US 5460524

Summary: US Patent 5,460,524 (US5460524A)

Search note

I searched for the specific patent number 5460524 (and its printed form 5,460,524) across USPTO-adjacent sources (Google Patents, Justia, FreePatentsOnline, and the USPTO PDF image copy). No CAFC 2026 docket entries referencing this patent were found — my searches for CAFC 2026 appeals citing this patent number returned no results. This is consistent with the patent's legal status: it lapsed in 2003 for failure to pay maintenance fees and is expired. I have no authoritative information indicating any 2026 CAFC or USPTO proceeding involving this patent, and I did not locate a USPTO Patent Center docket for it.

Bibliographic data

Abstract (paraphrased from the patent)

A dental device for removing saliva and retracting the tongue comprising a retraction unit (22) having a tongue shield (28). A bite handle (30) is connected to the tongue shield (28) to stabilize the unit (22), and is held between the biting teeth. At least one tube holder (36) is secured to the tongue shield (28) adjacent to a rearmost molar tooth, and a suction tube (24) is attached to each tube holder (36). A Y-tube adapter (26) may be used to connect two suction tubes (24) with a single conventional fitting of the operatory suction system. A method for removing saliva and retracting the tongue within an oral cavity includes retraction with a tongue shield (28), stabilizing the tongue shield (28) with a bite handle (30), and removing saliva along a tube holder (36) secured to the tongue shield (28) adjacent to a rearmolar molar tooth.

Independent claims — plain-language overview

The patent has 20 claims. The independent claims are claims 1, 5, and 7 (claims 2–4 depend from claim 1; claim 6 depends from claim 5; claims 8–20 depend from claim 7).

Claim 1 (apparatus). A saliva-removal dental device that retracts both tongue and cheek, having:

• a generally U-shaped tongue shield (with internal surface, external surface, and first and second rear ends) forming a wall between the tongue and the teeth to hold the tongue back;
• a bite handle attached to the shield's external surface forward of the first rear end, projecting outward so it can be clenched between the teeth, stabilizing the shield;
• a tube holder secured near the first rear end, extending outward so it sits behind the rearmost molar when in place;
• a suction tube (anterior end, posterior end, tube wall) whose posterior end attaches to the tube holder, drawing saliva from the holder region and also retracting the cheek; and
• at least one reinforcement (e.g., a wire) carried within the tube wall giving the tube enough stiffness to hold the cheek away.

Claim 5 (method). A method of saliva removal and tongue/cheek retraction away from the molars, comprising:

• (a) retracting the tongue with a generally U-shaped tongue shield;
• (b) stabilizing the shield with a bite handle (attached forward of the first rear end) held between the teeth;
• (c) removing saliva via a suction tube positioned at a tube holder secured near the first rear end, behind the rearmost molar; and
• (d) retracting the cheek with the suction tube, whose wall carries a reinforcement giving the tube enough sturdiness to retract the cheek.

Claim 7 (apparatus, broader functional combination). A dental device for saliva removal, for increasing tooth access by propping the teeth open, and for retracting the tongue and cheek, comprising:

• (a) a retraction unit having (i) the U-shaped tongue shield with internal/external surfaces and first/second rear ends, (ii) a bite handle forward of the first rear end that projects outward and is engaged by the teeth — serving both to stabilize the shield and to prop the teeth open, and (iii) at least one tube holder near the first rear end, projecting outward and sitting behind the rearmost molar;
• (b) a suction tube (with tube wall) connected to the tube holder for saliva removal and cheek retraction; and
• (c) a reinforcement inside the tube wall giving the tube sufficient sturdiness to retract the cheek.

Notable dependent-claim features (claims 2–4, 6, 8–20)

• A bilateral/full-arch version with a second tube holder, second suction tube, and a Y-tube adapter joining both tubes to a single operatory fitting (claim 2), optionally with concentric high-volume and low-volume attachments for compatibility with both standard fitting sizes (claim 3).
• A stabilizing shelf on the shield's internal surface (claim 4); a method step of propping the teeth open with the bite handle (claim 6).
• Removable/reattachable bite handle (claim 8); detachable tongue-shield subunits for packaging (claim 9); a separate cheek-retractor means (claim 10); reinforcement as a ductile wire (claim 11); plastic construction (claim 12); internal (claim 13) or external (claim 14) tube-holder attachment; notched bite handle (claim 15); asymmetric (claim 16) or symmetric (claim 17) shield; anterior vs. posterior bite engagement (claims 18–19); and an extension arm for lateral tube positioning (claim 20).

Uncertainty disclosure

The bibliographic data above is corroborated by the Google Patents record (fetched 2026-09-06), Justia, FreePatentsOnline, and the USPTO PDF at patentimages.storage.googleapis.com/90/ff/25/1510989f87512c/US5460524.pdf. I did not directly query the USPTO Patent Center or the CAFC docket database in this session; my "no CAFC 2026 docket" conclusion is based solely on web searches returning no results and on the patent's expired status, so I cannot rule out the existence of an unindexed or non-public proceeding with complete certainty.

I'll search for litigation involving US Patent 5,460,524 across available sources.

The initial results reference different patents (e.g., a tire-pressure '524 patent and others) — not the dental-device patent at issue. I'll search more precisely.

I've confirmed the patent identity (Ross W. Anderson's dental saliva-suction/tongue-retractor device). Now let me check litigation-specific databases directly.

Based on my searches of the available sources, I have no evidence of any litigation involving US Patent 5,460,524 (the Ross W. Anderson dental device for saliva suction with tongue retractor and bite handle).

Findings

No known litigation identified. I searched for the specific patent number and related identifiers ("5,460,524", "US5460524", "5460524") and found no district-court complaints, IPR/PGR proceedings, CAFC appeals, or PTAB actions naming this patent.

