Dental Herbalism: Natural Therapies for the Mouth by Leslie M. Alexander and Linda A. Straub-Bruce. Rochester, Vermont: Healing Arts Press; 2014. Softcover, 454 pages. ISBN: 978-162055195-0. $19.95.

Readers of Dental Herbalism: Natural Therapies for the Mouth should be advised that it is written from the perspectives of a dental hygienist and a practicing American herbalist and reflects their respective training and limitations thereof. Both authors have made an effort to be as comprehensive as possible, and also to simplify their presentations for the lay audience. However, it is difficult for me to understand the authors’ approach, not only based on what was written about a number of dental issues, but also because I question how successful self-medication can be achieved without the personal guidance of a skilled herbalist.

Unfortunately, much of the book’s information is incomplete, cursory at best, and repeated in a number of chapters. Also, while references are cited after each chapter, it is unclear how they are linked to many of the statements made. In other instances, certain references — the contents of which are utilized throughout each chapter and contain primary sources — should have been cited within the text; instead, those that represent popular books on herbalism and frequently lack primary sources have been given preference. Plant identification in the authors’ materia medica is challenging due to the omission of corresponding pictures. Most importantly, the content of many of the chapters is so diffuse as to be confounding and should have been edited appropriately in order to provide a clearer approach to each core subject.

The lists of plants and formulations in the materia medica are presented in a classic format and clearly reflect those familiar to the herbalist. Additional formulae and plant recommendations are inserted in chapters without explanations as to why they might take precedence over others. I find the ethnobotanical/dental overview to be understated at best and, as such, lacking a clear basis for the selection of those formulations cited and their comparative therapeutic worth. With only a few exceptions, most of the plants examined in detail are derived from European pharmacopeias or the Neo-Western herbalist tradition. Broad statements are provided about the plants’ possible value in dentistry, but connections between their cited bioreactivities and known constituents are superficial at best. Further, there is a dearth of proof as to their relative efficacy when used alone or in combination with other herbal constituents, many of which are not cited in the materia medica. The following paragraphs outline but a few examples of what I found to be the most disconcerting issues.

The selective criteria behind the herbal chew-sticks recommended in Chapters 1 and 12 and explanations as to why they may be more efficacious than others are never discussed. Unfortunately, the list of chew-sticks provided is confounding, since without accompanying botanical epithets and only an admixture of common and generic names to consider, it would be impossible to determine the true identity of some of these plants or how they might be obtained if not available locally. Citing marshmallow (Althaea officinalis, Malvaceae) as a common chew-stick also is perplexing since many references mention uses only for “teething babies”; overall, species within the Malvaceae family rarely are utilized for this purpose. Among the many chew-sticks used worldwide, some are well known for their therapeutic value and the proven clinical efficacies associated with known anti-inflammatory and antimicrobial activities against odontoperiopathic organisms. Numerous commercial dental products in the form of wood chips, extracts, and oils have undergone clinical analyses to authenticate their value. While the authors of Dental Herbalism were reticent to include any of these data in the book, a simple table citing commercial names, ingredients, and proven bioreactivities and clinical efficacies would have been an invaluable addition to the text or its appendix.

Noteworthy among the omitted chew-sticks is miswak (Salvadora persica, Salvadoraceae), which, to many in Eastern and Northern Africa, the Middle East, and Western Asia, has proven its value not only as a chew-stick but also as an extract in a number of dentifrices (i.e., toothpastes and powders). This plant has been studied extensively for both its clinical virtues and the therapeutic basis for its bioreactive compounds. Agreeably, the cautionary note regarding neem (Azadirachta indica, Meliaceae) and fertility has merit, albeit this association has not been proven in humans. Also, there is no mention of allergic reactions that may be elicited by certain dental products that include flavoring and antimicrobial essential oils such as peppermint (Mentha x piperita, Lamiaceae), eugenol (a component of clove [Syzygium aromaticum, Myrtaceae] and cinnamon [Cinnamomum spp., Lauraceae] leaf oils), tea tree (Melaleuca alternifolia, Myrtaceae) oil, and bloodroot (Sanguinaria canadensis, Papaveraceae).

