• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.3
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• pp.276-281
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• 2010

The maxillary posterior area is the most challenging site for the dental implant. After missing of teeth on maxillary posterior area due to periodontal problems, the remaining alveolar ridge is usually very thin because of not only pneumatization of maxillary sinus but also destruction of alveolar bone. The maxillary sinus bone graft procedure is one of the most predictable and successful treatments for the rehabilitation of atrophic and pneumatized endentulous posterior maxilla. But, in case of severe destruction of alveolar bone due to periodontal problems, very long crown length is still remaining problem after successful sinus graft procedures. We performed vertical augmentation of maxillary posterior alveolar ridge using mandibular ramal block bone graft with simultaneous sinus graft. After this procedures, we could get more favorable crown-implant ratio of final prosthodontic appliance and more satisfactory results on biomechanics. This is a preliminary report of the vertical augmentation of maxillary posterior alveolar ridge using mandibular ramal block bone graft with simultaneous sinus graft, so requires more long-term follow up and further studies.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.241-243
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• 2006

Central pain is defined as pain associated with lesions of the central nervous system, and is among the most intractable of chronic pain syndromes. A 47 year-old-female, who had right arm and shoulder pain, was diagnosed with syringomyelia of the Arnold Chiari malformation type I and received foramen magnum decompression and a syringo-subarachnoid shunt. After the operation, the evoked pain was improved, but she complained of a continuous burning pain, coupled with cold and tactile allodynia. This symptom failed to fully subside on administration of oral medicine; therefore, brachial plexus block was performed, which relieved her pain transiently. Through repeated trials, a gradual decrease in the pain intensity and frequency was found. However, the way in which brachial plexus block improves spinal central pain is not completely known.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.2
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• pp.123-129
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• 2016

Whereas a somatic pain notifies tissue damage, a neuropathic pain presents disorder of the nerve itself. The causes of neuropathic pains are trauma, infection, chronic irritation by adjacent tissue and so on. The iatrogenic trauma or infection also causes traumatic neuropathy, which may exert a bad influence on doctor-patient relationship. Some of related dental treatments are implantation (directly or indirectly through heating), root canal treatment, teeth extraction, block anesthesia, mandibular surgery. If inappropriate management is performed after nerve trauma, there will be many chances to develop chronic neuropathy for the patient. It is important that the sign of nerve trauma have to be caught by the practitioner as soon as possible and treated properly.

• The korean journal of orthodontics
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• v.44 no.2
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• pp.69-76
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• 2014

Objective: This study aimed to evaluate the accuracy and precision of polyurethane (PUT) dental arch models fabricated using a three-dimensional (3D) subtractive rapid prototyping (RP) method with an intraoral scanning technique by comparing linear measurements obtained from PUT models and conventional plaster models. Methods: Ten plaster models were duplicated using a selected standard master model and conventional impression, and 10 PUT models were duplicated using the 3D subtractive RP technique with an oral scanner. Six linear measurements were evaluated in terms of x, y, and z-axes using a non-contact white light scanner. Accuracy was assessed using mean differences between two measurements, and precision was examined using four quantitative methods and the Bland-Altman graphical method. Repeatability was evaluated in terms of intra-examiner variability, and reproducibility was assessed in terms of interexaminer and inter-method variability. Results: The mean difference between plaster models and PUT models ranged from 0.07 mm to 0.33 mm. Relative measurement errors ranged from 2.2% to 7.6% and intraclass correlation coefficients ranged from 0.93 to 0.96, when comparing plaster models and PUT models. The Bland-Altman plot showed good agreement. Conclusions: The accuracy and precision of PUT dental models for evaluating the performance of oral scanner and subtractive RP technology was acceptable. Because of the recent improvements in block material and computerized numeric control milling machines, the subtractive RP method may be a good choice for dental arch models.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.3
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• pp.113-119
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• 2015

Background: The inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristics Methods: In total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed. Results: The IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups. Conclusions: IANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.2
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• pp.69-76
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• 2015

