Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 3 complete abstracts (569 words), 9 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Heads.
Where it fits in the MeSH classification
- Broader topics
- Body Regions
- Narrower topics
- Ear; Face; Scalp; Skull Base
- See also
- Facial Bones; Skull
Research landscape
PubMed indexes 248,024 records tagged with the MeSH heading “Head” (counts retrieved 2026-10-31). 38,833 of them (15.7%) were published from 2020 onward, and the busiest period so far is through 1999 with 109,314 records.
Reviews account for 19,818 records (8.0%) and meta-analyses for 766. Randomized controlled trials number 4,828 (1.9%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 109,314 |
| 2000-2009 | 40,476 |
| 2010-2019 | 59,401 |
| 2020 onward | 38,833 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 19,818 | 8.0% |
| Meta-analyses | 766 | 0.3% |
| Randomized controlled trials | 4,828 | 1.9% |
Method: PubMed query "Head"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in anatomy and physiology
Anatomy describes how body structures are built and physiology describes how they normally work, so most findings here are descriptive or mechanistic rather than evidence about treatment. Much of what is known comes from dissection, imaging, tissue studies and experiments in animals, and measurements in healthy volunteers can differ from those in people with disease or at different ages. Normal ranges vary between individuals and populations. Check whether a result was measured in people or in another species, the age and health of the participants, and the method used.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Type I hair cells of striolar and central zones in vestibular organs are essential for head stability and postural control | 2026 | Research article Design not recorded in structured metadata | 2 | cc by PMID 42224603 · DOI · PMC13250592 |
| The redefined identity of Prevotella: new implications for oral, respiratory, and vaginal health | 2026 | Review article Design not recorded in structured metadata | 1 | cc by PMID 42430221 · DOI · PMC13492131 |
| Comparing Facial Attractiveness and Professional Acceptance Between Real and AI-Generated Orthodontic Treatment Outcome Images | 2026 | Research article Design not recorded in structured metadata | 1 | cc by PMID 42149127 · DOI · PMC13543177 |
Type I hair cells of striolar and central zones in vestibular organs are essential for head stability and postural control [1]
Abstract reading summary — source excerpts
- Opening excerpt
- The vestibular system of the inner ear provides head motion and orientation information required for maintaining balance and spatial orientation.
- Closing excerpt
- Furthermore, loss of striolar/central zone-specific type I HCs causes head tremor in pups and abnormal head motion in adults, indicating that these HCs are essential for mediating head stability and postural control.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (244 words)
The vestibular system of the inner ear provides head motion and orientation information required for maintaining balance and spatial orientation. Each of the five vestibular sensory organs contains type I and type II hair cells (HCs). Type I HCs are particularly notable for their evolutionary adaptability and unique calyceal synapses, in which the vestibular afferent nerve ending envelopes the HC body. In vitro studies indicate that calyceal synapses can transduce signals from HCs to afferents via nonquantal transmission, a mechanism proposed to be faster than conventional bouton synaptic transmission. In specialized regions of vestibular organs-striolae and central zones-many afferents form calyces that encase multiple type I HC bodies, suggesting that nonquantal transmission could be especially important in these regions. Consistently, striolar/central zone afferents are thought to preferentially mediate rapid and high-frequency stimulations. However, the direct consequences of selectively losing these HCs remain unknown. Here, we investigated the role of type I HCs within striolar/central zones by genetically ablating these cells. Reduction of type I HCs in these regions led to a loss of calyces and a compensatory increase in striolar type II HCs. These mutants exhibit reduced vestibular-evoked potentials, a response driven predominantly by striolar activity. In contrast, the vestibulo-ocular reflex, which is thought not to require striolar/central zone function, remained intact. Furthermore, loss of striolar/central zone-specific type I HCs causes head tremor in pups and abnormal head motion in adults, indicating that these HCs are essential for mediating head stability and postural control.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42224603 · DOI · PMC13250592
The redefined identity of Prevotella: new implications for oral, respiratory, and vaginal health [2]
Abstract reading summary — source excerpts
- Opening excerpt
- For much of the 20th century, the field of bacteriology was dominated by a pathogen-centric view, which rightly focused scientific resources on identifying, characterizing, and eliminating the agents of infectious disease.
