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 (828 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 most posterior teeth on either side of the jaw, totaling eight in the deciduous dentition (2 on each side, upper and lower), and usually 12 in the permanent dentition (three on each side, upper and lower). They are grinding teeth, having large crowns and broad chewing surfaces. (Jablonski, Dictionary of Dentistry, 1992, p821)
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: Molars.
Where it fits in the MeSH classification
- Broader topics
- Tooth
- Narrower topics
- Molar, Third
Research landscape
PubMed indexes 36,504 records tagged with the MeSH heading “Molar” (counts retrieved 2026-10-31). 6,409 of them (17.6%) were published from 2020 onward, and the busiest period so far is through 1999 with 12,673 records.
Reviews account for 1,658 records (4.5%) and meta-analyses for 376. Randomized controlled trials number 2,986 (8.2%) as a share of all records on the topic. Randomized trials make up a comparatively large share of this literature, which means many treatment questions have been tested directly.
Show the data
| Period | Records |
|---|---|
| through 1999 | 12,673 |
| 2000-2009 | 7,540 |
| 2010-2019 | 9,882 |
| 2020 onward | 6,409 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 1,658 | 4.5% |
| Meta-analyses | 376 | 1.0% |
| Randomized controlled trials | 2,986 | 8.2% |
Method: PubMed query "Molar"[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 |
|---|---|---|---|---|
| Using injectable Platelet-Rich fibrin to improve recovery after impacted lower third molar extraction: a randomized controlled clinical trial | 2025 | Randomized controlled trial Design not recorded in structured metadata | 8 | cc by PMID 40971054 · DOI · PMC12449355 |
| Two different short fiber-reinforced resin composites for extensive MOD cavities in premolars and molars | 2025 | Research article Design not recorded in structured metadata | 7 | cc by PMID 40960634 · DOI · PMC12443927 |
| Kdf1 Regulates Molar Cusp Morphogenesis via the PI3K/AKT/mTOR Signalling Axis | 2026 | Research article Design not recorded in structured metadata | 5 | cc by PMID 40739677 · DOI · PMC12961517 |
Using injectable Platelet-Rich fibrin to improve recovery after impacted lower third molar extraction: a randomized controlled clinical trial [1]
Abstract reading summary — source excerpts
- Opening excerpt
- ObjectivesThe aim of this RCT was to clinically evaluate swelling, pain and wound healing following submucosal infiltration of injectable Platelet-Rich Fibrin (i-PRF) after extraction of impacted lower third molar.
- Closing excerpt
- By potentially lowering the need for nonsteroidal anti-inflammatory drugs (NSAIDs) and minimizing associated adverse effects, i‑PRF represents a minimally invasive, autologous approach that could enhance patient comfort, reduce recovery time, and support faster return to daily activities.
- 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 (391 words)
ObjectivesThe aim of this RCT was to clinically evaluate swelling, pain and wound healing following submucosal infiltration of injectable Platelet-Rich Fibrin (i-PRF) after extraction of impacted lower third molar.Materials and methodsThe study was designed as a double-blinded, parallel group, randomized controlled clinical trial. 56 patients were divided into 2 groups: in the control group the socket was left to heal spontaneously, while the test group was treated with submucosal infiltration of i-PRF. Swelling was measured with a flexible ruler using the diagonals joining Trago and Pogonion, Gonion and labial cleft. The swelling was calculated as the sum of these diagonals before surgery, on day 3 and 7. Pain was assessed by VAS scale until the 7th postoperative day. Surgical wound healing was evaluated by the Healing Index by Landry on 3, 7 ,14 and 21st day postosperatively. The relation between duration of intervention and total swelling was also evaluated.Results56 patients were enrolled in this study (28 for the test group and 28 for the control group). Randomization resulted in groups with similar baseline characteristics. No patients were lost during the follow-up and no adverse events were noted. On day 3 the total swelling was 12.7 ± 0.92 mm for control group and 12.1 ± 0.75 mm for test group; on day 7 it was 12.3 ± 