Preoperative prediction of conversion from laparoscopic rectal resection to open surgery: a clinical study of conversion scoring of laparoscopic rectal resection to open surgery.

OBJECTIVE: The objectives of this paper were to establish a model for the conversion of laparoscopic rectal resection to open surgery and to predict possible conversion before surgery. METHODS: The clinical data of 602 cases of laparoscopic rectal resection were retrospectively assessed. Risk factors associated with conversion of laparoscopic rectal resection to open rectal surgery were identified by logistic regression analysis. Also, a scoring system was created to calculate a score for the conversion of laparoscopic rectal resection to predict possible conversion for patients who underwent laparoscopic rectal resection before surgery. RESULTS: A total of 90 patients required conversion (total conversion rate = 14.95%). The established model included six variables: male gender, surgical experience (≤25 cases), history of abdominal surgery, body mass index ≥ 28, tumor diameter ≥ 6 cm, and tumor invasion or metastasis, for which 6, 4, 5, 10, 15, and 21 points were assigned, respectively. A patient with a total score >14.5 points was considered to have a high probability of conversion, whereas a patient with a total score <14.5 points was considered at a low risk. CONCLUSION: Preoperative determination of conversion score may predict possible conversion of laparoscopic rectal resection and thus reduce unnecessary open rectal surgery.

Applying the temporal self-regulation theory to understand sugar-sweetened beverage consumption among Chinese college students.

Objective: Worldwide, there is a growing trend that college students are consuming more and more sugar-sweetened beverages (SSBs). In order to develop effective intervention strategies, it is important to explore what social-cognitive factors impact on college students' SSB consumption. Building on the temporal self-regulation theory (TST), the current study aimed to examine the effects of intention, behavioral prepotency, and self-regulatory capacity on SSB consumption among college students. Design: Data were collected from five hundred Chinese college students online. Participants self-reported their intention, behavioral prepotency (environmental cues and habits), self-regulatory capacity, and behaviors of SSB consumption. Results: Study findings showed that intention, behavioral prepotency, and self-regulatory capacity accounted for 32.9% of variance in SSB consumption. In terms of the direct effects, intention, behavioral prepotency, and self-regulatory capacity were significantly associated with the SSB consumption among college students. In addition, self-regulatory capacity and habits but not the environmental cues showed significant moderation effects on the intention-SSB consumption path, indicating that individual factors rather than environmental cues influenced the intention-behavior path of SSB consumption among college students. Conclusion: Findings of the current study demonstrated that the TST can be used to explain and understand the impacts of social-cognitive factors on college students' SSB consumption. Future research can apply TST to develop effective intervention programs targeting the reduction of SSB consumption among college students.

Equivalence of the Wei potential model and Tietz potential model for diatomic molecules.

By employing the dissociation energy and the equilibrium bond length for a diatomic molecule as explicit parameters, we generate improved expressions for the well-known Rosen-Morse, Manning-Rosen, Tietz, and Frost-Musulin potential energy functions. It is found that the well-known Tietz potential function that is conventionally defined in terms of five parameters [T. Tietz, J. Chem. Phys. 38, 3036 (1963)] actually only has four independent parameters. It is shown exactly that the Wei [Phys. Rev. A 42, 2524 (1990)] and the well-known Tietz potential functions are the same solvable empirical function. When the parameter h in the Tietz potential function has the values 0, +1, and -1, the Tietz potential becomes the standard Morse, Rosen-Morse, and Manning-Rosen potentials, respectively.

Microscopic removal of type III dens invaginatus and preparation of apical barrier with mineral trioxide aggregate in a maxillary lateral incisor: A case report and review of literature.

BACKGROUND: Invaginated teeth pose greater challenges in clinical management because of their complex configuration. With advancements in equipment and materials, such as the dental operation microscope, cone-beam computed tomography and mineral trioxide aggregate, the preservation rate of type III dens invaginatus could be greatly increased. CASE SUMMARY: This case report presented a 31-year-old woman with complaints of spontaneous swelling and pain in the right maxillary lateral tooth. With the aid of cone-beam computed tomography, type III dens invaginatus with apical periodontitis was diagnosed and confirmed. Three-visit endodontic treatment was performed. In the first visit, the invagination was carefully removed under the dental operation microscope, and chemomechanical preparation was done. In the second visit, mineral trioxide aggregate apical barrier surgery was performed in this tooth. In the third visit, the canal was finally obturated with thermoplastic gutta-percha to recover the crown morphology. A 26-mo follow-up revealed a satisfied outcome both in the radiographic and oral examinations. CONCLUSION: In this case, removal of the entire abnormal structure provided great convenience for the follow-up treatment. When confronted with the same clinical case in the future, we can take a similar approach to address it.

[Evaluation of the filling quality of different root canal obturation techniques using micro-CT].

PURPOSE: The aim of this study was to evaluate the quality of different root canal obturation techniques by micro-CT. METHODS: Forty single-canal upper incisors were collected and decoronated to obtain 12 mm root segments. The root canals were prepared by using ProTaper rotary files and allocated into 4 groups randomly（n=10）, then obturated with gutta-percha and(or) iRoot SP by cold lateral compaction (CLC), continuous wave condensation (CWC), single core (SC), sealer-only buckfill (SoB) techniques, respectively. Each tooth was then scanned with micro-CT, and the percentage of 3D volume and 2D slices of voids and gaps were calculated 1 week later. The data were analyzed using SPSS 22.0 software package. RESULTS: Percentage of cross-sections with voids and gaps in CWC group was significantly less than others (P<0.05) , and it had a significantly greater filling area in 3D volume in whole root canal, middle third and coronal third levels (P<0.05), while SOB group had the largest filling quality in apical third levels (P<0.05). CONCLUSIONS: No filling technology can avoid voids. CWC technology provides the best filling performance.

