• Imaging Science in Dentistry
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• v.48 no.2
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• pp.103-109
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• 2018

Purpose: To analyze cone-beam computed tomography (CBCT) use, indications, and exposure parameters in San $Jos{\acute{e}}$, Costa Rica. Materials and Methods: A cross-sectional study was performed. All CBCT examinations over a period of 6 months at 2 radiological centers in San $Jos{\acute{e}}$, Costa Rica were evaluated. The examinations were performed with Veraview EPOC X550 and Veraviewepocs 3D R100 equipment. The patients' age and sex, clinical indication for CBCT, region of interest (ROI), repeat examinations, specialty of the referring dentist, field-of-view (FOV), tube voltage (kV), tube current (mA), and radiation dose (${\mu}Gy$) were evaluated. Patients were classified by age as children (${\leq}12years$), adolescents(13-18 years), and adults(${\geq}19years$). Results: The mean age of the 526 patients was 49.4 years. The main indications were implant dentistry and dental trauma. The most frequent ROIs were posterior, while anterior ROIs were much less common. The highest percentage of repeat examinations was in children. Fifty-six percent of the referring dentists were specialists. The most commonly used FOV was small. The mean tube voltage and current were 79.8 kV and 7.4 mA for Veraview EPOC X550 and 89.9 kV and 6 mA for Veraviewepocs 3D R100, respectively. The mean doses for children, adolescents, and adults were $6.9{\mu}Gy$, $8.4{\mu}Gy$, and $7.8{\mu}Gy$, respectively. Conclusion: Although CBCT was most commonly used in adults for implant dentistry, most repeat examinations were in children, and the highest mean dose was in adolescents. Additional dose optimization efforts should be made by introducing low-dose protocols for children and adolescents.

• Journal of Periodontal and Implant Science
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• v.31 no.3
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• pp.625-631
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• 2001

The anatomic structure around interproximal area plays an important role not only in the natural teeth, but also in the implant. The loss of papilla can lead to cosmetic deformity, phonetic problem, food impaction on the anterior dentition, and masticatory problem, food impaction and proximal caries on the posterior dentition. The purpose of this study was to evaluate the relationship between interdental papilla existence and distance from contact point to alveolar crest in Korean posteior dentition. 45 Korean adult patients(31males, 14 females) participated in this study. Measurements were carreid out total 126 interproximal areas, 18 first premolar, 31 second premolar, 40 first molar, and 37 second molar areas. Papilla index was recorded as suggested by Jemt. Distance between contact point and alveolar crest measrued by Florida $probe^{R}$, after flap elevation. Each distance was measured 10 times by every 0.1mm unit. The results showed that the mean Papilla index 1.37 and mean distance between contact point and alveolar crest was 7.44mm. The correlation between the Papilla index and distance was high negative correlation(Pearson correlation=-0.47), and it was statistically significant(P=0.000) When the distance between contact point and alveolar crest was 5mm, the loss of papilla was appeared almost in half cases. When the distance was 6mm, the papilla loss was present 95%, when 7mm, the papilla loss was 100%.

• Imaging Science in Dentistry
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• v.36 no.3
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• pp.145-149
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• 2006

Purpose : To assess the width of the labial alveolar bone of the incisive canal and the width of the incisive canal on spiral computed tomographic images of the anterior portion of the maxilla. Materials and Methods : Study materials included 38 CT scans taken for preoperative planning of implant placement. Axial cross-sectioned image entirely showing the incisive canal was selected and scanned with 600 DPI resolution. The width of the labial alveolar bone of the incisive canal at an orifice to the oral cavity, middle portion, and an orifice to the nasal cavity and the diameter of the incisive canal at the middle portion were determined by two specialist using Digora for Windows 2.1 The statistical analyses were carried out using SPSS 12.0.1. Results : When the maxillary central incisors remained, the mean labial alveolar bone width were $6.81{\pm}1.41mm,\;6.46{\pm}1.33mm$, and $7.91{\pm}1.33mm$. When the maxillary central incisors were missed the mean width were $5.42{\pm}2.20mm,\;6.23{\pm}2.29mm$, and $7.89{\pm}2.13mm$. Conclusions : The labial alveolar bone width at middle portion and an orifice to the nasal cavity were of no statistical significant difference according to presence of the maxillary central incisors (P>0.05). The width between oral cavity and nasal cavity, middle portion and to nasal cavity revealed statistically significant difference (P<0.05).

