A worked example of post-coordinated expression and mapping to interface terminology using SNOMED CT

1. SNOMED CT:
Worked Example
Dental Term
Example of “Interface Terminology”
Extracted from “Introduction to SNOMED CT” ©
By Dr SB Bhattacharyya, Published by Springer™

2. Excerpt from Chapter 9
Using SNOMED CT
Dr SB Bhattacharyya 2016 2

3. Extraction of 36
(To Be Found In Dental Information Systems)
• An example of “Interface Terminology”
• Interface terminology are terms that allow users to interact easily with clinical
concepts through common colloquial terms and synonyms and generally embody a
rich set of flexible, “user friendly” phrases
• For those unfamiliar with dental “lingo”, the “36” – pronounced as “three six” –
above refers to the “permanent lower left first molar tooth”. The dental
procedure refers to the simple extraction of the permanent lower left first molar tooth. The
“permanent” is implicit through the use of “3” in the “36” above.
Dr SB Bhattacharyya 2016 3

4. Extraction of 36
• Let us look at how this particular procedure can be captured.
• A few of points need to be considered first.
• That this is a procedure and so, the entire term should either be available in the | procedure |
hierarchical tree or needs to be composed on-the-fly.
• The procedure is performed on a permanent tooth.
• The procedure has a site that is direct, which in this case is the | permanent lower left first
molar tooth | that corresponds to the “36” mentioned above.
• Through studying the SNOMED CT subtype hierarchy, one finds a concept called |
extraction of permanent tooth |. This is a fully defined concept. It has two defining
attributes (“has a”) of | method | and | procedure site – direct |.
Dr SB Bhattacharyya 2016 4

5. Extraction of 36
• It is important to note that there is no single concept with the term
“extraction of permanent lower left first molar tooth”. This means that
this clinical idea will need to be expressed as postcoordinated expression as no
corresponding precoordinated expression for the same exists.
• This | procedure site – direct | relates to the concept | body structure |.
• Under this concept, the term | permanent lower left first molar tooth | is
a synonym for the concept whose FSN is | entire permanent mandibular left
first molar tooth (body structure) |.
Dr SB Bhattacharyya 2016 5

6. Extraction of 36
• Thus, the procedure name “extraction of permanent lower left first molar
tooth” can be expressed as the postcoordinated expression as below:
• 57703000 | extraction of permanent tooth | : 405813007 | procedure site - Direct
| = 245604007 | permanent lower left first molar tooth |
• Let us consider that this specific term “extraction of permanent lower left
first molar tooth” is one term amongst a list of terms available to a dentist
from within a Dental Information System for data entry as “Procedure
Performed”.
Dr SB Bhattacharyya 2016 6

7. Extraction of 36
• The list of terms needs to be treated as an interface terminology and
mapping would need to be done to a series of postcoordinated expressions. This is
since all this 11 (representing the upper first incisor) and 36 (representing the
lower left first molar) etc. cannot be found as precoordinated expressions in the
SNOMED CT.
• There are two simple enough ways to approach this.
Dr SB Bhattacharyya 2016 7

8. Extraction of 36
1. Ask the dentists to choose from a different list of terms – not something
that the dentists will be very thrilled about since their existing list will be the
ones that are closest to what they prefer to record their procedures as.
2. Painstakingly map each term to its corresponding expression – mostly
postcoordinated although some precoordinated may also occasionally be
found – this will not be something that would delight the personnel
concerned with mapping, but will nevertheless need to in be done order to
keep the end-users happy thereby ensuring the successful and continued
use of the system.
Dr SB Bhattacharyya© 2016 8

9. Introduction to SNOMED CT
by Dr SB Bhattacharyya available at
• http://www.amazon.com/Introduction-SNOMED-CT-S-B-
Bhattacharyya/dp/9812878939/ref=sr_1_1?ie=UTF8&qid=1453269681&sr=8-
1&keywords=introduction+to+snomed+ct – hardcopy only
• http://www.amazon.in/Introduction-SNOMED-CT-2016-
Bhattacharyya/dp/9812878939/ref=sr_1_1?ie=UTF8&qid=1453269722&sr=8-
1&keywords=introduction+to+snomed+ct – hardcopy only
• http://www.springer.com/gp/book/9789812878939 – ebook and hardcopy
• http://link.springer.com/book/10.1007/978-981-287-895-3 – chapter-wise online access
only
9Dr SB Bhattacharyya 2016

10. sbbhattacharyya@gmail.com
10Dr SB Bhattacharyya 2016