An improved diagnostic method for taurodontism and a comparative study on its effectiveness evaluation.

OBJECTIVE: The two commonly used diagnostic methods for taurodontism are susceptible to aging changes, mastication wear and other factors. Therefore, this study proposed an improved diagnostic method for taurodontism, and compared it with the previous two methods as a supplement for taurodontism diagnosis. METHODS: The included patients were aged 10-89 years and admitted to the Department of Stomatology of Hebei Eye Hospital from June 1, 2022 to May 31, 2023. Eighty cone-beam computed tomography images were divided equally into 4 groups: 10-29, 30-49, 50-69, and 70-89 years old. The right mandibular first molars were selected as measurement objects. Firstly, |BD| and taurodontism index (TI)-related parameters were measured using Shifman and Chanannel's method and crown-body(CB) and root (R) lengths was measured by Seow and Lai's method. The improved method used the length from the cementoenamel junction(CEJ) to the root bifurcation point(body, B)and the root length(root, R)as the measurement objects. Finally, TI, CB/R ratios, and B/R ratios were calculated according to the formulas given below. One-way ANOVA analysis was mainly used to compare the differences in the values, indices and ratios of taurodontism among different age groups (p<0.05). RESULTS: With the increase of age, |BD| and TI values decreased significantly (p<0.01). The CB/R ratios of 70-89 years group were significantly lower than those of the other three groups (p<0.01). Ratios derived from the improved method were significantly lower in the 70-89 years than in 10-29 years group (p<0.05). CONCLUSIONS: The |BD| and TI parameters proposed by Shifman and channel are significantly influenced by age. The measurements of Seow and Lai (CB/R ratios) were less affected by age compared with those of the former. The improved method(B/R ratios) was least affected by age, which would reduce error and bias in the measurement of taurodontism and obtain more objective results in older patients.

Modern methods and materials used to treat root perforation: effectiveness comparison.

This study aims to experimentally compare the efficacy of different endodontic materials (iRoot BP Plus, Biodentine, MTA, Rootdent, and Trioxide) in the treatment of pulpitis and perforations on extracted tooth specimens. Additionally, the study aims to investigate the influence of iRoot BP Plus endodontic material on the regenerative processes following pulp amputation in laboratory animals. The secondary goal is to evaluate the effect of iRoot BP Plus on the restoration process in laboratory animals after pulp removal. The study presents a micropermeability analysis of the selected biomaterials performed on a sample of 50 single-rooted apical teeth in 2022. All teeth underwent endodontic treatment. Changes in molar morphology were investigated with eight laboratory animals (rabbits, 3 months old, all males) after simulated pulp removal and subsequent treatment with the iRoot BP Plus biomaterials. iRoot BP Plus appeared to be more effective in retrograde apical root filling than other biomaterials, as evidenced by its higher sealing effect. An experiment involving animal participants revealed the presence of protective adaptive mechanisms, which manifested in the form of an inflammatory process within 6 weeks after the dental pulp was removed. The connective tissue replaced the necrosis, and new capillaries began to form intensively. These dental outcomes suggest that iRoot BP Plus enables hermetical sealing in tooth restoration with good adhesion. Thus, it may have the ability to promote more active tissue regeneration after pulp removal.

High prevalence of taurodontism in North China and its relevant factors: a retrospective cohort study.

OBJECTIVE: The purpose of this study was to investigate the prevalence and relevant factors of taurodontism in North China. METHODS: We retrospectively analysed the cone beam computed tomography (CBCT) of 1025 patients (496 male and 529 female) aged between 10 and 59 years. The crown-body/root (CB/R) ratios of the maxillary and mandibular molars were measured. The prevalence of hypotaurodontism, mesotaurodontism, and hypertaurodontism was then calculated and the incidence of taurodontism along with its relevant factors, was evaluated. RESULTS: The overall rate of taurodontism in North China was as high as 78.9%. If the third molars (opsigenes) were excluded, which have a big morphological variation from each other, the rate was 52.4%. The mean CB/R ratio of taurodontism differs from tooth position: maxillary mandibular third molars > maxillary third molars > maxillary second molars > maxillary first molars > mandibular second molars > mandibular first molars (P < 0.05). In addition, the 1025 patients were divided into different age groups, and it was found that the mean CB/R ratio decreased with age (P < 0.05). Moreover, the CB/R ratio of the mandibular first and second molars in female patients was higher than males (P < 0.05). CONCLUSION: This study revealed that taurodontism is widely prevalent in North China. The incidence of taurodontism increases the closer the tooth is to the back end of the dental arch, and quite a few of the maxillary and mandibular third molars teeth have tapered roots. And the taurodontism is decreased by age, as there were more affected female than male patients.

