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.

AI/ML Overview

This document, K031696, is a 510(k) premarket notification for the "Lorenz External Mandibular Distractor." It is a request for clearance to market a medical device, based on substantial equivalence to a predicate device. This type of submission does not typically include studies demonstrating achievement of specific performance acceptance criteria as would be expected for a novel device or software cleared via de novo or PMA pathways.

Instead, the primary "study" involved in a 510(k) submission is a comparison to a legally marketed predicate device to establish substantial equivalence.

Therefore, providing a table of acceptance criteria and reported device performance in the way requested for an AI/software device with specific performance metrics and a dedicated validation study is not directly applicable to this physical medical device's 510(k) submission.

However, I can interpret the request in the context of what is provided in a 510(k) and explain why the other criteria (sample size, experts, ground truth, training set, MRMC) are not found here.

1. Table of Acceptance Criteria and Reported Device Performance

For a 510(k) submission like this one, "acceptance criteria" are generally met by demonstrating substantial equivalence to a predicate device. The performance is assessed against the predicate's known characteristics and intended use.

Acceptance Criteria (for Substantial Equivalence)	Reported Device Performance (as demonstrated for 510(k) clearance)
Intended Use Equivalence: Device has the same intended use as a legally marketed predicate device.	The "Lorenz External Mandibular Distractor" is an external Fixator used for mandibular bone lengthening, treating mandibular asymmetry and hypoplasia. This is stated as substantially equivalent to the predicate device K992873 (which is itself noted as "SAME AS ORIGINAL SUBMISSION K001238"). The FDA's letter (K031696) explicitly states that the device is "substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices."
Technological Characteristics Equivalence: Device has the same technological characteristics as the predicate, or if different, the differences do not raise new questions of safety and effectiveness.	The device description ("The distractor frame is comprised of two threaded rails, a longer straight rail, and a shorter, angled rail... These two rails are connected with a locking collar placing the ball joint in the center...") is likely compared against the predicate (K992873/K001238). The submission implicitly argues that its design, materials, and operation are either identical or sufficiently similar to the predicate that no new safety or effectiveness concerns arise. The FDA's clearance indicates agreement.
Performance Data (when applicable): Any performance data (e.g., mechanical testing, biocompatibility) submitted demonstrates equivalence or acceptable safety/effectiveness.	While not explicitly detailed in this summary, a 510(k) typically includes reports on mechanical testing (e.g., strength, fatigue of the rails, screws, and ball joint) and biocompatibility for novel materials or designs, compared to the predicate device. The "Possible risks" section indirectly implies these types of assessments were made (e.g., "Bending, loosening of bone screws... fracture of the device," "Nonunion, delayed union... may lead to breakage of the implant"). The absence of specific test results in this summary means we cannot list them here, but they would have been part of the full 510(k) submission.

Important Note: The concept of "acceptance criteria" for a 510(k) is less about achieving specific numerical performance thresholds (like sensitivity/specificity for AI) and more about demonstrating that the device is as safe and effective as a legally marketed predicate.

Regarding the other requested information (which is not typically found in this type of 510(k) filing for a physical device):

2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)

This information is not applicable to this 510(k) submission. There is no "test set" of patient data in the context of an AI/software performance study for this physical medical device. The "testing" done for this device would involve engineering verification and validation (e.g., bench testing, material testing) rather than clinical data analysis for performance metrics.

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

This information is not applicable. Since there is no "test set" requiring ground truth establishment by experts, this detail is not present.

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

This information is not applicable. There is no "test set" or adjudication process on clinical data in the context of an AI/software evaluation.

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

This information is not applicable. This device is a physical external mandibular distractor, not an AI software intended to assist human readers (e.g., radiologists). Therefore, an MRMC study is irrelevant.

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

This information is not applicable. This is a physical device, not an algorithm.

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

This information is not applicable. There is no ground truth derivation from clinical data in the context of this 510(k) for a physical device. Ground truth for a physical device pertains more to engineering specifications and material properties rather than diagnostic accuracy.

8. The sample size for the training set

This information is not applicable. This is a physical device, not an AI algorithm requiring a training set.

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

This information is not applicable. As above, no training set or ground truth in this context.

Summary

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JUN 1 7 2003

K031696

Summary of Safety and Effectiveness

Lorenz External Mandibular Distraction Device Name:

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

Contraindications:

1. Active infection and sepsis.
1. Foreign body sensitivity. Where material sensitivity is suspected, testing is to be completed prior to implantation.
Patients with limited blood supply, insufficient quantity or quality of bone, or latent 3. infection.
1. Patients with mental or neurologic conditions who are unwilling or incapable of following postoperative care instructions.
1. Bone disorders which limit bone generation.

K992873

(SAME AS ORIGINAL SUBMISSION KOOL238) "The distractor frame is Description: 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."

Sterility Information: The places and screws will be marketed as non-sterile, single use devices

Possible risks:

Bending, loosening of bone screws, K-wire, or ball joint, stripping of threaded rails, or 1. fracture of the device.
1. Nonunion, delayed union, or premature union may lead to breakage of the implant.
1. Metal sensitivity, or allergic reaction to a foreign body.
1. Pain, discomfort or abnormal sensations due to the presence of the device.
ર . Nerve damage due to surgical trauma.
1. Other conditions brought on by the surgical procedure including skin irritation and infection.
1. Biomechanical complications due to positioning of the device.

1. Poor done formation. Osteoporosis, Osteolysis, Osteomvelitis. inhibited revascularization, or infection can cause loosening, bending, cracking or fracture of the device.
1. Necrosis of bone or soft tissue.
Tension of the soft tissue depending on the speed of distraction and quality of the soft 10. tissues and therefore irritation and/or atrophy.
1. Inadequate healing.

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Public Health Service

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

JUN 1 7 2003

Ms. Kim Reed Sr. Regulatory Specialist Walter Lorenz Surgical, Incorporated 1520 Tradeport Drive Jacksonville, Florida 32218-2480

Re: K031696

Trade/Device Name: Lorenz External Mandibular Distractor Regulation Number: 21 CFR 872.4760 Regulation Name: Bone Plate Regulatory Class: II Product Codes: MON Dated: May 30, 2003 Received: June 05, 2003

Dear Ms. Reed:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially cquivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require annroval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions 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 (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

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Page 2 - Ms. Kim Reed

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding 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), please contact the Office of Compliance at (301) 594-4613. 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 entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97) you may obtain. Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely yours,

Simon Russe

Susan Runner, DDS, MA Interim Director Division of Anesthesiology, General Hospital, Infection Control and Dental Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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STATEMENT OF INDICATIONS FOR USE

510(k) Number:

K031696

Device Name: 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)

Prescription Use (Per 21 CFR 801.109)

ﺍ ﻣﺮﺩﺓ، ﺍ

Over-The-Counter-Use (Optional Format 1-2-96)

Kain Muluy for M.D.
(Division Sign-or)

Division of Anesthesiology, General Hospital,
Infection Control, Dental Devices

510(k) Number: K031696

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.