0.88 mm for control group and 11.7 ± 0.73 mm for test group. A statistically significant difference was found on day 3 (p = 0.006) and on day 7 (p = 0.018). The relation between total swelling and duration of intervention was not statistically significant (p = 0.276). A significant reduction in pain scores was observed in the i-PRF group on days 1 and 3 (p ConclusionsWithin the limit of our study, this randomized controlled clinical trial suggests that submucosal infiltration of i-PRF after the extraction of impacted lower third molars effectively reduces postoperative swelling and pain, while also promoting faster wound healing.Clinical relevanceThe adjunctive use of injectable platelet-rich fibrin (i‑PRF) after surgical removal of impacted mandibular third molars may contribute to improve early postoperative outcomes by attenuating soft tissue inflammation, reducing pain intensity, and accelerating wound healing. By potentially lowering the need for nonsteroidal anti-inflammatory drugs (NSAIDs) and minimizing associated adverse effects, i‑PRF represents a minimally invasive, autologous approach that could enhance patient comfort, reduce recovery time, and support faster return to daily activities.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40971054 · DOI · PMC12449355
Two different short fiber-reinforced resin composites for extensive MOD cavities in premolars and molars [2]
Abstract reading summary — source excerpts
- Opening excerpt
- ObjectivesTo assess the influence of (1) incorporating micro- and millimeter-scale short fiber-reinforced composite (SFC) on the fracture behavior of large direct restorations made in premolars (P) and molars (M); (2) tooth size on the fracture resistance and their correlation.
- Closing excerpt
- Molars could be restored with any type of SFC, however gaining a high volume of plain flowable or preferably hybrid SFC in premolars is highly important.
- 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 (259 words)
ObjectivesTo assess the influence of (1) incorporating micro- and millimeter-scale short fiber-reinforced composite (SFC) on the fracture behavior of large direct restorations made in premolars (P) and molars (M); (2) tooth size on the fracture resistance and their correlation.Materials and methodsWide MOD cavities with missing lingual walls were prepared in premolars and molars. Four groups were designed (n = 15/group). Teeth in PFC group were restored with particulate filler resin composite (Gaenial Universal Injectable) without fiber reinforcement. Teeth in bilayered group were made of micrometer-scale SFC-core (everX Flow) veneered with a resin composite layer 1 mm in thickness. Monolithic SFC restorations were made either with plain SFC (everX Flow) or with plain hybrid SFC. The hybrid SFC was composed of handmade mixture of micro- and millimeter-scale SFCs (everX Flow and everX Posterior). Specimens were stored in water for 12 months before quasi-static loading. Fractures were analyzed using scanning electron microscopy. Data were statistically analyzed with two-way ANOVA (p = 0.05), followed by the Tukey HSD test. Additionally, Pearson correlation analyses (p = 0.001) were conducted.ResultsRestorations in premolars exhibited statistically significant lower fracture resistance than those in molars, except for the plain SFC group (p ConclusionsThe volume and consistency of SFC significantly impact the fracture endurance and fracture mode of direct composite restorations.Clinical significanceTooth and short fiber reinforced composite (SFC) type are factors that should be taken into account when planning the SFC restoration. Molars could be restored with any type of SFC, however gaining a high volume of plain flowable or preferably hybrid SFC in premolars is highly important.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40960634 · DOI · PMC12443927
Kdf1 Regulates Molar Cusp Morphogenesis via the PI3K/AKT/mTOR Signalling Axis [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Keratinocyte differentiation factor 1 (Kdf1) reportedly plays a significant role in enamel formation.
- Closing excerpt
- Collectively, our findings provide in vivo evidence supporting the regulatory role of Kdf1 in molar cusp morphogenesis, highlighting its function in modulating dental epithelial cell proliferation via the PI3K/AKT/mTOR signalling pathway.
