Validation of the Prosthetic Esthetic Index

ORIGINAL ARTICLE

Validation of the Prosthetic Esthetic Index

Esben B. Özhayat & Katrine Dannemand

Received: 21 January 2013 /Accepted: 12 September 2013 /Published online: 26 September 2013# Springer-Verlag Berlin Heidelberg 2013

AbstractObjectives In order to diagnose impaired esthetics and evalu-ate treatments for these, it is crucial to evaluate all aspects oforal and prosthetic esthetics. No professionally administeredindex currently exists that sufficiently encompasses compre-hensive prosthetic esthetics. This study aimed to validate a newcomprehensive index, the Prosthetic Esthetic Index (PEI), forprofessional evaluation of esthetics in prosthodontic patients.Material and methods The content, criterion, and constructvalidity; the test–retest, inter-rater, and internal consistency reli-ability; and the sensitivity of the index were evaluated in 95patients in need of oral rehabilitation.Results The content validity was sufficient: Most correlationsbetween aspects of the PEI were low (R >0.5). The PEI wassignificantly correlated to the Dental Aesthetic Index (R =0.52)and could distinguish between subgroups of patients indicatingsufficient criterion and construct validity. The test–retest reli-ability showed an Interclass Correlation Coefficient (ICC) of0.80, the internal consistency reliability showed a Cronbach'salpha of 0.7; and the inter-rater reliability was excellent, with anICC of 0.94. The PEI could furthermore distinguish betweenparticipants and controls, indicating sufficient sensitivity.Conclusion The PEI is considered a valid and reliable instru-ment involving sufficient aspects for assessment of the pro-fessionally evaluated esthetics in prosthodontic patients.Clinical relevance With the validated PEI available, the cli-nician can directly assess and document the comprehensiveesthetics of prosthodontic patients in a structured manner.

Keywords Prosthodontics . Esthetics . Index . Validationstudies . Rehabilitation . Diagnosis

Background

Impaired oral esthetics represent important indicators of oralrehabilitation [1, 2] and are an important factor when judgingthe final treatment result [3]. It is thus surprising that studiesdiscussing the indication for or the effect of oral rehabilitationeither do not include a variable for esthetics [4–6] or include avery simple variable, such as the region of tooth space [7, 8].Current measures of dental esthetics likewise focus on specificesthetic values such as colour, size, morphology, and gingivalappearance [1, 3, 9–11]. In accordance with this, indices havebeen developed and validated with the aim of describing theesthetic result of specific treatments [12–14]. Esthetic con-cerns other than the specific aspects investigated so far could,however, be evident for patients with partial tooth loss in needof prosthodontic treatment. These patients often have manydifferent esthetic concerns, and a broader descriptionconsisting of many different aspects of oral and prostheticesthetics would therefore be relevant in the oral rehabilitationof these patients.

Greenberg and Bogert [15] present a checklist with sevenpoints for treatment planning in esthetic dentistry. In contrastwith most other esthetic indices in dentistry, this list featuresnot only incisor measurements but also facial appearance,which is relevant in oral rehabilitation. The checklist, how-ever, still lacks some vital elements of prosthetic esthetics,does not contain a summary score, and has not been vali-dated. Another index, the Smile's Aesthetic Evaluation Form(SAEF) [16] was developed to detect small dental anomalieswhen the patient is not content with his/her smile. The indexincludes many important elements of prosthetic estheticsincluding smile arch, lip line, gingival appearance, and teeth

E. B. Özhayat (*) :K. DannemandSection of Oral Rehabilitation, Department of Odontology,Faculty of Health Science, University of Copenhagen, Nørre Alle 20,2200 Copenhagen, Denmarke-mail: [email protected]

