Traumatic and surgically created defects in the craniofacial skeleton often require filling with a synthetic material for optimum clinical outcomes. Norian CRS (craniofacial repair system) offers a treatment solution for such cases. The Norian CRS family of products is completely synthetic self-setting calcium phosphate cements which closely resemble the mineral phase of bone. Once cured, both materials have identical chemistries and are gradually resorbed and replaced with bone during the bone remodeling process. The key difference between the two formulations is in the intraoperative handling and delivery properties.
Norian CRS is an injectable form of the cement which is mixed in the operating room using an automated mixing system. Once mixed, that material is transferred to a delivery syringe and injected into its intended site via a needle. These features make Norian CRS ideal for cases where delivery to a remote or deep site is necessary.
Features and benefits
The Norian CRS line of products hardens in a warm and wet environment, reducing the need to control moisture at the surgical site. The materials undergo in situ isothermal hardening, thereby eliminating thermal injury to the surrounding tissues. Both materials also achieve maximum compressive stress values which exceed that of native cancellous bone after 24 hours of hardening.
Norian CRS is indicated for filling or repairing craniofacial defects and craniotomy cuts with a surface area no larger than 25 cm2. The material is also indicated for the restoration or augmentation of bony contours of the craniofacial skeleton, including the fronto-orbital, malar, and mental areas. The product is not intended for use in the spine, and should not be used in the presence of infection. Clinical procedures appropriate for the use of Norian CRS products include:
- Cranial recontouring
- Cranial flap augmentation
- Augmentation genioplasty
- Onlay grafting
- Skull base defect repair
The application of the Norian products in layers is not recommended. Furthermore, they should not be used against an open sinus.
Figure Automatic mixer for Norian CRS.
The Norian CRS bone cements consist of a carbonated apatite that more closely resembles the mineral phase of bone than hydroxyapatite. Hydroxyapatite is commonly thought of as the mineral phase of bone. However, it is the mineral dahllite that actually comprises 6070% of total dry bone weight. Dahllite has higher carbonate content (46%) than hydroxyapatite (0%). Therefore, as carbonated apatites with a carbon content of 5%, the Norian CRS products more closely resemble the composition of natural bone.
Figure Delivery of Norian CRS into a simulated cranial defect.
Hazards and labeling
Due to varying countries’ legal and regulatory approval requirements, consult the appropriate local product labeling for approved intended use of the products described on this website. All devices on this website are approved by the AO Technical Commission. For logistical reasons, these devices may not be available in all countries worldwide at the date of publication.
This work was produced by AO Foundation, Switzerland. All rights reserved by AO Foundation. This publication, including all parts thereof, is legally protected by copyright.
Any use, exploitation or commercialization outside the narrow limits set forth by copyright legislation and the restrictions on use laid out below, without the publisher‘s consent, is illegal and liable to prosecution. This applies in particular to photostat reproduction, copying, scanning or duplication of any kind, translation, preparation of microfilms, electronic data processing, and storage such as making this publication available on Intranet or Internet.
Some of the products, names, instruments, treatments, logos, designs, etc referred to in this publication are also protected by patents, trademarks or by other intellectual property protection laws (eg, “AO” and the AO logo are subject to trademark applications/registrations) even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name, instrument, etc without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain.
Restrictions on use: The rightful owner of an authorized copy of this work may use it for educational and research purposes only. Single images or illustrations may be copied for research or educational purposes only. The images or illustrations may not be altered in any way and need to carry the following statement of origin “Copyright by AO Foundation, Switzerland”.
Check www.aofoundation.org/disclaimer for more information.
If you have any comments or questions on the articles or the new devices, please do not hesitate to contact us.
“approved by AO Technical Commission” and “approved by AO Foundation”
The brands and labels “approved by AO Technical Commission” and “approved by AO Foundation”, particularly "AO" and the AO logo, are AO Foundation's intellectual property and subject to trademark applications and registrations, respectively. The use of these brands and labels is regulated by licensing agreements between AO Foundation and the producers of innovation products obliged to use such labels to declare the products as AO Technical Commission or AO Foundation approved solutions. Any unauthorized or inadequate use of these trademarks may be subject to legal action.