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Nature Reviews. Microbiology Feb 2024The human oral microbiota is highly diverse and has a complex ecology, comprising bacteria, microeukaryotes, archaea and viruses. These communities have elaborate and... (Review)
Review
The human oral microbiota is highly diverse and has a complex ecology, comprising bacteria, microeukaryotes, archaea and viruses. These communities have elaborate and highly structured biogeography that shapes metabolic exchange on a local scale and results from the diverse microenvironments present in the oral cavity. The oral microbiota also interfaces with the immune system of the human host and has an important role in not only the health of the oral cavity but also systemic health. In this Review, we highlight recent advances including novel insights into the biogeography of several oral niches at the species level, as well as the ecological role of candidate phyla radiation bacteria and non-bacterial members of the oral microbiome. In addition, we summarize the relationship between the oral microbiota and the pathology of oral diseases and systemic diseases. Together, these advances move the field towards a more holistic understanding of the oral microbiota and its role in health, which in turn opens the door to the study of novel preventive and therapeutic strategies.
Topics: Humans; Microbiota; Mouth; Bacteria; Archaea; Viruses
PubMed: 37700024
DOI: 10.1038/s41579-023-00963-6 -
Otolaryngologic Clinics of North America Aug 2023This summary provides a concise overview of oral cavity reconstruction to optimize functional outcomes in the modern era. Soft tissue and osseous reconstruction options... (Review)
Review
This summary provides a concise overview of oral cavity reconstruction to optimize functional outcomes in the modern era. Soft tissue and osseous reconstruction options for a wide range of oral cavity sites including lip, oral tongue, floor of mouth, buccal, hard palate, and composite oromandibular resections are reviewed. The appropriate applications of primary closure, secondary intention, skin grafts, and dermal substitute grafts are included. Anatomic considerations, indications, contraindications, and complications of local, regional, and free flaps in oral cavity reconstruction are discussed. Specific defects and the appropriate options for reconstruction of those defects are delineated.
Topics: Humans; Mouth Neoplasms; Plastic Surgery Procedures; Free Tissue Flaps; Tongue; Carcinoma, Squamous Cell
PubMed: 37164898
DOI: 10.1016/j.otc.2023.04.002 -
Nature Apr 2024Fusobacterium nucleatum (Fn), a bacterium present in the human oral cavity and rarely found in the lower gastrointestinal tract of healthy individuals, is enriched in...
Fusobacterium nucleatum (Fn), a bacterium present in the human oral cavity and rarely found in the lower gastrointestinal tract of healthy individuals, is enriched in human colorectal cancer (CRC) tumours. High intratumoural Fn loads are associated with recurrence, metastases and poorer patient prognosis. Here, to delineate Fn genetic factors facilitating tumour colonization, we generated closed genomes for 135 Fn strains; 80 oral strains from individuals without cancer and 55 unique cancer strains cultured from tumours from 51 patients with CRC. Pangenomic analyses identified 483 CRC-enriched genetic factors. Tumour-isolated strains predominantly belong to Fn subspecies animalis (Fna). However, genomic analyses reveal that Fna, considered a single subspecies, is instead composed of two distinct clades (Fna C1 and Fna C2). Of these, only Fna C2 dominates the CRC tumour niche. Inter-Fna analyses identified 195 Fna C2-associated genetic factors consistent with increased metabolic potential and colonization of the gastrointestinal tract. In support of this, Fna C2-treated mice had an increased number of intestinal adenomas and altered metabolites. Microbiome analysis of human tumour tissue from 116 patients with CRC demonstrated Fna C2 enrichment. Comparison of 62 paired specimens showed that only Fna C2 is tumour enriched compared to normal adjacent tissue. This was further supported by metagenomic analysis of stool samples from 627 patients with CRC and 619 healthy individuals. Collectively, our results identify the Fna clade bifurcation, show that specifically Fna C2 drives the reported Fn enrichment in human CRC and reveal the genetic underpinnings of pathoadaptation of Fna C2 to the CRC niche.
Topics: Animals; Humans; Mice; Adenoma; Case-Control Studies; Colorectal Neoplasms; Feces; Fusobacterium nucleatum; Gastrointestinal Tract; Genome, Bacterial; Mouth; Female
PubMed: 38509359
DOI: 10.1038/s41586-024-07182-w -
Journal of the American Dental... Dec 2023Stem cells are present in most of the tissues in the craniofacial complex and play a major role in tissue homeostasis and repair. These cells are characterized by their... (Review)
Review
BACKGROUND
Stem cells are present in most of the tissues in the craniofacial complex and play a major role in tissue homeostasis and repair. These cells are characterized by their capacity to differentiate into multiple cell types and to self-renew to maintain a stem cell pool throughout the life of the tissue.