Changes in vesicular glutamate transporter 2 (Vglut2) and vesicular GABA transporter 1 (Vgat1) in the orofacial pain and temperature perception pathway under low estrogen conditions.

OBJECTIVE: To investigate the effects of estrogen on the threshold and temperature of orofacial pain and explore the influence on the function of glutamate and GABA neurons in the orofacial pain temperature perception pathway by observing the expression of vesicular glutamate transporter 2 (Vglut2) and vesicular GABA transporter 1 (Vgat1). METHODS: A total of 24 adult female Sprague-Dawley rats were divided into three groups: sham operation (SHAM), ovariectomized (OVX) and ovariectomized plus estrogen intervention (OVX+E) (n = 8 per group). The threshold of mechanical pain of the orofacial region was assessed with von Frey filaments, and the temperature of the rat orofacial region was monitored by infrared thermography. Changes in the expression of Vglut2 and Vgat1 in glutamatergic and GABAergic neurons in the trigeminal ganglion (TG), spinal trigeminal nucleus (Sp5C), lateral parabrachial nucleus (LPB) and ventral posteromedial nucleus of the thalamus (VPM) were assessed by immunostaining and Western blotting. RESULTS: Under low-estrogen conditions, the mechanical pain threshold of the orofacial region of rats decreased significantly, and the temperature of the orofacial region increased significantly. The expression of Vglut2 and Vgat1 in the TG and Sp5C showed a downward trend, and the decline in Vgat1 was greater than that in Vglut2. Conversely, both proteins were upregulated in the LPB and VPM, and the magnitude of the changes in Vglut2 was greater than that in Vgat1. Estrogen therapy reversed these changes. CONCLUSION: Under low-estrogen conditions, the proportion of glutamate and GABA neurons in the orofacial pain and temperature sensation pathway changes, which leads to the imbalance of neurotransmission function and the enhancement of excitatory transmission of these two kinds of neurons and finally leads to a decrease in the orofacial pain threshold and an increase in temperature.

Effect of estradiol and Remifemin on the dorsal lingual epithelium of ovariectomized rats.

BACKGROUND: In this study, the ovariectomized rat model was used to explore the impact of menopause on rats' dorsal lingual epithelium; at the same time, the curative effects of Remifemin and estradiol were also observed. METHODS: 28 adult female Sprague-Dawley rats were divided into four groups randomly, including sham-operated group (SHAM), an ovariectomized group (OVX), an ovariectomized treated with estradiol (OVX + E), an ovariectomized treated with Remifemin (OVX + iCR). Variation and possible mechanisms were studied via morphology, immunohistochemistry and electron microscope. RESULTS: The results showed that the dorsal lingual epithelium became thinner significantly in the apex part in OVX group, as well as the levels of proliferating cell nuclear antigen (PCNA) and the epidermal growth factor (EGF) were lower than that in other three groups. However, they could reverse close to normal after estradiol and Remifemin treatment respectively. CONCLUSION: The thinning in the apex of dorsal lingual epithelium might be due to the reduced proliferation in the germinal layer led by the abating of estrogen level, instead of apoptosis. This might play an important role in the pathogenesis of the menopause female tongue burning sensation. Remifemin had certain curative effect on the dorsal lingual mucosa, but a little more inferior than estrogen.

Knockdown of long non-coding RNA prostate cancer-associated transcript 1 inhibits the proliferation and metastasis of tongue squamous cell carcinoma cells by upregulating p21.

Long non-coding RNA (lncRNA) prostate cancer-associated transcript 1 (PCAT-1) is a long non-coding RNA involved in the development of various cancer types. Tongue squamous cell carcinoma (TSCC) is the most frequently diagnosed type of oral cancer worldwide. The present study aimed to explore the role of lncRNA PCAT-1 in TSCC, and to provide a preliminary assessment of the downstream pathways involved. The expression levels of lncRNA PCAT-1 in TSCC specimens were first assessed. Subsequently, lncRNA PCAT-1 was knocked down in TSCC cell lines and the resulting effect on the proliferation and apoptosis, as well as the metastatic and invasive potential of TSCC cells was investigated. To assess the downstream signaling resulting from lncRNA PCAT-1 inhibition, the expression of p21 was also detected. The results indicated that lncRNA PCAT-1 was upregulated in clinical TSCC compared with peri-tumor tissues. Inhibition of lncRNA PCAT-1 resulted in reduced proliferation and apoptosis of TSCC cells, in addition to the suppression of migration and invasion. Furthermore, the expression of p21 was induced following lncRNA PCAT-1 inhibition. Collectively, the present study demonstrated an oncogenic role for lncRNA PCAT-1 in TSCC; inhibition of lncRNA PCAT-1 reduced the growth, metastasis and invasion of TSCC, at least in part via the induction of p21 signaling.