Adult stem cell-based apexogenesis.

Generally, the dental pulp needs to be removed when it is infected, and root canal therapy (RCT) is usually required in which infected dental pulp is replaced with inorganic materials (paste and gutta percha). This treatment approach ultimately brings about a dead tooth. However, pulp vitality is extremely important to the tooth itself, since it provides nutrition and acts as a biosensor to detect the potential pathogenic stimuli. Despite the reported clinical success rate, RCT-treated teeth are destined to be devitalized, brittle and susceptible to postoperative fracture. Recently, the advances and achievements in the field of stem cell biology and regenerative medicine have inspired novel biological approaches to apexogenesis in young patients suffering from pulpitis or periapical periodontitis. This review mainly focuses on the benchtop and clinical regeneration of root apex mediated by adult stem cells. Moreover, current strategies for infected pulp therapy are also discussed here.

[Effect of KH2PO4 on the odonto- and osteogenic differentiation potential of human stem cells from apical papillae].

OBJECTIVE: To determine the effects of KH2PO4 on the odonto- and osteogenic differentiation potential of human stem cells from apical papillae (SCAP) in vitro. METHODS: SCAP were isolated and cultured respectively in alpha minimum essential medium (α-MEM) or α-MEM containing 1.8 mmol/L KH2PO4. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to examine the odonto and osteogenic potential of SCAP in the two media. RESULTS: SCAP cultured in α-MEM containing 1.8 mmol/L KH2PO4 exhibited a higher ALP activity [(0.370 ± 0.013) Sigma unit×min(-1)×mg(-1)] at day 3 than control group [(0.285 ± 0.008) Sigma unit×min(-1)×mg(-1)] and KH2PO4-treated SCAP formed more calcified nodules at day 5 [(0.539 ± 0.007) µg/g] and day 7 [(1.617 ± 0.042) µg/g] than those in normal medium [(0.138 ± 0.037) µg/g, P < 0.01]. The expression of odonto- and osteogenic markers were significantly up-regulated after the stimulation of KH2PO4 at day 3 and 7 respectively, as compared with control group. CONCLUSIONS: 1.8 mmol/L KH2PO4 can promote the odonto and osteogenic differentiation potential of human SCAP.

Bilateral maxillary fused second and third molars: a rare occurrence.

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.

Nonlinear finite element analysis of three implant- abutment interface designs.

The objective of this study was to investigate the mechanical characteristics of implant-abutment interface design in a dental , using nonlinear finite element analysis (FEA) method. This finite element simulation study was applied on three commonly used commercial dental implant systems: model I, the reduced-diameter 3i implant system (West Palm Beach, FL, USA) with a hex and a 12-point double internal hexagonal connection; model II, the Semados implant system (Bego, Bremen, Germany) with combination of a conical (450 taper) and internal hexagonal connection; and model III, the Brinemark implant system (Nobel Biocare, Gothenburg,Sweden) with external hexagonal connection. In simulation, a force of 170 N with 45" oblique to the longitudinal axis of the implant was loaded to the top surface of the abutment. It has been found from the strength and stiffness analysis that the 3i implant system has the lowest maximum von Mises stress, principal stress and displacement while the Br Bnemark implant system has the highest. It was concluded from our preliminary study using nonlinear FEA that the reduced-diameter 3i implant system with a hex and a 12-point double internal hexagonal connection had a better stress distribution, and produced a smaller displacement than the other two implant systems.

Risk factors analysis and scoring system application of conversion to open surgery in laparoscopic colorectal surgery.

To analyze the risk factors of laparoscopic colorectal surgery conversion rate, and establish the scoring system, retrospective study was performed and 429 patients who underwent laparoscopic colorectal surgery were analyzed. Conversion rate was 15.58%, and the risk factors include age, body mass index (BMI), operation number, abdominal operation history, invasion or metastasis, and tumor size. Scoring system established with age (≥ 65: 7, <65: 0), weight (BMI ≥ 25: 11, BMI <25: 0), operation number ≤ 25 (yes: 5, no: 0), abdominal operation history (yes: 12, no: 0), tumor size (≥ 6 cm: 22<6 cm: 0), and invasion or metastasis (yes: 34, no: 0). 18.5 uses to predict the conversion. Conversion rate below 18.5 is 5.21%, and above 18.5 is 42.62%. We concluded that scoring system is simple, convenient, and applicable.

[Study on the quality of life and social support among people living with HIV/AIDS and their family members].

OBJECTIVE: To explore the quality of life and related social support among people living with HIV/AIDS with related factors. METHODS: 331 people living with HIV/AIDS and 148 of their family members were selected using a typical sampling method. Questionnaires on general conditions, tables on history of infection, generic quality of life inventory-74 (GQOLI-74) and social support scale (SSS) were used. RESULTS: Data from one-way analysis suggested that people living with HIV/AIDS and their family members with the different sexs, different villages and different cultural backgrounds had differences in GQOLI-74 scores (P < 0.05) while people living with HIV/AIDS with the different villages had differences in SSS scores (P < 0.05). Results from Multiple linear regression analysis revealed that being elderly and negative life events were negatively associated with social support (P < 0.05), while factors as more advanced educational background, harmonious neighborhood relationship and having bother pouring nature were the predictive factors (P < 0.05). CONCLUSION: Many factors might affect dimensions of quality of life among people living with HIV/AIDS and their family members in rural areas of northern Anhui. Community care and social support of HIV/AIDS should still be greatly enhanced in the countryside of China. A community care mode based on family and neighborhood was expected to be developed.