• Archives of Plastic Surgery
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• v.46 no.4
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• pp.365-370
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• 2019

The syndrome of the trephined is a neurologic phenomenon that manifests as sudden decline in cognition, behavior, and sensorimotor function due to loss of intracranial domain. This scenario typically occurs in the setting of large craniectomy defects, resulting from trauma, infection, and/or oncologic extirpation. Cranioplasty has been shown to reverse these symptoms by normalizing cerebral hemodynamics and metabolism. However, successful reconstruction may be difficult in patients with complex and/or hostile calvarial defects. We present the case of a 48-year-old male with a large cranial bone defect, who failed autologous cranioplasty secondary to infection, and developed rapid neurologic deterioration leading to a near-vegetative state. Following debridement and antibiotic therapy, delayed cranioplasty was accomplished using a polyetheretherketone (PEEK) implant with free chimeric latissimus dorsi/serratus anterior myocutaneous flap transfer for vascularized resurfacing. Significant improvements in cognition and motor skill were noted in the early postoperative period. At 6-month follow-up, the patient had regained the ability to speak, ambulate and self-feed-correlating with evidence of cerebral/ventricular re-expansion on computed tomography. Based on our findings, we advocate delayed alloplastic implantation with total vascularized soft tissue coverage as a viable alternative for reconstructing extensive, hostile calvarial defects in patients with the syndrome of the trephined.

• The korean journal of orthodontics
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• v.51 no.4
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• pp.260-269
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• 2021

Objective: To identify the most favorable sites that optimize the initial stability and survival rate of orthodontic mini-implants, this study measured hard and soft tissue thicknesses in the median and paramedian regions of the palate using cone-beam computed tomography (CBCT) and determined possible sex- and age-related differences in these thicknesses. Methods: The study sample comprised CBCT images of 189 healthy subjects. The sample was divided into four groups according to age. A grid area was set for the measurement of hard and soft tissue thicknesses in the palate. Vertical lines were marked at intervals of 0, 1.5, and 3.0 mm lateral to the midpalatal suture, while horizontal lines were marked at 2-mm intervals up to 24 mm from the posterior margin of the incisive foramen. Measurements were made at 65 points of intersection between the horizontal and vertical lines. Results: The palatal hard tissue thickness decreased from the anterior to the posterior region, with a decrease in the medial-to-lateral direction in the middle and posterior regions. While the soft tissue was rather thick around the lateral aspects of the palatal arch, it formed a constant layer that was only 1-2-mm thick throughout the palate. Statistically significant differences were observed according to sex and age. Conclusions: The anterolateral palate as well as the midpalatal suture seem to be the most favorable sites for insertion of orthodontic mini-implants. The thickness of the palate differed by age and sex; these differences should be considered while planning the placement of orthodontic mini-implants.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.41-47
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• 2021

Purpose: This study aimed to compare the accuracy of 3-dimensional(3D) printed models derived from multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) systems with different fields of view (FOVs). Materials and Methods: Five human dry mandibles were used to assess the accuracy of reconstructions of anatomical landmarks, bone defects, and intra-socket dimensions by 3D printers. The measurements were made on dry mandibles using a digital caliper (gold standard). The mandibles then underwent MDCT imaging. In addition, CBCT images were obtained using Cranex 3D and NewTom 3G scanners with 2 different FOVs. The images were transferred to two 3D printers, and the digital light processing (DLP) and fused deposition modeling (FDM) techniques were used to fabricate the 3D models, respectively. The same measurements were also made on the fabricated prototypes. The values measured on the 3D models were compared with the actual values, and the differences were analyzed using the paired t-test. Results: The landmarks measured on prototypes fabricated using the FDM and DLP techniques based on all 4 imaging systems showed differences from the gold standard. No significant differences were noted between the FDM and DLP techniques. Conclusion: The 3D printers were reliable systems for maxillofacial reconstruction. In this study, scanners with smaller voxels had the highest precision, and the DLP printer showed higher accuracy in reconstructing the maxillofacial landmarks. It seemed that 3D reconstructions of the anterior region were overestimated, while the reconstructions of intra-socket dimensions and implant holes were slightly underestimated.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.456-462
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• 2023