Clin Oral Invest (2014) 18:1447–1456DOI 10.1007/s00784-013-1109-x

proportion and colour. Again, some vital elements of pros-thetic esthetics are not included in the SAEF, it does notcontain a summary score, and the index has not been vali-dated. The reason no professional index has been validatedfor evaluation of oral and prosthetic esthetics in patients withpartial tooth loss is probably that appearance can be difficultto quantify in these patients. One validated index with arelatively wide range of esthetic items is the Dental Aesthet-ic Index (DAI) [17]. This index was developed in orthodon-tics and quantifies esthetics by evaluating tooth loss andmalocclusions. The index does not, however, include thecolour and morphology of teeth and restorations, making itdifficult to use in prosthodontic patients. There is thus aclear need to develop an index more relevant for patientswith partial tooth loss and various prosthetic replacements.A standardised measure, including a wide range of estheticaspects, would help make studies on the indication andeffect of oral rehabilitation more comparable and clinicallyrelevant. The index could further open up for much neededstudies concerning professional and patient-reported evalua-tion of oral esthetics.

Besides the usefulness of such an index as a research toolfor use in population studies, the index could also be used in aclinical setting. Traditionally, dentists have made decisionsregarding rehabilitation based on experience rather than on ascientific and structured basis [18, 19]. With an esthetic index,clinical examination and diagnosis could be guided in a morestructured manner. The index could also be used as an intro-duction to discussing treatment goals with the patient andcould be an easy way of documenting the change in appear-ance as a result of treatment.

This study aimed to validate a new comprehensive index,the Prosthetic Esthetic Index (PEI), for professional evaluationof esthetics in prosthodontic patients. The hypothesis was thatthe index would have sufficient content, criterion, and con-struct validity as well as test–retest, inter-rater, and internalconsistency reliability and sensitivity.

Material and methods

Participants

Participants were patients missing at least one tooth (thirdmolar not included) and registered for oral rehabilitation atthe Department of Odontology, University of Copenhagen.Exclusion criteria were inability to read and answer thequestionnaires in Danish. Data was obtained in autumn2012, and 99 patients were contacted during this period.Four patients refused to participate (one because of illness,

one who did not want further tooth-related focus, and twowho did not want to fill in the questionnaires), leaving 95participants for inclusion in the study. A control group,consisting of 23 patients in the same age-range as theparticipants but without missing teeth (third molar not in-cluded) and therefore with no need for oral rehabilitation,was also included.

Before any treatment was performed, participants wereesthetically evaluated using the PEI and DAI, and a clinicalexamination was performed. The same researcher undertookall registrations.

Prosthetic Esthetic Index (PEI)

Aspects of facial, oral, prosthetic, and dental esthetics werelisted on the basis of the literature on oral and prostheticesthetics as well as on the written guidelines used for historytaking and clinical examination at the Section of Oral Reha-

after independently added further aspects to the list. Thesewere finally consolidated into 13 individual specific facial,oral, prosthetic, and dental esthetic aspects: facial symmetry,dental arch symmetry, tooth spaces, morphology of the teeth,colour of the teeth, position of the teeth, spacing/crowding,margins of fixed dental prostheses, metal from removabledental prostheses, discolouration of the teeth, colour of gingi-va, retraction of gingiva, and wear of the teeth. Besides these13 aspects, an overall esthetic evaluation of the patient wasincluded in the PEI. The 13 specific aspects and the overallappearance are esthetically evaluated on a five-point Likertscale with the categories and corresponding scores: reallygood (score 1), good (score 2), average (score 3), poor (score4), and really poor (score 5). The three following aspects alsohave the category ‘not applicable’ (score 0): tooth spaces,margins of fixed dental prosthesis and metal from removabledental prosthesis. The rater is instructed to mark the categoryhe or she find most appropriate for each aspect in the patient,and the overall PEI score is calculated by adding the scoresfrom each of the 13 aspects, resulting in a total score of 10–65.The higher the score, the worse the esthetic appearance. Twoclinical examples of the PEI are shown in Figs. 1 and 2. In ourstudy, the patient was placed in the dental chair, and the raterused mouth mirrors for the intraoral examination. A pilotstudy was performed on 20 patients to evaluate the PEI priorto data collection. The pilot study led only to minor changes inthe wording of the PEI, but the pilot patients were not includedin the study.

