VOHC Policy on Segementation of Teeth during Scoring in VOHC Trials
This policy is subjrct to public comment until October 31st, 2013.
VOHC Policy on Segmentation of Teeth During Scoring
Use of vertical segmentation will not be accepted in VOHC trials.
Either whole tooth or horizontally segmented tooth surfaces can be used for scoring. Only the scores from the gingival half of the tooth are to be considered in the analysis when horizontal segmentation is used.
The specific VOHC Recommendation is:
Dogs: Score only the gingival half of all of the scored teeth.
Cats: Score only the gingival half of the canine teeth, and the whole surface of all other teeth in the VOHC set.
1. Shape and Size of Teeth of Dogs and Cats-Relevance to Studies of Plaque and Calculus Accumulation. Harvey CE: J Vet Dent 19(4); 186 -195, 2002.
Summary: Crown width, height and buccal surface areas were measured on heads or skulls of four dogs and four cats, and were compared with similar measurements on models of human dentition. Buccal surface area variability was greater in dogs and cats than in humans, and teeth of cats were smaller. Horizontal (gingival and occlusal halves) and vertical (mesial, middle, and distal thirds) buccal surface area variability was also greater in canine and feline teeth compared with human teeth. This increased variability suggests the need for testing of reliability and repeatability of scoring when using plaque and calculus indices based on horizontal or vertical segmentation. Buccal surface area variability between teeth also prompts questioning the validity of equal weighting of smaller, irregularly-shaped teeth when calculating a mean mouth score. Whether equal or more reliable results would be obtained from scores of whole teeth in comparison with segmentation indices used currently has yet to be determined.
2. Evaluation of the Logan and Boyce Plaque Index for the Study of Dental Plaque Accumulation in Dogs. Hennet P, Servet E, Salesse H, Soulard Y: Res Vet Sci, 80, 175-180, 2006.
Summary: The objectives of this study were to assess intra-examiner (experienced examiner) and inter-examiner agreements (experienced versus non-experienced examiners) of scores assessed with the Logan & Boyce plaque index and to evaluate whether a modification of this index, where anatomical landmarks are used for horizontal division [mod L&B-AL] and dye references are used for assessing intensity of dye (plaque thickness) [mod L&B-DR], would improve repeatability. The Logan & Boyce index was found to be inaccurate when scoring plaque coverage as it underestimated the total crown surface. The contribution of the gingival part to the total tooth score was minimized by the Logan & Boyce index compared to the mod L&B-AL/DR. Precision of global plaque scorings was significantly improved by the mod L&B-AL/DR. Intra-examiner agreement of plaque thickness and plaque coverage scorings on the gingival part of the tooth was significantly improved by the mod L&B-AL/DR. Studies evaluating plaque accumulation in dogs should therefore use the mod L&B-AL/DR rather than the Logan & Boyce index.
Brushing Policy for Cats
VOHC Trials Involving Tooth Brushing in Cats
What Brush to Use in Cats:
Because the mouths of cats are too small for use of most standard-sized human tooth brushes, a brush marketed for use in cats can be used.
‘Finger-brushes” (small brushes that are mounted on a cover placed over a finger) are not to be used as the control brush in VOHC trials.
The trial sponsor is to select a small head, soft bristle brush; the selection will be reviewed by VOHC during the required pre-trial protocol review. Once a particular brush has been shown to meet or exceed the VOHC standard in dental effectiveness, this will be adopted as a VOHC ‘control brush’; subsequently, novel brushes can be submitted for VOHC review if trial data show that they are statistically ‘at least as good as’ the VOHC control brush in dental efficacy and provided that the trial demonstrates that the test brush does not injure oral soft tissues.
Brushing Strokes for Cats:
For VOHC trials, the following sequence is to be used, to ensure consistency between trials.
- Conditioning the cats pre-trial to accept brushing is recommended.
- Recommended method for restraining cats while the teeth are brushed: Place the cat on the operators lap with the cat’s hind-quarters facing the abdomen and with your arms acting as gentle ‘side bars’. For a right-handed individual, the palm of the left hand is placed on the top of the head of the cat, with the middle finger and thumb placed on the side of the face to retract the commissures of the lips. This exposes the canine and premolar teeth on each side of the mouth. The little finger of the hand holding the brush can be placed below and between the mandibles to control movement of both jaws. The brush, held in the right hand, is laid against the teeth and stroked horizontally as described below. Initially during the conditioning period, very light brushing pressure is used, increasing the pressure each time until the bristles just start to curve.
- To assist in restraint, and to provide more consistency in the application of the brush, the cat’s mouth is to be gently held closed.
