(271 days)
Smile Dx® is a computer-assisted detection (CADe) software designed to aid dentists in the review of digital files of bitewing and periapical radiographs of permanent teeth. It is intended to aid in the detection and segmentation of suspected dental findings which include: caries, periapical radiolucencies (PARL), restorations, and dental anatomy.
Smile Dx® is also intended to aid dentists in the measurement (in millimeter and percentage measurements) of mesial and distal bone levels associated with each tooth.
The device is not intended as a replacement for a complete dentist's review or their clinical judgment that takes into account other relevant information from the image, patient history, and actual in vivo clinical assessment.
Smile Dx® supports both digital and phosphor sensors.
Smile Dx® is a computer assisted detection (CADe) device indicated for use by licensed dentists as an aid in their assessment of bitewing and periapical radiographs of secondary dentition in adult patients. Smile Dx® utilizes machine learning to produce annotations for the following findings:
- Caries
- Periapical radiolucencies
- Bone level measurements (mesial and distal)
- Normal anatomy (enamel, dentin, pulp, and bone)
- Restorations
The provided FDA 510(k) Clearance Letter for Smile Dx® outlines the device's acceptance criteria and the studies conducted to prove it meets those criteria.
Acceptance Criteria and Device Performance
The acceptance criteria are implicitly defined by the performance metrics reported in the "Performance Testing" section. The device's performance is reported in terms of various metrics for both standalone and human-in-the-loop (MRMC) evaluations.
Here's a table summarizing the reported device performance against the implied acceptance criteria:
Table 1: Acceptance Criteria and Reported Device Performance
| Feature/Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Standalone Testing: | ||
| Caries Detection | High Dice, Sensitivity | Dice: 0.74 [0.72 0.76] |
| Sensitivity (overall): 88.3% [83.5%, 92.6%] | ||
| Periapical Radiolucency (PARL) Detection | High Dice, Sensitivity | Dice: 0.77 [0.74, 0.80] |
| Sensitivity: 86.1% [80.2%, 91.9%] | ||
| Bone Level Detection (Bitewing) | High Sensitivity, Specificity, Low MAE | Sensitivity: 95.5% [94.3%, 96.7%] |
| Specificity: 94.0% [91.1%, 96.6%] | ||
| MAE: 0.30 mm [0.29mm, 0.32mm] | ||
| Bone Level Detection (Periapical) | High Sensitivity, Specificity, Low MAE (percentage) | Sensitivity: 87.3% [85.4%, 89.2%] |
| Specificity: 92.1% [89.9%, 94.1%] | ||
| MAE: 2.6% [2.4%, 2.8%] | ||
| Normal Anatomy Detection | High Dice, Sensitivity, Specificity | Dice: 0.84 [0.83, 0.85] |
| Sensitivity (Pixel-level): 86.1% [85.4%, 86.8%] | ||
| Sensitivity (Contour-level): 95.2% [94.5%, 96%] | ||
| Specificity (Contour-level): 93.5% [91.6%, 95.8%] | ||
| Restorations Detection | High Dice, Sensitivity, Specificity | Dice: 0.87 [0.85, 0.90] |
| Sensitivity (Pixel-level): 83.1% [80.3%, 86.4%] | ||
| Sensitivity (Contour-level): 90.9% [88.2%, 93.9%] | ||
| Specificity (Contour-level): 99.6% [99.3%, 99.8%] | ||
| MRMC Clinical Evaluation - Reader Improvement: | ||
| Caries Detection (wAFROC Δθ) | Statistically significant improvement | +0.127 [0.081, 0.172] (p |
§ 892.2070 Medical image analyzer.
(a)
Identification. Medical image analyzers, including computer-assisted/aided detection (CADe) devices for mammography breast cancer, ultrasound breast lesions, radiograph lung nodules, and radiograph dental caries detection, is a prescription device that is intended to identify, mark, highlight, or in any other manner direct the clinicians' attention to portions of a radiology image that may reveal abnormalities during interpretation of patient radiology images by the clinicians. This device incorporates pattern recognition and data analysis capabilities and operates on previously acquired medical images. This device is not intended to replace the review by a qualified radiologist, and is not intended to be used for triage, or to recommend diagnosis.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Design verification and validation must include:
(i) A detailed description of the image analysis algorithms including a description of the algorithm inputs and outputs, each major component or block, and algorithm limitations.
(ii) A detailed description of pre-specified performance testing methods and dataset(s) used to assess whether the device will improve reader performance as intended and to characterize the standalone device performance. Performance testing includes one or more standalone tests, side-by-side comparisons, or a reader study, as applicable.
(iii) Results from performance testing that demonstrate that the device improves reader performance in the intended use population when used in accordance with the instructions for use. The performance assessment must be based on appropriate diagnostic accuracy measures (
e.g., receiver operator characteristic plot, sensitivity, specificity, predictive value, and diagnostic likelihood ratio). The test dataset must contain a sufficient number of cases from important cohorts (e.g., subsets defined by clinically relevant confounders, effect modifiers, concomitant diseases, and subsets defined by image acquisition characteristics) such that the performance estimates and confidence intervals of the device for these individual subsets can be characterized for the intended use population and imaging equipment.(iv) Appropriate software documentation (
e.g., device hazard analysis; software requirements specification document; software design specification document; traceability analysis; description of verification and validation activities including system level test protocol, pass/fail criteria, and results; and cybersecurity).(2) Labeling must include the following:
(i) A detailed description of the patient population for which the device is indicated for use.
(ii) A detailed description of the intended reading protocol.
(iii) A detailed description of the intended user and user training that addresses appropriate reading protocols for the device.
(iv) A detailed description of the device inputs and outputs.
(v) A detailed description of compatible imaging hardware and imaging protocols.
(vi) Discussion of warnings, precautions, and limitations must include situations in which the device may fail or may not operate at its expected performance level (
e.g., poor image quality or for certain subpopulations), as applicable.(vii) Device operating instructions.
(viii) A detailed summary of the performance testing, including: test methods, dataset characteristics, results, and a summary of sub-analyses on case distributions stratified by relevant confounders, such as lesion and organ characteristics, disease stages, and imaging equipment.