Quantitative sensory testing for assessment of somatosensory function in human oral mucosa: a review

<p><b>Objective:</b> This narrative review provides an overview of the quantitative sensory testing (QST) to assess somatosensory function in human oral mucosa.</p> <p><b>Material and methods:</b> A literature search was conducted in the PubMed database to identify studies <i>in vivo</i> on human oral mucosa using QST methods. A list of 149 articles was obtained and screened. A total of 36 relevant articles remained and were read in full text. Manual search of the reference lists identified eight additional relevant studies. A total of 44 articles were included for final assessment.</p> <p><b>Results:</b> The included studies were divided into six categories according to the study content and objective. In each category, there was a great variety of aims, methods, participants and outcome measures. The application of QST has nevertheless helped to monitor somatosensory function in experimental models of intraoral pain, effects of local anesthesia, after oral and maxillofacial surgery and after prosthodontic and orthodontic treatment.</p> <p><b>Conclusions:</b> QST has been proved to be sufficiently stable and reliable, and valuable information has been obtained regarding somatosensory function in healthy volunteers, special populations and orofacial pain patients. However, as most of the studies were highly heterogeneous, the results are difficult to compare quantitatively. A standardized intraoral QST protocol is recommended and expected to help advance a mechanism-based assessment of neuropathies and other intraoral pain conditions.</p

Genetic Variants of <i>BMP2</i> and Their Association with the Risk of Non-Syndromic Tooth Agenesis

<div><p>Non-syndromic tooth agenesis (or non-syndromic congenitally missing tooth) is one of the most common congenital defects in humans affecting the craniofacial function and appearance. Single nucleotide polymorphisms (SNPs) have been associated with an individual’s susceptibility to these anomalies. The aim of the present study was therefore to investigate the roles of the potentially functional SNPs of <i>BMP2</i> in the occurrence of tooth agenesis. Overall, four potentially functional SNPs of <i>BMP2</i> (rs15705, rs235768, rs235769 and rs3178250) were selected, and their associations with the susceptibility of tooth agenesis were evaluated in a case-control study of 335 non-syndromic tooth agenesis cases and 444 healthy controls. The SNPs rs15705 and rs3178250 were found to be associated with an individual’s risk of tooth agenesis (<i>P</i> = 0.046 and <i>P</i> = 0.039, respectively). Both SNPs showed an increased risk of mandibular incisor agenesis (rs15705, AA/AC <i>vs</i>. CC = 1.58, 95% CI = [1.06–2.34], <i>P</i> = 0.024; rs3178250, TT/TC <i>vs</i>. CC = 1.60, 95% CI = [1.08–2.37], <i>P</i> = 0.020). Bioinformatics analysis indicated that these two SNPs located at the 3’-untranslated region (3’-UTR) of <i>BMP2</i> might alter the binding ability of miR-1273d and miR-4639-5p, respectively, which was confirmed by luciferase activity assays in the 293A and COS7 cell lines (<i>P</i> < 0.001 in 293A and <i>P</i> < 0.01 in COS7 for miR-1273d; and <i>P</i> < 0.001 in both cells for miR-4639-5p). Furthermore, <i>BMP2</i> mRNA expression decreased after transfecting either miR-1273d or miR-4639-5p into these two cell lines (<i>P</i> < 0.01 in 293A and <i>P</i> < 0.001 in COS7 for miR-1273d, and <i>P</i> < 0.01 in both cell lines for miR-4639-5p). Taken together, our findings indicate that rs15705 and rs317250 are associated with the susceptibility of non-syndromic tooth agenesis by possibly affecting miRNAs and mRNA interaction.</p></div

Association of <i>BMP2</i> SNPs and risk of mandibular incisor agenesis.

<p>Association of <i>BMP2</i> SNPs and risk of mandibular incisor agenesis.</p

The renilla-to-firefly luminescence ratio comparison when co-transfecting 293A and COS7 cells with the <i>BMP2</i> 3’-UTR reporter and miR-mimics.

<p>PsiCHECK-2 without the insert or with the WT or MT plasmids was transfected respectively (A) or co-transfected with the miR-1273d mimics (B) or miR-4639-5p mimics (C) in the 293A and COS7 cell lines. Data were derived from three independent experiments with three replicates.</p

Distributions of congenitally missing tooth.

<p>Distributions of congenitally missing tooth.</p

<i>BMP2</i> mRNA expression in cells after transfenction with miRNA mimics.

<p>MiR-1273d mimics (A) or miR-4639-5p mimics (B) were transfected into 293A or COS7 cells. Transcript levels were analyzed by qPCR and normalized to <i>GAPDH</i> levels. Error bars indicate the +SD obtained from three independent experiments following three replicates.</p