5.4. Orthodontic Imaging Data Model#
5.4.1. Orthodontic Progress (Informative)#
During orthodontic treatment, it is common for providers to monitor progress by regularly collecting records such as photographs or intra-oral surface scans [provide reference]. Identifying the timing of these records in relation to the treatment is crucial. Specifically, the provider needs to know if, at the time of acquisition, the patient:
was undergoing treatment (progress photos)
had never undergone treatment before (observation/pretreatment photos)
had completed treatment (posttreatment photos)
Orthodontic photograph progress shall be stored in three key areas:
Longitudinal Temporal Event Type (Registration, Treatment, Posttreatment)
Longitudinal Temporal Offset From Event (in days)
The mapping below provides a reference for translating orthodontic progress into codesets that DICOM can understand.
orthodontic progress |
description |
event type |
offset (days) |
|---|---|---|---|
First Time Observation |
Patient has just registered with the practice for the first time and has not agreed any treatment yet. The provider collects first time records. |
NCIt-C37948 Enrollment |
0 |
Observation |
Patient comes back for regular visits. The provider collects observation records. |
NCIt-C37948 Enrollment |
Number of days past the day the patient registers. |
Pretreatment |
Images acquired before treatment starts. Only used when the patient and doctor have agreed to start a treatment. This should be treated as Observation above. |
See Observation |
See Observation |
Initial |
Patient and provider agreed to start treatment. Records are taken to mark the Baseline for comparison with treatment progress. |
SCT-1332161000 Orthodontic Treatment started |
0 |
Progress |
Images taken during treatment. |
SCT-1332161000 Orthodontic Treatment started |
Number of days past the day the treatment started. |
Final |
Image taken at the end of active treatment (after appliance removal, if applicable). Sequence number is not required. |
SCT-1340210007 Orthodontic Treatment stopped |
0 |
Posttreatment |
Image acquired after treatment. |
SCT-1340210007 Orthodontic Treatment stopped |
Number of days past the day the treatment ended (see Final above). |
Note
Distinguishing Pretreatment from Observation is not always straightforward. In some cases, there may be a clear Pretreatment definition by the provider, which could be properly coded in the practice management system. However, in many other cases, it may not be clearly defined, or what was considered Pretreatment might not lead to treatment.
Consequently, the orthodontic domain experts of the working group have decided to disregard Pretreatment status and consider it as Observation.
5.4.2. Study Description (0008,1030)#
This optional DICOM tag, part of the General Study module, can contain a Long String (up to 64 characters). In the context of orthodontic photographs, the Study Description is used to represent treatment progress as defined above.
Most PACS systems display the Study Description in search results when listing studies after a query. Therefore, it is recommended to include the information from the Concept Codes described in Longitudinal Temporal Event Type and Longitudinal Temporal Offset from Event here, in a more human-readable form. For example, you might choose a Study Description based on progress names defined by the main practice management system used by the practice that initially acquired the photographs. Examples include:
Pre-treatment 1
Initial
Progress 12
Final
Note
The Study Description is typically used by the medical provider who treats the patient and acquires the images.
Other software may also use the Study Description. But with the limit of 64 characters, it is advisable to keep the string under 16 characters to allow other systems to append their own text.
When importing images from other institutions, the Study Description may not be relevant to the receiving practice.
The Study Description is not a reliable tag for ensuring interoperability across systems and institutions.
For reliable interoperability, refer to Acquisition Context codes as defined in Longitudinal Temporal Event Type and Longitudinal Temporal Offset from Event.