Objective:To observe the clinical effects of extraoral manual reposition approach in the treatment of acute anterior disloca-tion of temporomandibular joint. Methods:98 patients with acute anterior dislocation of temporomandibular joint were divided into 2 groups(n=49) by random digit table and treated by manual reposition through intraoral and extraoral approach respectively. The suc-cess rate, success time, patient pain during treatment, SBP, DBP, HR and patient satisfaction were evaluated respectively. Results:The success rate(95. 92%) and the patient satisfaction rate(76%) of extraoral method group were higher than those of the intraoral method group (81. 63% and 66%);success time(3. 91 ± 0. 55)s and patient pain during treatment(3. 51 ± 0. 25) in extraoral method group were less than those in the intraoral method group[(5. 57 ± 0. 51) s and (6. 6 ± 0. 21)]. The degree of changes of SBP, DBP and HR in extraoral method group were less than those in the intraoral method group(P<0. 05). Conclusion:Extraoral manual reposi-tion approach is more effective than intraoral approach in the treatment of acute anterior dislocation of temporomandibular joint.

OBJECTIVETo observe the changes of surface morphology and temperature of dental pulp cavity in vitro after irradiated by Er:YAG laser with different energy and irradiation time.

METHODSAll of the 96 samples from 24 teeth in vitro were collected from dental clinical departments then divided into two groups (group A and group B) randomly. We chose the energy of 20 Hz, and 1, 2, 3, 4, 5, 6 W to treat the samples in group A and group B and the irradiation time was 10s or 20s. We recorded the temperature changes of dental pulp cavity by digital thermometer and observe the morphology of tooth enamel by scanning electron microscope (SEM).

RESULTSWith the extension of irradiation time and increasing of energy, the temperatures of dental pulp cavity were significantly increased after the treatment of Er: YAG laser. The two groups of tooth enamel surface morphology were changed after irradiated by Er: YAG laser with different energy and irradiation time. However, there was no melting and carbonation on the surface of tooth enamel after the treatment of Er:YAG laser in two groups.

CONCLUSIONThe temperatures of dental pulp cavity were increased after irradiated by increasing laser energy density fom 1 W to 6 W. No melting or carbonized phenomenon was found in enamel within the energy of 1 W to 6 W. All the data would provide evidences for clinical treatment of cavity.

Dental Caries ; Dental Enamel ; Dental Pulp Cavity ; Humans ; In Vitro Techniques ; Lasers ; Lasers, Solid-State ; Microscopy, Electron, Scanning ; Temperature

OBJECTIVETo compare the consistency of root canal configuration types of mandibular first premolar by using micro-CT and radio visio graphy (RVG).

METHODSOne hundred extracted mandibular first premolars with complete dental root and apex which received no endodontic treatment were randomly selected. Each tooth was radiographed with RVG through a buccolingual and mesiodistal direction, and then scanned with micro-CT and reconstructed. The classifications of the root canal types according to Vertucci's type with the two methods were compared.

RESULTSThe canal patterns were classified as type I (67%), type III (3%), type V (18%), type VII (2%), additional type (10%) with micro-CT and canal patterns as type I (71%), type III (2%), type V (23%), type VII (1%), additional type (3%) with RVG. 63% of teeth showed one canal in both micro-CT and RVG. Only 25% of teeth were diagnosed as complex canal by the same canal type in both micro-CT and RVG. The Kappa value between micro-CT and RVG was 0.541 which suggested that the two kinds of methods had intermediate consistency. 82.8% of the premolars with root groove had two or more than two canals.

CONCLUSIONAlthough RVG can basically reflect the root canal system type of the mandibular first premolars in vitro, it offers poor accuracy images to complex root canals. Micro-CT three-dimensional images could clearly and precisely display the root canal system morphology of the mandibular first pre-molars in vitro.

Bicuspid ; Dental Pulp Cavity ; Humans ; Mandible ; Molar ; Root Canal Therapy ; Tooth Root ; X-Ray Microtomography

The p75 neurotrophic factor receptor is a low affinity receptor for neurotrophic factors and plays an important role in nerve growth, development and function integrity. It is closely related to dental development, oral and maxillofacial tumor, nerve repair and tissue engineering. It shows good prospect for application. In this paper, the research progress of p75 neurotrophic factor receptor in Stomatology is reviewed.