The complete index is shown in the Appendix and can bedistributed upon request to the authors.

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bilitation, Department of Odontology, University of Copen-hagen. Five senior dentists employed at the Section then here-

Dental Aesthetic Index (DAI)

The DAI was developed for evaluation of esthetics in ortho-dontics [17] and measures ten occlusal features: anteriormaxillary overjet, anterior mandibular overjet, number ofmissing visible teeth, diastema, anterior open bite, crowding,spacing, largest upper anterior irregularity, largest loweranterior irregularity, and antero-posterior molar relation.The measurement for each feature is multiplied by itsweight, and the addition of these scores to a constant givesthe total score. The higher the score the, worse the estheticappearance.

Clinical registrations

Age and gender were registered, and participants werecategorised into three clinically different treatment groups

according to the planned treatment. The first group consistedof participants in need only of a single minor fixed dentalprosthesis (FDP). The second group consisted of participantsin need only of a removable dental prosthesis (RDP). Thethird group consisted of participants in need of comprehen-sive treatment, including prosthodontic, cariologic, and peri-odontal treatment. Also registered were the number of teethpresent, whether incisors were missing, and whether onlymolars were missing. The following standardised photo-graphs were taken of the patients: face frontal and in profile,mouth in normal and maximum smiling, fully exposed teethin occlusion frontal and from the sides, and the upper andlower jaws.

Validity

Content validity

Content validity relates to the adequacy of the content of theindex, in terms of the scope of the individual aspects [20].Content validity was ensured by reviewing the literature onprosthetic esthetics and having input from five independentsenior dentists before constructing the PEI. The content valid-ity was further investigated by creating a correlation matrixbased on Pearson's correlation of the aspects in the PEI. If thecorrelation between any two aspects was large (above 0.5),overlap between the aspects was evident [21]. Correlationbetween the individual aspects and the PEI score was under-taken after subtracting the score of the individual aspect fromthe PEI score [21].

Criterion validity

Criterion validity relates to the agreement of the index with atrue value [20]. In this study, the true value or gold standardwas the DAI. The specific hypotheses were that the PEI scoreand overall esthetic evaluation would be correlated to the DAIscore and that the item concerning number of missing teeth inthe DAI would be correlated to the aspects concerning estheticevaluation of tooth spaces and dental arch symmetry as well asthe overall esthetic evaluation. Since the DAI measures dif-ferent and more orthodontically detailed esthetics, correlationsabove 0.5 were considered acceptable and above 0.7 conside-red good.

Construct validity

Construct validity relates to assessment of the degree to whichthe index measures that which it was designed to measure.The construct validity is high if the results from the study

Fig. 1 Clinical example: a 53-year-old male patient. PEI score: 43 (facialsymmetry: 3, dental arch symmetry: 3, tooth spaces: 3, morphology ofteeth: 4, colour of teeth: 4, position of teeth: 3, spacing/crowding: 4,margins of fixed dental prostheses: 3, metal from removable dental pros-theses: n.a., discolouration of the teeth: 5, colour of gingiva: 3, retraction ofgingiva: 4, wear of teeth: 4). Overall professional evaluation: 4

Fig. 2 Clinical example: a 66-year-old male patient. PEI score: 33 (facialsymmetry: 2, dental arch symmetry: 4, tooth spaces: 4, morphology ofteeth: 3, colour of teeth: 3, position of teeth: 2, spacing/crowding: 2,margins of fixed dental prostheses: 3, metal from removable dental pros-theses: n.a., discolouration of the teeth: 3, colour of gingiva: 2, retraction ofgingiva: 2, wear of teeth: 3). Overall professional evaluation: 3

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confirm hypotheses created before the study was performed[20]. Specific hypotheses regarding the outcome were:

1. Women will have lower PEI scores than men. This washypothesised because oral health is perceived as being ofgreater importance for women than for men [22], andwomenwould therefore seek oral rehabilitation before men.