Effects of standardized isopropanolic black cohosh and estrogen on salivary function in ovariectomized rats.

Oral dryness is a common feature in menopausal women. Estrogen therapy can relieve this symptom; however, the underlying mechanism was not clear. Standardized isopropanolic black cohosh (Actaea racemosa; Remifemin) can also relieve menopausal symptoms, such as hot flashes and sweating. Our previous study showed that standardized isopropanolic black cohosh could protect the submandibular gland structure. To investigate the effects and possible mechanisms of action of estrogen and standardized isopropanolic black cohosh on submandibular gland function in ovariectomized (OVX) rats, we measured body weight, daily water consumption, and blood flow in the submandibular glands. Immunohistochemistry and western blotting were used to detect the expression of muscarinic acetylcholine receptors 1 (M1) and 3 (M3), and aquaporin 5 (AQP5) in the submandibular gland. OVX increased daily water consumption and reduced vasodilation in the submandibular gland. It suggested that ovariectomy could damage the salviary function. Moreover, the expression of M1 and M3 receptors decreased, whereas that of AQP5 increased. These changes may explain the dysfunction of saliva secretion in menopause. Estrogen and standardized isopropanolic black cohosh treatment had the same effect on daily water consumption and vasodilation in the submandibular gland. It indicated that estrogen and standardized isopropanolic black cohosh could relieve oral dryness in menopause. However, the mechanism of the two treatments may differ because standardized isopropanolic black cohosh only protected against changes in M1 expression, whereas estrogen protected against variations in M1, M3, and AQP5 expression.

Does Cimicifuga racemosa have the effects like estrogen on the sublingual gland in ovariectomized rats?

BACKGROUND: Cimicifuga racemosa is one of the herbs used for the treatment of climacteric syndrome, and it has been cited as an alternative therapy to estrogen. Apart from hectic fevers, dyspareunia and so on, dry mouth also increase significantly after menopause. It has not yet been reported whether C. racemosa has any impact on the sublingual gland, which may relate to dry mouth. In an attempt to determine this, we have compared the effects of estrogen and C. racemosa on the sublingual gland of ovariectomized rats. RESULTS: HE staining showed that the acinar cell area had contracted and that the intercellular spaces were broadened in the OVX (ovariectomized rats) group, while treatment with estradiol (E2) and iCR (isopropanolic extract of C. racemosa) improved these lesions. Transmission electron microscopy showed that rough endoplasmic reticulum expansion in mucous and serous acinar epithelial cells and apoptotic cells was more commonly seen in the OVX group than in the SHAM (sham-operated rats) group. Mitochondria and plasma membrane infolding lesions in the striated ducts were also observed. These lesions were alleviated by both treatments. It is of note that, in the OVX + iCR group, the volume of mitochondria in the striated duct was larger than in other groups. Immunohistochemical staining showed that the ratio of caspase-3 positive cells was significantly increased in the acinar cells of the OVX group compared with the SHAM group (p < 0.05); and the MA (mean absorbance) of caspase-3 in the striated ducts also increased (p < 0.05). Estradiol decreased the ratio of caspase-3 positive cells and the MA of caspase-3 in striated ducts significantly (p < 0.05). ICR also reduced the ratio of caspase-3 positive cells and the MA in the striated ducts (p < 0.05), but the reduction of the MA in striated ducts was inferior to that of the OVX + E2 group (p < 0.05). CONCLUSION: Both estradiol and iCR can inhibit subcellular structural damage, and down-regulate the expression of caspase-3 caused by ovariectomy, but their effects were not identical, suggesting that both drugs confer a protective effect on the sublingual gland of ovariectomized rats, but that the specific location and mechanism of action producing these effects were different.

Does Cimicifuga racemosa have the effects like estrogen on the sublingual gland in ovariectomized rats?

