Comprehensive characterization of epidemiological and 3D radiographic features of non-third molar impacted teeth in a Chinese dental population.

OBJECTIVE: This retrospective study aimed to comprehensively delineate the epidemiological and 3-dimensional radiographic characteristics of non-third molar (non-M3) impacted teeth in a Chinese dental population. MATERIAL AND METHODS: Patients with impacted teeth except for the third molar (ITEM3) were retrospectively screened via cone-beam CT images from 75,021 patients treated at our institution from June 2012 to December 2018. Demographic and clinical data of patients with ITEM3 were retrieved from medical records. CBCT coupled with 3-dimensional reconstruction was employed to characterize the radiographic features of ITEM3. Associations between these epidemiological, clinical, and radiographic features were further statistically analyzed. RESULTS: Among 1975 eligible patients, 2467 ITEM3s were identified with a prevalence of 2.63% (1975/75,021). Females slightly outnumbered males with a ratio of 1.12:1. The majority of ITEM3 was single (1577, 79.85%) in the maxilla. The maxillary canine teeth were the most frequently impacted (52.45%), followed by maxillary incisors. The mesioangular position was the most common orientation (43.8%), followed by vertical and buccal-lingual orientations. The most frequently associated lesion was external root resorption of the adjacent tooth, which was significantly correlated with the morphology and position of the impacted tooth. CONCLUSION: Most ITEM3 was single, mesioangular, found at maxillary canines, sometimes associated with diverse complications. Our data advance the current understanding of ITEM3 and offer insights into the management of this dental abnormality. CLINICAL RELEVANCE: These findings are useful for clinicians to comprehensively understand the prevalence, radiographic features, and complications of non-M3 impacted teeth.

Semaphorin3A promotes osseointegration of titanium implants in osteoporotic rabbits.

OBJECTIVE: In the present study, we intend to assess the function of Sema3A in osteointegration of titanium implants both in vivo and in vitro. MATERIAL AND METHODS: Briefly, Sema3A was transfected in HBMSCs cells to detect its effect on osteogenesis. Subsequently, an in vivo rabbit model was established. Eighteen female rabbits were randomly assigned into three groups (n=6), and rabbits in the two treatment groups (OVX groups) were subjected to bilateral ovariectomy, while those in the control group were treated with sham operation. Twelve weeks later, we first examined expression levels of Sema3A in rabbits of the three groups. Titanium implants were implanted in rabbit proximal tibia. Specifically, rabbits in sham group were implanted with Matrigel, while the remaining in the OVX experimental group (OVX+Sema3A group) and OVX group were implanted with Matrigel containing Sema3A adeno-associated virus or empty vector, respectively. RESULTS: Histomorphometry results uncovered that rabbits in the OVX+Sema3A group had a significantly higher BIC compared with those of the OVX group on the 12th week of post-implantation. And compared with the OVX group, the maximum push-out force increased by 89.4%, and the stiffness increased by 39.4%, the toughness increased by 63.8% in the OVX+Sema3A group at 12 weeks. CONCLUSION: Sema3A has a positive effect on promoting early osseointegration of titanium implants in osteoporotic rabbits. CLINICAL RELEVANCE: Our research found that Sema3A can improve the osteogenic ability of bone marrow stem cells and promotes osseointegration during osteoporosis.

Effect of verbascoside on apoptosis and metastasis in human oral squamous cell carcinoma.

Despite significant advances in therapy, the 5-year survival rates for patients with advanced stage oral cancers still remains poor as an appropriate treatment has not been found yet, due to side effects of chemo/radiotherapy. Verbascoside (VB), a major bioactive constituent of the Tsoong herb, displays pharmacological properties by exhibiting anti-oxidative, anti-inflammatory and anti-cancer activities. However, the underlining function and mechanism of VB in human oral squamous cell carcinoma (OSCC) remains unclear. In this study, we show that VB significantly decreased the viability and metastasis of HN4 and HN6 tumor cells, while promoting apoptosis. A xenograft OSCC mouse model further showed that intraperitoneal injection of VB strongly inhibited growth and lung metastasis of implanted tumor cells. Immunoblot analysis confirmed that VB effectively suppressed nuclear factor (NF)-κB activation and downstream Bcl-2/Bcl-XL expression, resulting in increased OSCC cell apoptosis. In addition, VB suppressed mRNA and protein expression of matrix metalloproteinase-9 via suppression of NF-κB activation, thereby inhibiting tumor cell metastasis. Inspiringly, compared to cisplatin-treated group, VB is a biocompatible agent without signficant side effects in vivo. Collectively, our results demonstrate that VB effectively inhibits OSCC tumor cell growth and metastasis via suppression of IκB kinase complex (IKK)/NF-κB-related signaling activation, suggesting that VB has potential use as a potent anticancer agent in OSCC therapeutic strategies.