2. Participants in the FDP group will have lower PEI scorethan participants in the RDP and comprehensive treatmentgroups. This was hypothesised because this group ingeneral was missing fewer teeth, no incisors, and mostoften only molars relative to the two other groups.

Test–retest reliability

Test–retest reliability was performed to judge the intra-ratervalidity of the PEI and was tested by having the same exam-iner who did all of the baseline examinations reevaluate 25participants with the PEI 2–4 weeks after baseline but beforeany treatment was performed. Pearson's correlation and theInterclass Correlation Coefficient (ICC) were used to test ifretest scores were correlated to test scores. A Pearson's corre-lation of 0.8 or above was considered good, and an ICC of 0.5was considered acceptable, between 0.7 and 0.9 large, andabove 0.9 excellent [20].

Inter-rater reliability

Inter-rater reliability was clinically tested by allowing an-other examiner to independently fill in the PEI for 26 ofthe participants at baseline. Furthermore, the inter-raterreliability was tested by having 10 dentists employed atthe Department of Odontology, University of Copenhagen,fill in the PEI for 26 of the participants using the photo-graphs presented in a standardised manner. Inter-rater reli-ability was tested by ICC. An ICC of 0.5 was consideredacceptable, between 0.7 and 0.9 large, and above 0.9excellent.

To evaluate if registrations with PEI differed betweenthe clinical setting and the standardised photographs, theexaminer who did all of the baseline examinations alsoevaluated the 26 participants on the basis of the photo-graphs, and the scores were correlated to the scores fromthe clinic.

Internal consistency reliability

Internal consistency reliability tests how well the aspects inthe index are interrelated and was tested using Cronbach's

alpha. A Cronbach's alpha of 0.7 was considered acceptableand 0.8 or above good [20].

Sensitivity

Sensitivity relates to the ability of the index to distin-guish between different groups that are expected to score

Table 1 Distribution ofclinical variablesaccording to treatmentgroup

Distribution of clinical variables

Age median (range)

All 56 (38–76)

FDP 53 (38–70)

RDP 59 (41–76)

Comprehensive 54 (39–70)

Control 52 (41–65)

Gender (%)

All

Female 44 (46 %)

Male 51 (54 %)

FDP

Female 10 (59 %)

Male 7 (41 %)

RDP

Female 9 (53 %)

Male 8 (47 %)

Comprehensive

Female 25 (41 %)

Male 36 (59 %)

Control

Female 13 (57 %)

Male 10 (43 %)

Number of teeth median (range)

All 22 (9–30)

FDP 27 (18–30)

RDP 16 (9–26)

Comprehensive 22 (10–30)

Missing molars only (%)

All 33 (35 %)

FDP 14 (82 %)

RDP 3 (18 %)

Comprehensive 16 (26 %)

Missing incisors (%)

All 16 (17 %)

FDP 0 (0 %)

RDP 6 (35 %)

Comprehensive 10 (16 %)

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differently from one another [20]. In this study, the PEIscores from participants missing teeth and in need of oralrehabilitation were compared to scores from the controlgroup.

Analyses

SAS® (version 9.2, SAS Institute Inc., Cary, NC, USA) andSPSS (version 19.0, SPSS inc. IBM® Company) statisticalsoftware were used for the analyses. The statistical significancelevel was P <0.05.

Descriptive statistics were used to calculate frequency ofgender, mean age, and mean score of the PEI and DAI forparticipants and the control group. No difference in age orgender distributionwas found between participants and controls.

Student's t test was used to test differences in the PEI scoreand overall esthetic evaluation between genders, treatmentgroups, and controls and participants.

Results

Distribution of participants

Of the 95 participants, 17 (18 %) were in the FDP group,17 (18 %) were in the RDP group, and 61 (64 %) were

in the comprehensive group. The distribution of clinicalvariables according to treatment group as well as the ageand gender distribution of the controls is presented inTable 1. The FDP group evidently stands out somewhatfrom the other treatment groups as this group was missingfewer teeth, did not lack any incisors, and most often wasonly missing molars.