BACKGROUND: Cimicifuga racemosa is one of the herbs used for the treatment of climacteric syndrome, and it has been cited as an alternative therapy to estrogen. Apart from hectic fevers, dyspareunia and so on, dry mouth also increase significantly after menopause. It has not yet been reported whether C. racemosa has any impact on the sublingual gland, which may relate to dry mouth. In an attempt to determine this, we have compared the effects of estrogen and C. racemosa on the sublingual gland of ovariectomized rats. RESULTS: HE staining showed that the acinar cell area had contracted and that the intercellular spaces were broadened in the OVX (ovariectomized rats) group, while treatment with estradiol (E2) and iCR (isopropanolic extract of C. racemosa) improved these lesions. Transmission electron microscopy showed that rough endoplasmic reticulum expansion in mucous and serous acinar epithelial cells and apoptotic cells was more commonly seen in the OVX group than in the SHAM (sham-operated rats) group. Mitochondria and plasma membrane infolding lesions in the striated ducts were also observed. These lesions were alleviated by both treatments. It is of note that, in the OVX + iCR group, the volume of mitochondria in the striated duct was larger than in other groups. Immunohistochemical staining showed that the ratio of caspase-3 positive cells was significantly increased in the acinar cells of the OVX group compared with the SHAM group (p < 0.05); and the MA (mean absorbance) of caspase-3 in the striated ducts also increased (p < 0.05). Estradiol decreased the ratio of caspase-3 positive cells and the MA of caspase-3 in striated ducts significantly (p < 0.05). ICR also reduced the ratio of caspase-3 positive cells and the MA in the striated ducts (p < 0.05), but the reduction of the MA in striated ducts was inferior to that of the OVX + E2 group (p < 0.05). CONCLUSION: Both estradiol and iCR can inhibit subcellular structural damage, and down-regulate the expression of caspase-3 caused by ovariectomy, but their effects were not identical, suggesting that both drugs confer a protective effect on the sublingual gland of ovariectomized rats, but that the specific location and mechanism of action producing these effects were different.

A comparison of the effects of estrogen and Cimicifuga racemosa on the lacrimal gland and submandibular gland in ovariectomized rats.

This study aims to observe the effects of estradiol and Cimicifuga racemosa on the lacrimal gland and submandibular gland of ovariectomized rats. We randomly divided 20 adult female SD rats into four groups-a sham-operated group (SHAM), ovariectomized (OVX) group, ovariectomized group treated with estradiol (OVX+ E), and ovariectomized group treated with the isopropanolic extract of Cimicifuga racemosa (OVX+ iCR). The SHAM group and OVX group used distilled water to instead the drugs. Two weeks after ovariectomy, the estradiol and iCR were administered for 4 weeks. Next, we used H&E staining and electron microscopy to observe any histological changes in the lacrimal and submandibular glands and immunohistochemical staining to observe the expressions of cleaved caspase-3 (Casp-3) and Cu-Zn SOD (superoxide dismutase). The H&E staining find that both drugs can prevent the cells of area from shrinkage in the two kinds of gland. But under the electron microscopy, estradiol and iCR have different efficacy. Estradiol is more effective at protecting mitochondria in lacrimal gland acinar cells than iCR, and iCR is more effective at suppressing endoplasmic reticulum expansion than estradiol. Both estradiol and iCR have a similar protective function on mitochondria in the submandibular gland. The protective function of the two glands may inhibit apoptosis by suppressing the expression of Casp-3. In addition, iCR increases the expression of Cu-Zn SOD in duct system of submandibular gland. The results suggest that both estradiol and iCR confer a protective effect on the lacrimal and submandibular glands of ovariectomized rats via different mechanisms.

Effects of estradiol valerate and remifemin on norepinephrine signaling in the brain of ovariectomized rats.

AIMS: We investigated the norepinephrine pathway changes from the locus coeruleus (LC) to the preoptic area of the hypothalamus (POAH) in the brain of ovariectomized rats under low estrogen levels and explored the therapeutic effects of estradiol valerate (E2) and Remifemin (ICR) on these changes. METHODS: 40 female Sprague-Dawley rats were randomly divided into the following groups: surgery with vehicle (SHAM), ovariectomy surgery with vehicle (OVX), ovariectomy with E2 treatment (OVX + E2), and ovariectomy with Remifemin (OVX + ICR). After 4 weeks of treatment, we observed the changes by immunohistochemistry. RESULTS: (1) The average optical density of DBH-ir fibers and the number of α1-adrenoreceptor- and estrogen receptor (ER)α-positive neurons in the main nuclei of POAH were all reduced in OVX rats compared with the SHAM group. The above changes were normalized in all nuclei of the POAH in the E2 group, while they were normalized in some nuclei in the ICR group. Coexpression of ERα and α1-adrenoreceptor was observed in the POAH. (2) The number of DBH- and ERα-positive neurons in the LC decreased in the OVX group compared with the SHAM group and increased after treatment with E2 and ICR. Coexpression of ERα and DBH was observed in the LC. CONCLUSION: Low estrogen (OVX) altered norepinephrine synthesis in the LC, the projection of norepinephrine fibers and α1-adrenoreceptor expression in the POAH. Both E2 and ICR normalized the norepinephrine pathway, but E2 achieved greater effects than ICR. ICR had different effects in different nuclei in the POAH and its therapeutic effect was better in the LC.