- 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 (178 words)
Keratinocyte differentiation factor 1 (Kdf1) reportedly plays a significant role in enamel formation. In terms of tooth morphogenesis, human KDF1 variants are associated with crown morphological abnormalities, suggesting that Kdf1 may also be essential for tooth morphogenesis. However, the involvement of Kdf1 in tooth morphogenesis and its underlying mechanisms remains unclear. In this study, we observed that mice lacking epithelial Kdf1 (K14-Cre;Kdf1 fl/fl ) displayed rounded and blunt molar cusps, resembling the morphological anomalies observed in patients with Kdf1 variants. 5-Ethynyl-2'-deoxyuridine assays revealed increased proliferative activity of the inner enamel epithelial (IEE) cells in the cusp region of K14-Cre;Kdf1 fl/fl mice during the bell stage. RNA sequencing and western blot analysis confirmed the overactivation of PI3K/AKT/mTOR signalling in the molar IEE cells of K14-Cre;Kdf1 fl/fl mice. Furthermore, in utero microcapillary injection of the PI3K/AKT/mTOR pathway inhibitor LY294002 partially rescued the molar cusp defects in K14-Cre;Kdf1 fl/fl mice. Collectively, our findings provide in vivo evidence supporting the regulatory role of Kdf1 in molar cusp morphogenesis, highlighting its function in modulating dental epithelial cell proliferation via the PI3K/AKT/mTOR signalling pathway.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40739677 · DOI · PMC12961517
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 Predictors of Third Molar Impaction: A Systematic Review and Meta-analysis [4]
- Research article Tooth loss in molars with and without furcation involvement - a systematic review and meta-analysis [5]
- Research article Managing molar-incisor hypomineralization: A systematic review [6]
- Research article Corticosteroids reduce postoperative morbidity after third molar surgery: a systematic review and meta-analysis [7]
- Research article Morphologic and Demographic Predictors of Third Molar Agenesis: A Systematic Review and Meta-analysis [8]
- Research article Sealants for preventing and arresting pit-and-fissure occlusal caries in primary and permanent molars: A systematic review of randomized controlled trials-a report of the American Dental Association and the American Academy of Pediatric Dentistry [9]
References
- Aliberti A, Mariniello M, Bergaminelli M, Dolce P, Gargiulo D, Sammartino G, et al.. Using injectable Platelet-Rich fibrin to improve recovery after impacted lower third molar extraction: a randomized controlled clinical trial. . 2025. PMID 40971054 · DOI · PMC12449355
- Oksanen V, Bijelic-Donova J, Vallittu PK, Lassila L, Garoushi S. Two different short fiber-reinforced resin composites for extensive MOD cavities in premolars and molars. . 2025. PMID 40960634 · DOI · PMC12443927
- Wang J, Yu M, Liu H, Sun K, Geng C, Liu H, et al.. Kdf1 Regulates Molar Cusp Morphogenesis via the PI3K/AKT/mTOR Signalling Axis. . 2026. PMID 40739677 · DOI · PMC12961517
- Carter K, Worthington S. Predictors of Third Molar Impaction: A Systematic Review and Meta-analysis. J Dent Res. 2016. PMID 26561441 · DOI
- Nibali L, Zavattini A, Nagata K, Di Iorio A, Lin GH, Needleman I, et al.. Tooth loss in molars with and without furcation involvement - a systematic review and meta-analysis. J Clin Periodontol. 2016. PMID 26932323 · DOI
- Elhennawy K, Schwendicke F. Managing molar-incisor hypomineralization: A systematic review. J Dent. 2016. PMID 27693779 · DOI
- Markiewicz MR, Brady MF, Ding EL, Dodson TB. Corticosteroids reduce postoperative morbidity after third molar surgery: a systematic review and meta-analysis. J Oral Maxillofac Surg. 2008. PMID 18718396 · DOI
- Carter K, Worthington S. Morphologic and Demographic Predictors of Third Molar Agenesis: A Systematic Review and Meta-analysis. J Dent Res. 2015. PMID 25883107 · DOI
- Wright JT, Tampi MP, Graham L, Estrich C, Crall JJ, Fontana M, et al.. Sealants for preventing and arresting pit-and-fissure occlusal caries in primary and permanent molars: A systematic review of randomized controlled trials-a report of the American Dental Association and the American Academy of Pediatric Dentistry. J Am Dent Assoc. 2016. PMID 27470524 · DOI
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.