TYPES OF STUDIES REVIEWED
The authors discuss original data from experiments and comparative analyses and review articles describing the identification and characterization of stem cells of the oral cavity.
RESULTS
Every oral tissue except enamel, dentin, and cementum contains stem cells for the entire life span. These stem cells self-renew to maintain a pool of cells that can be activated to replace terminally differentiated cells (for example, odontoblasts) or to enable wound healing (for example, dentin bridge in pulp exposures and healing of periodontal tissues after surgery). In addition, dental stem cells can differentiate into functional blood vessels and nerves. Initial clinical trials have shown that transplanting dental pulp stem cells into disinfected necrotic teeth has allowed for the recovery of tooth vitality and vertical and horizontal root growth in immature teeth with incomplete root formation.
PRACTICAL IMPLICATIONS
As a consequence of these groundbreaking discoveries, stem cell banks are now offering services for the cryopreservation of dental stem cells. The future use of stem cell-based therapies in the clinic will depend on the collaboration of clinicians and researchers in projects designed to understand whether these treatments are safe, efficacious, and clinically feasible.
Topics: Humans; Dental Pulp; Tissue Engineering; Stem Cells; Tooth; Dentistry
PubMed: 37804275
DOI: 10.1016/j.adaj.2023.08.007 -
Oral and Maxillofacial Surgery Clinics... Aug 2023
Topics: Humans; Skull Base; Diagnostic Imaging; Mouth; Endoscopy
PubMed: 37032174
DOI: 10.1016/j.coms.2023.03.003 -
The Cochrane Database of Systematic... Aug 2023Surgery is a common treatment option in oral cavity cancer (and less frequently in oropharyngeal cancer) to remove the primary tumour and sometimes neck lymph nodes.... (Review)
Review
BACKGROUND
Surgery is a common treatment option in oral cavity cancer (and less frequently in oropharyngeal cancer) to remove the primary tumour and sometimes neck lymph nodes. People with early-stage disease may undergo surgery alone or surgery plus radiotherapy, chemotherapy, immunotherapy/biotherapy, or a combination of these. Timing and extent of surgery varies. This is the third update of a review originally published in 2007.
OBJECTIVES
To evaluate the relative benefits and harms of different surgical treatment modalities for oral cavity and oropharyngeal cancers.
SEARCH METHODS
We used standard, extensive Cochrane search methods. The latest search date was 9 February 2022.
SELECTION CRITERIA
Randomised controlled trials (RCTs) that compared two or more surgical treatment modalities, or surgery versus other treatment modalities, for primary tumours of the oral cavity or oropharynx.
DATA COLLECTION AND ANALYSIS
Our primary outcomes were overall survival, disease-free survival, locoregional recurrence, and recurrence; and our secondary outcomes were adverse effects of treatment, quality of life, direct and indirect costs to patients and health services, and participant satisfaction. We used standard Cochrane methods. We reported survival data as hazard ratios (HRs). For overall survival, we reported the HR of mortality, and for disease-free survival, we reported the combined HR of new disease, progression, and mortality; therefore, HRs below 1 indicated improvement in these outcomes. We used GRADE to assess certainty of evidence for each outcome.