Important — results for similar numbers are unrelated. Several search hits referenced a "'524 patent," but those were different patents and must not be conflated:

• US 5,602,524 — a tire-pressure monitoring patent involved in Wasica Finance GmbH v. Continental Automotive Systems, Inc. (IPR2014-00295, IPR2014-00476, CAFC appeal decided April 4, 2017). Not the dental patent.
• Various other "'524" patents (e.g., a Nuance transcription patent, a Dialight LED patent) also surfaced, none of which is US 5,460,524.

Context supporting the absence of litigation. The patent's USPTO legal-event history (as shown on the Google Patents record) indicates:

• Filed June 24, 1994; granted October 24, 1995;
• Maintenance fee paid in 1998 (year 4);
• Lapsed October 24, 2003 for failure to pay maintenance fees ("LAPS – Lapse for failure to pay maintenance fees"; "PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362"); status: Expired – Fee Related.

The patent expired roughly two decades ago, which is consistent with the absence of any reported litigation.

Caveat

My search coverage was limited to general web/litigation-index searches (including Unified Patents-style sources attempted). I did not exhaustively search every PACER jurisdiction or paywalled docket services (Docket Navigator, RPX, Lexis/ Westlaw litigation tabs). If you need a definitive clearance statement, I recommend a formal docket search (PACER) across all district courts plus the PTAB and CAFC dockets for the exact patent number "5,460,524."

Bottom line: Based on the available information, there is no known litigation involving US Patent 5,460,524 as of the current date.

The initial searches returned no relevant hits — one empty result, one unrelated pharma IPR (IPR2025-00464 on patent 8,895,546). Let me verify further against USPTO and CAFC sources.

Proceedings overview

Total AIA trial proceedings (IPR/PGR/CBM): 0 — zero active, zero with claims invalidated, zero with claims sustained, zero settled, zero institution-denied. The USPTO Open Data Portal (canonical structured data) returns no AIA trial proceedings for US 5,460,524 as of the most recent ingest, and independent web searches confirmed no PTAB docket, PTAB decision, or Federal Circuit appeal referencing this patent. Defensive posture bottom line: this patent has never been through a single AIA trial — but it has been expired since 2003, so no proceeding was ever needed; the patent is unenforceable for any post-expiration conduct, and an IPR-based attack is unnecessary (and untimely) when expiration alone is a complete defense.

Proceedings

No proceedings to report. There are no IPR, PGR, or CBM cases against US 5,460,524.

Per the operating rules, I will not fabricate proceeding numbers, judge panels, grounds, or decisions. The structured USPTO ODP data block included in this prompt — which is the canonical list — contains no AIA trial proceedings. Web searches for "5,460,524" inter partes review, "US5460524" IPR, and site-restricted USPTO/PTAB queries all returned either empty results or unrelated matters (e.g., IPR2025-00464 concerns patent 8,895,546; a Japanese patent numbered 5460524 is an unrelated digital-receiver patent; a Supreme Court cert petition in Tehrani references an "Anderson" prior-art paper in a ventilation case — not this dental patent).

That absence is not a coincidence; it is structural:

• The patent expired before AIA trials existed. US 5,460,524 lapsed 2003-10-24 for failure to pay maintenance fees (USPTO legal events: "LAPS – Lapse for failure to pay maintenance fees"; "PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362"). AIA review proceedings (IPR/PGR/CBM) only became available on 2012-09-16 — nine years after this patent was already dead.
• An IPR petition on an expired patent is only viable where a petitioner faces an actual infringement controversy (e.g., a pending suit seeking pre-expiration damages). The separate litigation review found no district-court actions naming this patent, so no such controversy ever materialized.

Strategic summary

Claim status: all 20 claims (1–20) are UNTESTED in any AIA trial — and equally, all are unenforceable. No PTAB panel has ever canceled, sustained, or construed a single claim of US 5,460,524. The claims are also unenforceable in district court as a matter of law for any act after the patent lapsed in 2003. The only theoretical exposure would be pre-2003 damages in a long-since-barred suit — the statute of limitations and laches foreclose any realistic assertion today.

Estoppel landscape (§ 315(e)(2)): irrelevant, but note the asymmetry. No petitioner exists, so no § 315(e)(2) estoppel has attached to anyone. That said, a defendant does not need a § 102/§ 103 defense at all: the patent's expiration is a complete, non-invalidity defense to infringement (35 U.S.C. § 271 ends at expiration; no remedy lies for post-expiration practice). If a would-be plaintiff is threatening suit over an expired patent, the correct response is not an IPR — it's a declaratory-judgment action or a motion to dismiss asserting no post-expiration liability, plus a hard look at Rule 11 / fee-shifting exposure for the demand letter.

Pattern signals: none. No petitioner has filed multiple IPRs; no defensive aggregator (e.g., Unified Patents) appears in any chain; the patent owner (individual inventor Ross W. Anderson) never pursued PTAB proceedings because there were none to defend. Notably, the inventor's later family of dental dry-field patents (e.g., US 7,785,105, and the related applications US 2004/0101804, US 2005/0074720, US 2007/0148619) cites US 5,460,524 as its own prior art — the inventor built on, rather than enforced, this patent.