Clinicopathological Characteristics and Outcome Predictors in Squamous Cell Carcinoma of the Maxillary Gingiva and Hard Palate.

PURPOSE: Squamous cell carcinoma (SCC) located in the maxillary gingiva and hard palate is relatively rare. There are few published guidelines for the treatment of SCC of the maxilla. The aim of the present study was to characterize the clinicopathologic features of SCC of the maxillary gingiva and hard palate and determine factors that predict outcome and lead to a strategic treatment plan. MATERIALS AND METHODS: A retrospective cohort study of patients with SCC of the maxillary gingiva and hard palate was conducted from 2003 to 2012 at the Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University. Clinicopathologic characteristics, treatments, outcome predictors, and 3- and 5-year overall survival rates were analyzed. The Kaplan-Meier method was used to evaluate 3- and 5-year overall survival rates. Univariate and multivariate Cox regression analyses were used to identify predictors of survival. A P value less than .05 was considered statistically significant. RESULTS: The 3- and 5-year survival rates of the 62 participants were 66.6 and 57.3%, respectively. Univariate analyses showed statistically significant (P < .05) associations between patient survival rate and tumor differentiation grade, T classification, marginal status, cervical lymphatics, and local recurrence. Occult lymph node metastases of maxillary SCC in tumor stages T2 to T4 occurred in 20 to 40% of patients. Patients who presented with lesions located after the first premolar plane area and received postoperative radiotherapy had a better prognosis. CONCLUSION: Elective neck dissection is recommended for management of T2 to T4 SCCs in the maxillary gingiva and hard palate. Postoperative radiotherapy can improve the prognosis and decrease the recurrence of SCC after the first premolar plane area.

Effect of Nd: YAG laser irradiation on surface properties and bond strength of zirconia ceramics.

This study investigated the effect of neodymium-doped yttrium aluminum garnet (Nd: YAG) laser irradiation on surface properties and bond strength of zirconia ceramics. Specimens of zirconia ceramic pieces were divided into 11 groups according to surface treatments as follows: one control group (no treatment), one air abrasion group, and nine laser groups (Nd: YAG irradiation). The laser groups were divided by applying with different output power (1, 2, or 3 W) and irradiation time (30, 60, or 90 s). Following surface treatments, the morphological characteristics of ceramic pieces was observed, and the surface roughness was measured. All specimens were bonded to resin cement. After, stored in water for 24 h and additionally aged by thermocycling, the shear bond strength was measured. Dunnett's t test and one-way ANOVA were performed as the statistical analyses for the surface roughness and the shear bond strength, respectively, with α = .05. Rougher surface of the ceramics could be obtained by laser irradiation with higher output power (2 and 3 W). However, cracks and defects were also found on material surface. The shear bond strength of laser groups was not obviously increased, and it was significantly lower than that of air abrasion group. No significant differences of the shear bond strength were found among laser groups treated with different output power or irradiation time. Nd: YAG laser irradiation cannot improve the surface properties of zirconia ceramics and cannot increase the bond strength of the ceramics. Enhancing irradiation power and extending irradiation time cannot induce higher bond strength of the ceramics and may cause material defect.

Development and validation of a nomogram to predict occult cervical metastasis in early oral squamous cell carcinoma.