MAIN RESULTS
We identified four new trials, bringing the total number of included trials to 15 (2820 participants randomised, 2583 participants analysed). For objective outcomes, we assessed four trials at high risk of bias, three at low risk, and eight at unclear risk. The trials evaluated nine comparisons; none compared different surgical approaches for excision of the primary tumour. Five trials evaluated elective neck dissection (ND) versus therapeutic (delayed) ND in people with oral cavity cancer and clinically negative neck nodes. Elective ND compared with therapeutic ND probably improves overall survival (HR 0.64, 95% confidence interval (CI) 0.50 to 0.83; I = 0%; 4 trials, 883 participants; moderate certainty) and disease-free survival (HR 0.56, 95% CI 0.45 to 0.70; I = 12%; 5 trials, 954 participants; moderate certainty), and probably reduces locoregional recurrence (HR 0.58, 95% CI 0.43 to 0.78; I = 0%; 4 trials, 458 participants; moderate certainty) and recurrence (RR 0.58, 95% CI 0.48 to 0.70; I = 0%; 3 trials, 633 participants; moderate certainty). Elective ND is probably associated with more adverse events (risk ratio (RR) 1.31, 95% CI 1.11 to 1.54; I = 0%; 2 trials, 746 participants; moderate certainty). Two trials evaluated elective radical ND versus elective selective ND in people with oral cavity cancer, but we were unable to pool the data as the trials used different surgical procedures. Neither study found evidence of a difference in overall survival (pooled measure not estimable; very low certainty). We are unsure if there is a difference in effect on disease-free survival (HR 0.57, 95% CI 0.29 to 1.11; 1 trial, 104 participants; very low certainty) or recurrence (RR 1.21, 95% CI 0.63 to 2.33; 1 trial, 143 participants; very low certainty). There may be no difference between the interventions in terms of adverse events (1 trial, 148 participants; low certainty). Two trials evaluated superselective ND versus selective ND, but we were unable to use the data. One trial evaluated supraomohyoid ND versus modified radical ND in 332 participants. We were unable to use any of the primary outcome data. The evidence on adverse events was very uncertain, with more complications, pain, and poorer shoulder function in the modified radical ND group. One trial evaluated sentinel node biopsy versus elective ND in 279 participants. There may be little or no difference between the interventions in overall survival (HR 1.00, 95% CI 0.90 to 1.11; low certainty), disease-free survival (HR 0.98, 95% CI 0.90 to 1.07; low certainty), or locoregional recurrence (HR 1.04, 95% CI 0.91 to 1.19; low certainty). The trial provided no usable data for recurrence, and reported no adverse events (very low certainty). One trial evaluated positron emission tomography-computed tomography (PET-CT) following chemoradiotherapy (with ND only if no or incomplete response) versus planned ND (before or after chemoradiotherapy) in 564 participants. There is probably no difference between the interventions in overall survival (HR 0.92, 95% CI 0.65 to 1.31; moderate certainty) or locoregional recurrence (HR 1.00, 95% CI 0.94 to 1.06; moderate certainty). One trial evaluated surgery plus radiotherapy versus radiotherapy alone and provided very low-certainty evidence of better overall survival in the surgery plus radiotherapy group (HR 0.24, 95% CI 0.10 to 0.59; 35 participants). The data were unreliable because the trial stopped early and had multiple protocol violations. In terms of adverse events, subcutaneous fibrosis was more frequent in the surgery plus radiotherapy group, but there were no differences in other adverse events (very low certainty). One trial evaluated surgery versus radiotherapy alone for oropharyngeal cancer in 68 participants. There may be little or no difference between the interventions for overall survival (HR 0.83, 95% CI 0.09 to 7.46; low certainty) or disease-free survival (HR 1.07, 95% CI 0.27 to 4.22; low certainty). For adverse events, there were too many outcomes to draw reliable conclusions. One trial evaluated surgery plus adjuvant radiotherapy versus chemotherapy. We were unable to use the data for any of the outcomes reported (very low certainty).
AUTHORS' CONCLUSIONS
We found moderate-certainty evidence based on five trials that elective neck dissection of clinically negative neck nodes at the time of removal of the primary oral cavity tumour is superior to therapeutic neck dissection, with increased survival and disease-free survival, and reduced locoregional recurrence. There was moderate-certainty evidence from one trial of no difference between positron emission tomography (PET-CT) following chemoradiotherapy versus planned neck dissection in terms of overall survival or locoregional recurrence. The evidence for each of the other seven comparisons came from only one or two studies and was assessed as low or very low-certainty.
Topics: Humans; Immunotherapy; Mouth; Neck; Neoplasm Recurrence, Local; Oropharyngeal Neoplasms; Randomized Controlled Trials as Topic
PubMed: 37650478
DOI: 10.1002/14651858.CD006205.pub5 -
International Journal of Molecular... Nov 2023Pyogenic granuloma (PG) is a benign vascular lesion found predominantly in the oral cavity. Characterized by rapid growth and propensity to bleed, PG presents diagnostic... (Review)
Review
Pyogenic granuloma (PG) is a benign vascular lesion found predominantly in the oral cavity. Characterized by rapid growth and propensity to bleed, PG presents diagnostic challenges due to its similarity and alarming proliferation. This narrative review synthesizes current knowledge on the epidemiology, etiopathogenesis, clinical manifestations, and management of oral PG, with emphasis on recent advances in diagnostic and therapeutic approaches. The epidemiology of the injury is meticulously analyzed, revealing a higher incidence in women and a wide range of ages of onset. It delves into the etiopathogenesis, highlighting the uncertainty surrounding the exact causal factors, although historical attributions suggest an infectious origin. It exhaustively analyzes the clinical and histopathological aspects of oral PG, offering information on its various presentations and the importance of an accurate diagnosis to guide effective treatment. It details treatment strategies, emphasizing the personalized approach based on individual patient characteristics. This comprehensive review consolidates current knowledge on oral PG, highlighting the need for further research to clarify its pathogenesis and optimize treatment protocols.