Background: There have been few studies on the effect of an elevated concentration of lidocaine hydrochloride in the surgical removal of an impacted lower third molar. This study aimed to examine the efficacy of 4% lidocaine along with 1:100,000 epinephrine compared to 2% lidocaine along with 1:100,000 epinephrine as inferior alveolar nerve block for the removal of an impacted lower third molar. Methods: This single-blind study involved 31 healthy patients (mean age: 23 y; range: 19-33 y) with symmetrically impacted lower third molars as observed on panoramic radiographs. Volunteers required 2 surgical interventions by the same surgeon with a 3-week washout period. The volunteers were assigned either 4% lidocaine with 1:100,000 epinephrine or 2% lidocaine with 1:100,000 epinephrine as local anesthetic during each operation. Results: We recorded the time of administration, need for additional anesthetic administration, total volume of anesthetic used. We found that the patient's preference for either of the 2 types of local anesthetic were significantly different (P < 0.05). However, the extent of pulpal anesthesia, surgical duration, and duration of soft tissue anesthesia were not significantly different. Conclusions: Our study suggested that inferior alveolar nerve block using 4% lidocaine HCl with 1:100,000 epinephrine as a local anesthetic was clinically more effective than that using 2% lidocaine HCl with 1:100,000 epinephrine; the surgical duration was not affected, and no clinically adverse effects were encountered.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.6
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• pp.339-347
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• 2018

Background: There are many techniques of inferior alveolar nerve block injection (IANBI); one among them is the computer-assisted intraosseous injection (CAIOI). Here we aim to evaluate the effectiveness of CAIOI with $Quicksleeper^{(R)}$ in mandibular third molar surgery. Methods: This study is a clinical, single-blind, randomized, split-mouth, controlled trial including 25 patients (10 males and 15 females, mean age 21 years). The patients underwent surgical removal of bilateral mandibular third molars with two different IANBI techniques. One side was injected using $Quicksleeper^{(R)}$, and the other side was injected using a conventional IANBI. Both techniques used one cartridge (1.7 ml) of 1:100,000 epinephrine 4% articaine. A supplementary injection was used if necessary. All volumes of anesthetic agent used were recorded. Statistical analysis was performed using paired t-test and Wilcoxon test. Results: This research showed that CAIOI has faster onset and shorter duration of action than IANBI (P < 0.05). The pain was similar in both techniques. In the CAIOI group, one-third of the cases could be completed without additional anesthesia. The remaining two-thirds required minimal supplementary volume of anesthesia. The success rates were 68% for CAIOI and 72% for IANBI, respectively. Conclusion: CAIOI is an advantageous anesthetic technique. It can be used as an alternative to conventional IANBI for mandibular third molar surgery.

• Journal of Periodontal and Implant Science
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• v.53 no.6
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• pp.406-416
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• 2023

Purpose: No evidence exists regarding the advantages of periodontal regeneration treatment for furcation defects using soft block bone substitutes. Therefore, this randomized controlled trial aimed to assess the clinical and radiographic outcomes of regenerative therapy using porcine-derived soft block bone substitutes (DPBM-C, test group) compared with porcine-derived particulate bone substitutes (DPBM, control group) for the treatment of severe class II furcation defects in the mandibular molar regions. Methods: Thirty-five enrolled patients (test group, n=17; control group, n=18) were available for a 12-month follow-up assessment. Clinical (probing pocket depth [PPD] and clinical attachment level [CAL]) and radiographic (vertical furcation defect; VFD) parameters were evaluated at baseline and 6 and 12 months after regenerative treatment. Early postoperative discomfort (severity and duration of pain and swelling) and wound healing outcomes (dehiscence, suppuration, abscess formation, and swelling) were also assessed 2 weeks after surgery. Results: For both treatment modalities, significant improvements in PPD, CAL, and VFD were found in the test group (PPD reduction of 4.1±3.0 mm, CAL gain of 4.4±2.9 mm, and VFD reduction of 4.1±2.5 mm) and control group (PPD reduction of 2.7±2.0 mm, CAL gain of 2.0±2.8 mm, and VFD reduction of 2.4±2.5 mm) 12 months after the regenerative treatment of furcation defects (P<0.05). However, no statistically significant differences were found in any of the measured clinical and radiographic parameters, and no significant differences were observed in any early postoperative discomfort and wound healing outcomes between the 2 groups. Conclusions: Similar to DPBM, DPBM-C showed favorable clinical and radiographic outcomes for periodontal regeneration of severe class II furcation defects in a 12-month follow-up period.

