• 대한치과의사협회지
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• 제57권7호
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• pp.392-402
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• 2019

The most important part of everyday root canal treatment is diagnosis about the morphology of tooth, root and root canal. Usually this procedure is performed by visual examination and radiographic (panoramic/periapical) examination. However, 2-dimentional radiography has several limitations such as imposition of anatomic structures including buccal/lingual root canals and distortion of images. Recently, owing to the increased interest in dental implant and affordable cost of CBCT equipment, CBCT has been introduced widely in local dental clinics. CBCT is characterized by their lower radiation dose and shorter exposure time than conventional CT scan, and ability of 3-dimentional reconstruction of the dento-alveolar structure. Also in endodontic field, the data from CBCT could be very helpful in diagnosing complex root canal anatomy, apical periodontitis, cause of failure and in determining treatment plan. However, there are some limitations such as radiation dose and artifact. Therefore, clinicians should know about indication, advantages and limitations of CBCT, and properly use it for successful root canal treatment to save the natural teeth.

• 대한치과교정학회지
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• 제43권4호
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• pp.160-167
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• 2013

Objective: To evaluate the shapes and sizes of nasopharyngeal airways by using cone-beam computed tomography and to assess the relationship between nasopharyngeal airway shape and adenoid hypertrophy in children. Methods: Linear and cross-sectional measurements on frontal and sagittal cross-sections containing the most enlarged adenoids and nasopharyngeal airway volumes were obtained from cone-beam computed tomography scans of 64 healthy children ($11.0{\pm}1.8$ years), and the interrelationships of these measurements were evaluated. Results: On the basis of frontal section images, the subjects' nasopharyngeal airways were divided into the following 2 types: the broad and long type and the narrow and flat type. The nasopharyngeal airway sizes and volumes were smaller in subjects with narrow and flat airways than in those with broad and long airways (p < 0.01). Children who showed high adenoid-nasopharyngeal ratios on sagittal imaging, indicating moderate to severe adenoid hypertrophy, had the narrow and flat type nasopharyngeal airway (p < 0.01). Conclusions: Cone-beam computed tomography is a clinically simple, reliable, and noninvasive tool that can simultaneously visualize the entire structure and a cross section of the nasopharyngeal airway and help in measurement of adenoid size as well as airway volume in children with adenoid hypertrophy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권2호
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• pp.78-86
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• 2010

Introduction: Cone beam computed tomography (CBCT) has various advantages and is used favorably in many fields in dentistry. Especially, CBCT is being used as basic diagnostic tool for 3-dimensional analysis in orthognathic patient. Two-dimensional cephalograms can be synthesized from CBCT digital imaging and communications in medicine (DICOM) data. In this study, conventional cephalograms and CBCT were taken simultaneously, and representative landmarks were located and analyzed in its accuracy and reproducibility. Materials and Methods: Ten patients who had orthognathic surgery in Wonkwang University Daejeon Dental Hospital participated in this study. For each patient, CBCT and conventional cephalogram was taken. By using Ondemand (Cybermad, Korea), 2-dimensional cephalograms was established on CBCT. In addition, 19 landmarks were designated and measured by 3 orthodontists twice a week. After these landmarks were transferred to a coordinate, distance of landmark and axis, standard error, distribution degree were measured, compared and analyzed. Results: Comparing the CT ceph group and conventional cephalogram group, CT ceph group had shown shorter distance of landmark and axis in S, Hinge axis, Bpt, Ba, Or, Corpus left. Standard error of the mean shows that CT ceph group has better reproducibility in Or, Corpus left, Hinge axis at X axis and Na, U1R, U1T, Bpt, PNS, Ba Corpus left, Hinge axis at Y axis. In both groups, mean error was less than 1.00 mm, no significant difference were found between CT ceph group and conventional cephalogram group in all measurements. Furthermore, comparing two groups, each 17 landmarks out of 19 had its characteristic in distribution degree. Conclusion: No significant difference were found between CBCT composed cephalographic radiograph and conventional cephalograghic radiograph, clinical application may be possible if improved.

