GB-12 (Wan Gu) Completion Bone

What does GB-12 Wan Gu do?

GB-12 eliminates wind, benefits the head and alleviates pain, and it calms the spirit — and its insomnia indication makes it the one point in this region where that second action is borne out.

• Eliminates wind, benefits the head and alleviates pain
• Calms the spirit — and unlike several records this library has flagged, the indication list supports it

Where the fields agree, that is worth saying. This project has documented eight records whose action field claims something the indications do not support — BL-11, BL-51, BL-55, KI-19, KI-20, KI-26, SJ-15 and GB-17. GB-12 is the opposite case: it records calms the spirit, and insomnia sits in its indication list. Its neighbour GB-09 also names the spirit, and its convulsive indications bear that out too. Where the two fields correspond, either can be relied on.

It carries the longest indication list of the five points behind and above the ear — six entries against GB-09’s four, GB-10’s three, GB-11’s four and GB-08’s. Sitting lowest, closest to the jaw, ear and neck, its list reflects its position.

A name collision, and one of eight in this library. “Wan Gu” is the name of two points: GB-12, here behind the mastoid, and SI-04, on the ulnar border of the hand. Verified by querying every pinyin value in our data. They are on different channels at opposite ends of the body, and only the channel code tells them apart. The full audit — Fu Tu, He Liao, Ju Liao, Tong Gu, Wan Gu, Yin Jiao, Zhong Du and Zhong Zhu — is recorded in our reference notes.

This one matters more than most, because GB-12 is used as a landmark. Our GB-10 and GB-11 records place those points along a curved line running to Wan Gu, and our SJ-16 record locates that point about one cun below Wan Gu. A description reading “a third of the way to Wan Gu” is unambiguous only with the channel code attached.

On the name. “Wan Gu” is rendered here as Completion Bone — wan in the sense of complete or finished, gu bone: the mastoid process, which the point sits behind. SI-04’s wan is a different character meaning the wrist, which is why that point is often rendered Wrist Bone. In toneless pinyin the two are identical, and that is exactly how the collision arises — the same mechanism our SJ-22 record describes for He Liao.

Source: Sacred Lotus sources & references (channel, category, action and translation records; every pinyin value queried for duplicates and the eight collisions counted, the eight field-mismatch cases queried, and the GB-08 to GB-11, SI-04 and SJ-16 records checked, against our own data), cross-referenced against multiple online sources.

What is GB-12 Wan Gu used for?

GB-12 is used for headache, insomnia, swelling of the cheek, pain behind the ear, deviation of the eye and mouth, and toothache. Our own indication record is reproduced here in full.

• Headache
• Insomnia
• Swelling of the cheek
• Retroauricular pain (pain behind the ear)
• Deviation of the eye and mouth
• Toothache

Four of the six are face and jaw, and one is the region itself. Pain behind the ear is as local as an indication gets — the point sits there. Cheek swelling, toothache and facial deviation all belong to the jaw and face immediately in front. Only insomnia reaches beyond the region, and it is what the recorded spirit-calming action refers to.

An honest note, and two entries need one stated plainly.

• DEVIATION OF THE EYE AND MOUTH — facial weakness or droop — REQUIRES URGENT MEDICAL ASSESSMENT. A new facial droop can be a sign of stroke, which is a medical emergency where treatment given quickly changes outcomes; it can also be Bell’s palsy, where early treatment improves recovery. Either way it needs same-day care. Facial droop with weakness elsewhere, difficulty speaking, or sudden visual loss is an emergency — call for help immediately. This record documents a classical indication and makes no claim that acupuncture treats stroke or its consequences.
• PAIN, REDNESS OR SWELLING OF THE BONE BEHIND THE EAR NEEDS URGENT CARE, especially with fever, earache or discharge — that is how mastoiditis presents, and this point sits directly on the mastoid.

The others. Toothache and cheek swelling need dental assessment; a dental infection with facial swelling and fever is a medical emergency. Persistent insomnia deserves proper assessment rather than repeated self-treatment. Sudden severe headache, or headache with fever and neck stiffness, requires urgent assessment.

How it is combined. With GB-20 Feng Chi below at the occiput — but see the needling section, because the two sit on opposite sides of a real anatomical boundary. With GB-11 and GB-10 above on the curved line this point anchors. With SJ-17 Yi Feng behind the earlobe and SJ-16 Tian You below on the neck. With ST-06 and ST-07 at the jaw and LI-04 He Gu distally for the face. All held here.

Source: Sacred Lotus sources & references (indication and action records, with the GB-08 to GB-12 lists counted and compared; the GB-10, GB-11, GB-20, LI-04, SJ-16, SJ-17, ST-06 and ST-07 records queried from our own data), cross-referenced against multiple online sources.

Where is GB-12 Wan Gu located?

GB-12 is in the definite hollow just behind and below the mastoid process — the bony lump you can feel behind the ear.

• In the depression just posterior and inferior to the mastoid process
• GB-11 Tou Qiao Yin and GB-10 Fu Bai lie above on a curved line running up to GB-09
• SJ-16 Tian You lies about one cun below, on the back edge of sternocleidomastoid

This is one of the firmest landmarks on the head, which is why other points are measured from it. The mastoid process is unmistakable and its posterior hollow is palpable in everyone — no counting, no proportion, no hairline. Our GB-10 and GB-11 records use GB-12 as the lower anchor of the curve whose thirds place them, and our SJ-16 record measures down from it. A point that is easy to find becomes a reference for points that are not.