Validity

Content validity

The inclusion of relevant elements from the current liter-ature on prosthetic esthetics and the clinical guideline atthe section as well as the inclusion of five experts in thechoosing of aspects in the PEI ensured sensibility andcoverage of relevant issues. The correlation matrix forthe aspects in the PEI is shown in Table 2. Most corre-lations were small, but high correlations were found be-tween dental arch symmetry and tooth spaces, tooth posi-tioning and dental arch symmetry, tooth shape and wear,colour of the teeth and discolouration of the teeth, andcolour of gingiva and retraction of the gingival margin. Itis also evident that most aspects showed an acceptablecorrelation with the overall esthetic evaluation and the PEIscore.

Table 2 Correlation matrix for the individual aspects, overall estheticevaluation and PEI score. Aspects: 1, facial symmetry; 2, dental archsymmetry; 3, tooth spaces; 4, morphology/shape of teeth; 5, colour of

teeth; 6, position of teeth; 7, spacing/crowding; 8, margins of crowns orFDPs; 9, metal from RDPs; 10, discolouration of teeth; 11, discolourationof gingiva; 12, retraction of gingiva; 13, wear

Correlation matrix for the PEI

1 2 3 4 5 6 7 8 9 10 11 12 13 Overall PEI score

1 1.00

2 0.20 1.00

3 0.17 0.56 1.00

4 0.10 0.36 0.43 1.00

5 0.12 0.26 0.29 0.47 1.00

6 0.18 0.52 0.23 0.25 0.34 1.00

7 0.02 0.24 0.23 0.31 0.27 0.35 1.00

8 −0.04 −0.13 −0.04 0.08 0.07 −0.00 0.05 1.00

9 −0.03 0.18 −0.08 0.05 0.02 0.33 −0.16 −0.09 1.00

10 0.32 0.36 0.47 0.46 0.59 0.28 0.14 0.02 0.03 1.00

11 0.03 0.18 0.25 0.16 0.34 0.24 0.31 0.00 0.07 0.36 1.00

12 0.10 0.36 0.41 0.25 0.29 0.37 0.34 0.20 0.21 0.38 0.50 1.00

13 0.11 0.35 0.38 0.69 0.46 0.16 0.16 0.01 −0.05 0.42 0.19 0.15 1.00

Overall 0.33 0.58 0.71 0.59 0.56 0.45 0.33 −0.02 0.05 0.68 0.44 0.48 0.53 1.00

PEI score 0.32 0.54 0.51 0.58 0.56 0.51 0.34 0.02 0.07 0.60 0.41 0.58 0.47 0.82 1.00

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Criterion validity

There was a significant (P <0.01) correlation of R =0.52between the DAI and PEI scores and R =0.68 betweenthe DAI score and the overall esthetic evaluation. Thecorrelations between number of missing teeth registeredby the DAI and esthetic evaluation of missing teethwith the PEI (R =0.77), dental arch symmetry (R =0.50),and the overall esthetic evaluation (R =0.64) were signifi-cant (P <0.01).

Construct validity

Women had a significantly lower PEI score and overall es-thetic evaluation than did men (P <0.05), and participantsregistered for FDP had a significantly lower PEI score andoverall esthetic evaluation than did participants registered forRDP (P <0.01) or comprehensive treatment (P <0.01).

Test–retest reliability

The correlations between test and retest PEI scores andoverall esthetic evaluation showed significant large cor-relations of R =0.80 and R =0.82 respectively. The ICCbetween the test and retest PEI scores and overall es-thetic evaluation was 0.80, suggesting a large degree ofagreement.

Inter-rater reliability

The clinical inter-rater reliability test between raters 1 and 2showed an ICC of 0.90 for the PEI score and of 0.91 for theoverall esthetic evaluation, indicating excellent agreementbetween raters. The inter-rater reliability between the 10 den-tists who filled in the PEI from photographs showed an ICC of0.94 for both the PEI score and the overall esthetic evaluationindicating an excellent agreement between the raters. Thereliability in PEI score between clinical and photographicevaluation showed an ICC of 0.89 for the PEI score and0.93 for the overall esthetic evaluation, indicating excellentagreement between rating in the clinic and rating fromphotographs.