Recommended next steps

1. Do not file an IPR. The statutory bar and the complete expiration defense make a PTAB petition wasted spend. The USPTO ODP confirms zero proceedings; there is no FWD to cite and no claim-narrowing to exploit.
2. If you are a defendant facing a demand letter or suit citing US 5,460,524: respond that the patent expired 2003-10-24 (USPTO legal-event record: LAPS/FP — lapsed for nonpayment of maintenance fees; status "Expired – Fee Related"). No cause of action can reach your current or past-recent conduct. If suit is filed, move to dismiss under Fed. R. Civ. P. 12(b)(6) on the ground that the patent is expired, and consider seeking fees under 35 U.S.C. § 285 if the assertion is objectively baseless.
3. Watch for the real risk — a different, live patent. Anderson and related entities hold later, unexpired dental dry-field patents (e.g., US 7,785,105, issued 2010-08-31 and still within its term, plus continuation family members listed in the "Cited By" record such as US 2004/0101804 A1, US 2005/0074720 A1, US 2007/0148619 A1, and Dryshield/Solmetex family members like US 9,788,924 and US 11,589,970). If a demand letter cites US 5,460,524, it may be a decoy or a mistaken cite — check whether the asserted product is actually accused under one of the later, live Anderson-family patents, and run a fresh PTAB ODP and PACER search on those numbers if so.
4. If you want a definitive clearance record: the absence of PTAB activity is already documented via the ODP ingest cited here; for completeness, a formal PACER search across all district courts for the exact patent number "5,460,524" plus assignee "Anderson" will memorialize the no-litigation position. Expect it to confirm what the maintenance-fee lapse already tells you: this patent has been commercially dead for over two decades.

Based on the searches available in this session (which did not include a direct, successful query of the USPTO Assignment Center live database — I was rate-limited before I could load reel/frame results), the following reconstruction is built from Google Patents legal-event data, patent-front-page data, and the inventor's later patent family. Where I could not verify a record directly, I say so rather than fabricate reel/frame entries.

Inventors

• Ross W. Anderson — sole named inventor. His employer at the time of filing (June 24, 1994) is not determinable from the patent record; the patent issued with no corporate assignee. Later filings by the same person (Ross William Anderson, of 6287 Mercedes La., Plymouth, MI 48170, per the front page of USD564658) were made in his own name as an individual, which is consistent with an independent dentist/clinical inventor rather than an employee-inventor of a corporate assignee. No "all inventors departed the assignee" pattern is present — there was no corporate assignee to depart.

Original assignee

• None (individual ownership). Google Patents lists the "Original Assignee" as Individual, and the patent's front page shows no corporate assignee (no (73) entity). There is no evidence that any company shipped a product embodying the claims during the patent's life; the inventor continued developing the concept personally, filing related applications (US 2004/0101804, US 2005/0074720, US 2007/0148619, and US 7,785,105 B2, all titled "Apparatus for Maintaining a Dry Field During Dental Procedures") in his own name through the 2000s. The patent lapsed October 24, 2003 for failure to pay maintenance fees (USPTO legal-event codes: LAPS; "PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362"); status is Expired – Fee Related. The original owner's chain therefore ended by simple expiration, not by sale or bankruptcy.

Assignment timeline

• No recorded assignments located. Searches for the patent number, the application number (08/264,903), and the inventor's name surfaced no recorded conveyances — no execution dates, recording dates, or reel/frame numbers are available to report. Google Patents' legal-event history for US 5,460,524 shows only prosecution/maintenance events (filing 1994-06-24; grant 1995-10-24; maintenance fee paid 1998; lapse 2003-10-24) and no assignment events. Because the patent issued to the inventor as an individual and his later continuation family remained in his own name, the absence of recorded assignments is consistent with the original owner (the individual inventor) holding the patent until expiry.

Caveat: I could not complete a direct query of assignmentcenter.uspto.gov / assignment.uspto.gov within this session's step limit. If a definitive clearance statement is required, verify by searching the USPTO Assignment Center by patent number 5460524 (verification link: https://assignmentcenter.uspto.gov/). Based on all secondary evidence, I expect that search to return no records.

Timeline diagram

timeline
    title Ownership of US 5460524
    1994 : Filed by Ross W Anderson as individual
    1995 : Patent issued to inventor
    1998 : Maintenance fee paid year four
    2003 : Patent lapsed fee not paid
    2003 : Expired fee related status

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No transfer to any LLC, "IP Holdings," licensing entity, or registered-agent address exists in any record located. The patent never left the individual inventor.
2. Known asserter in the chain — not present. No Acacia, Marathon, IV, Wi-LAN, Conversant, or any Unified Patents/RPX-listed entity appears anywhere in the chain (there is no chain to appear in).
3. Repeat correspondent across the chain — not present. With zero recorded conveyances, there is no correspondent of record on any assignment to analyze.
4. Cascading transfers — not present. No consecutive chained assignments exist.
5. Pre-litigation transfer — not present. The prior litigation analysis found no infringement suits naming this patent, and there are no assignments of any kind, let alone transfers timed within six months of a complaint.
6. Bankruptcy fire-sale — not present. The owner was an individual; the patent expired by non-payment of maintenance fees, not through any bankruptcy proceeding.
7. Privateering — not present. No operating company transferred rights to an NPE; there is no evidence of any SEC disclosure or EFF/Patent Progress coverage to that effect.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at expiration.

Additional affirmative signal against NPE activity: the owner allowed the patent to lapse in 2003 for non-payment of maintenance fees (USPTO legal events, LAPS dated 2003-10-24). An expired, unmaintained patent has no assertion value, which is strongly inconsistent with any NPE acquisition or monetization intent.

Verdict

Insufficient data (no recorded assignments located; the patent issued to the inventor as an individual and expired in 2003).

The absence of any recorded assignment, combined with the inventor-owned continuation family and the patent's lapse for unpaid maintenance fees in 2003, points to a straightforward individual-inventor history with no NPE involvement — but because I could not complete a live USPTO Assignment Center query this session (rate-limited), I cannot certify the assignment record with the reel/frame specificity this analysis normally requires. Verify at https://assignmentcenter.uspto.gov/ (search patent number 5460524) to confirm the expected empty result.

I'll verify the patent at USPTO and examine each cited reference. Let me run targeted searches.

Let me verify the content of the individual cited references.

Let me verify the remaining cited references.

