The Lorenz External Mandibular Distractor is an external fixator used for mandibular bone lengthening. It is used in treatment of mandibular asymmetry and hypoplasia.

Device Description

The distractor frame is comprised of two threaded rails, a longer straight rail, and a shorter, angled rail to accommodate the anatomic angles of the mandible. These two rails are connected with a locking collar placing the ball joint in the center allowing three dimensional contouring to match facial curvatures. This biplanar distractor allows for up to 40mm distraction with the straight rail, and up to 30mm distraction with the angled rail.

Bone screws (or K-wire) are inserted percutaneously into the bone and attached to the distractor frame with a clamp.

The frame is locked by set screws which tighten and thereby lock the ball joint and rails in place. Adjustments can be made intra-operatively or post-operatively.

AI/ML Overview

Due to the detailed nature of your request and the specific information needed from the provided text, it's important to note that the provided document is a 510(k) summary for the Lorenz External Mandibular Distractor. This type of submission focuses on demonstrating substantial equivalence to a predicate device rather than presenting a full clinical study with acceptance criteria and detailed performance data as one might find in a Premarket Approval (PMA) application or a dedicated clinical trial report.

Therefore, many of the requested items, particularly those related to rigorous statistical studies, multi-reader multi-case analyses, or
extensive ground truth establishment, are not typically present or required in a 510(k) submission for a device like an external mandibular distractor. The focus is on comparing the new device's design, materials, and intended use against a legally marketed predicate device to establish that it is as safe and effective.

Here's an analysis based on the provided text, with explanations where information is not available:

# Summary of Safety and Effectiveness

Device Name: Lorenz External Mandibular Distractor
Predicate Device: Lorenz Mandibular Distractor, 510(k) number [K955640](https://510k.innolitics.com/search/K955640)
Classification Name: External Mandibular Fixator and/or Distractor
Device Product Code and Regulation Number: MQN, 21 CFR 872.4760

#### Intended use:

The Lorenz External Mandibular Distractor is an external fixator used for mandibular bone lengthening. It is used in treatment of mandibular asymmetry and hypoplasia.

1. Table of acceptance criteria and the reported device performance

As a 510(k) submission for a mechanical device undergoing modifications to materials and design, explicit "acceptance criteria" and "reported device performance" in the sense of statistical endpoints from a clinical trial are not provided in this document. The "performance" is implicitly demonstrated through the comparison to the predicate device and the design changes.

The document highlights the capabilities of the device:

Feature	Reported Device Performance (Modified Distractor)	Implied Acceptance Criteria (relative to Predicate)
Distraction Capability	Up to 40mm (straight rail), Up to 30mm (angled rail)	Maintain or improve distraction range
Distraction Mechanism	Biplanar distraction with ball joint	Provide multi-directional control
Screw Type/Pitch	6mm screw (rail) M6 x 1 thread (1mm pitch)	Maintain or improve mechanical advantage
Bone Fixation Screws/K-wire	3.0/2.5mm taper & 2.5/2.0mm taper trocar tipped bone fixation screws; 1.6 & 2.0mm K-wire	Provide secure bone attachment
Frame Design	Two threaded rails (longer straight, shorter angled), locking collar with ball joint in center	Accommodate anatomic angles, 3D contouring
Loading/Fatigue	(Not specified in this document)	(Implicit: withstand anticipated physiological loads without failure)
Biocompatibility	Stainless steel, Ti-6Al-4V, 316 LVM Stainless Steel, hard coat anodized aluminum	(Implicit: materials are known to be biocompatible for intended use)

The acceptance criteria are generally to demonstrate that the modified device is "substantially equivalent" to the predicate device in terms of safety and effectiveness, meaning it performs similarly and does not raise new questions of safety or effectiveness. This is achieved by showing that the materials, design, and mechanisms of action are comparable or improved, and that any potential risks are understood and managed.

2. Sample size used for the test set and the data provenance

Not applicable/Not provided. This is a 510(k) submission primarily based on design and material changes and a comparison to a predicate device. It does not describe a clinical evaluation with a "test set" of patients in the way a clinical trial would. The assessment of "performance" here is largely based on engineering design analysis and comparison.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Not applicable/Not provided. Since there isn't a "test set" of patient data requiring ground truth establishment, this information is not relevant to this submission.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

Not applicable/Not provided. No test set or expert adjudication process is described in this 510(k) summary.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, if so, what was the effect size of how much human readers improve with AI vs without AI assistance

Not applicable. This device is a mechanical surgical distractor, not an imaging or diagnostic device that would involve "human readers" or "AI assistance." Therefore, an MRMC study is not relevant.

6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done

Not applicable. This is a mechanical device, not an algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

Not applicable/Not provided. For a 510(k) of this nature, the "ground truth" is fundamentally the understanding of biomechanical principles, material science, and prior clinical experience with similar devices, specifically the predicate device. The changes are evaluated against these established engineering and medical principles to ensure equivalence. There is no specific "ground truth" for a study as there is no specific study described.