And a name collision at exactly that landmark. “Wan Gu” is also SI-04, on the ulnar border of the hand — verified by querying every pinyin value in our data, one of eight genuine collisions in this library. Because GB-12 is used as a reference in three other records, a description reading “measured from Wan Gu” carries a real risk of ambiguity unless the code is given.

The boundary below. GB-20 Feng Chi sits below and medial, in the soft hollow beneath the occipital bone. GB-12 is on bone, behind the mastoid. The two are close, they are often used together, and they are anatomically quite different — which the needling section sets out.

On the name. “Wan Gu” — Completion Bone, an old name for the mastoid process itself. Purely anatomical.

Source: Sacred Lotus sources & references (location and translation records, retained unchanged; every pinyin value queried for duplicates, and the GB-09, GB-10, GB-11, GB-20, SI-04 and SJ-16 records checked, against our own data).

• A Manual of Acupuncture (p. 430): In the depression just posterior and inferior to the mastoid process.
• Chinese Acupuncture and Moxibustion (p. 211): In the depression posterior and inferior to the mastoid process.

How is GB-12 Wan Gu needled?

Our own record states OBLIQUE insertion of 0.3–0.5 inch, with moxibustion applicable — and it is the one point in this run whose recorded angle is not subcutaneous. What follows is a neutral record of what the reference literature documents. It is not instruction, and this page does not teach technique.

• Angle and depth as recorded: oblique, 0.3–0.5 inch. Our records give GB-08, GB-09, GB-10 and GB-11 as subcutaneous — and GB-12 alone as oblique. The change tracks the anatomy: the four above lie on the flat of the skull under thin scalp, while this point sits in a hollow behind a bony prominence, where a transverse needle has nowhere flat to run.
• Moxibustion: recorded as applicable.
• Regional anatomy: sternocleidomastoid and splenius capitis attach to the mastoid process here; the posterior auricular artery and the lesser occipital nerve run in the region; the mastoid air cells lie within the bone, and the facial nerve emerges from the skull base just in front of and deep to the mastoid tip.

The boundary that matters in this region, stated precisely. GB-20 Feng Chi, close by and often used with this point, sits in the soft hollow below the occipital bone — where there is no bone to stop a needle and the brainstem lies deep — and our GB-20 record carries an explicit caution for exactly that reason, as does our DU-16 Feng Fu record on the midline. GB-12 is on bone, behind the mastoid. Neither caution is imported here, and GB-12’s comparative safety is not exported to the points below where it does not hold. Our BL-09 and GB-19 records draw the same line from their own positions.

Hazard, stated proportionately. Bone lies beneath, and the recorded depth is three to five tenths of an inch. This is a low-hazard point in that sense. Our record carries no arterial caution — nine points in this library do, counted by query, and GB-12 is not among them.

What is not claimed. No study measuring a safe depth at GB-12 could be located, and none is borrowed. Neither measured-depth study this library uses reaches the head. No case report naming GB-12 was located.

Source: Sacred Lotus sources & references (needling record, retained unchanged, and the recorded angles across GB-08 to GB-12 compared; every needling record queried and the nine arterial cautions counted; the BL-09, DU-16, GB-19 and GB-20 records queried and their cautions attributed to those points), cross-referenced against multiple online sources; regional anatomy from standard anatomical description.

Is there research on GB-12, and what should a reader know?

No trial isolates GB-12. Where the point appears it is one component of a headache, insomnia or facial-paralysis protocol, and a study that includes a point in a protocol is not evidence about that point.

Its neighbour below is one of the most-used points in acupuncture. GB-20 Feng Chi appears in most headache, neck and dizziness protocols, and much of the literature a reader finds near GB-12 is really about GB-20. Evidence about GB-20 is evidence about GB-20 — and since the two sit on opposite sides of a real anatomical boundary, the distinction matters more here than usual.

What this page can state with confidence. GB-12 sits in the hollow behind the mastoid — one of the firmest landmarks on the head, which is why three other records in this library measure from it: GB-10 and GB-11 along the curve it anchors, and SJ-16 one cun below. It has the longest indication list of the five points behind and above the ear. Its recorded angle is oblique where the four points above it are subcutaneous — the one angle change in that run, tracking the point coming off the flat of the skull onto a bony prominence. And its action and indications agree: it calms the spirit, and insomnia is recorded.

The facial-deviation warning is the operative content on this page. A new facial droop needs same-day assessment — stroke is an emergency where speed changes outcomes, and Bell’s palsy responds better to early treatment. No acupuncture claim is made.

A note on searching for it. “GB 12”, “G 12” and “Wangu” searches return protocol trials, the Small Intestine point of the same name on the hand, and unrelated material. “Wan Gu” is one of eight names in this library belonging to two different points — search on the code. Any claim attached to this point should be checked against which Wan Gu a study actually used.

Source: Sacred Lotus sources & references (action, indication, location and needling records; every pinyin value audited for duplicates, the GB-08 to GB-12 angles and lists compared, and the GB-10, GB-11, SI-04 and SJ-16 records queried, against our own data).