§ 102 Anticipation Analysis — US 5,460,524 (Anderson)

A. Search verification of the target patent

I searched specifically for 5460524 / 5,460,524 and did not return results for similar numbers. The citation set below is the "Patent Citations (8)" plus "Non-Patent Citations" block of the '524 record — i.e., the references actually cited of record against this patent. I did not substitute any other "'524" patent.

Distinction worth flagging (consistent with the earlier sections): the '524 background text discusses only six of the eight cited patents (Cofresi, Nelson, Diamond, Dyfvermark, Hickham, Duggan). The two remaining examiner-cited references — Reichley (4,215,984) and Neil (4,260,378) — appear in the citation table but are not discussed in the specification. These are exactly the two whose full texts I could not fully retrieve in this session, and I say so below rather than characterize them beyond the title/field data.

B. Legal framework (controlling version)

Because the application was filed 1994-06-24, the pre-AIA version of 35 U.S.C. § 102 governs (§ 3(n)(1) of the AIA; AIA § 102 applies only to applications filed on or after 2013-03-16).

• § 102(b) critical date: 1993-06-24. Every reference below was published/issued before that date, so all nine items are § 102(b) prior art.
• Consequently, each is available both for anticipation (§ 102) and for obviousness (§ 103). This is why the examiner's rejections in this family were combination-based.
• Anticipation test: a single reference must disclose each and every element of the claim, arranged as in the claim, and enable it. Net MoneyIN v. VeriSign, 545 F.3d 1359 (Fed. Cir. 2008). A dependent claim can only be anticipated if the independent claim it depends from is also anticipated, because it incorporates all of that claim's limitations (35 U.S.C. § 112(d)).
• Many limitations here are functional/means-plus-function ("reinforcement means ... for providing said tube with sufficient strength to retract the cheek," claim 1). For § 102 the reference must disclose the corresponding structure (spec discloses a ductile wire 48 embedded in the tube wall; claimed structurally in claim 11).

C. The cited prior-art set at a glance

Hickham date note: the '524 record's citation table lists Hickham's priority date as 1985-11-25; independent records for US 5,037,298 show the granted application as app. 07/071,488, filed 1987-07-09, granted 1991-08-06 — i.e., a later filing claiming the 1985 priority. Either date is well before the 1993-06-24 critical date, so the discrepancy does not affect § 102 status.

D. Reference-by-reference: citation, date, description, § 102 mapping

1. US 3,049,806 — Cofresi, "Multiple Saliva Ejector"

• Full citation: U.S. Patent No. 3,049,806, R. Cofresi, "Multiple Saliva Ejector," filed 1959-10-09, issued 1962-08-21.
• Description (per '524 background, which the applicant adopts): a device for suctioning saliva from the oral cavity having a tubular member with inlet orifices on both sides of a set of teeth and an adjustable brace serving as a tongue depressor.
• § 102 potential: No claim is anticipated. It lacks the U-shaped tongue shield, the external bite handle engaged between the teeth, the tube holder located rearward of a rearmost molar, and the in-tube-wall reinforcement.
• Best element mapping: claim 2 (bilateral/multiple suction across the arch) and claim 1(d) generically (suction while a tongue-depressing structure is present). Relevance is essentially § 103.

2. US 4,215,984 — Reichley, "Dental Suction Device"

• Full citation: U.S. Patent No. 4,215,984, J. P. Reichley, "Dental Suction Device," filed 1979-01-15, issued 1980-08-05.
• Description: Not independently verified in this session. The only corroboration I obtained is a cross-listing in US 4,802,851 (Rhoades), which classifies 4,215,984 in Class 433/93 (mouth prop, tongue guard/depressor, or cheek spreader). It is cited of record in the '524 citation table but is not discussed anywhere in the '524 specification.
• § 102 potential: Not determinable from the evidence gathered. I decline to assert a claim-level § 102 map for a reference whose disclosure I could not read. It is at most a field-corroborating reference for the suction-retractor architecture (claims 1, 7).

3. US 4,259,067 — Nelson, "Combined Saliva Ejector, Tongue Retractor and Throat Protector" ★ key reference for the tube reinforcement

• Full citation: U.S. Patent No. 4,259,067, D. P. Nelson, "Combined Saliva Ejector, Tongue Retractor and Throat Protector," filed 1977-10-25, issued 1981-03-31.
• Description (verified from the patent text): a dental device placed vertically between the teeth and tongue comprising (i) a shield member disposed between the patient's teeth and tongue that "shields and retracts the tongue"; (ii) a frame means that "compressively engage[s] the roof and floor of the mouth"; (iii) a saliva-collecting tube with apertures affixed along the lingual edge, ejecting through an end opening; and, critically, (iv) "the wire is disposed within the saliva and debris ejection tube" and provides "structural rigidity" to the material. The frame "also assists in holding the patient's mouth open." The device is described as low-cost and disposable.
• § 102 potential — element-level, and it is the strongest single-reference hit on one element:
  • Claim 1(e) ("at least one reinforcement means carried within said tube wall of said suction tube") — disclosed. Nelson's wire 46 is received within tube 30.
  • Claim 5(d) and claim 7(c) (same reinforcement-in-tube-wall limitation) — disclosed.
  • Claim 11 ("said reinforcement is a ductile wire") — disclosed (a wire in the ejection tube).
  • BUT: Nelson lacks the bite handle on the external surface engaged between the teeth, the U-shaped tongue shield with first/second rear ends, the tube holder located rearward of a rearmost molar, and any express cheek retraction by the suction tube. Nelson's mouth-opening assist is achieved by the frame biasing against the palate and floor of the mouth, not by a bite handle. Accordingly, no claim of the '524 patent is fully anticipated by Nelson alone — every claim containing the reinforcement element also requires the bite-handle and rearmost-molar tube-holder elements that Nelson does not disclose.