8. The sample size for the training set

Not applicable/Not provided. There is no "training set" as this is not a machine learning algorithm or a clinical trial in that sense.

9. How the ground truth for the training set was established

Not applicable/Not provided. As there is no training set, this is not relevant.

In summary: The provided document is a 510(k) summary, which is a premarket notification to the FDA demonstrating substantial equivalence to a predicate device. It relies on comparisons of design, materials, and intended use rather than presenting comprehensive clinical study data with detailed acceptance criteria, sample sizes, and ground truth establishment as would be found for a novel device or a clinical trial for a PMA. The "study" proving the device meets criteria is primarily the engineering analysis and comparison to the predicate device, K955640.

Summary

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K992873

:・

Summary of Safety and Effectiveness

Device Name: Lorenz External Mandibular Distractor

Predicate Device: Lorenz Mandibular Distractor, 510(k) number K955640

Classification Name: External Mandibular Fixator and/or Distractor

Device Product Code and Regulation Number: MQN, 21 CFR 872.4760

Intended use:

The Lorenz External Mandibular Distractor is an external fixator used for mandibular bone lengthening. It is used in treatment of mandibular asymmetry and hypoplasia.

Device Description:

Bone screws (or K-wire) are inserted percutaneously into the bone and attached to the distractor frame with a clamp.

The frame is locked by set screws which tighten and thereby lock the ball joint and rails in place. Adjustments can be made intra-operatively or post-operatively.

Device Modifications:

1. Materials:

. Predicate distractor K955640:
- 1. external distractor frame- hard coat anodized aluminum
- 1. bone fixation pins-Ti-6Al-4V
- 1. lengthening screw- stainless steel
. Modified distractor:
- 1. external distractor frame (rails and ball joint)- stainless steel
- 1. ball locking collar-Ti-6Al-4V
- 1. bone screws/k-wire-316 LVM Stainless Steel
- 1. clamp-hard coat anodized aluminum

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Device Modifications cont.

1. Device:
. Predicate distractor K955640:
- unilateral distraction with ball joint 1.
- 4mm screw with 0.5mm pitch 2.
- 1. 2.7mm percutaneous bone fixation pins
. Modified distractor:
- Biplanar distraction with ball joint 1.
- 6mm screw (rail) M6 x 1 thread (1mm pitch) 2.
- 3.0/2.5mm taper trocar tipped bone fixation screws 3. 2.5/2.0mm taper trocar tipped bone fixation screw
  - 1.6 & 2.0mm K-wire

3. Design:

. Predicate distractor
- 1. The frame has a ball joint at one end and a lengthening screw at opposite end.
. Modified distractor
- Frame has two threaded rails, a longer straight ball rail, and a shorter, angled 1. rail to accommodate the anatomic angles of the mandible. The two rails are connected with a locking collar placing the ball joint in the center.
- Bone screws/K-wire attach to frame by clamps. 2.

Potential Risks:

1. Bending, loosening of bone screws, k-wire, or ball joint, stripping the threads, or fracture of the device.
1. Nonunion, delayed union, or premature union.
1. Metal sensitivity or allergic reaction.
1. Pain, discomfort or abnormal sensations due to the presence of the device.
1. Nerve damage.
1. Other conditions brought on by the surgical procedure including skin irritation and infection.
1. Biomechanical complications due to improper positioning of the device.

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Image /page/2/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo is circular and contains the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is an abstract image of an eagle.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

SEP 1 7 1999

Ms. Diana Preston Requlatory Affairs Specialist Walter Lorenz Surgical, Incorporated 1520 Tradeport Drive Jacksonville, Florida 32218

K992873 Re : Lorenz External Mandibular Distractor Trade Name: Requlatory Class: II Product Code: MON Dated: Auqust 23, 1999 Received: August 26, 1999

Dear Ms. Preston:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions The general controls provisions of the Act of the Act. include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major requlations affecting your device can be found in the Code of Federal Requlations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Good Manufacturing Practice for Medical Devices: General (GMP) requlation (21 CFR Part 820) and that, through periodic GMP inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP requlation may result in requlatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of

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Page 2 -Ms. Preston

the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA findinq of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4690. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entiled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

Timothy A. Ulatowski

Director Division of Dental, Infection Control, and General Hospital Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Page __ 1_ of __1

510(k) Number (if known): unknown

Device Name: Lorenz External Mandibular Distractor

Indications For Use: The Lorenz External Mandibular Distractor is an external fixator used for mandibular bone lengthening. It is used in treatment of mandibular asymmetry and hypoplasia.

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

(Division Sign-Off)
Division of Dental, Infection Control,
and General Hospital Devices
510(k) Number K992873

Prescription Use
(Per 21 CFR 801.109)
OR
Over-The-Counter Use_

(Optional Format 1-2-96)

Regulation Number and Section

§ 872.4760 Bone plate.

(a)
Identification. A bone plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to the plate with screws to prevent movement of the segments.(b)
Classification. Class II.