Background: Lack of adequate objectivity and universality, available models are still difficult to be applied to clinical practice in predicting occult cervical metastasis of early oral squamous cell carcinoma (OSCC). Taking abnormal metabolic state into consideration, the current model is helpful to distinguish those patients with or without occult cervical metastasis. Methods: This study retrospectively analyzed 330 OSCC patients initially diagnosed cT1-2N0M0 stage and received neck dissection from January 2020 to July 2022. The occult cervical metastasis was identified by pathological examination.. After screening independent risk factors using logistic regression, patients were divided into training and validation cohorts at the ratio of 2:1 randomly, and a novel diagnostic model was constructed. Performances of this model were evaluated by the area under the curve (AUC), calibrating curve, decision curve analysis (DCA) and clinical impact curve (CIC). Results: Of the 330 included patients {age mean [standard deviation (SD)], 61.24 (12.99) years; 202 (61.2%) males}, 49 (14.8%) had occult nodal metastasis. Five variables, including body mass index (BMI) [high odds ratio (OR): 1.132; 95% confidence interval (CI): 1.019-1.258, P=0.021], primary tumor site (tongue & floor of mouth (TF) OR: 3.756; 95% CI: 1.295-10.898, P=0.015), depth of invasion (DOI) (5-10 mm OR: 2.973; 95% CI: 1.266-6.981; P=0.012), pathological differentiation (Poor differentiation OR: 2.65; 95% CI: 1.341-5.239; P=0.005), and diabetes (OR: 3.123; 95% CI: 1.23-7.929; P=0.017) were screened to establish the predictive model. In training cohort (n=220), this model achieved an AUC of 0.814 and had a sensitivity of 78.1% and specificity of 70.2%. Calibration plots showed favorable consistency between the prediction of the model and actual observations (Hosmer-Lemeshow value >0.05). Decision curve analysis (DCA) and clinical impact curve (CIC) showed the model was clinically useful and had better discriminative ability under the threshold probability of 0.5. Above evaluations were verified in the validation cohort (n=110). Compared to previous reported models, the concordance index (C-index), net reclassification index (NRI), and integrated discrimination improvement (IDI) values were superior in both training and validation cohorts (P<0.05). Conclusions: This constructed model might have reference value for clinicians in making neck management decisions of early OSCC patients.

Effect of Intracapsular Pressure on Decompression Effectiveness.

AIM: The objective of this research was to analyse the correlation between intracapsular pressure and shrinkage rate of cystic lesion volume at different time points after decompression and to evaluate the relationship between the concentration of interleukin-1α (IL-1α) in cystic fluid and intracapsular pressure. METHODS: Fifty patients with jaw cystic lesions who underwent decompression were included. We measured the intracapsular pressure and IL-1α concentration in the cyst fluid. Moreover, we calculated the rate of shrinkage (RS) of cystic cavity volume at different time points. In addition, data on age, sex, preoperative cystic cavity volume, and lesion location were collected. Linear correlation analysis and variance analysis were used for statistical analysis. RESULTS: Fastest volume decline was observed between 0 and 3 months after surgery; the average RS0-3 was 45.71%. RS3-6 presented the second-fastest volume decline, with an average of 17.46%, and RS6-12 presented the slowest volume decline, with an average of 3.933%. A statistically significant difference in RS was observed amongst the 3 time points (P < .0001). RS0-3 was negatively correlated with intracapsular pressure (r = -0.6326, n = 50, P < .0001). A negative correlation between the preoperative cystic cavity volume and intracapsular pressure (r = -0.6384, n = 50, P < .001) was also observed. A significant positive correlation was observed between preoperative cystic cavity volume and RS0-3 (r = 0.611, n = 50, P < .0001). Moreover, a significant positive correlation was observed between the intracapsular pressure and IL-1α concentration in the cystic fluid (r = 0.03477, n = 50, P < .0001). CONCLUSIONS: Intracapsular pressure and the preoperative volume were the factors that affected the RS during the first 3 months after surgery. Therefore, the effectiveness of decompression can be evaluated by the intracapsular pressure and preoperative volume.

In vitro evaluation of the antibacterial effect of colloidal bismuth subcitrate on Porphyromonas gingivalis and its biofilm.