Although plant quids are used by many cultures to clean teeth, the authors’ recommendation of using betel (Piper betle, Piperaceae) quid for this purpose makes little sense given that the quid often contains tobacco (Nicotiana tabacum, Solanaceae), the practice usually stains teeth red to black, and it has been known to cause oral cancer. Also lacking in the discussion of toothpastes and powders is the fact that many herbal formulations contain calcium carbonate, which can vary widely in its abrasive qualities. Charcoal is not mentioned for the purpose of teeth-cleaning and appears only in the appendix. Throughout the book, plants frequently are recommended in a general fashion without specifications as to the plant part used or how compositions can be formulated safely when they are combined from a number of taxa.

There is a plethora of information regarding dental anatomy and dental practices throughout the Dental Herbalism, only some of which is pertinent. It appears that much of this material was derived directly from professional texts without consideration as to how it would be of value to the lay reader or, frankly, how it is related to the title of the book. Furthermore, explanations of the causes and consequences of dental disease suggest an apparent lack of expertise in this area. For example, in Chapter 1, the discussion of inflammatory processes and their causes (e.g., stress and other factors) should have included information about the evolution of oral disease. The authors did not thoroughly elucidate that stress-related hormones can promote, inhibit, or have no effect on certain periopathic species, or that their endotoxins can serve to increase inflammatory cytokines. This can result in periodontal inflammation, and it can initiate or exacerbate artherogenesis and thromboembolic events when these organisms are found with calcifying oral organisms in arterial plaque. The causes and results of bacteremia (i.e., bacteria in the blood) should have been delineated more fully and accurately as well. To be precise, bacteremia is less likely to occur after chewing and more likely to happen after tooth extraction, gum chewing, or tooth brushing. While it is possible that any one of these factors could contribute to the distribution of normal oral flora and oral pathogens in the blood stream, predisposing factors are essential for any of these to colonize aortic heart valves or joints, which can lead to endocarditis and arthritis, respectively.

It would have been useful if oral infection treatments were presented in one chapter rather than being interspersed throughout the book. Referring to microorganisms as “bugs or germs” clearly is outdated, as the terms do not specify the bacteria or viruses associated with a disease. For example, thrush due to the fungus Candida albicans (Saccharomycetaceae) was discussed in regard to its presence in the neonate, but elsewhere no reference was made to it being one of the first cardinal signs of immunosuppression due to AIDS. Also, there are many bacteria — not just Streptococcus mutans (Streptococcaceae) — that can cause caries (i.e., tooth decay), some of which are more prevalent during certain stages of life. I find the description of this disease symptom to be superficial at best.

Acknowledging that there are many contributing factors to the development of these diseases, I am puzzled as to why the authors discussed sugar in alcoholic beverages and glucose in carbonated beverages at some length without noting the primary cause of tooth decay: sucrose with its glucan-forming plaque and acidogenic potential. There appears to be a lack of understanding regarding the fact that sweetened beverages can differ in their cariogenic potential depending on whether or not they contain the disaccharide sucrose, the monosaccharide isomers of glucose/dextrose, or fructose. Of no relevance whatsoever were the authors’ comments concerning the sourcing of glucose from genetically modified corn or if sea salt has any benefits over iodized sodium chloride as pertaining to dental disease. Factors that serve to inhibit the cariogenic process should have been discussed in greater detail. For example, Dental Herbalism excludes the protective effects of phytates found in a number of foods, including sugar cane (Saccharum officinarum, Poaceae). Also, while fluoride is mentioned in a number of places, its natural presence in soils, water, certain foods, beverages (including tea [Camellia sinensis, Theaceae]), or some chew-sticks and how this trace element and others can impact the cariogenic process are neglected.

Regrettably, I cannot recommend this book for either laypeople or a professional audience.

—Memory Elvin-Lewis, PhD, DSc (Honoris Causa) Professor of Microbiology and Ethnobotany in Biomedicine, Adjunct Professor of Biology Washington University St. Louis, Missouri