• Restorative Dentistry and Endodontics
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• v.32 no.1
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• pp.37-46
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• 2007

The C-shaped canal system is an anatomical variation mostly seen in mandibular second molars, although it can also occur in maxillary and other mandibular molars. The main anatomical feature of C-shaped canals is the presence of fins or web connecting the individual root canals. The complexity of C-shaped canals prevents these canals from being cleaned, shaped, and obturated effectively during root canal therapy, and sometimes it leads to an iatrogenic perforation from the extravagant preparation. The purpose of this study was to provide further knowledge of the anatomical configuration and the minimal thickness of dentinal wall according to the level of the root. Thirty extracted mandibular second molars with fused roots and longitudinal grooves on lingual or buccal surface of the root were collected from a native Korean population. The photo images and radiographs from buccal, lingual, apical direction were taken. After access cavity was prepared, teeth were placed in 5.25% sodium hypochlorite solution for 2 hours to dissolve the organic tissue of the root surface and from the root canal system. After bench dried and all the teeth were embedded in a self-curing resin. Each block was sectioned using a microtome (Accutom-50, Struers, Denmark) at interval of 1 mm. The sectioned surface photograph was taken using a digital camera (Coolpix 995, Nikon, Japan) connected to the microscope. 197 images were evaluated for canal configurations and the minimal thickness of dentinal wall between canal and external wall using 'Root Thickness Gauge Program' designed with Visual Basic. The results were as follows : 1. At the orifice level of all teeth, the most frequent observed configuration was Melton's Type C I (73%), however the patterns were changed to type C II and C III when the sections were observed at the apical third. On the other hand, the type C III was observed at the orifice level of only 2 teeth but this type could be seen at apical region of the rest of the teeth. 2. The C-shaped canal showed continuous and semi-colon shape at the orifice level, but at the apical portion of the canal there was high possibility of having 2 or 3 canals 3. Lingual wall was thinner than buccal wall at coronal, middle, apical thirds of root but there was no statistical differences.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.12 no.2
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• pp.222-247
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• 1999

The back ground and purpose : The acupuncture of oriental medicine is very important in treatments. Until now it has been researched according to the meridian and qi xue(氣血) phenomenon of oriental medicine's theory. As electroacupuncture is one of acupuncture treatments, it will show more objective index to observe the meridian and qi xue(氣血) phenomenon. And then, I studied the effects on the thermal change of the face following electroacupuncture treatment. Objective and Methods : This study was performed from January 1999 to March 1999 on 10 healthy students. The objective was divided into three groups, those were the control group A(n=10), the group B(n=10) of electroacupuncture on Hapkok($LI_4$), Samgan($LI_3$) and the group C(n=10) of electroacupuncture on Shinmun($H_7$), T' ongni($H_5$). First, in the control group A, we took a picture for 10 men without any stimulation with the Digital Infrared Thermograph Imaging(D.I.T.I.) and did 3min after, 10min after, 15min after, 25min after, 45min after respectively. Second, in the electroacupuncture treatment group B, we took a picture for 10 men without any stimulation, and then treat electroacupuncture on Hapkok($LI_4$), Samgan($LI_3$) and took a picture immediately(3min after), 10min after, 15min after and remove needle and took a picture in the same way respectively. Third, in the electroacupuncture treatment group C, we took a picture for 10 men without any stimulation, and then treat electroacupuncture on Shinmun($H_7$), T'ongni($H_5$) and took a picture in the second way respectively. Results: 1. In healthy men, average skin temperture about Yonghyang($LI_{20}$) area was higher than Soryo($G_{25}$) or Chich'ang($S_4$) area. They were Soryo($G_{25}$) area $31.495{\pm}0.766^{\circ}C$, Rt. Yonghyang($LI_{20}$) area $31.664{\pm}0.936^{\circ}C$, Lt. Yonghyang ($LI_{20}$)area $31.686{\pm}0.767^{\circ}C$, Rt. Chich'ang($S_4$) area $31.226{\pm}0.875^{\circ}$, Lt. Chich'ang ($S_4$) area $31.453{\pm}0.855^{\circ}C$. 2. In the control group A, the skin temperature of Soryo($G_{25}$) showed the increase or decrease in below ${\Delta}0.1^{\circ}C\;except\;0.265{\pm}0.594^{\circ}C$ in 25min, but not significantly. 3. About Soryo($G_{25}$) area, the skin temperature decreased significantly after electroacupuncture immediately. ${\Delta}T $of the group B was $-0.970{\pm}0.87\;1^{\circ}C$, which was larger than one of the group C which was $-0.707{\pm}0.624^{\circ}C$ at 3min. And then ${\Delta}T$ of the group C was increase valuable at 25min, 45min. 4. About Yonghyang($L1_{25}$) area, the left ${\Delta}T$ of the group B showed below $0.2^{\circ}C$ or so in contrast to the right it. In the group C, on the both side showed continous increase of temperature as following times. 5. About Chich'ang($S_4$) area, the skin temperature increased valuable $0.3^{\circ}C$ or so on the both side and later inclined to decrease in the group B but not significantly. In the group C, it increased valuable on the both side. 6. The skin temperature of electroacupuncture treatment group B, C were more increase than the control group A except Lt. Yonghyang($LI_{20}$) area in the group B. The temperature of group C were more increase than the group B wholly. Conclusion : The above results indicate that D.I.T.I. is a useful method to observe and fallow-up the effects and the changes by electroacupuncture stimulation on objective evaluation of phenomenon for the meridian system and character. Thus, continuous thermographic study will be needed for more clinical application such as acupuncture and medicine or laser therapy according to oriental medicine.