Internal consistency reliability

The Internal Consistency reliability test showed a Cronbach'salpha of 0.78, indicating good interrelation of the aspects ofthe PEI.

Sensitivity

The mean PEI score and overall esthetic evaluation forthe participants were 36.65 and 3.19, respectively. Forthe control group, the mean PEI score and overallesthetic evaluation were 26.13 and 2.17, respectively.The differences between participants and controls weresignificant (P <0.01).

Discussion

The PEI was developed due to the evident lack of a method ofevaluating and measuring oral esthetics in a broad sense inprosthodontics patients. The goal was to develop an index thatcould be used in both research and clinical settings as aguideline for diagnosing and documenting oral and prostheticesthetics. It was therefore necessary to investigate the validityof the PEI.

Even though the number of participants in the FDPand RDP group was small, the size of the populationwas considered sufficient to produce significant andreliable results. Likewise, the somewhat diverse popula-tion used to validate the PEI in this study was seen asappropriate since it is preferable if the PEI captures thegreat diversity that exists in oral esthetics when itcomes to prosthodontic patients.

The methods chosen to validate the PEI in this studywere plentiful, but it is necessary to consider which ofthese tests should be emphasised most. As the PEI isdesigned to be used by different raters, one of the mostimportant features was deemed to be inter-rater reliability.Inter-rater reliability is usually judged between two orthree raters, but in a study on the requested number ofraters for inter-rater reliability studies, it was stated that ahigh ratio between subjects and raters was necessary toestimate a correct ICC [23]. The number of raters used forthe inter-rater reliability test in this study was thereforeconsidered more than sufficient. In our study, both clinicalrating and rating from photographs showed excellent inter-rater reliability. It must be noted, however, that the highinter-rater reliability found in the photographic evaluationshould be taken with caution: The photographs werepresented in a standardised manner, and the PEI wouldnormally be used with the patient in person. In order toexplain the high inter-rater reliability, one must considerthe construct of the index. In a study on the effect of thenumber of items on inter-rater reliability, it was concluded

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that inter-rater reliability increased up to seven items,beyond which no substantial increase in reliability wasfound [24]. The 13 aspects of the PEI thus seem to laythe groundwork for high inter-rater reliability. The use of afive-point Likert scale, which limits the categories substan-tially, also increased inter-rater reliability, and even thougha dichotomous scale would have yielded even more reli-able scores, the extra information gained from the Likertscale was preferred.

As consistency is a key feature of the esthetic evaluation,the high intra-rater and internal consistency reliability wereconsidered high-quality features of the PEI. Even though thetest–retest showed a large degree of agreement, the intra-raterreliability here was not as overwhelmingly in agreement aswas the inter-rater reliability, which could indicate that therater somehow changed perspectives between the ratings. Asthe ICCwas large, this change in perspective was not regardedas systematic.

Content validity was also considered an importantfeature as the PEI was developed to serve as a guidelineor checklist for prosthetic esthetics, capable of quanti-fying the specific aspects. The content validity testshowed that few of the aspects were interrelated, indi-cating that many different aspects of prosthetic estheticswere measured by the PEI. The overlap found betweensome of the aspects is, however, a point of concernsince some aspects could be redundant. The aspectswere, however, thought to be professionally distinguish-able, and the overlap was expected: Wear does indeedalter tooth morphology, loss of teeth influences archstability, tooth colour is influenced by discolouration,and gingival retractions are typically found in periodon-tal patients in whom the gingiva is often inflamed. Theanalysis furthermore showed that facial symmetry andspacing/crowding only influenced the PEI score and theoverall esthetic evaluation to a limited degree in com-parison to the rest of the individual aspects. Althoughinteresting, it is beyond the scope of this study toexplain why these findings occurred. This could, how-ever, serve to encourage further studies on the subject.