4. US 4,260,378 — Neil (recorded as "Neil, Robert J. O."), "Self Stabilizing Intra-Oral Saliva Evacuator"

• Full citation: U.S. Patent No. 4,260,378, R. J. O. Neil, "Self Stabilizing Intra-Oral Saliva Evacuator," filed 1979-06-01, issued 1981-04-07.
• Name variant to note: the '524 citation table renders the inventor as "Neil Robert J O." An independent listing (US 4,802,851) renders the same number as "O'Neil." I am reporting both as found and am not auto-correcting either.
• Description: Not independently verified in this session. It is cited of record (Class 433/93 field, per the cross-listing) but not discussed in the '524 specification.
• § 102 potential: Not determinable. Its title ("Self Stabilizing ... Saliva Evacuator") suggests relevance to the "stabilizing ... against the tongue" functional language of claims 1/5/7, but I will not assert anticipation without reading the disclosure.

5. US 4,511,329 — Diamond, "Moisture Controlling Lingual Dental Mirror"

• Full citation: U.S. Patent No. 4,511,329, M. K. Diamond, "Moisture Controlling Lingual Dental Mirror," filed 1984-01-26, issued 1985-04-16.
• Date discrepancy to flag (do not auto-correct): the '524 specification text states this patent "was issued Aug. 16, 1985," while the '524 citation table (and the patent itself) show 1985-04-16. Every element of the reference predates the critical date under either date, but the internal inconsistency is worth recording.
• Description: a dental instrument for viewing the lingual (inside) surface of the teeth, providing saliva suction, and serving as a tongue retractor.
• § 102 potential: No claim is anticipated. It has no bite handle, no rearmost-molar tube holder with shield, and no in-tube-wall reinforcement.
• Best element mapping: claim 1(a)/5(a) — the settled idea of combining tongue retraction with suction. § 103 only. (The '524 specification itself notes Diamond's bite block "directly obstructs access to the molars.")

6. US 4,975,057 — Dyfvermark, "Dental Appliance"

• Full citation: U.S. Patent No. 4,975,057, U. T. Dyfvermark, "Dental Appliance," filed 1988-02-19, issued 1990-12-04.
• Description (per '524 background): a bite block appliance with an aperture serving as an evacuation nozzle for saliva suction.
• § 102 potential: No claim is anticipated. Dyfvermark discloses the bite-block/evacuation concept, not a U-shaped tongue shield with a tube holder behind the rearmost molar.
• Best element mapping: claims 1(b), 7(a)(ii) (bite structure propping the teeth) and dependent claim 18 (bite handle engaged between the posterior teeth). § 103 only.

7. US 5,037,298 — Hickham, "Apparatus and Improved Process for Removing Saliva While Retracting Cheeks and Lips" ★ closest overall reference

• Full citation: U.S. Patent No. 5,037,298, J. J. Hickham, "Apparatus and Improved Process for Removing Saliva While Retracting Cheeks and Lips," priority 1985-11-25 (granted application filed 1987-07-09, app. 07/071,488), issued 1991-08-06.
• Description (verified from the patent text and prosecution-style excerpts):
  • A tongue retractor comprising a cross-over plate with first and second tongue shield plates (pivotally secured so the retractor can be formed into a generally V-shape) that border the tongue — i.e., a bilateral arch-shaped shield system.
  • "A pair of saliva ejectors ... is secured to the tongue retractor" at the two retractor ends, and the ejectors "should be positioned behind the last teeth of the lower teeth" — i.e., rearward of the rearmost molar, the exact location claimed in '524 claim 1(c)/7(a)(iii).
  • Cheek and lip retractors connected via retainer arms.
  • Process claim 21: "(a) expanding the cheeks and lips ...; (b) retracting the tongue ...; (c) retaining the tongue ...; and (d) removing saliva along a structural position of said tongue retractor means."
• § 102 potential — no claim is anticipated, but the overlap is substantial and specific:
  • Claim 1(d) ("removing saliva from along a structural position of said tube holder") is foreshadowed almost verbatim by Hickham's claim 21(d) "removing saliva along a structural position of said tongue retractor means"; and claim 1(c) (tube holder rearward of the rearmost molar) is met by Hickham's "behind the last teeth" placement. Claim 1's cheek-retraction function is also present (cheek/lip retractors).
  • However, claim 1 as a whole is not anticipated, because Hickham: (i) has no bite handle on the external surface engaged between the teeth — it stabilizes by resting the retractor on the floor of the mouth with a tongue retainer on top of the tongue; (ii) does not disclose reinforcement carried within the suction-tube wall (its cheek retraction is done by separate retractor arms, not by the tube); and (iii) its shield is described as V-shaped, not the claimed "generally U-shaped" tongue shield.
  • Claim 5: Hickham's claim 21 supplies steps approximating 5(a) and 5(c), but claim 5 requires the bite-handle stabilization step (5(b)) and the reinforced-tube cheek-retraction step (5(d)) — neither is in Hickham. Not anticipated.
  • Claim 7: same analysis; Hickham lacks (a)(ii)'s bite handle and (c)'s in-wall reinforcement. Not anticipated.
  • Claim 10 ("cheek retractor means secured to said retraction unit") is literally disclosed by Hickham's cheek and lip retractor means — but claim 10 depends from claim 7, so it cannot be anticipated unless claim 7 is, which it is not. Hickham is instead the strongest § 103 primary reference for claim 10.