• 대한치과교정학회지
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• 제41권6호
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• pp.431-439
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• 2011

Objective: To determine whether there is any difference between the cleft and non-cleft sides of the mandible in unilateral cleft lip and palate (UCLP) patients, or the right and left sides in control patients; and to determine if there is any difference between the mandibular asymmetry of UCLP patients and that of control patients. Methods: We examined cone-beam computed tomography (CBCT) scans of 15 patients with UCLP and 15 age- and gender-matched control patients. We evaluated 8 linear, 3 surface, and 3 volumetric measurements and compared the cleft/non-cleft sides of UCLP patients and the right/left sides of controls. Results: There were no statistically significant gender differences in any linear, surface, or volumetric measurement. The single significant side-to-side difference in UCLP patients was a longer coronoid unit on the cleft side than on the non-cleft side ($p$ = 0.046). Body volume was significantly lower in the UCLP group than in the control group ($p$ = 0.008). Conclusions: In general, UCLP patients have symmetrical mandibles, although the coronoid unit length is significantly longer on the cleft side than on the non-cleft side. UCLP patients and controls differed only in body volume.

• Imaging Science in Dentistry
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• 제48권3호
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• pp.185-190
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• 2018

Purpose: The aim of this study was to compare the location and the shape of the mandibular lingula in skeletal class I and III patients using panoramic radiography and cone-beam computed tomography. Materials and Methods: The sample group included 190 skeletal class I patients and 157 class III patients. The location of the lingula in relation to the deepest point of the coronoid notch was classified into 3 types using panoramic radiographs. The shapes of the lingulae were classified into nodular, triangular, truncated, or assimilated types using cone-beam computed tomographic images. The data were analyzed using the chi-square test. Results: The tips of the lingulae were at the same level as the coronoid notch in 75.3% of skeletal class I patients and above the coronoid notch in 66.6% of class III patients. The positions of the lingulae in relation to the deepest point of the coronoid notch showed statistically significant differences between class I and class III patients. The most common shape was nodular, and the least common was the assimilated shape. Although this trend was not statistically significant, the triangular shape was more frequently observed in class III patients than in class I patients. Conclusion: The locations and the shapes of the mandibular lingulae were variable. Most of the lingulae were at the same level as the coronoid notch in skeletal class I patients and above the coronoid notch in skeletal class III patients. The nodular and assimilated-shaped lingulae were the most and the least prevalent, respectively.

• 구강회복응용과학지
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• 제31권2호
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• pp.104-111
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• 2015

목적: 이 후향적 연구의 목적은 한국인에서 콘빔CT를 이용하여 상악 대구치에서 C-형 치근 및 근관의 발현빈도와 형태를 분류하기 위함이다. 연구 재료 및 방법: 총 357개 상악 대구치(제1대구치 186개, 제2대구치 171개)의 콘빔CT 영상을 두 명의 치과보존과 전문의가 평가하였다. 결과: 8가지의 C-형 치근 형태와 5가지의 C-형 근관형태로 분류할 수 있었으며, C-형 치근 및 근관의 발현빈도는 각각 21.0%와 5.3%였다. 결론: 이러한 해부학적 변이는 제1대구치보다 제2대구치에서 많이 발견되었다. 상악 대구치의 성공적인 근관치료를 위해 다양한 형태의 C-형 치근 및 C-형 근관에 대한 해부학적 지식이 필요하다.

• Imaging Science in Dentistry
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• 제49권1호
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• pp.59-63
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• 2019

Purpose: This study evaluated the prevalence and characteristics of maxillary antroliths using cone-beam computed tomography (CBCT) scans performed for maxillofacial diagnostic purposes. Materials and Methods: CBCT scans of 13,946 patients over the age of 20 were reviewed for maxillary antroliths, and prevalence according to sex, age, and the side of the jaw was calculated. The relationships of single or multiple antroliths with sex, side, and the degree of sinus inflammation were evaluated. The shape and dimension of antroliths were also assessed. The data were analyzed using descriptive statistics, the chi-square or Fisher exact tests, and Kendall's tau-b. Results: A total of 138 (0.99%) of the 13,946 patients showed an antrolith in at least 1 sinus. Only 18 patients presented a bilateral manifestation, which brought the total number of sinuses containing an antrolith to 156 (0.56%). Multiple antroliths were observed in 36 sinuses, and the total number of antroliths was 207: 110 punctate, 65 linear, and 32 amorphous. The antrolith dimensions varied from $1mm^2$ to $91mm^2$ (average, $10.2{\pm}15.5mm^2$). No statistically significant differences were found according to sex, side, and age group (P>0.05). However, there was a statistically significant difference between the multiplicity of antrolith and the degree of sinus inflammation (P<0.05). Conclusion: Cone-beam computed tomography is an effective modality for the detection of incidental antroliths. Maxillary antroliths were found to be very rare and were usually asymptomatic. Dentists should have a comprehensive understanding of their diagnosis and treatment in light of possible associated dental problems.