OBJECTIVE: To investigate the antibacterial and anti-biofilm effects of colloidal bismuth subcitrate (CBS) on Porphyromonas gingivalis (P. gingivalis) in its planktonic and biofilm forms and also compare it with that of 0.2% chlorhexidine (CHX). DESIGN: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CBS were determined by the microdilution method; the bacteriostatic rate of CBS was determined by the MTT assay; the effect of CBS on the membrane integrity of P. gingivalis was investigated by the flow cytometric methods. The effects of CBS on the biomass and bacterial activity of biofilm were investigated. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to investigate the activity and structure of biofilms. RESULTS: The MIC and MBC values were 18.75 µg/mL and 37.5 µg/mL. CBS could damage the cell membrane of P. gingivalis. CBS effectively inhibited biofilm formation and promoted dissociation at higher concentrations of 37.5 µg/mL and 75 µg/mL, respectively. The results also indicated an altered biofilm structure and reduced biofilm thickness and bacterial aggregation. CONCLUSIONS: CBS affected the metabolic and physiological processes of P. gingivalis, inhibited the formation of biofilm, and disrupted the mature biofilm.

Intraoral versus transcervical approaches in mandibular reconstruction with free flaps: A retrospective study.

This study aims to investigate the clinical and functional differences between intraoral and transcervical approaches for segmental mandible resection and reconstruction with free flaps. Patients diagnosed as benign and low-grade mandibular malignant tumors without neck dissections were retrospectively reviewed and divided into intraoral and transcervical groups. Patients of intraoral group underwent intraoral mandibulectomy and vascular anastomosis was performed through a 2-cm submandibular incision, while traditional submandibular approach was used in transcervical group. Clinical characteristics of two groups were assessed including body mass index (BMI), defect types and number of fibular segments, as well as perioperative variables such as operation time, blood loss, drainage volume. The score of appearance, swallowing and speech using the University of Washington Quality of Life Questionnaire (UW-QOL) was recorded and analyzed 6-month postoperatively. A total of 14 patients in intraoral group and 21 patients in transcervical group was collected, respectively. In intraoral group, intraoperative blood loss and postoperative drainage volume were significantly reduced in comparison with transcervical group (p = 0.0146, p = 0.0017; respectively). The score of appearance was 87.50 ± 12.97 in intraoral group, which was significantly higher than 64.29 ± 12.68 in transcervical group (p < 0.0001). Similar results were found in patients of subtype Class II mandibular defect between two groups. However, patients of intraoral group had a significant increase in operative time and a comparable amount of intraoperative blood loss (p = 0.0472, p = 0.1434; respectively). Within the limitations of the study it seems that an intraoral approach combined with a 2-cm submandibular incision should be preferred over a transcervical approach for segmental mandibulectomy and free flap reconstruction whenever appropriate.

Radial forearm free flap for reconstruction of a large defect after radical ablation of carcinoma of the tongue and floor of the mouth: some new modifications.

BACKGROUND: A modified radial forearm free flap was designed to rehabilitate function and to reduce the complications at both donor and recipient sites. METHODS: Between 2003 and 2007, 15 patients with infiltrating squamous cell carcinoma (T(3)-T(4)) of the tongue and/or floor of the mouth underwent hemiglossectomy and resection of the floor of the mouth with microvascular reconstruction using a modified radial forearm flap. The mean size of the forearm flap was 7.5 x 14 cm, and the de-epithelialized area was 7 x 6 cm, requiring no skin graft from the abdomen. Speech intelligibility tests were administered to test postoperative speech and the functional oral intake scale was applied to assess the postoperative swallowing function, and patients reconstructed with pectoralis major myocutaneous flap were used for comparison. RESULTS: All the flaps were successfully transferred. No obvious complications were found in either the oral-maxillofacial or forearm region. The speech intelligibility was better in the modified flap group (p < 0.01). An acceptable swallowing function was also achieved, although the difference was not significant (p > 0.05). CONCLUSIONS: The modified flap used for reconstructing large defects of the tongue and floor of the mouth might be a valid substitute for pectoralis major myocutaneous flap to improve the outcome in individuals with significant oral carcinoma.

Application of lateral arm free flap in oral and maxillofacial reconstruction following tumor surgery.

