Medical interviews are not merely unilateral exchanges in which healthcare providers elicit information from patients, but rather collaborative processes aimed at achieving accurate diagnoses and fostering patient involvement in treatment. While the procedure of history taking has traditionally relied heavily on the individual clinician’s experience, the recent implementation of the Objective Structured Clinical Examination (OSCE) has begun to standardize this skill across educational settings. Nonetheless, the experiential and subjective nature of history taking continues to result in variation in the information elicited, depending on the clinician.

Clinical reasoning, which underpins diagnostic decision-making, poses a significant educational challenge due to its dependence on disease-specific knowledge and context. Accordingly, it is often best cultivated through case-based discussions and the analysis of concrete clinical examples [1,2].

Although the concordance rate between diagnoses based solely on history taking and final confirmed diagnoses is reported to range from 60% to 80%, detailed empirical investigations in this area remain limited. In the field of dentistry, Kurihara et al [3]. Reported a diagnostic accuracy rate of 92.9% (13 out of 14 cases) for pericoronitis using interview data alone. However, since these interviews were conducted in person, it is unclear to what extent non-verbal cues such as facial appearance or expression may have contributed to diagnostic accuracy, making it difficult to isolate the diagnostic value of verbal information alone.

During the interview process, dentists are believed to engage in complex cognitive processes that integrate scientific, situational, interpersonal, narrative, ethical, and practical elements to generate diagnostic hypotheses and formulate treatment plans [4]. Experienced clinicians are often able to arrive at a diagnosis with minimal questioning, relying on tacit knowledge that is difficult to articulate. In typical clinical practice, dentists communicate in lay terms, selectively extract relevant patient information, internally translate it into clinical terminology, and engage in reasoning to form hypotheses. They then determine appropriate clinical or radiographic tests to confirm the diagnosis. Once confirmed, they explain the condition, expected progression, and treatment plan in plain language to obtain informed consent. Furthermore, they provide preoperative and postoperative explanations to promote patient understanding.

Through repeated clinical encounters, experienced dentists acquire the ability to fluidly shift between lay and technical vocabulary, mastering the full cycle from information gathering to diagnosis and patient explanation. However, for dental students or novice clinicians, observing this process does not necessarily lead to the acquisition of interpretive and selective skills for verbal information. In the early stages of training, making the verbal communication between dentist and patient explicit may support the development of diagnostic reasoning. To this end, codifying the tacit knowledge held by experienced practitioners is essential.

Although textbooks on diagnostic methods and medical interviewing often present classifications and lists of patient verbal expressions, such resources are typically derived from anecdotal experiences or case reports rather than from systematic empirical research. Our previous studies have examined verbal information used in diagnosing acute pericoronitis and acute suppurative pulpitis, revealing differences between novices and experts in how verbal cues are selected and interpreted [5,6].

Building upon this prior work, the present study focuses on acute suppurative apical periodontitis (ASAP) and aims to elucidate how dentists extract and utilize verbal information in the diagnostic process. Furthermore, by comparing novice and experienced dentists, we seek to clarify how diagnostic expertise involving verbal cues develops with clinical experience.

1. Questionnaire Development

To identify relevant verbal information used in the diagnosis of acute dental pain conditions-including acute pericoronitis, acute suppurative pulpitis, and acute suppurative apical periodontitis (ASAP)-semi-structured interviews were conducted with three experienced dentists (with over 10, 15, and 20 years of clinical experience, respectively). The interviews focused on two main areas: (1) the types of questions posed to patients presenting with dental pain, and (2) specific verbal expressions considered useful for diagnosing each of the three aforementioned conditions.

Based on the interview data, 25 verbal indicators deemed essential for differential diagnosis were extracted and used to construct a structured questionnaire. The questionnaire presented respondents with the following scenario:

“A new patient calls. From the conversation, you suspect ' acute suppurative apical periodontitis'. What information did you gather that led you to this diagnosis (acute suppurative apical periodontitis)?”

Respondents were asked to evaluate each of the 25 verbal expressions using a five-point Likert scale, where:

5 = Strongly supports the diagnosis

4 = Somewhat supports the diagnosis

3 = Neutral

2 = Somewhat contradicts the diagnosis

1 = Strongly contradicts the diagnosis

An example of the questionnaire format is shown in Figures 1 and 2.

2. Questionnaire Survey

Participants

A total of 259 dentists with at least one year of clinical experience participated in the survey. All participants provided informed consent.

Survey Period

The survey was conducted between February 2015 and January 2016.

Survey Procedure

For dentists with one year of experience (i.e., trainee dentists), the questionnaires were distributed and collected on-site. For those with two or more years of experience, the questionnaires, along with explanatory documents, were mailed in advance to designated coordinators at participating institutions. After completion, the questionnaires were returned in pre-addressed envelopes via the coordinators.

