Dental Hygiene Research: Medical Subject Headings (MeSH)

MeSH is the National Library of Medicine's controlled vocabulary thesaurus.

Each bibliographic reference is associated with a set of MeSH terms that are assigned to describe the content of an article. 

Medline groups the MeSH terms in a hierarchical arrangement. This allows the searcher to either search a broad MeSH term alone (to retrieve those articles that talk about the general aspect of that topic only) or to explode that broad MeSH term to also include all of its indented narrower MeSH terms, grouped together in an "OR" Boolean operation.

Consider the tree structure of the MeSH term "mouth neoplasms":

Exploding the MeSH "mouth neoplasms", retrieves articles talking about any of the narrower MeSH terms included in all the above list combined in an "OR" relationship.

Whereas exploding the MeSH "salivary gland neoplasms" retrieves articles talking about it or talking about any of its narrower MeSH terms"parotid neoplasms", or "sublingual gland neoplasms", or "submandibular gland neoplasms".

If your search retrieves too many articles, consider the following techniques to get less results:

• Limit to the main theme of the article by using major concept on main subject heading(s)
• Select subheadings to limit to a particular aspect of your topic (e.g. therapeutic use, complications)
• Apply limits such as age groups, clinical queries, or publication types
• Add another concept to your search, then combine it with your other terms using "and"
• Try taking out keywords which may be retrieving too much

If your search retrieves few or no citations, consider the following techniques to broaden your search:

• Use the Explode feature to include more specific terms e.g. exploding Fractures, Bone includes Spinal Fractures, Tibial Fractures, etc, (Note that Explode is the default in PubMed)
• Think of additional synonyms or related terms, then combine them with "or"
• Find a relevant citation and look at the MeSH subject headings for ideas for subject headings to use
• Remove limiters
• Use keywords in addition to MeSH headings, combined with "or"
• When keyword searching, try truncating the search term with * e.g. child* retrieves children, childhood, child