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General product and regulatory information only. This page is not medical advice and does not describe how any instrument is used on a patient.
Short answer
A trephine is a cutting instrument for removing a circular section of tissue. In FDA records the word is not one device: the same name appears under ophthalmic, orthopedic, ear-nose-throat and neurological product codes, and most are Class I while the manual cranial type is Class II. The class comes from the product code and regulation, not from the word “trephine”. Checked against openFDA and 21 CFR on 2026-10-30.
Definition and scope
FDA does not publish a single “trephine” definition. It classifies trephines inside broader instrument regulations, each tied to a specialty. For example, 21 CFR 882.4300 describes manual cranial drills, burrs, trephines and their accessories as bone cutting and drilling instruments used without a power source on a patient’s skull. Under 21 CFR 886.4350, a manual ophthalmic surgical instrument is a nonpowered, handheld device intended to aid or perform ophthalmic surgical procedures, and the list of examples ends with the ophthalmic manual trephine.
That is why a search for a single meaning misleads: a corneal trephine, a bone trephine and a sinus trephine are separate entries with separate regulatory homes.
How FDA records label trephines
The table lists the FDA product codes whose device name contains “trephine”, from the openFDA device classification database (checked 2026-10-30), plus the cranial code that names trephines in its regulation.
| Product code | FDA device name | Specialty | Regulation (21 CFR) | Class |
|---|---|---|---|---|
| HRH | Trephine, Manual, Ophthalmic | Ophthalmic | 886.4350 | I |
| HRG | Engine, Trephine, Accessories, AC-Powered | Ophthalmic | 886.4070 | I |
| HRF | Engine, Trephine, Accessories, Battery-Powered | Ophthalmic | 886.4070 | I |
| HLD | Engine, Trephine, Accessories, Gas-Powered | Ophthalmic | 886.4070 | I |
| HWK | Trephine | Orthopedic | 888.4540 | I |
| KBF | Trephine, Sinus | Ear, Nose, Throat | 874.4420 | I |
| HBG | Drills, Burrs, Trephines & Accessories (Manual) | Neurology | 882.4300 | II |
Corneal trephine and the other trephines
Corneal trephine
FDA’s classification database has no product code literally named “corneal trephine”. The ophthalmic manual entry is HRH, “Trephine, Manual, Ophthalmic”, regulated under 21 CFR 886.4350 as a Class I device that is exempt from premarket notification, subject to the limitations in 21 CFR 886.9.
Powered “trephine engines”
The three ophthalmic engine codes (HRF, HRG, HLD) are filed under 21 CFR 886.4070, titled “Powered corneal burr”. That regulation describes an AC-powered or battery-powered device that is a motor and drilling tool intended to remove rust rings from the cornea, and its text does not contain the word trephine. Searching the CFR for the word will therefore miss these codes.
Orthopedic and sinus trephines
21 CFR 888.4540 covers a nonpowered hand-held device intended for medical purposes to manipulate tissue, or for use with other devices in orthopedic surgery, and lists the trephine. 21 CFR 874.4420 covers ENT manual surgical instruments and lists the sinus trephine. Both are Class I.
Cranial trephines
21 CFR 882.4300 is the exception in the table: Class II, with performance standards named in the regulation, where the others are Class I.
Where it matters for labs, clinics and supply decisions
- Reading a catalog or device record. The class and regulation in a record come from its product code. Two items both called “trephine” can sit in different classes (for example HRH, Class I, and HBG, Class II).
- Searching regulations. Search by product code or by specialty regulation as well as by the word, since the powered ophthalmic codes sit under a regulation that never uses it.
- Related instrument pages. Trephines are listed within the instrument groupings in ophthalmic surgical instruments, orthopedic surgical instruments and ENT surgical instruments; the neurosurgical side is touched on in the cerebellar retractor guide.
Common misunderstandings
- “A trephine is one device class.” It is not: the table above shows Class I and Class II entries.
- “Class I means unregulated.” Class I devices are subject to general controls; the ones above are exempt from premarket notification, with limitations stated in the cited sections.
- “Every trephine is the same kind of instrument.” The regulations above group them with different instrument families, from ophthalmic manual instruments to cranial drills and burrs.
FAQ
What is a corneal trephine?
In FDA terms it falls under “Trephine, Manual, Ophthalmic” (product code HRH), a manual ophthalmic surgical instrument regulated under 21 CFR 886.4350 as Class I.
Is a trephine Class I or Class II?
It depends on the product code. The ophthalmic, orthopedic and sinus trephine codes above are Class I; the manual cranial drills, burrs and trephines code (HBG, 21 CFR 882.4300) is Class II.
Sources
All sources checked 2026-10-30.
- FDA, openFDA device classification database (product codes HRH, HRG, HRF, HLD, HWK, KBF, HBG): https://api.fda.gov/device/classification.json?search=device_name:trephine&limit=30
- 21 CFR 886.4350, manual ophthalmic surgical instrument: https://www.law.cornell.edu/cfr/text/21/886.4350
- 21 CFR 886.4070, powered corneal burr: https://www.law.cornell.edu/cfr/text/21/886.4070
- 21 CFR 888.4540, orthopedic manual surgical instrument: https://www.law.cornell.edu/cfr/text/21/888.4540
- 21 CFR 874.4420, ear, nose, and throat manual surgical instrument: https://www.law.cornell.edu/cfr/text/21/874.4420
- 21 CFR 882.4300, manual cranial drills, burrs, trephines, and their accessories: https://www.law.cornell.edu/cfr/text/21/882.4300