Ethical Considerations

All questionnaires were anonymized, and participation was entirely voluntary. Participants were free to withdraw at any time, even after initially consenting to participate. The study protocol was reviewed and approved by the Ethics Committee of Kyushu Dental University (Approval No. 13-35).

3. Data Analysis

The five-point Likert scale responses were converted into numerical values based on the simplified scoring method proposed by Likert. All analyses were conducted using Python in Google Colaboratory and BellCurve for Excel (version 2.0).

Analysis of Verbal Information

For each of the 25 verbal expressions, the mean and standard deviation were calculated based on responses from all participants.

Comparison by Clinical Experience

Participants were categorized into three groups based on their years of clinical experience:

Less than 5 years

5 to less than 10 years

10 years or more

For the purpose of statistical comparison, those with 1 to less than 5 years of experience were classified as the “novice group,” and those with 10 years or more as the “expert group.” The Mann–Whitney U test was applied to examine differences between the two groups for each of the 25 verbal items.

Figure 1: Questionnaire form (Original Japanese Version).

       4. Free-Response Section

Open-ended responses provided by participants regarding additional verbal expressions they considered relevant to the diagnosis were also collected.

1. Response Collection

A total of 259 responses were collected from dental professionals across nine institutions, including faculties of dentistry and affiliated dental hospitals. The detailed participant distribution is shown in Table 1. While the overall response rate was 100%, a small number of individual items were left unanswered, resulting in item-level response rates ranging from 97.2% to 99.2%. All returned questionnaires were included in the analysis. Among the respondents, 106 were classified as members of the novice group, and 110 as members of the expert group.

Table 1: Participant Demographics by Clinical Experience.

       2. Evaluation of Linguistic Information

The overall results for the 25 verbal expressions are presented in Table 1, sorted in descending order based on mean scores. Five expressions had a mean score of 4.0 or higher, indicating strong diagnostic relevance for ASAP:

• “I can’t chew things”
• “I was in pain last night and couldn't sleep”
• “I have treated the same tooth before”
• “The pain is throbbing”
• “My gums are swollen”

Conversely, one expression received a mean score of 2.0 or lower:

• “My tongue feels numb”

This suggests that it was generally perceived as contradicting a diagnosis of ASAP.

      3. Differences Bases on Clinical Experience

Table 3 shows the average scores for each of the 25 verbal expressions, comparing the novice and expert groups. The items are arranged in descending order of the expert group’s average scores. Statistical analysis revealed significant differences (p < 0.05) between the two groups for 13 of the 25 items, while the remaining 12 items showed no statistically significant difference. These 13 items with significant differences are visually presented in Figure 2.

      4. Additional Linguistic Indicators from Free-Response Section

Responses from the open-ended section of the questionnaire revealed additional verbal cues considered important for diagnosis by participants. Frequently mentioned examples included:

• “Have you experienced similar symptoms before?”
• “Are there any covered teeth such as crowns?”
• “I have a dull pain”
• “My gums feel heavy”
• “Is the affected tooth in the anterior or posterior region?”
• “When did the pain start, and how has it progressed?”
  

  Figure 1: Questionnaire form (Original Japanese Version).

  

  Figure 3: Verbal Expressions Showing Significant Differences by Clinical Experience.

As shown in Table 2, the item “I can’t chew things” received the highest average score (4.24), indicating that most dentists considered it a strong verbal indicator of acute suppurative apical periodontitis (ASAP). Similarly, the statements “I was in pain last night and couldn’t sleep,” “I have treated the same tooth before,” “The pain is throbbing,” and “My gums are swollen” were also widely regarded as supporting the diagnosis of ASAP. In contrast, the item “My tongue feels numb,” with a mean score below 2.0, was interpreted as contradicting an ASAP diagnosis, potentially suggesting other conditions such as neuropathic involvement or non-endodontic pathology.

Table 2: Verbal Expressions Relevant to the Diagnosis of Acute Suppurative Apical Periodontitis.

To examine the influence of clinical experience on interpretation of verbal cues, participants were divided into a novice group (less than 5 years of experience) and an expert group (10 years or more), based on the commonly cited “10-year rule” for expertise acquisition [7,8] and supporting evidence identifying approximately 5 years as characteristic of novices [9]. While this approach does not account for individual variations in clinical exposure or competency, it provides a practical framework for analysis.

Table 3 and Figure 2 show that significant differences emerged between novice and expert groups for several key verbal items, including “I can’t chew things,” “I was in pain last night and couldn’t sleep,” “I have treated the same tooth before,” “The pain is throbbing,” and “I have swollen lymph nodes.” Expert dentists more strongly associated these statements with a diagnosis of ASAP, suggesting that clinical experience enhances the ability to recognize relevant verbal cues and integrate them into diagnostic reasoning.