OBJECTIVE: To describe the application of lateral arm free flap (LAFF) in reconstruction of defects in the oral and maxillofacial regions following ablative oncological surgery. SUBJECTS AND METHODS: The study included 16 patients (13 male, 3 female, mean age 56, range 35-69 years). Sixteen LAFF were harvested to reconstruct defects caused by the dissection of malignant tumors of the oral and maxillofacial regions. The tumor was squamous cell carcinoma of the tongue (6 cases), floor of the mouth (4), retromolar area (3), inner cheek (2), and lower gingival (1). Flap sizes ranging from 5 x 7 to 6 x 9 cm were harvested using a sterile tourniquet for bloodless technique. The anastomoses were carried out using a magnifier or microscope. All donor defects were closed primarily. RESULTS: Fourteen flaps healed without venous insufficiency. One flap, in a female patient, survived with mild local microcirculatory obstruction but that of another female patient developed necrosis. There was no significant complication at the donor sites. The advantages of this flap include anatomically reliable vascular supply, accessible donor site, and the aesthetic quality of donor tissue is good. Compared with the radial artery, the posterior radial collateral artery is a nonessential vessel of the arm. The disadvantages are the relatively smaller vessel size for anastomosis and thicker subcutaneous tissue. CONCLUSIONS: For the repair of moderate-sized defects of the maxillofacial area, especially in male patients, the LAFF can be recommended.

Differential expression of inducible nitric oxide synthase in keratocystic odontogenic tumors prior and subsequent to decompression.

The aim of the present study was to investigate the expression of inducible nitric oxide synthase (iNOS) in keratocystic odontogenic tumors (KCOTs) prior and subsequent to decompression and to explore the association between iNOS expression and changes in clinical features. Sixteen pairs of specimens obtained at the time of decompression and subsequent curettages were collected and immunohistochemically examined using an antibody against iNOS. The intensity of iNOS staining was evaluated semi-quantitatively for statistical analysis. Prior to decompression, 87.5% of KCOT samples showed no immunohistochemical reactivity for iNOS. Only 12.5% of samples exhibited slight staining for iNOS in the cytoplasm of cells in the epithelial layer. Subsequent to decompression, all the samples exhibited moderate to intense staining for iNOS in the cytoplasm and membrane of cells in the epithelial and fibrous layers. This increased expression of iNOS following decompression was statistically significant (P<0.01). The results demonstrated distinct expression of iNOS in KCOT samples prior and subsequent to decompression, indicating that iNOS may have a role in mediating changes in clinical features.

[Expression of full-length spleen tyrosine kinase in the oral squamous cell carcinoma and its relationship with tumor invasion and metastasis].

OBJECTIVE: To investigate the expression of full-length spleen tyrosine kinase [SYK (L)] mRNA and protein in human oral squamous cell carcinoma (OSCC) as well as its possible effects on the invasion and metastasis of OSCC. METHODS: The expression of SYK (L) was detected in 27 cases of OSCC tissues and its matched adjacent non-cancerous tissues by real-time quantitative polymerase chain reaction (RT-qPCR), Western blot, and immunohistochemistry. Fourteen cases of normal oral gingival tissues were also analyzed as a normal control. RESULTS: Reduced mRNA and protein expression of SYK (L) in OSCC tissues was observed compared with that in normal oral gingival tissues (P<0.01) and adjacent non-cancerous tissues (P<0.05). SYK(L) expression was significantly associated with lymph-node metastasis (P<0.05). CONCLUSION: SYK(L) is a candidate tumor suppressor for OSCC tissues, and has an inhibitive effect on the initiation, proliferation, and lymph-node metastasis of human OSCC.

Effect of Er:YAG laser irradiation on bonding property of zirconia ceramics to resin cement.