• Imaging Science in Dentistry
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• 제52권1호
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• pp.1-9
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• 2022

Purpose: This systematic review aimed to compare assessments of the healing of periapical endodontic surgery using conventional radiography and cone-beam computed tomography (CBCT). Materials and Methods: This review of clinical studies was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. All articles published from 1990 to March 2020 pertaining to clinical and radiographic healing assessments after endodontic surgery using conventional radiography and CBCT were included. The question was "healing assessment of endodontic surgery using cone-beam computed tomography." The review was conducted by manual searching, as well as undertaking a review of electronic literature databases, including PubMed and Scopus. The studies included compared radiographic and CBCT assessments of periapical healing after periapical endodontic surgery. Results: The initial search retrieved 372 articles. The titles and abstracts of these articles were read, leading to the selection of 73 articles for full-text analysis. After the eligibility criteria were applied, 11 articles were selected for data extraction and qualitative analysis. The majority of studies found that CBCT enabled better assessments of healing than conventional radiography, suggesting higher efficacy of CBCT for correct diagnosis and treatment planning. A risk of bias assessment was done for 10 studies, which fell into the low to moderate risk categories. Conclusion: Three-dimensional radiography provides an overall better assessment of healing, which is imperative for correct diagnosis and treatment planning.

• 대한치과교정학회지
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• 제53권4호
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• pp.264-275
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• 2023

Objective: To investigate the effects of maxillary orthodontic expansion on the alveolar bone tissue in adult patients treated with aligners by using cone-beam computed tomography. Methods: Thirty patients (22 females and 8 males; mean age: 36.3 years) were treated with Invisalign^® aligners. Cone-beam computed tomography and digital models were obtained before (T0) and after (T1) upper arch expansion. The bone thicknesses in the cervical, middle, and apical areas of the incisors, canines, premolar, and first molars were buccally and palatally measured, totaling 96 areas and 2,880 measurements. The buccolingual inclinations and transverse measurements of the teeth were obtained from digital models to correlate them with the bone changes. The statistical tests used were Student's t-test, analysis of variance, and Pearson's correlation tests (p < 0.05). Results: From the 96 areas evaluated, 84 revealed an increase or stability in the alveolar bone thickness and twelve displayed significant bone loss. Bone changes did not correlate with the tooth inclination and transverse measurements. Conclusions: Within the limitation of the present study, mild levels of upper arch expansion obtained with Invisalign^® aligners in adult patients did not result in any clinically significant loss of alveolar bone thickness.

• Imaging Science in Dentistry
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• 제53권4호
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• pp.345-353
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• 2023

Purpose: The objective of this study was to propose a method for developing a clinical phantom to reproduce various diseases that are clinically prevalent in the field of dentistry. This could facilitate diverse clinical research without unnecessarily exposing patients to radiation. Materials and Methods: This study utilized a single dry skull, which was visually and radiographically examined to evaluate its condition. Existing lesions on the dry skull were preserved, and other relevant lesions were artificially created as necessary. These lesions were then documented using intraoral radiography and cone-beam computed tomography. Once all pre-existing and reproduced lesions were confirmed by the consensus of 2 oral and maxillofacial radiologists, the skull was embedded in a soft tissue substitute. To validate the process, cone-beam computed tomography scans and panoramic radiographs were obtained of the fabricated phantom. All acquired images were subsequently evaluated. Results: Most lesions could be identified on panoramic radiographs, although some sialoliths and cracked teeth were confirmed only through cone-beam computed tomographic images. A small gap was observed between the epoxy resin and the bone structures. However, 2 oral and maxillofacial radiologists agreed that this space did not meaningfully impact the interpretation process. Conclusion: The newly developed phantom has potential for use as a standardized phantom within the dental field. It may be utilized for a variety of imaging studies, not only for optimization purposes, but also for addressing other experimental issues related to both 2- and 3-dimensional diagnostic radiography.