- The brush is to be applied to the surface of the teeth at a 45o angle, with the tips of the bristles pointed towards the gingival tissue of the upper jaw teeth. The head of the brush is to be wide enough so that the lower layers of bristles will brush the teeth in the lower jaw during each horizontal brush stroke.
- The brush is pressed gently against the surface of the teeth during the brush stoke - if the bristles visibly deflect (curve), the pressure applied is too high.
- Three horizontal strokes, each consisting of a back and forth movement across the dental arcade, are made on each side. No attempt is made to brush the interior (palatal or lingual surfaces) of the teeth – in cats, dental plaque and tartar accumulate most rapidly on the buccal surfaces of the teeth.
- Each horizontal stroke is to include the canine and premolar teeth in the upper jaw and canine, premolar and molar teeth in the lower jaw.
Assignment to groups:
Cats will vary in their willingness to allow their teeth to be brushed. A pre-trial conditioning exercise (see above) is recommended to identify as many cats as possible as being ‘willing’ to have their teeth brushed. When the total number of cats potentially available for a brushing study is insufficient to permit only cats willing to have their teeth brushed to be randomly assigned to either brushing and control groups, cats in the ‘willing’ group can be assigned to the brushing group(s) and ‘unwilling’ cats can be assigned to the non-brushed group(s).
Although doing so may increase the number of cats that are ‘willing’ to have their teeth brushed, palatability agents applied to the brush are not to be used in trials designed to test the effectiveness of a brush or similar device, because the palatability agent may predispose to accumulation of plaque.
Pre-trial Screening Examination for Cats in VOHC Trials (This would apply to all VOHC trials using cats)
Cats often have tooth resorption, sometimes in multiple teeth. When this is present and open to the oral environment, gingival inflammation and pain are common. Cats with tooth resorption at the gingival margin are not suitable for VOHC trails because they are likely to be more painful than cats without such lesions.
Cats are to be pre-screened by an awake oral examination consisting of visual inspection of the buccal surfaces of the teeth required to be scored in a VOHC trial (upper C, P3, P4, lower C, P3, P4, M1) - the teeth are not touched with an instrument during the inspection.
Any cats with the following findings are to be excluded from the pool for assignment to one of the trial groups:
1. Severely inflamed gingiva (bright red, rough surfaced, may be spontaneously bleeding) anywhere along the buccal gingival margin of scored teeth.
2. A focused lesion of inflamed gingiva of the sort often associated with an area of tooth resorption at the gingival margin of a particular tooth.
3. Evidence of loss of attachment, seen as exposure of part of the root.
Presence of plaque and tartar on the crown of the teeth is not of itself reason to exclude the cat, as this will be removed during the pre-trial professional dental cleaning procedure.
New Products added to the VOHC Accepted List
Several new products were added to the VOHC Accepted Seal list. They are:
Dog::ESSENTIAL healthymouth Water additive with mobility health formulation (plaque claim).
Dog::ESSENTIAL healthymouth Anti-plaque topical spray (plaque claim).
Cat::ESSENTIAL healthymouth Anti-plaque topical spray (plaque claim).
SANOS Dental sealant, for application to the clean surface of teeth at the end of a professional scaling procedure (plaque and tartar claims).
Supersmile toothpaste for dogs (plaque claim). This product will be launched to the market in 2012 (exact date not know at time of this listing).
Royal Canin Feline Dental Diet (plaque claim). This product will be launched to the market in 2012 (tentative launch date September).
On the unanimous recommendation from Council, the AVDC Board approved a 'VOHC Policy on Trials Involving Use of Brushes or Similar Mechanical Devices'.
Click VOHC Brushing to view the full VOHC brushing policy document.
Three new products have been added to the VOHC Accepted Product list. They are:
Dog::ESSENTIAL healthymouth anti-plaque gel
Cat::ESSENTIAL healthymouth anti-plaque water additive
Cat::ESSENTIAL healthymouth anti-plaque gel
These products are marketed by HealthyMouth, LLC.
Protocol Change: Pre-Trial Protocol Review
VOHC requires pre-trial protocol review, to ensure that trials will be conducted in compliance with VOHC requirements. Pre-trial protocol review is designed to avoid potentially costly mistakes in how VOHC trials are conducted. This policy is in effect for all submissions received after January 1st, 2012. Pre-trial review for submissions received prior to January 1st, 2012 is very strongly encouraged; however, VOHC recognizes that some submissions that it may receive in calendar 2011 may be based on trials that were underway before the pre-trial protocol review requirement was adopted by VOHC. Pre-trial protocol review is provided as a free, confidential service by VOHC. Send the proposed protocol to VOHC@AVDC.org. A response to a request for pre-trial review will be provided by VOHC within two weeks of receiving the request.