8. US 5,152,686 — Duggan et al., "Dental Appliance" ★ key reference for the bite engagement

• Full citation: U.S. Patent No. 5,152,686, C. Duggan et al., "Dental Appliance," filed 1991-04-25, issued 1992-10-06.
• Description (per '524 background): an appliance for suctioning debris from the oral cavity, including a tongue stabilizer and a removable suction tube secured to a bite block.
• § 102 potential: No claim is anticipated, but Duggan is the best single-reference hit on the bite-handle element. Duggan combines, in one appliance, (i) a bite block engaged by the teeth, (ii) a tongue stabilizer, and (iii) a suction tube. That maps onto claim 1(b) (bite handle engaged between the teeth stabilizing the shield), claim 5(b) (stabilizing step), and claim 7(a)(ii) (bite handle that props the teeth open).
• Why it still does not anticipate: Duggan does not disclose a generally U-shaped tongue shield with first and second rear ends used as the tongue-retracting wall (its tongue element is a stabilizer), does not locate a tube holder rearward of a rearmost molar on such a shield, and does not disclose reinforcement within the suction-tube wall. I was unable to retrieve Duggan's full claim text in this session, so I flag that an unknown (if low) possibility remains that Duggan's removable suction tube is itself a reinforced ejector tube — this is the single most worthwhile full-text check before closing the § 102 question.

9. Non-patent literature — "Denta Pops™ Dry Field Aspirator"

• Full citation: David Kanas, D.D.S., "Denta Pops™ Dry Field Aspirator," Amera Dent Inc. of Nevada, May 1993.
• Status: printed publication cited of record (listed twice in the NPL block); published May 1993, i.e., before the 1993-06-24 § 102(b) critical date.
• Description: a disposable dry-field aspirator product literature. Its evidentiary value on this record is contextual: it shows the market already had disposable dry-field aspirators integrating suction with an isolation mouthpiece — corroborating the '524 specification's own "trend towards sterile and disposable dental devices" (§ 103 context), not an element of any claim.
• § 102 potential: No claim is anticipated on the face of the citation; it is a catalog/literature item without the claimed combination. (A full copy of this NPL was not retrieved this session, so I cannot rule out that its product drawings show additional structure; I make no assertion beyond the citation itself.)

E. Anticipation summary — no claim is fully anticipated by any single reference

F. Bottom line and caveats

1. The most relevant prior art is US 5,037,298 (Hickham) — closest on the tongue shield, the "removing saliva along a structural position" language, the rear-molar suction placement, and cheek retraction.
2. The second and third key references are US 4,259,067 (Nelson) — the only cited reference that discloses a reinforcement (wire) carried within the saliva-ejection tube, which is the '524 claims' distinguishing structural element — and US 5,152,686 (Duggan) — the cited reference that discloses tooth-engaged bite-block stabilization of a combined tongue-stabilizer/suction appliance.
3. No single cited reference anticipates any of claims 1–20. Each independent claim requires, in combination: (i) a U-shaped tongue shield, (ii) an external bite handle engaged between the teeth, (iii) a tube holder rearward of a rearmost molar, and (iv) a suction tube whose wall carries a reinforcement. No reference in the cited set contains all four; Hickham, Nelson, and Duggan each supply a different subset. The examiner-cited art is therefore a § 103 combination set, not a § 102 set — which is consistent with the previously generated obviousness analysis.
4. Caveats I will not paper over:
   • I could not retrieve the full disclosures of US 4,215,984 (Reichley) or US 4,260,378 (Neil) in this session; both are cited of record but are absent from the '524 background narrative. I therefore give no § 102 claim map for them.
   • I could not retrieve US 5,152,686 (Duggan)'s claim text; because Duggan is the reference combining a bite block, a tongue stabilizer, and a suction tube, a full-text read is the highest-value remaining step for a complete § 102 clearance.
   • Two internal inconsistencies in the '524 record are noted but not auto-corrected: Diamond's issue date (spec text "Aug. 16, 1985" vs. record 1985-04-16), and the "Neil"/"O'Neil" inventor-name variant for 4,260,378.
   • Any § 102 conclusion here is academic for enforcement purposes: the patent expired 2003-10-24 for non-payment of maintenance fees and is unenforceable for any post-expiration conduct.

§ 103 Obviousness Analysis — US Patent 5,460,524 (Anderson, "Device and method for saliva suction with tongue retractor and bit handle")

Scope and evidentiary basis

This memorandum evaluates whether the claims of US 5,460,524 would have been obvious under 35 U.S.C. § 103 as of the June 24, 1994 filing date, using only the prior art listed in the "Prior Art" / citations section of the patent record (the eight U.S. patents cited by the examiner and the single non-patent literature item). Where I verified reference content by live search, I ground the analysis in that content; where I could not independently verify details (noted below for Reichley and Neil), I rely only on what the '524 specification itself states about those references and flag the limitation.

Prior-art set under consideration (examiner-cited):

1. US 3,049,806 — Cofresi, "Multiple Saliva Ejector" (1962)
2. US 4,259,067 — Nelson, "Combined Saliva Ejector, Tongue Retractor and Throat Protector" (1981)
3. US 4,215,984 — Reichley, "Dental Suction Device" (1980)
4. US 4,260,378 — Neil, "Self Stabilizing Intra-Oral Saliva Evacuator" (1981)
5. US 4,511,329 — Diamond, "Moisture Controlling Lingual Dental Mirror" (1985)
6. US 4,975,057 — Dyfvermark, "Dental Appliance" (1990)
7. US 5,037,298 — Hickham, "Apparatus and Improved Process for Removing Saliva While Retracting Cheeks and Lips" (1991)
8. US 5,152,686 — Duggan et al., "Dental Appliance" (1992)
9. NPL: David Kanas, D.D.S., "Denta Pops™ Dry Field Aspirator," Amera Dent Inc. of Nevada (May 1993)

I. Legal framework

Obviousness is assessed under the Graham factors: (1) scope and content of the prior art; (2) differences between the prior art and the claims; (3) level of ordinary skill in the art; and (4) objective indicia of non-obviousness. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), confirms that a combination of known elements is obvious when a PHOSITA would have had reason to combine them to achieve a predictable result — "the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results." Motivation may be found in the nature of the problem, the teachings of the references, and the general knowledge of persons skilled in the art; there is no rigid teaching-suggestion-motivation requirement.

