The essential tool to assess your dental patients' anxiety

In a dental survey among UK adults in 2009, 30 % of the 11,380 individuals interviewed said that having a tooth drilled would make them very or extremely anxious. 28 % reported similar levels of anxiety about having a local anesthetic injection. Anxiety and fear are important factors of distress to patients in the dental surgery and represent the common reason for people avoiding dental treatment. Patients with high level of anxiety present a major management problem. It is crucial for any management plans of anxious patients to include an evaluation of their degree of anxiety before any treatments, especially the most invasive ones.

MDAS is the most used anxiety assessment tool

Several questionnaire-based scales have been developed to assess patients’ dental anxiety. Modified Dental Anxiety Scale (MDAS), Corah’s Dental Anxiety Scale, General Geer Fear Scale, and so forth are some of the most commonly used scales. Today MDAS is the most used as it includes a question on local anaesthesia recognised as  a motivation for some patients' anxiety. The MDAS is a brief of 5-question questionnaire with a scale ranging from 'not anxious' to 'extremely anxious'. The responses are summed together to construct a Likert scale with a minimum score of 5 and a maximum of 25. The rank score includes: “MDAS 5-9 (minimal anxiety), MDAS 10-12 (moderate anxiety), MDAS 13-17 (high anxiety), MDAS 18-25 (very high anxiety)”. However, this scale does not take into account specific variables within the dental treatment, such as complexity of medical history and dental treatment. As an example, there are no specific questions on dento-alveolar surgery procedures.

IOSN is the tool you should know about

In 2011 Coulthard et al came up with a comprehensive assessment tool (download here) that looks at patient’s care holistically and includes three important domains, critical for any oral surgeons:

  1. Anxiety score
  2. Medical history
  3. Treatment complexity

For each patient the anxiety score, clinical complexity and medical history details are collected, ranked and entered into the Indicator of Sedation Need (IOSN) tool. The summation of the three ranking scores gives an overall score between 3 and 12. The lowest possi­ble score is 3, suggesting there is a minimal need for sedation while the highest is 12. Scores above 9 suggest that a referring clinician should be considering general anaesthesia and/or that the sedation epi­sode of care may require a secondary care environment Table I.

The need for conscious sedation could be considered by assessing and ranking a combination of information on patient anxiety, medical history and the complex­ity of the clinical treatment planned. This tool has become a requirement for any sedation decision-making.

Download the IOSN survey and the table below.

Patient management is part of our oral surgery and sedation courses. Check out our upcoming courses in London. They have limited places available to ensure you get the most of our trainers. Interested in 1:1 mentoring instead? Tell us what your challenge is and will develop a programme tailored for you, with you

Table I: IOSN scoring tool

IOSN domain





MDAS 5-9 (minimal anxiety) 1

MDAS 10-12 (moderate anxiety) 2

MDAS 13-17 (high anxiety) 3

MDAS 18-25 (very high anxiety) 4

Medical history


Ranges of medical and behavioural indicators are provided including gag reflex, fainting attacks, hypertension, angina, asthma, epilepsy, arthritis and Parkinson’s disease.

Treatment complexity


An indicative list of treatments is provided – if the referrer is in doubt about the complexity of any given treatment they are asked to score high.

IOSN metric

IOSN descriptor

Sedation need?


Minimal need






High need



Very high need