Protocol Change: Anesthesia and Intubation During Dental Scaling
To ensure that the required “clean-tooth model” is safely used in trials conducted under the VOHC protocol, animals whose teeth are scaled at day zero of a trial are to be anesthetized and the trachea is to be intubated during the scaling procedure.
Protocol Change: Use of Client-Owned Animals in VOHC Trials
An information/informed consent document (‘Owner document’) is to be signed by the owners before entry of the subject into the trial. A blank copy of the Owner document is to be included in the submission.
The Owner document is to include a requirement that the owners complete a daily compliance log, and copies of the completed owner’s daily compliance logs are to be included in the submission. Out-of-protocol events reported by the owners are to be described and comments by the sponsor on significance of the out-of-protocol events are to be provided in the submission.
Two products that are no longer marketed have been removed from the VOHC Accepted list. They are Friskies Feline Dental Diet and Del Monte Tartar Check Biscuits for Dogs
Change in VOHC Standard
The Board of Directors of the American Veterinary Dental College approved a recommendation from the Veterinary Oral Health Council to change the standard required for awarding the VOHC Accepted Seal.
This change is effective from January 1st, 2011.
Purpose of the Change: Eliminate the difference between the VOHC chemical and non-chemical plaque standards and bring the calculus (tartar) claim standard into line with the plaque claim standard by adopting the current American Dental Association standard, whether the dental effectiveness is achieved mechanically or chemically.
New VOHC standard, as of January 1st, 2011
The VOHC standard for required minimum reduction in plaque and/or calculus in the product group compared with the control group is 15% (minimum in each of the two trials) and 20% (minimum mean of both trials), with each trial having a statistically significant difference between the control and product groups.
Reduction (VOHC efficacy %) is defined as:
([Control group mouth mean] minus [Test group mouth mean]) divided by (Control group mouth mean) x 100
Impact on products that currently carry the VOHC Accepted Seal: Products that currently carry the VOHC Seal but for which the trial data submitted to VOHC do not meet the new standard will grand-fathered (permitted to use the VOHC Accepted Seal) for five years following the date on which the change becomes effective (January 1st, 2011).
Healthymouth, an anti-plaque water additive, has been added to the VOHC accepted list in the Plaque claim category for dogs.
The Board of Directors of AVDC accepted a recommendation from Council to add the following statement to the Safety and Regulatory Issues statement at the bottom of the Protocol page:
'Safety ' in the VOHC context includes:
A. Major extra-oral or body-wide issues such as toxicity, esophageal or gastro-intestinal obstruction or perforation, or gross nutritional imbalance;
B. Trauma to oral tissues, such as fracture of teeth or laceration or penetration of oral mucosa.
Complaints from consumers that relate to any of the product safety issues mentioned above are to be promptly copied to VOHC, and annual confirmation of continuation of use of the VOHC Accepted Seal is contingent on affirmation that no safety complaints that have not already been brought to VOHC's attention have been received by the product sponsor.
VOHC Accepted Seal awarded to Vetradent's Baby Bluechews and dc TinyToy Dental Chews in the Tartar claim category.
VOHC Accepted Seal awarded to Diamond Food's Bright Bites and Checkups Dog Treats, all sizes, in the Plaque and Tartar claim categories.
VOHC Accepted Seal awarded to Canine Greenies Senior and Canine Greenies Lite dog treats, all sizes, in the Plaque and Tartar claim categories.
Dogs do love to chew......
Thurs., Dec. 20, 2007
BOSTON - The World Series ball is gone, and Jonathan Papelbon has an excuse: My dog ate it. Farfetched or not, that’s what the Red Sox closer insists happened to the souvenir from the final out of Boston’s sweep this year. Really, Papelbon blamed it on his bulldog, Boss. “He plays with baseballs like they are his toys,” Papelbon told the Hattiesburg (Miss.) American. “He jumped up one day on the counter and snatched it. He likes rawhide. He tore that thing to pieces. I’ll keep what’s left of it.”
New Canine Greenies Treat is awarded the VOHC Seal of Acceptance for Plaque and Tartar. New Canine Greenies is available in five sizes.
Tartar Shield Soft Rawhide Chews is awarded the VOHC Seal of Acceptance for Tartar. Tartar Shield Chews are available in five sizes.
Feline Greenies has been removed from the VOHC Accepted list because the manufacturers have changed the formulation, and the old formulation is no longer in stock at point-of-purchase.