In contrast, sensitivity in relation to the control groupwas not considered the most prominent feature of thevalidation. The sensitivity of other comparable professionaloral esthetic indices has not been presented (14, 25), andthis study treated this as simply a step on the way toother results since the study placed greater emphasis onthe PEI being able to distinguish between subgroups ofprosthodontic patients considered to be clinically different.

The treatment groups used in this study reflect the treat-ment categories used at the Department of Odontology inCopenhagen. The dental status of the RDP and compre-hensive groups advocated for higher PEI scores comparedto the FDP group, which most often was only missingmolars. The PEI did indeed identify the FDP group as thetreatment group with the best esthetic score. It must bestated, however, that the number of participants in thecontrol, FDP, and RDP groups was rather low. In addition,no other studies have compared professionally rated pros-thetic esthetics between the treatment groups presented inthis study, meaning that comparison with other studiesproved impossible.

Because the DAI was developed in orthodontics andmeasures other esthetic aspects than the PEI, criterion va-lidity was not seen as the most important feature and wasnot expected to be high. The DAI was, however, consid-ered the best current measure to use as a ‘gold standard’,and the PEI score showed acceptable agreement with it.From a more detailed perspective, we could note that theitem in the DAI concerning the number of teeth wascorrelated to the individual aspects of the PEI hypothesised.Responsiveness represents one important aspect of the PEInot included in this study. Hopefully, the prosthetic treat-ments performed on the participants will improve the pro-fessionally evaluated esthetics: The participants of thisstudy will be followed, and responsiveness will beinvestigated.

Diagnosis of impaired oral esthetics and evaluation ofprosthetic treatment should not, however, be performed with-out reference to the patient's perspective [25]. It is known thatesthetic rating differs between dentists and patients [26], but itis not known to what degree and which aspects of prostheticesthetics could be used to predict patient-reported impairmentof oral esthetics. With the PEI considered to be a valid andreliable instrument, it should now be possible to investigatethis.

Conclusion

The PEI is considered a valid and reliable instrument involv-ing sufficient individual aspects for assessment of profession-ally evaluated esthetics in prosthodontic patients.

Conflict of interest The study was reported to the Danish Data Protec-tion Agency. The authors declare no conflict of interest.

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Appendix

Evaluate the 13 aspects of esthetics marking that category you find best suitable. All aspects include

both natural and artificial teeth. At the bottom of the paper the overall esthetic evaluation is scored.

Prosthetic Esthetic Index (PEI)

ID Number: ____________ Date: __________

Researcher: _____________________

Type of current replacements (fixed, removable, full, partial): ______________________________

Type of planned replacements (fixed, removable, full, partial): ______________________________

Stage in treatment course: Before Under Just after Control

1. Please rate the esthetics of the facial symmetry, including profile:

Very poor Poor Average Good Very good

2. Please rate the esthetics of the dental arch symmetry (occlusion curve, horizontal, vertically or sagittal):


3. Please rate the esthetics of the missing teeth:

Very poor Poor Average Good Very good N.A.

4. Please rate the esthetics of the tooth morphology/-shape:


5. Please rate the esthetics of the color of the teeth:


1454 Clin Oral Invest (2014) 18:1447–1456

6. Please rate the esthetics of the tooth position (rotation, tilting, migration, elongation):


7. Please rate the esthetics of crowding/spacing:


8. Please rate the esthetics of the margins on crowns and FDPs:


9. Please rate the esthetics of metal parts of the partial denture (bars, clasps etc.):


10. Please rate the discoloration of the teeth (margins of fillings, dark fillings, tartar etc.):


11. Please rate the esthetics of the color of gingiva (and the acrylic):


12. Please rate the esthetics of the retractions of gingiva, including missing papilla:


13. Please rate the esthetics of the wear of the teeth:


Please rate the overall evaluation of the appearance (face, mouth, teeth and replacements):


Clin Oral Invest (2014) 18:1447–1456 1455

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Documents

Validation of the Prosthetic Esthetic Index