Written and maintained by CASRAI Editorial Board
Last updated
General product and regulatory information only, not medical advice and not a procedure guide.
Short answer
A bite block is a mouth-held accessory used during endoscopy, where the scope is inserted orally. FDA defines the endoscopic bite block as a device “to prevent patient from biting down in order to protect fragile endoscope equipment,” and classifies it under product code MNK as Class I and exempt from 510(k) premarket notification (21 CFR 876.1500(b)(2)), subject to the limitations in 21 CFR 876.9.
Definition and scope
In this page, “bite block” means the endoscopic device. FDA’s classification record for code MNK names it “endoscopic bite block,” lists its physical state as a bite block, and gives its technical method as “placed into mouth over teeth.” The same record describes what it is meant to protect: the endoscope, the patient’s teeth and gums, and the endoscopist’s fingers during oral insertion.
The phrase is also used outside endoscopy, for example in dental contexts. Those uses are different products and are not covered here.
How it is used in practice
FDA’s own description is the whole of the regulatory use statement: a mouth-held barrier that keeps the patient from biting down on the instrument. This page does not describe insertion or placement steps; those belong in the manufacturer’s instructions for use and the facility’s clinical protocol.
Bite block for endoscopy
The regulation that classifies it, 21 CFR 876.1500 (“Endoscope and accessories”), covers devices that provide access, illumination, observation or manipulation of body cavities, hollow organs and canals. Esophagogastroduodenoscopes appear in its list of examples. The bite block is named separately, as an accessory, in paragraph (b)(2).
Bite block and intubation or airway devices
The endoscopic classification above does not address airway management. Separately, CASRAI’s guide to laryngeal mask airway types records that the i-gel supraglottic airway is described by its maker, Intersurgical, as having an integral bite block, so in that device the feature is built into the airway rather than supplied as a separate accessory.
Related concepts: accessory versus endoscope
Regulation text draws a line between the scope and the items used with it. The comparison below uses only what 21 CFR 876.1500 states.
| Item in 21 CFR 876.1500 | Paragraph | Class and exemption stated |
|---|---|---|
| Bite block for endoscope | (b)(2) | Class I; exempt from premarket notification, subject to 21 CFR 876.9 |
| Cleaning brush for endoscope | (b)(2) | Class I; exempt from premarket notification, subject to 21 CFR 876.9 |
| Inflation bulb | (b)(2) | Class I; exempt from premarket notification, subject to 21 CFR 876.9 |
| Smoke removal tube | (b)(2) | Class I; exempt from premarket notification, subject to 21 CFR 876.9 |
| Endoscope disinfectant basin; LED light source; endoscopic sponge carrier | (b)(1) | Class II (special controls); exempt from premarket notification, subject to 21 CFR 876.9 |
The scope itself is an example of the generic type in paragraph (a). For the scope side, see what is an endoscope and what is a sigmoidoscope.
Where it matters for labs, clinics and supply decisions
Two sourced points help when a bite block appears on a product list or a regulatory file.
- Regulatory file. Class I with a 510(k) exemption means no premarket notification is required for a device that stays within the generic type. Under 21 CFR 876.9, a manufacturer must still submit a 510(k) if the device is intended for a different use than legally marketed devices of that type, or operates on a different fundamental scientific technology. Product-specific claims should therefore be read from the manufacturer’s labeling, not inferred from the exemption.
- Supply list. CASRAI’s endoscopy center supply checklist lists bite blocks among its procedure-site supplies and describes them as a consumable rather than a shared reusable item at most centers. For the wider regulatory path, see FDA 510(k) premarket notification.
Common misunderstandings
- “Exempt” does not mean unregulated. The device is still a Class I medical device; the exemption concerns premarket notification only, and 21 CFR 876.9 sets its limits.
- It is not part of the scope. The regulation lists it as a separate accessory with its own classification entry.
- One word, several products. FDA’s MNK record covers the endoscopic device; dental and other products with the same name are outside it.
FAQ
What is a bite block?
In endoscopy, a mouth-held accessory that prevents the patient from biting down, protecting the endoscope, the patient’s teeth and gums and the endoscopist’s fingers (FDA product code MNK, checked 2026-10-30).
What is a bite block used for in endoscopy?
FDA states its purpose as preventing the patient from biting down in order to protect fragile endoscope equipment. Technique is set by the manufacturer’s instructions and clinical protocol.
How does FDA classify an endoscopic bite block?
Class I, 510(k) exempt, under 21 CFR 876.1500(b)(2) and subject to the limitations in 21 CFR 876.9.
Is a bite block part of intubation?
The FDA endoscopic classification does not cover intubation. Some airway devices, such as the i-gel, are described by their manufacturer as having an integral bite block. Device choice and use are clinical decisions outside this page.
Sources
All three sources were checked on 2026-10-30.
- FDA, Product Classification, code MNK, endoscopic bite block: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpcd/classification.cfm?id=MNK
- 21 CFR 876.1500, Endoscope and accessories: https://www.ecfr.gov/current/title-21/section-876.1500
- 21 CFR 876.9, Limitations of exemptions from section 510(k): https://www.ecfr.gov/current/title-21/section-876.9