VOHC Council approved use of the Gingival Contour Plaque Index scoring system ( described by Scherl et al in the March 2007 issue of the Journal of Veterinary Dentistry), provided that the plaque score and calculus score in each dog on day 0 of the trial is zero. In a related item,
VOHC changed the minimum seven day trial period for plaque by adding: unless a scoring method validating a shorter period has been previously approved by Council.
The Canine Greenies formulation that was awarded the VOHC Accepted Seal in 2004 has been withdrawn from the market, and the listing for Canine Greenies has been removed from the VOHC Accepted list.
the recommendation of VOHC Council, the AVDC Board of Directors
has ratified changes in protocols:
wording on use of segments of teeth when scoring.
a safety requirement for chemical agents included as plaque
or tartar inhibitors.
the need for three arm/leg trials when evaluating products
with both mechanical and chemical effects.
specific information on statistical analysis procedures.
changes are incorporated in the documents currently available
on the VOHC web site.
Dog Chews, manufactured by Vetradent Inc. awarded the VOHC Seal
of Acceptance for Plaque and Tartar.
Greenies, manufactured by S&M Nu-Tec, Inc, awarded the VOHC
Seal of Acceptance for Tartar.
Purina PVD (Dental Health) Diets awarded the VOHC Accepted Seal
for Feline Formula (Plaque and Tartar) and Small Bites and Regular
Size Canine Formula (Tartar).
Flavor Infused Oral Chews awarded the VOHC Accepted Seal for
Plaque and Tartar for two sizes: Large Dogs and Small Dogs Sizes.
Edible Treats for Dogs awarded the VOHC Accepted Seal for Plaque
and Tartar for the Teenies size.
Edible Treats for Dogs awarded the VOHC Accepted Seal for Plaque
and Tartar for four sizes: Petite, Regular, Large and Jumbo.
correction was made in the VOHC criteria for testing products
of different size in dogs. Click Product
Line and then scroll down to the Differences in Size of
Product section to read the corrected policy.
is the start of National Pet Dental Health Month in North America
(NPDHM), and to help celebrate this important yearly milestone
in the oral and general health of North American companion animals,
VOHC launched its revised and updated web-site, which now includes
consumer information on periodontal disease in cats
and dogs. To find out more about National Pet Dental Health
Month, click NPDHM.
to the list of Organizations Recognizing VOHC
is also celebrating the recent addition of the American Veterinary
Dental Society and the Academy of Veterinary Dentistry to the
list of dental organizations that endorse the VOHC Seal of Acceptance
system. The VOHC Seal system is now recognized on four continents
(Asia, Australasia, Europe and North America). For a full list
of the organizations who are on-board with VOHC, click World-Wide.
Members rotate off: Two dental scientists
who were critical in establishing the Veterinary Oral Health
Council in 1997 and were original members of the Council have
rotated off the Council.
Drs. John Hefferren and George Stookey brought to the VOHC discussions
and decisions many years of experience in efficacy recognition
from the human dental arena. The immense contributions that
Drs. Hefferren and Stookey made in building credibility and
avoiding pot-holes in VOHC's early years are very much appreciated
by VOHC Director Colin Harvey and by the Board of Directors
of the American Veterinary Dental College, which administers
Members. Recognizing the international reach of the VOHC
system, the Board of Directors of the American Veterinary Dental
College appointed Drs. Marco Gioso (Sao Paulo, Brazil) and Philippe
Hennet (Paris, France) to the Council for three-year terms,
effective January 1, 2004. The Council now consists of ten Diplomates
of the American Veterinary Dental College. For a full list of
Council members and a brief description of what Council members
do, click Council.
in Protocols and Fees
revised web site contains an enlarged and updated series of
documents on VOHC protocols and submission
procedures for companies marketing products that may qualify
to carry the VOHC Seal of Acceptance.
addition to web site changes designed to make the VOHC protocols
and related requirements clearer and easier to access, some changes
in content have been made in the VOHC protocols:
A category for tooth-brushes and similar mechanical aids designed
to be used by pet owners has been added to the protocol document
(see "Mechanical" on the Protocol
The body-weight section of the "Product Line" document
has been revised to make identification of dogs for inclusion
in trials involving defined body weight groups more practical
(see "Differences in Size of Product and in Body Size Classes
of Dogs" on the "Product
The requirement for a separate fee for each claim (plaque
or calculus) has been eliminated. A single fee now is payable
for a submission for either or both claims. Since most past
submissions have included review of trials of products for
both claims, the effect of the revised fee structure is
to maintain or reduce the submission fee for review of plaque
and (tartar) calculus claims for a single product.
Fees for products applied by owners, such as brushes, have
a separate, lower fee structure.
The standard fee now covers use of the VOHC Seal world-wide,
and a separate fee structure has been established for submissions
on behalf of products that are marketed only in one country.