Notably, certain expressions-such as “The pain does not go away even after taking painkillers,” “I have pain in my face (jaw),” “I have a headache,” and “It hurts when I open and close my mouth”—were often interpreted by novices as inconsistent with ASAP, while experts tended to view them as supportive. This divergence may stem from ambiguity regarding the specific stage of apical periodontitis being referenced [10] or inconsistencies in how respondents interpreted diagnostic categories, such as those defined by the American Association of Endodontists [11]. These findings suggest that expert clinicians may draw on tacit knowledge and broader clinical patterns beyond formal diagnostic criteria.

Moreover, while novices rated 13 items as supportive (mean score >3), experts rated 19 items above this threshold, reflecting a broader and more nuanced interpretation of verbal information by experienced practitioners. This aligns with prior research in medical education indicating that expert clinicians develop sophisticated pattern recognition systems in which even seemingly ambiguous or negative findings contribute meaningfully to clinical judgments [12].

The free-response section further highlighted that clinicians value additional verbal information, including history of prior treatment, recurrence of similar symptoms, tooth location, presence of crowns, tenderness on palpation, nocturnal awakening due to pain, localized gingival swelling or tenderness, symptom progression, and onset timing. These insights suggest that experienced dentists do not rely solely on pain characteristics but also actively seek anatomical, temporal, and historical context to inform their diagnostic decisions.

Table 3: Verbal Expressions Perceived as Potentially Relevant to Diagnosis by Novice and Experienced Dentists.

Collectively, these results indicate that expert dentists associate a wider range of verbal expressions with ASAP than their novice counterparts. This likely reflects the evolution of clinical reasoning processes, where experience facilitates efficient extraction, interpretation, and integration of relevant information into diagnostic hypotheses. Importantly, this pattern recognition capacity allows experienced clinicians to make rapid and accurate decisions in time-sensitive clinical contexts, such as the management of acute dental pain.

Despite these insights, the present study has limitations. Clinical experience was categorized solely by years since licensure, without accounting for the frequency or depth of exposure to cases of ASAP. Future research should incorporate metrics such as actual case volume, specialty training, or diagnostic accuracy to more precisely evaluate expertise. Additionally, the acquisition of diagnostic competence is often informal and observational, typically occurring through case-based discussions, mentorship, and reflective practice rather than explicit instruction. Supporting the development of these reflective and integrative processes may enhance training for less experienced clinicians.

In conclusion, this study revealed clear differences in how verbal information is recognized and utilized by novice and experienced dentists in the diagnosis of acute suppurative apical periodontitis. The findings underscore that clinical experience facilitates both the selection of relevant verbal cues and the development of diagnostic reasoning skills. Sharing the interpretive frameworks used by expert clinicians with trainees may bridge the gap between theoretical knowledge and clinical application, thereby contributing to more effective education in diagnostic interviewing and clinical decision-making.

This study aimed to identify specific verbal information that either supports or contradicts the diagnosis of acute suppurative apical periodontitis (ASAP) and to examine whether recognition and interpretation of such information differ between dentists with varying levels of clinical experience. Based on the findings, the following conclusions were drawn:

1. Verbal expressions commonly associated with a diagnosis of ASAP included: “I can’t chew things,” “I was in pain last night and couldn’t sleep,” “I have treated the same tooth before,” and “The pain is throbbing.” In contrast, the statement “My tongue feels numb” was generally perceived as inconsistent with a diagnosis of ASAP.
2. Comparison between novice and expert dentists revealed that those with greater clinical experience assigned significantly higher diagnostic value to 12 verbal items, including: “I can’t chew things,” “I was in pain last night and couldn’t sleep,” “I have treated the same tooth before,” “The pain is throbbing,” “I have swollen lymph nodes,” “The pain does not go away even after taking painkillers,” “I have pain in my face (jaw),” “I have a headache,” “It’s hard to open my mouth,” and “It hurts when I open and close my mouth.” The only item rated significantly lower by the expert group was “Cold things make the pain worse.”
3. The results suggest that clinical experience facilitates the development of diagnostic expertise, enabling dentists to more effectively recognize and integrate patient-reported verbal information into clinical reasoning and decision-making processes.

Conflict of Interest

The authors declare no conflicts of interest.

Acknowledgment

This work was supported by JSPS KAKENHI Grant Numbers JP26463190, JP19K03088 and 25K06571.

The author acknowledges the use of ChatGPT, developed by OpenAI, to assist with proofreading and enhance the manuscript’s clarity.

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