Level of ordinary skill (POSITA): A designer of dental suction/isolation devices — e.g., an individual with a dental degree or a B.S./equivalent in mechanical or biomedical engineering plus roughly 2–5 years of experience designing saliva ejectors, retractors, and isolation mouthpieces for operatory suction systems, familiar with the standard low-volume/high-volume (LV/HVE) operatory fittings, disposable-plastic product economics, and infection-control requirements. The field is crowded and incremental; the POSITA's skill level is moderate.

II. Closest prior art — and the differences the claims present

Hickham (5,037,298) is the closest single reference. Verified content (FreePatentsOnline/Justia) shows Hickham discloses:

• A tongue retractor formed of a cross-over plate and first and second tongue shield plates pivotally secured to it — i.e., a bilateral, arch-shaped shield system that, when opened and placed in the mouth, borders and retracts the tongue;
• Two saliva ejectors/conduits, one secured at each of the two tongue-retractor ends, expressly positioned "behind the last teeth of the lower teeth" (i.e., rearward of the rearmost molar — the same location claimed in '524);
• Saliva removal "along a structural position of said tongue retractor means" (Hickham claim 21(d)) — language nearly identical to '524 claim 1's "removing saliva from along a structural position of said tube holder";
• Cheek and lip retractors for expanding the cheeks away from the teeth;
• An explicit objective that "no part of the apparatus [crosses] over the tops of any teeth," preserving access to molar biting surfaces;
• A process claim (claim 21) covering tongue retraction, cheek/lip retraction, saliva removal along the retractor — substantially anticipating the method of '524 claim 5 minus the bite-handle stabilization and the in-tube-wall reinforcement.

Material differences between Hickham and the independent claims:

1. Bite handle (claims 1, 5, 7): Hickham stabilizes the device by resting the tongue retractor on the floor/base of the oral cavity, using a tongue retainer on top of the tongue and separate cheek retractors — no handle engaged between the biting teeth. Claim 1 requires a bite handle on the external surface of the shield, forward of a rear end, engaged between the teeth; claim 7 additionally requires that the handle prop the teeth open.
2. Reinforcement inside the suction-tube wall (claims 1, 5, 7): Hickham's suction conduits are separate from its cheek retractors. No reference in Hickham teaches a wire/ductile reinforcement carried within the tube wall that gives the tube itself enough stiffness to retract the cheek.
3. Y-tube adapter and dual-tube architecture (claim 2) is not expressly in Hickham (which shows two hoses to a suction source without a single Y-connector fitting).

Those gaps are precisely the kind of known, modular elements a POSITA would have supplied from the other cited references.

III. Proposed combinations and motivation to combine

A. Claim 1 (apparatus) — Hickham + Duggan + Nelson (+ conventional wire-reinforced ejector tube)

Motivation to combine: All references address the same recognized problem — maintaining a clear, dry, full-arch operating field without obstructing the molars (Hickham's background describes the identical unmet need; '524's background repeats it). A POSITA reading Hickham would immediately see that its elaborate support system (pivot hinges, tongue retainer, spring-loaded cheek retractors, base-of-mouth resting) is complicated — the very deficiency '524 concedes in the prior art. Duggan teaches a far simpler, proven stabilization mechanism for a combined tongue-stabilizing/suction appliance: the patient's own bite on a toothed engagement surface. Substituting Duggan's bite engagement for Hickham's retainer-and-hinge assembly is a simple substitution of one known element for another to yield the predictable result of a self-retaining device — classic KSR. Likewise, Nelson teaches both (i) a wire running inside the suction tube and (ii) mouth-propping, so the "reinforced tube that props/retains" concept was already in the field. Because Hickham identifies cheek retraction at the rearmolar area as a design goal, giving the suction tube a wire core (Nelson; conventional ejectors) so the tube itself can hold the cheek is the routine application of a known structural feature to a known purpose.

B. Claim 7 (apparatus with teeth-propping function) — same combination; Nelson/Duggan supply the prop

Claim 7 adds only the express function of "propping open the teeth" by the bite handle. That function is taught independently by Duggan (bite block raises/locks the jaw open), Nelson (wire frame "aiding in holding the mouth open"), and Dyfvermark (bite-block appliance). Claim 7's remaining limitations mirror claim 1 and are met by the Hickham + Duggan + Nelson combination for the same reasons. Claim 7 is the broadest apparatus claim and is the most vulnerable to an obviousness challenge.

C. Claim 5 (method) — Hickham's own process claim 21 + obvious modifications

Hickham claim 21 already recites a method of (a) expanding cheeks/lips with retractors, (b) retracting the tongue with a tongue retractor supported by the base of the oral cavity, (c) retaining the tongue with a retainer, and (d) removing saliva "along a structural position of said tongue retractor means." The '524 method claim 5 is this same method with two substitutions: (i) stabilizing the shield with a bite handle engaged between the teeth (taught by Duggan/Nelson/Dyfvermark) in place of Hickham's tongue retainer/base support, and (ii) retracting the cheek with the reinforced suction tube itself (Nelson's wire-in-tube + Hickham's cheek-retraction goal). Each substitution is the known use of a known element for its known function; the method as claimed is the obvious procedural analogue of the obvious apparatus. Claim 6 (propping open the teeth) adds nothing beyond the known function of Duggan's/Nelson's bite-engagement structures.

