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The Lapdoc navigation system is a computerized navigational system intended to provide assistance in both the preoperative planning and the intra-operative surgical phases of dental implantation surgery. The system provides precise navigational guidance of surgical instruments such as a dental bur, with regard to the pre-operative planning in the dental implantation procedure.

The Lapdoc System is a computer based assistance system for dental implantologists. It supports surgeons during planning and execution phase of dental implant procedures by providing highly precise quiding assistance during the implantation process within the human jaw. The systems supports the surgical implantation process by providing visual guidance for position and orienting of a dental bur relative to a planned implant position.

The Lapdoc system is designed to support clinicians by decreasing complication rates of surgical interventions in the field of dental implantology. Using the system will allow precise orientation of the surgeon within the human jaw both in the medical image model of the jaw during the planning phase as well as in real anatomy during the execution phase. This is achieved by objective measuring the spatial positions of surgical instruments and the patients anatomy. Based on three dimensional medical image data, the surgeon plans an intervention by virtually placing models of implants within the graphical depiction (of the medical image set) of the jaw. The surgeon views and interprets the medical images which are graphically augmented with the computer models of the implants. It is further possible to manually mark the outlines of sensitive anatomical structures (i.e. nerves) within the medical images. To perfectly understand the geometric dimensions of the patients anatomy and the later intervention, a three dimensional model is created from isodense surfaces in the CT images and displayed on the computer screen. Lapdoc uses the geometric information of the planned implants within the medical images to generate highly precise information to guide the surgeon's instrument directly to the intended implant position and orientation.

An optical measurement system consisting of an infrared-based stereo camera system and a set of two rigid structures (also known as rigid bodies or trackers) with attached reflectors is used to measure the spatial positions of the patient and the instruments. Therefore, the trackers are reproducible attached to the patient (using a dental splint) and to the surgical bur (using a cone nut connector). The stereo camera system comprises an internal position measurement processor and is connected to the Lapdoc computer. It senses the positions of the instruments and the patients tracker and communicates it to the Lapdoc computer. The computer calculates in real time the deviation between the actual and the desired (from the planning phase) transformation of the positions of both trackers. The actual bur position and the planned implant position and orientation are graphically displayed to the surgeon using a mini-display is placed within the vicinity of the surgeon and near the patient's mouth. The surgeon minimizes this deviation during the drill procedure by moving the bur in a way, that position and orientation of both the dental bur and planned implant are congruent. The system supports the surgeon by actieving a highly precise surgical outcome according to the planned scenario.

Lapdoc system will graphically and audibly signal to the surgeon, if the plan is fulfilled and the surgical bur has reached its designated position and orientation. It will further warn the surgeon by reaching a minimal proximity value close to sensitive anatomical structures (i.e. nerves) and therefore avoids injury of such structures. Lapdoc is specifically designed to minimize the interaction between the user and the system. The application of the system follows simple ergonomic rules. The usage and working principle is easy to understand by the surgeon. The clinical workflow is not altered using Lapdoc.

To describe the patients anatomy and the medical image model in one common coordinate system, it is necessary to perform an image registration process. This registration process comprises a navigation bow of known geometry and an algorithm to detect and measure the position of the navigation bow within the medical image data set. Lapdoc correlates the positions of the navigation bow within the image data with its measured spatial position. Since the navigation bow is attached reproducible to the patients jaw by click-snaping it onto the patient's teeth, positions on or within the patients anatomy can also be described within the medical image data set using the registration function.

This document describes the Lapdoc system, a computer-based assistance system for dental implantologists that supports surgeons during the planning and execution phases of dental implant procedures by providing highly precise guiding assistance.

Safety & Performance Studies:

1. Acceptance Criteria and Device Performance:

The primary acceptance criterion for the Lapdoc system is its navigational accuracy.

This acceptance criterion was established based on:

• Review of state-of-the-art technology (Appendix documents No. 8 to No. 12).
• Opinions by experts in the field (Appendix documents No. 6 to No. 8).
• Accuracy specified for FDA cleared predicate devices (Appendix documents No. 13 to No. 16).

2. Sample Size and Data Provenance for Test Set:

The provided document does not explicitly state the sample size used for a test set or the data provenance (e.g., country of origin, retrospective or prospective) for validating the accuracy. The reported accuracy of +/- 1.0 mm appears to be a general system specification derived from predicate devices and expert opinion rather than a specific performance study on a defined test set.

3. Number and Qualifications of Experts for Ground Truth:

The document mentions that the accuracy level was defined based on "opinions by experts in the field (see Appendix documents No. 6 to No. 8)." However, it does not specify the exact number of experts used or their specific qualifications (e.g., "radiologist with 10 years of experience").

4. Adjudication Method for Test Set:

No information is provided regarding an adjudication method for a test set, as a specific performance study with a test set and ground truth generation is not detailed.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

No MRMC comparative effectiveness study is reported in the provided text. The document focuses on the system's standalone accuracy in guiding surgical instruments rather than comparing human reader performance with and without AI assistance.

6. Standalone Performance (Algorithm Only):

Yes, a standalone performance assessment was conducted for the device's accuracy. The stated "overall system accuracy" of +/- 1.0 mm represents the standalone accuracy of the Lapdoc system in guiding surgical instruments according to pre-operative planning. The system calculates in real-time the deviation between the actual and desired positions and orientations, and the surgeon minimizes this deviation. The system itself measures and guides, indicating a standalone performance metric.

7. Type of Ground Truth Used:

The ground truth for the +/- 1.0 mm accuracy criterion seems to be a combination of:

• Expert Consensus: "opinions by experts in the field".
• Predicate Device Specifications: "accuracy specified for the FDA cleared predicate devices."
• State-of-the-Art Technology Review: This implies a benchmark derived from existing reliable technologies.

It is not based on pathology or outcomes data for this specific accuracy metric.

8. Sample Size for Training Set:

The document does not provide information about a distinct training set sample size. The Lapdoc system is described as a computer-based assistance system that uses geometric information and optical measurement in real-time, rather than a machine learning model that would typically have a separate training phase with a labeled dataset.

9. How Ground Truth for Training Set Was Established:

As there is no mention of a traditional training set for a machine learning model, the concept of establishing ground truth for a training set in that context does not apply here. The system's functionality relies on established principles of optical tracking and computer-assisted navigation rather than learning from a vast dataset.

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