• Journal of Technologic Dentistry
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• v.36 no.1
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• pp.9-15
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• 2014

Purpose: Generally dental technicians clinically decide the sintering temperature of zirconia artificial teeth to match the color of the teeth. However, the sintering temperature influence the microstructure and mechanical strength of ceramic body. In this study, to evaluate the free choice of sintering temperature which leads to color the problems in zirconia false teeth, the variation of microstructure, mechanical strength, and colortone of zirconia ceramics according to the change of sintering temperature was investigated. Methods: Bar type specimens were prepared from commercial zirconia blocks by cutting and polishing into $0.8cm(L){\times}1.0cm(W){\times}4.8cm(H)$. Specimens were fired from 1,400 to $1,700^{\circ}C$ at $50^{\circ}C$ intervals and held for 1hour at highest temperature. Apparent porosity, water absorption, firing shrinkage, bulk density, bend strength, whiteness were tested. Microstructures were observed by SEM. Results: When fired above $1450^{\circ}C$, all specimens showed 0% apparent porosity and water absorption, 20% firing shrinkage, and $6.1g/cm^3$ bulk density regardless of firing temperatures. SEM photomicrographs showed grain growth of zirconia occurred above $1,600^{\circ}C$. Whiteness was also largely changed above this temperature. Maximum bend strength of 1,05MPa was obtained at $1,550^{\circ}C$. Bend strength lowered slightly above this temperature and showed $950{\ss}\acute{A}$ at $1,700^{\circ}C$. Conclusion: In order to fit the colortone of zirconia artificial teeth, arbitrary choice of firing temperature higher than $1,500^{\circ}C$, up to $1,700^{\circ}C$ did not influence the mechanical strength.

• Journal of Technologic Dentistry
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• v.39 no.3
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• pp.145-152
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• 2017

Purpose: This study sought to identify changes in the mechanical characteristics and color of zirconia according to different sintering temperatures of the substance. Methods: This study processed some specimens of zirconia into those of $8mm(H){\times}10mm(W){\times}50mm(L){\pm}0.1$ each, and sintered them at $1450{\sim}1600^{\circ}C$ on a $50^{\circ}C-interval$ basis in order to examine how their mechanical characteristics and color are changed. Each specimen sintered using the spectral colorimetric apparatus (Easyshade, VITA, Germany) was observed for each of the color change by sintering temperature. Results: When those specimens were sintered at $1450{\sim}1600^{\circ}C$, they were 0% in absorption ratio and porosity, 20% in shrinkage ratio and $6.10g/cm^3$ in specific gravity. Absorption ration, porosity, shrinkage ratio and specific gravity all didn't vary depending on the sintering temperature. The fracture strength of the specimens was highest or 1037MPa at the sintering temperature of $1550^{\circ}C$ and a little lower or 989MPa at that of $1600^{\circ}C$. No variation in L* value was found depending on the sintering temperature of the specimens, while c* value was highest at that of $1450^{\circ}C$. In addition, h* value was highest when the specimens was sintered at $1550^{\circ}C$. Conclusion: This study could determine how zirconia shows changes in mechanical characteristics and color in accordance with different temperatures of its sintering. It is necessary to supplement the physical data of colored transparent zirconia block which is expected to be widely used in clinical practice.