The application of “bone window technique” using piezoelectric saws and a CAD/CAM-guided surgical stent in endodontic microsurgery on a mandibular molar case

Apical surgery for a mandibular molar is still challenging for many reasons. This report describes the applications of computer-guided cortical ‘bone-window technique’ using piezoelectric saws that prevented any nerve damage in performing endodontic microsurgery of a mandibular molar. A 49-year-old woman presented with gumboil on tooth #36 (previously endodontically treated tooth) and was diagnosed with chronic apical abscess.Periapical lesions were confirmed using cone-beam computed tomography (CBCT).Endodontic microsurgery for the mesial and distal roots of tooth #36 was planned. Following the transfer of data of the CBCT images and the scanned cast to an implant surgical planning program, data from both devices were merged. A surgical stent was designed, on the superimposed three-dimensional model, to guide the preparation of a cortical window on the buccal side of tooth #36. Endodontic microsurgery was performed with a printed surgical template. Minimal osteotomy was required and preservation of the buccal cortical plate rendered this endodontic surgery less traumatic. No postoperative complications such as mental nerve damage were reported. Window technique guided by a computer-aided design/computer-aided manufacture based surgical template can be considerably useful in endodontic microsurgery in complicated cases.

The application of “bone window technique” using piezoelectric saws and a CAD/CAM-guided surgical stent in endodontic microsurgery on a mandibular molar case

Apical surgery for a mandibular molar is still challenging for many reasons. This report describes the applications of computer-guided cortical ‘bone-window technique’ using piezoelectric saws that prevented any nerve damage in performing endodontic microsurgery of a mandibular molar. A 49-year-old woman presented with gumboil on tooth #36 (previously endodontically treated tooth) and was diagnosed with chronic apical abscess.Periapical lesions were confirmed using cone-beam computed tomography (CBCT).Endodontic microsurgery for the mesial and distal roots of tooth #36 was planned. Following the transfer of data of the CBCT images and the scanned cast to an implant surgical planning program, data from both devices were merged. A surgical stent was designed, on the superimposed three-dimensional model, to guide the preparation of a cortical window on the buccal side of tooth #36. Endodontic microsurgery was performed with a printed surgical template. Minimal osteotomy was required and preservation of the buccal cortical plate rendered this endodontic surgery less traumatic. No postoperative complications such as mental nerve damage were reported. Window technique guided by a computer-aided design/computer-aided manufacture based surgical template can be considerably useful in endodontic microsurgery in complicated cases.

Observation of an extracted premolar 2.5 years after mineral trioxide aggregate apexification using micro-computed tomography

Although numerous studies have been conducted on apexification using mineral trioxide aggregate (MTA), direct observation of extracted human teeth after the procedure has been rarely reported. This case report describes a mandibular premolar treated 2.5 years ago and extracted recently for orthodontic treatment. The tubercle of the right mandibular premolar of a 12-year-old boy with dens evaginatus was fractured and the pulp was exposed. The tooth was diagnosed with pulp necrosis and asymptomatic periapical abscess. During the first visit, copious irrigation was performed with 2.5% sodium hypochlorite. Calcium hydroxide paste was placed as an intracanal medicament. The sinus tract had disappeared at the second visit after 3 weeks. MTA was applied on to the bleeding point as a 4-mm-thick layer, followed by a 3-mm-thick gutta-percha filling and resin core build-up. After 2.5 years, the tooth and three other premolars were extracted for orthodontic treatment. The right and left mandibular premolars were scanned with micro-computed tomography to determine the root shape and canal anatomy. Irregular root growth was observed and the root outline of the right mandibular premolar differed from that of the contralateral tooth. Apexification with MTA leads to the formation of roots with irregular morphology, without any pulpal space.

Development of a mouse model for pulp-dentin complex regeneration research: a preliminary study

OBJECTIVES: To achieve pulp-dentin complex regeneration with tissue engineering, treatment efficacies and safeties should be evaluated using in vivo orthotopic transplantation in a sufficient number of animals. Mice have been a species of choice in which to study stem cell biology in mammals. However, most pulp-dentin complex regeneration studies have used large animals because the mouse tooth is too small. The purpose of this study was to demonstrate the utility of the mouse tooth as a transplantation model for pulp-dentin complex regeneration research. MATERIALS AND METHODS: Experiments were performed using 7-week-old male Institute of Cancer Research (ICR) mice; a total of 35 mice had their pulp exposed, and 5 mice each were sacrificed at 1, 2, 4, 7, 9, 12 and 14 days after pulp exposure. After decalcification in 5% ethylenediaminetetraacetic acid, the samples were embedded and cut with a microtome and then stained with hematoxylin and eosin. Slides were observed under a high-magnification light microscope. RESULTS: Until 1 week postoperatively, the tissue below the pulp chamber orifice appeared normal. The remaining coronal portion of the pulp tissue was inflammatory and necrotic. After 1 week postoperatively, inflammation and necrosis were apparent in the root canals inferior to the orifices. The specimens obtained after experimental day 14 showed necrosis of all tissue in the root canals. CONCLUSIONS: This study could provide opportunities for researchers performing in vivo orthotopic transplantation experiments with mice.