D. Dependent claims

• Claim 2 (second holder/tube + Y-tube adapter): Hickham discloses two saliva ejectors, one at each retractor end; joining two ejector tubes to a single suction source via a Y-connector is a routine plumbing choice in dental operatory suction. Cofresi (3,049,806) also discloses a tubular ejector with inlet orifices on both sides of the teeth — a bilateral suction concept. Obvious.
• Claim 3 (concentric high-volume/low-volume attachments): Providing a dual-size adapter to fit both standard female fittings (LV and HVE) is a conventional design option for operatory suction accessories; the '524 identifies both fitting sizes as "conventional." (Note: claim 3 depends from claim 1 but references the Y-adapter introduced in claim 2 — a drafting artifact that does not affect the obviousness analysis.)
• Claim 4 (stabilizing shelf on the internal surface): Hickham's tongue guides/retainer already position the device relative to the tongue; a shelf is a simple structural expedient for vertical stabilization. Obvious.
• Claims 8–9 (removable bite handle; detachable shield subunits): Hickham's shield plates are pivotally secured (claim 20), teaching adjustability/disassembly of a multi-part shield; Duggan teaches slideably removable/reattachable components on a bite appliance. Making a handle removable or the shield snap-fit for packaging is a routine manufacturing choice. Obvious.
• Claim 10 (separate cheek-retractor means): Expressly disclosed by Hickham (cheek and lip retractors). If not obvious over Hickham alone, it is at least obvious in combination.
• Claims 11–12 (ductile-wire reinforcement; plastic materials): Nelson discloses wire in the tube; conventional saliva ejectors (which the '524 admits are ubiquitous) use ductile-wire-reinforced plastic tubing. Obvious.
• Claims 13–14 (internal vs. external tube attachment): Hickham attaches conduits at/along the retractor ends (internal-type mounting); external gripping holders are shown in the '524's own alternative embodiment and were conventional. Both alternatives are obvious design selections.
• Claim 15 (notched bite handle): Duggan's raised-area ridges for stable tooth engagement are functionally identical to notches. Obvious.
• Claims 16–17 (asymmetric vs. symmetric shield): Hickham's pivotally adjustable plates permit asymmetric positioning; a symmetric arch shield is the default configuration of Cofresi/Nelson-type arch devices. Both are obvious configurations.
• Claims 18–19 (posterior vs. anterior bite engagement): Duggan/Dyfvermark show posterior bite blocks; a forward/anterior handle is an obvious relocation, and '524 itself discloses both in its embodiments. Obvious.
• Claim 20 (extension arm for lateral tube positioning): Hickham's cheek-retractor arms position structure laterally away from the teeth; an extension arm for lateral tube placement is an obvious mechanical equivalent. Obvious.

E. Additional corroborating references

• Cofresi (3,049,806): adds an early example of an arch-spanning multiple-ejector with a tongue-depressor brace — supporting the combination of tongue control with bilateral suction.
• Diamond (4,511,329): confirms the settled idea of combining tongue retraction with lingual saliva suction in a single intraoral instrument.
• Dyfvermark (4,975,057): confirms the settled idea of combining a bite block (teeth-engagement/mouth-prop) with an evacuation aperture.
• NPL "Denta Pops™ Dry Field Aspirator" (May 1993): demonstrates that, immediately before the filing date, the market already had inexpensive disposable dry-field aspirators integrating suction with a mouthpiece/isolation structure — corroborating that the "simple, single-use" design direction of '524 (its own stated objective) was a known market pressure, not an inventive step.

IV. Secondary considerations (Graham factor 4)

No objective indicia of non-obviousness are evident from the record. There is no showing of commercial success, licensing, copying, or unexpected results. To the contrary, the '524 patent lapsed in October 2003 for failure to pay maintenance fees — consistent with the absence of a demonstrated commercial embodiment — and its own later-family continuation work (e.g., US 7,785,105 to the same inventor) was necessary to pursue the dry-field concept further. The specification's "synergistic effect" rhetoric describes the combined benefits of known elements performing their known functions (tongue retraction, suction at the molars, bite stabilization), which under KSR is not enough to defeat obviousness where the combination is predictable.

V. Conclusion

Claims 1, 5, and 7, and all dependent claims, would likely be held obvious under 35 U.S.C. § 103 over the examiner-cited art. The strongest case is:

• Primary: Hickham (5,037,298) — bilateral tongue shield, suction inlets positioned rearward of the rearmost molars, cheek retraction, saliva removal "along a structural position of" the retractor, and an analogous process claim;
• Gap 1 (bite handle / teeth-prop): Duggan (5,152,686) and/or Nelson (4,259,067) — teeth-engaged stabilization and mouth-propping of a tongue-control/suction appliance;
• Gap 2 (reinforcement within the tube wall): Nelson — a wire frame disposed within the saliva-ejection tube — plus the POSITA's background knowledge of conventional ductile-wire-reinforced saliva-ejector tubing (which the '524 itself concedes).

The POSITA's motivation is grounded in the shared problem acknowledged across the references (a stable, full-arch, dry operating field with clear access to the molars), the known simplicity advantage of bite-stabilization over Hickham's hinged assembly, and the known structural capability of wire-reinforced suction tubing. Each substitution yields a predictable result.

Robustness ranking (most to least vulnerable): Claim 7 > claims 1/5 > dependent claims 2–4, 6, 8–20. Claims 2–3 (bilateral + Y-adapter) and 16–17 (arch symmetry) are the most easily shown obvious given Hickham's bilateral ejectors and pivotable plates.

Confidence caveats: (1) I could not independently verify the full disclosures of Reichley (4,215,984) and Neil (4,260,378) within the search budget; my analysis does not depend on them, but they likely further corroborate conventional dual/self-stabilizing suction architectures. (2) Hickham's shield is described as "generally V-shaped" in its claims; treating it as the "generally U-shaped" shield of the '524 claims relies on the insubstantiality of that shape difference and Hickham's own bilateral-arch function — the stronger argument is combination with Nelson/Cofresi, which use arch-conforming shields. (3) This is a paper analysis of the cited art; a definitive validity opinion would require full-text review of all eight references and the NPL, and would be academic in any event because the patent is expired and long since lapsed (no live enforceability, and any post-grant challenge would be time-barred under 35 U.S.C. § 315(b)).