Topics: Humans; Female; Granuloma, Pyogenic; Mouth Mucosa; Mouth
PubMed: 38069207
DOI: 10.3390/ijms242316885 -
Oral and Maxillofacial Surgery Clinics... Aug 2023Acute infections of the oral cavity and suprahyoid neck range from simple superficial conditions that can be treated as an outpatient to complex multispatial processes... (Review)
Review
Acute infections of the oral cavity and suprahyoid neck range from simple superficial conditions that can be treated as an outpatient to complex multispatial processes that require surgical intervention and inpatient admission. This article provides an imaging overview of the range of infections in this region that may be encountered by oral and maxillofacial surgeons, emergency physicians, and primary care providers.
Topics: Humans; Neck; Mouth
PubMed: 37032180
DOI: 10.1016/j.coms.2023.01.001 -
Journal of Dental Research Mar 2024The oral cavity is an epidemiologically relevant route of viral transmission due to the shedding of viruses in saliva. With advancements in salivary diagnostics, an... (Review)
Review
The oral cavity is an epidemiologically relevant route of viral transmission due to the shedding of viruses in saliva. With advancements in salivary diagnostics, an increasing number of viruses have been detected. However, the anatomic source of virus in saliva is still largely unknown. Some viruses have a well-established tropism for the salivary glands (SGs), and recent studies have emphasized the importance of the glands as potential reservoirs for infectious viruses. Viral infections of the SGs have been linked to acute and chronic SG pathology and may be associated with SG dysfunction, with phenotypes similar to those seen in SjÖgren's disease (SjD), an autoimmune condition that affects the salivary and lacrimal glands. Understanding the breadth of viruses that infect the SG and the conserved or distinct host responses to these infections may provide insights into the pathogenesis of virus-mediated SG diseases. There is a need for further research to fully understand the molecular mechanisms by which viruses enter and replicate in the glands, their physiologic impact on SG function, and whether the SGs can serve as a long-term reservoir for infectious viral particles. The purpose of this review is to highlight a group of viruses that infect the salivary gland: hepatitis C virus, hepatitis D virus, severe acute respiratory syndrome coronavirus 2, enteric viruses, human T-cell leukemia virus type I, human immunodeficiency virus, human cytomegalovirus, and BK polyomavirus. We focus on the effects of viral infection on salivary gland (SG) inflammation, function, and its association with SjD.
Topics: Humans; Salivary Glands; Sjogren's Syndrome; Saliva; Inflammation
PubMed: 38344753
DOI: 10.1177/00220345231222871 -
Current Opinion in Otolaryngology &... Aug 2023Oral cavity reconstruction using local flaps is an area of head and neck surgery that has been overshadowed since the introduction of free flaps. Here, we discuss new... (Review)
Review
PURPOSE OF REVIEW
Oral cavity reconstruction using local flaps is an area of head and neck surgery that has been overshadowed since the introduction of free flaps. Here, we discuss new developments, predominantly modifications to existing techniques for intraoral reconstruction, the utility of different local flaps and a review of functional outcomes.
RECENT FINDINGS
The facial artery musculomucosal (FAMM) flap has seen the greatest number of modifications to technique, most notably the extended double-pedicled, kite-shaped tunnelized and osseous myomucosal approaches. The tunnelled buccal fat pad flap has gained popularity as well as the use of combining two flaps such as the buccal fat pad and palatal island flap to reconstruct oral cavity defects with good effect. There is still a paucity of literature surrounding functional outcomes post reconstruction. Despite this, the complication rate for local flaps remains low.
SUMMARY
The value of intraoral flaps for oral cavity reconstruction is undisputed. However, they are potentially underutilised in the modern era of expanding availability and indications for free tissue transfer. As many practices see greater numbers of aging patients, often with multisystem comorbidities, local flaps are an important tool that can provide the surgeon with a greater number of reconstructive options.
Topics: Humans; Plastic Surgery Procedures; Mouth; Free Tissue Flaps
PubMed: 36942833
DOI: 10.1097/MOO.0000000000000884