OpenWide — active brief

CONFIDENTIAL — pre-IP. Private use only. Personal R&D for Devin's son. NOT a commercial product. No sales, no distribution, no marketing. No public-remote pushes, no third-party uploads, no social mentions. IP optionality preserved via dated invention log in case scope ever expands.

Read first. Source of truth for "what is OpenWide right now." Cross-refs: projects/openwide.yaml (config), decisions/2026-06-02-openwide-conception.md (conception ADR), deliverables/LEGAL-openwide_invention_log_v1.0_2026-06-02.md (invention log).

One-liner

A toothbrush engineered for users who cannot open their mouth normally (clinical term: trismus). Cleans posterior teeth without requiring vertical clearance to angle the brush. Initial target: pediatric user with ~½" max opening at the front teeth.

Origin

Personal caregiving need — Devin's 3-year-old son: TMJ-related limited opening, ~½" front-teeth clearance only, poor access for standard brushes → high caries risk that is also hard to treat conventionally. Moved off cloud chat into local FounderOS to protect concept pre-filing.

Target user & problem

• Primary: young child / anyone with trismus or severely limited mouth opening (special-needs, post-surgical, TMJ disorders).
• Problem: standard brush heads can't reach posterior teeth through a small opening; poor cleaning → cavities; conventional drill-and-fill also hard when mouth won't open.
• Goal: effective daily plaque removal (esp. molars) with a tool a caregiver can operate.

Core design insight

The jaw is a lever pivoting at the TMJ → opening is widest at the front incisors, narrowest at the back molars. Binding constraint is vertical clearance, not width.

Design rules: - Head thin top-to-bottom (flat-paddle or curved-bristle profile, not a chunky block). - Cleaning element works without angling the brush (angling consumes vertical room he doesn't have) → curved/wrap-around bristles OR bristles on broad faces of a thin blade. - Neck geometry keeps the handle outside the mouth — steep bend / bayonet offset; only the slim head enters. - Bite-safe, soft, food/medical-grade materials, no detachable small parts (choking hazard).

Competitive scan (don't reinvent these)

Product	What it is	Fit for sub-½" opening
Collis Curve Baby (~$10–15)	Curved 3-sided bristles, no angling needed; baby head ≈ ¾"L × ~¼–⅓"W	Closest existing analog — fits in ½" gap
End-tuft / single-tuft (GUM, TePe, ~$5–8)	Tiny conical head, marketed for limited opening	Great spot tool; slow whole-mouth
Three-sided / U-shaped whole-mouth brushes	Bulkier heads	Harder to seat at molars through small opening

The gap we'd fill: purpose-built low-profile, bent-neck, no-angle-required brush sized for a sub-½" opening, marketed specifically for trismus / pediatric limited opening. Nothing is squarely aimed at this.

Concept direction — LOCKED 2026-06-02

Head geometry: E. Wedge paddle. 2D taper — thick at incisor side, thin at molar tip. Bristles on top + bottom broad faces clean upper and lower molars in a single pass. Geometry exploits the jaw-opening wedge (widest at incisors, narrowest at TMJ) rather than fighting it. No angling required.

Bristle medium: silicone / rubber. Bite-safe, soft, mouldable in one shot with the head — sidesteps tufting (the hard manufacturing step). Weaker on plaque than nylon, acceptable trade-off for a kid / special-needs caregiver tool. Matches the original "rubber safe end" framing.

Operation: manual, caregiver-driven. No electronics, no detachable small parts, no choking risk. Right for Tier-1 and Tier-2. Powered rotation deferred to Tier-3 (if ever).

Rejected this round (do not revisit without new info): F (360° cone), nylon tufts, hybrid silicone+nylon, powered rotation, parallel E+F branches.

Earlier candidates A/B/C/D from the original brief are subsumed by E (A's bayonet neck + paddle head and B's curved bristles inform the wedge geometry; C's malleable neck and D's snap-in tuft are off the table).

Development path — pursue cheapest first

• Tier 1 (weekend, ~$20): heat-bend an end-tuft / kids brush neck, trim head profile, in-mouth test, document what works as the spec. → see deliverables/OPS-openwide_tier1_test_protocol_v1.0_2026-06-02.md (PENDING).
• Tier 2 (1–3 wks, ~$50–150): parametric CAD → print handle (food-grade resin / PETG, fit/shape prototypes only) → bristles are the hard part: silicone (bite-safe, weaker on plaque), harvested commercial tufts, or snap-in tuft (concept D). Iterate.
• Tier 3 (months, $10k–50k+): injection-molded PP handle + industrial tufting via private-label contract manufacturer. Gate: only if Tier 2 validates AND demand is real.

Regulatory & IP (verify; not legal/regulatory advice)

• FDA: Manual toothbrush = Class I medical device, generally 510(k)-exempt; selling would require establishment registration, device listing, labeling/general controls, oral-contact biocompatible materials. Not applicable while scope = private use only. Re-engage a regulatory consultant only if scope ever expands to distribution.
• IP optionality: Provisional patent (~$70–300 self-filed) holds priority for 12 months. Current scope is private use, so no rush to file — but the invention log carries today's conception date in case future-Devin wants to commercialize. Conception logged 2026-06-02 (this file = entry #0; deliverables/LEGAL-openwide_invention_log_v1.0_2026-06-02.md = entry #1).
• Filing trigger: if Tier-1 in-mouth test works AND Devin decides to expand scope beyond private use → file provisional within 1–2 weeks.

Current priority

1. Tier-1 test on Devin's son — bend a store-bought end-tuft brush, verify the wedge-geometry insight works in his mouth. Result decides whether to print a Tier-2 prototype.
2. Print Tier-2 wedge-paddle prototype in food-grade resin/PETG with silicone bristles, iterate. Personal use.
3. Keep invention log current — every material design tweak or test result gets a dated entry. Cheap insurance for IP optionality.

Open questions (for Devin)

• Handle grip preference: slim pen-grip vs chunky palm-grip (caregiver-operated)?
• Overall brush length target?
• Is "OpenWide" an acceptable working name, or use a codename until filing? (slug locked = openwide)

Closed 2026-06-02: head geometry (E wedge paddle) · bristle medium (silicone) · operation (manual) · provisional-patent timing (after Tier-1 in-mouth validation).

Confidentiality rules

• No public-remote pushes referencing OpenWide concept (FounderOS origin is private — safe).
• No social / marketing mentions, period — current scope is private use.
• No third-party uploads (diagram tools, pastebins, gists) — even if "deleted," they may be cached/indexed.
• Treat all files in this vertical as pre-IP confidential.

Do NOT

• Push to any public remote.
• Reference OpenWide in StampReady / KindredPics marketing copy or external comms.
• Use AI tools that send prompts to public-facing services without scrubbing IP detail.
• Treat this as a commercial product roadmap — current scope is private use for Devin's son. Re-scope decision goes through a new ADR.
• Claim "ready to file" without an attorney consultation — invention log is preparation, not legal advice.