OBJECTIVE: This study aimed to investigate whether or not an erbium: yttrium-aluminum-garnet (Er:YAG) laser could improve the bonding property of zirconia ceramics to resin cement. BACKGROUND DATA: Surface treatments can improve the bonding properties of dental ceramics. However, little is known about the effect of Er:YAG laser irradiated on zirconia ceramics. MATERIALS AND METHODS: Specimens of zirconia ceramic pieces were made, and randomly divided into 11 groups according to surface treatments, including one control group (no treatment), one air abrasion group, and nine Er:YAG laser groups. The laser groups were subdivided by applying different energy intensities (100, 200, or 300 mJ) and irradiation times (5, 10, or 15 sec). After surface treatments, ceramic pieces had their surface morphology observed, and their surface roughness was measured. All specimens were bonded to resin cement. Shear bond strength was measured after the bonded specimens were stored in water for 24 h, and additionally aged by thermocycling. Statistical analyses were performed using one way analysis of variance (ANOVA) and Tukey's test for shear bond strength, and Dunnett's t test for surface roughness, with α=0.05. RESULTS: Er:YAG laser irradiation changed the morphological characteristics of zirconia ceramics. Higher energy intensities (200, 300 mJ) could roughen the ceramics, but also caused surface cracks. There were no significant differences in the bond strength between the control group and the laser groups treated with different energy intensities or irradiation times. Air abrasion with alumina particles induced highest surface roughness and shear bond strength. CONCLUSIONS: Er:YAG laser irradiation cannot improve the bonding property of zirconia ceramics to resin cement. Enhancing irradiation intensities and extending irradiation time have no benefit on the bond of the ceramics, and might cause material defect.

[Effect of jaw forward distance on forced inspiratory airflow in patients with obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To study the effect of different jaw forward distance on forced inspiratory airflow(FIF) in non-apnea subjects and patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and to evaluate the effective jaw forward distance for the treatment of OSAHS with the oral appliance. METHODS: FIF was measured in 18 non-apnea subjects and 18 OSAHS patients at supine and lateral body positions with different jaw forward distances (the percentages of maximum jaw forward distance): 0%, 25%, 50% and 75%. FIF were converted to percentage values (FIF%, x(-) ± s) followed by averaged. Then the results were analyzed by one-way analysis of variance and paired t-test with α = 0.05. RESULTS: For non-apnea subjects, there was no significant difference in the FIF values between different jaw forward distances as well as different body positions. For OSAHS patients, the mean FIF% at supine and lateral body positions were 107.1% ± 29.0% and 112.0% ± 33.1% at jaw forward 50%, and were 106.4% ± 20.7% and 116.8% ± 36.4% at jaw forward 75%, respectively, which were significantly higher than those (84.0% ± 18.3% and 98.3% ± 24.0%) at jaw forward 0% or those (92.7% ± 21.8% and 103.7% ± 22.6%) at jaw forward 25%, respectively. But there was no statistical difference in FIF between the two groups of jaw forward 50% and jaw forward 75% and no statistical difference in FIF between supine and lateral body positions in the same forward position. CONCLUSION: Jaw forward 50% is a effective jaw forward distance by oral appliance for the treatment of OSAHS and can improve the airway ventilation in OSAHS patients.

Effects of head and body positions on 2- and 3-dimensional configuration of the oropharynx with jaw protruded: a magnetic resonance imaging study.

OBJECTIVE: The aim of this study was to evaluate the effect of altering changing head and body positions on the 2- and 3-dimensional (3D) configuration of the oropharynx with jaw protrusion. STUDY DESIGN: Twelve healthy individuals (8 male, 4 female) with no history of sleep disturbances were invited to participate. For each subject, an acrylic splint was made with the mandible in protruded position. Subjects were imaged using magnetic resonance imaging in 4 different jaw, head, and body positions: 1) supine without protrusion; 2) supine with jaw protrusion; 3) supine with head rotation and jaw protrusion; and 4) laterally recumbent position with jaw protrusion. The 2- and 3D images of the upper airway in different positions were reconstructed by using a free DICOM reconstruction software. The dimension changes (anteroposterior and lateral dimensions, cross-sectional area, and volume) of the oropharynx (divided into retropalatal region and retroglossal region) were calculated and analyzed. Statistical analyses were performed using the Bartlett test and 1-way analysis of variance with α = .05. RESULTS: Compared with nonprotruded position, dimensions of the oropharynx for both retropalatal region and retroglossal regions were found to be greater than with jaw protrusion. Head and body positions had little effect on configuration of the oropharynx with jaw protrusion in either 2- or 3D. The only change noted was a greater anteroposterior dimension of retropalatal region with head rotation and lateral supine position compared with the supine position. CONCLUSIONS: Head and body positions have little effect on 2- and 3D airway dimensions on supine patients with jaw protrusion.