Rehabilitation of Transplantee and Transplant Games / 대한이식학회지

Many transplant recipients believe that exercise or physical activity after transplantation will have adverse effects on the body and the grafted organ, and even more, some of them believe that the grafted organ will tear off from the vascular bed inside of the abdominal cavity. As a result, many recipients are isolated from social life even after successful recovery of the grafted organ function. However, rehabilitation by physical exercise and activity is essential to return to normal social life. In 1978, a transplantee's sport game known as the Transplant Olympics, which later changed to the World Transplant Games, was started to improve the quality of life and develop friendships between transplant recipients globally. This event promotes improvement of recipient's life quality while delivering an important message to the public. This is because by engaging in sports activities, transplantees can show their healthy life after transplantation to the public. This can also improve self-esteem of the family of organ donors and allow them to verify that their decision to donate was not in vain. Additionally, the public can realize the benefits of transplantation and necessity for organ donation. Finally, the early return to social life and normal family life after transplantation will also reduce the national budget for health insurance. Although sports clubs are located in all transplant centers in Korea, no continuous athletic meetings or transplant sport organization exist nationwide. This problem is exacerbated by the lack of concern that transplant physicians and surgeons show toward recipients' physical activity and exercise. Therefore, in this study, we reviewed the significance of physical activity after transplantation and describe the world transplant games and domestic games to enable development of a recipient rehabilitation plan.

The Efficiency of Plasma Exchange for Renal Allograft Recipients with HLA Antibody before Transplantation / 대한수혈학회지

BACKGROUND: Therapeutic plasma exchange (TPE) is used to remove antibodies from the blood stream, thereby preventing them from attacking their targets. We evaluated the strategies to increase the efficiency of TPE for renal allograft recipients with HLA antibody. METHODS: A total of 11 patients were evaluated from January 2002 to April 2004. All the patients had been diagnosed with end stage renal disease (ESRD) and then they were scheduled for renal transplantation from a living unrelated donor or a living related donor. TPE was performed for all lymphocyte cross-matching (LCM) positive recipients before renal transplantation. One to three sessions of TPE were performed in 8 patients and four to seven sessions of TPE were performed in 3 patients (mean: 2.81 times). We used normal saline and 4% albumin as a replacement solution. RESULTS: Eleven patients, after the patients' LCM positive serum converted to negative, received the renal transplantation. Of the 11 recipients, only 1 recipient suffered from chronic rejection. Ten recipients maintained normal renal function. Among the 11 recipients, 4 recipients were diagnosed with posttransplantation diabetes mellitus. 3 recipients had a past history of graft failure via acute or chronic rejection. Even these 3 recipients experienced successful renal allograft through pre-transplantation TPE. Also, all the recipients were followed up until June, 2005. CONCLUSION: For ESRD patients with positive LCM, pre-transplantation TPE dramatically decreases the incidence of acute or chronic rejections by converting positive LCM into negative LCM.

Tibial Plateau Coverage in total knee Replacement arthroplasty

Maximizing tibial coverage is an important consideration in total knee replacement arthroplasty to provide stability and even load transfer and to improve long term survival rate of the implants. We evaluated the coverage, underhang and overhang ratio for the proximal tibial resection surface during total knee replacement arthroplasty in Koreans. After cutting the proximal tibia, the outline of tibial resection surface was traced manually. We compared 5 tibial tray designs, AGC(Biomet, Warsaw, U.S.A.), Advantim(Wright medical technology, Arlington, U.S.A.), AMK(DePuy, Warsaw, U.S.A), MG II(Zimmer, Indiana, U.S.A.), Series 7000(Osteonics, New Jersey, U.S.A.), which have been commercially used in Korea for total knee replacement arthroplasty. The average percentage of coverage area were 83.3% in AGC, 81.6% in AMK, 80.3% in MG II, 80.2% in Advantim and 76.9% in Series 7000. The average percentage of underhang were 16.7% in AGC, 18.4% in AMK, 19.6% in MG II, 19.8% in Advantim and 23,1% in Series 7000. The average percentage of overhang were measured 7.97% in AGC, 7.86% in AMK, 8.01% in MG II, 8.77% in Advantim and 10.14% in Series 7000. So average coverage percentage of tibial cutting surface was 80.5% in Koreans. The factors which affect the optimal coverage, were the shape, dimensional interval of tibial trays and the number of practically useful tibial trays for Koreans.