- Closing excerpt
- The knowledge derived from a mechanistic focus will offer profound benefits for understanding and treating complex polymicrobial diseases across multiple systems, including chronic respiratory infections, oral inflammatory conditions, and recurrent genitourinary dysbiosis.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (171 words)
For much of the 20th century, the field of bacteriology was dominated by a pathogen-centric view, which rightly focused scientific resources on identifying, characterizing, and eliminating the agents of infectious disease. However, this perspective has resulted in the relative neglect of abundant yet poorly characterized members of the human microbiota. Few genera embody this oversight more clearly than Prevotella. Despite being consistently found in high abundance across diverse human mucosal sites, including the oral cavity, airways, and vagina, the underlying physiological roles of the genus in both health and disease contexts remain largely unclear. This review traces the evolution of Prevotella research and classification, arguing that the traditional "friend or foe" dichotomy is insufficient. We contend that more mechanistic work at the species level is needed to elucidate the biology of Prevotella, especially after the most recent taxonomic reclassification. The knowledge derived from a mechanistic focus will offer profound benefits for understanding and treating complex polymicrobial diseases across multiple systems, including chronic respiratory infections, oral inflammatory conditions, and recurrent genitourinary dysbiosis.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42430221 · DOI · PMC13492131
Comparing Facial Attractiveness and Professional Acceptance Between Real and AI-Generated Orthodontic Treatment Outcome Images [3]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundFacial attractiveness influences social and professional perceptions, including competence and employability.
- Closing excerpt
- AI-generated images were perceived as more attractive and had a greater positive impact on employability judgements compared to real post-treatment images.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (154 words)
BackgroundFacial attractiveness influences social and professional perceptions, including competence and employability. With the increasing use of artificial intelligence (AI) to generate photorealistic faces, it is important to understand how these images compare to real orthodontic treatment outcomes.ObjectiveTo compare perceptions of real versus AI-generated orthodontic treatment results in terms of attractiveness, employability, and distinguishability.MethodsA cross-sectional online survey included 288 Brazilian adults.ParticipantsDentists (n = 76), dental students (n = 63), and laypeople (n = 149). Each evaluated three sets of images (pre-treatment, post-treatment, and AI-generated post-treatment) for three patients. Participants rated facial attractiveness (VAS 0-100), assessed employability, and identified whether the image was AI-generated.ResultsAI-generated images were rated significantly more attractive than real post-treatment ones (mean VAS: AI = 68.8; Real = 54.4; p ConclusionParticipants showed limited ability to accurately distinguish between real and AI-generated images. AI-generated images were perceived as more attractive and had a greater positive impact on employability judgements compared to real post-treatment images.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42149127 · DOI · PMC13543177
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Treatment and follow-up of oral dysplasia - a systematic review and meta-analysis [4]
- Research article A meta-analysis and review of holistic face processing [5]
- Research article Variation in Reported Human Head Tissue Electrical Conductivity Values [6]
- Research article Head circumference and brain size in autism spectrum disorder: A systematic review and meta-analysis [7]
- Research article The Clinical Utility of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Screening to Rule Out MRSA Pneumonia: A Diagnostic Meta-analysis With Antimicrobial Stewardship Implications [8]
- Research article Effectiveness of a bundled intervention of decolonization and prophylaxis to decrease Gram positive surgical site infections after cardiac or orthopedic surgery: systematic review and meta-analysis [9]
References
- Ono K, Lee HJ, Chang HHV, Verdone BM, Wafa T, Ji Y, et al.. Type I hair cells of striolar and central zones in vestibular organs are essential for head stability and postural control. . 2026. PMID 42224603 · DOI · PMC13250592
- Ntamubano S, Parker D, Kozik AJ. The redefined identity of Prevotella: new implications for oral, respiratory, and vaginal health. . 2026. PMID 42430221 · DOI · PMC13492131
- Gasparello GG, Tirkkonen O, Mota-Júnior SL, Martins FC, da Silva MAD, Tanaka OM. Comparing Facial Attractiveness and Professional Acceptance Between Real and AI-Generated Orthodontic Treatment Outcome Images. . 2026. PMID 42149127 · DOI · PMC13543177
- Mehanna HM, Rattay T, Smith J, McConkey CC. Treatment and follow-up of oral dysplasia - a systematic review and meta-analysis. Head Neck. 2009. PMID 19455705 · DOI
- Richler JJ, Gauthier I. A meta-analysis and review of holistic face processing. Psychol Bull. 2014. PMID 24956123 · DOI · PMC4152424
- McCann H, Pisano G, Beltrachini L. Variation in Reported Human Head Tissue Electrical Conductivity Values. Brain Topogr. 2019. PMID 31054104 · DOI · PMC6708046
- Sacco R, Gabriele S, Persico AM. Head circumference and brain size in autism spectrum disorder: A systematic review and meta-analysis. Psychiatry Res. 2015. PMID 26456415 · DOI
- Parente DM, Cunha CB, Mylonakis E, Timbrook TT. The Clinical Utility of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Screening to Rule Out MRSA Pneumonia: A Diagnostic Meta-analysis With Antimicrobial Stewardship Implications. Clin Infect Dis. 2018. PMID 29340593 · DOI
- Schweizer M, Perencevich E, McDanel J, Carson J, Formanek M, Hafner J, et al.. Effectiveness of a bundled intervention of decolonization and prophylaxis to decrease Gram positive surgical site infections after cardiac or orthopedic surgery: systematic review and meta-analysis. BMJ. 2013. PMID 23766464 · DOI · PMC3681273
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.