Plate fixation has become the preferred approach for treating displaced midshaft clavicle fractures. However, plate fixation of the clavicle presents several unique challenges, including its complex bony architecture and its immediate subcutaneous location. In many cases, we have observed that precontoured implants do not conform to the clavicular anatomy, and many patients complain of postoperative implant-related discomfort. A total of 111 clavicles, both left and right sides, were examined to match two commonly used designs of anatomical pre-contoured superior anterior clavicle plates, with and without lateral extension. The anteroposterior (AP) plane congruence of the plate to the underlying bone, the vertical gap between the bone and plate, and the length of the plate that was off the bone either anteriorly and/or posteriorly at both ends of the clavicle were measured. The scoring system was used to determine the fit of the implant on the clavicle as anatomic, good, or poor. We found that the maximum superior bow of the clavicle was lateral to the midline by 30.75 mm and 30.5 mm on the right and left sides, respectively. The magnitude of the bow was 4.28 mm and 4.46 mm on the right and left sides, respectively. We also found that the plate was a poor fit in 75.86% of cases on the left side and 73.5% of cases on the right side. Manipulating the plates during surgery was very difficult in the AP plane.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.1
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• pp.72-81
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• 2024

To rehabilitate a patient with inappropriate occlusion due to posterior support loss, it is necessary to achieve an appropriate occlusal vertical dimension and create prostheses that demonstrate stable occlusion at the centric relation for full mouth restoration. This case shows full mouth rehabilitation in a patient with missing posterior teeth and tooth wear, achieved through implant-supported prostheses and zirconia full-veneer crowns. To assess adaptation to the increased occlusal vertical dimension, an occlusal splint and temporary restorations were secured. By fabricating the definitive restorations based on the anterior guidance of the temporary restorations, stable occlusal rehabilitation was successfully achieved.

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.14-23
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• 1995

Cyclosporin A is a powerful immunosuppressive agent commonly used for patients receiving organ transplants. Like phenytoin and the calcium channel blockers, the drug is associated with gingival overgrowth. The purpose of this study was to compare the correlation with gingival overgrowth score and clinical indices(i.e, : plaque index, papillary bleeding index, probing depth) and correlation with gingival overgrowth score and microorganism distribution in use of phase contrast microscope. After renal tranplant, taking cyclosporin A 40 patients participating in this investigation. Post - transplatation cyclosporin medication period was average $17.53{\pm}15.75$ months. In previous study reported that gingival overgrowth is an adverse side - effects seen in about 25-81% of patient taking cyclosporin A. The results were as follows : 1. Gingival overgrowth prevalence in taking cyclosporin A patients was 77.5%. Prevalence rate of region was anterior region(26 teeth, 55.3%), molar region(14 teeth, 29.8%), premolar region(7 teeth, 14.8%) in turns. Gingival overgrowth score by Angelopoulos & Goaz method was molar region($1.56{\pm}0.81$), anterior region($1.52{\pm}0.75$), premolar region($1.14{\pm}0.90$) in turns. 2. Medication period was not correlation with gingival overgrowth score. 3. Clinical indices and gingival overgrowth score were as follows. 1) Plaque index and gingival overgrowth score was significantly correlated(p

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.390-396
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• 1994

This study investigates the effect of wind instrument playing on the periodontal condition by comparing and analyzing wind instrument players and non-wind instrument players by various clinical paramenters, including periodontal index, bleeding index, simplified oral hygiene index, and non-functional tooth index. The subjects consist of 65 wind instrument players and 31 non-players. The players were divided into 4 groups ; Those who use cup-shaped mouthpieces as Group A, single reed mouthpieces as Group B, double reed mouthieces as Group C, and hole mouthpieces as Group D. Non-players are designated as Group E. The results are as follows ; 1. Periodontal Index Group A recorded $1.2{\pm}0.7$, Group B $1.1{\pm}0.7$, Group C $1.3{\pm}0.5$, Group D $2.1{\pm}0.5$, and Group E $0.9{\pm}0.6$, with no statistically significant differences among the groups. 2. Bleeding Index Group A shwed 0.23, Group B 0.25, Group C 3.0, Group D 0.38, and Group E 0.23, with no statistically significant differences among the groups. 3. Non-functional Tooth Index Group A recorded 2.0, Group B 1.0, Group C 3.0, Group D 0, Group E 0.7, with no statistically significant differences among the groups. 4. Simplified Oral Hygiene Index Buccal sides of maxillary 1st molars, lingual sides of mandibular 1st molars, labial sides of maxillary anterior teeth, and lingual sides of mandibular anterior teeth were investigated, and there was no statistically significant differences among the groups.