of both the POC and the TMD/
OFPOC the psychological impairment reached values that
were located in the range of psychotherapeutic outpa-
tients and psychotherapeutic inpatients. Indeed, this
important finding supports numerous studies which
revealed psychological characteristics in TMD patients
[13-17,26-28]. Moreover, these results particularly stress
the fact that patients from a POC represent a different
group of patients showing a similar pronounced psycho-
logical impairment than do TMD patients.
Apart from dentistry, previous investigations have
recorded the urban prevalence of psychiatric disorders in
general practices. While depressive and anxiety disorders
were detected in 15% to 25% of the patients from a gen-
eral practice [29], surveys which have analyzed the entire
prevalence of psychiatric disorders obtained values rang-
ing from 21% to 52% [25,30-33]. With respect to the por-
tion of psychologically impaired patients, it might be
concluded that the present values established in the two
Table 3: Comparison of patients from the POC vs. patients from the TMD/OFPOC regarding the SCL-90-R subscales and the GSI
values
Patients from the POC (n = 64) Patients from the TMD/OFPOC (n = 59)
Mean SD Mean SD p
Somatization 6.97 8.36 8.71 7.78 n. s.
Obsessive-compulsive 6.08 6.62 6.51 5.70 n. s.
Interpersonal sensitivity 4.91 6.57 4.07 4.63 n. s.
Depression 7.81 9.53 7.14 7.5 n. s.
Anxiety 4.67 7.52 4.68 5.02 n. s.
Hostility 2.69 4.16 2.36 2.63 n. s.
Phobic anxiety 2.30 5.18 1.19 2.48 n. s.
Paranoid ideation 3.59 4.51 2.98 3.71 n. s.
Psychoticism 3.44 4.99 3.25 4.57 n. s.
GSI 0.517 0.621 0.496 0.434 n. s.Page 5 of 8
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For group comparisons the Mann-Whitney U test was applied: n. s. = not significant; * = p < 0.05; ** = p < 0.01; *** = p < 0.001