• Title/Summary/Keyword: Dental noise

Search Result 80, Processing Time 0.029 seconds

Backprojection Filtering Method for Limited Angle Tomography (제한된 각도에서 단층영상 획득을 위한 역투사 후 필터링 방법)

  • Cho, Min-Kook;Kim, Ho-Kyung;Yin, Z-Hye;Kim, Tae-Woo
    • Journal of Biomedical Engineering Research
    • /
    • v.29 no.1
    • /
    • pp.46-51
    • /
    • 2008
  • We describe a backprojection filtering method for limited angle tomography. In order to reduce blur artifacts originated from the out-of-planes and control high-frequency noise, we employed two band-limited window functions, and which were realized by Hann filters in this study. Based on the experimentally measured data, the performance of the developed method is demonstrated by comparing with the conventional shift-and-add and filtered backprojection methods. Application of the developed method to the dental imaging has a potential to be used for the preoperative evaluation of the jaw for dental implants with much reduced patient dose instead of the conventional dental computed tomography.

Prognosis Followoing the Arthrocentesis for the Painful TMJ (악기능 장애에 있어 악관절세척술의 효과)

  • Lee, Sunmi;Kim, Jiyoung
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.3 no.3
    • /
    • pp.43-47
    • /
    • 2015
  • Purpose : The aim of this study was to report a follow-up study on the prognosis following the arthrocentsis for the painful temporomandibular dysfunction not responsible to the conservative splint therapies. Arthrocentsis of TMJ is a simple precedure that can be performed in the out-patient clinic under the local anesthesia without any reported complications. Method : Seventy patients had been followed after the arthrocentsis for over 6 months. Maximum mouth opening, TMJ pain, TMJ noise, and their changes by time were examined and compared statistically. The effectiveness of the treatment was evaluated in terms of the postoperative range of maximal mouth opening (MMO) and the degree of postoperative pain score. Predictors which was analyzed were age, duration of painful locking, MMO, the degree of pain, preoperative clicking and the amounts of irrigation fluid. Result : The result of this study were as follow; 1) Mouth opening was improved from 32.6 mm to 42.4 mm in the maximum inter-incisal distance. 2) TMJ pain was decreased in 45.7%. 3) TMJ clicking and noise disappeared in 60.0%, but recurred in 40.0%. Conclusion : Amounts of irrigated solution recovered to normal MMO and the appeareance of perioperative clkicking may be predictors of the successful results of arthrocenetesis of ADD without reduction of TMJ.

The effects of noise reduction, sharpening, enhancement, and image magnification on diagnostic accuracy of a photostimulable phosphor system in the detection of non-cavitated approximal dental caries

  • Kajan, Zahra Dalili;Davalloo, Reza Tayefeh;Tavangar, Mayam;Valizade, Fatemeh
    • Imaging Science in Dentistry
    • /
    • v.45 no.2
    • /
    • pp.81-87
    • /
    • 2015
  • Purpose: Contrast, sharpness, enhancement, and density can be changed in digital systems. The important question is to what extent the changes in these variables affect the accuracy of caries detection. Materials and Methods: Forty eight extracted human posterior teeth with healthy or proximal caries surfaces were imaged using a photostimulable phosphor (PSP) sensor. All original images were processed using a six-step method: (1) applying "Sharpening 2" and "Noise Reduction" processing options to the original images; (2) applying the "Magnification 1:3" option to the image obtained in the first step; (3) enhancing the original images by using the "Diagonal/"option; (4) reviewing the changes brought about by the third step of image processing and then, applying "Magnification 1:3"; (5) applying "Sharpening UM" to the original images; and (6) analyzing the changes brought about by the fifth step of image processing, and finally, applying "Magnification 1:3." Three observers evaluated the images. The tooth sections were evaluated histologically as the gold standard. The diagnostic accuracy of the observers was compared using a chi-squared test. Results: The accuracy levels irrespective of the image processing method ranged from weak (18.8%) to intermediate (54.2%), but the highest accuracy was achieved at the sixth image processing step. The overall diagnostic accuracy level showed a statistically significant difference (p=0.0001). Conclusion: This study shows that the application of "Sharpening UM" along with the "Magnification 1:3" processing option improved the diagnostic accuracy and the observer agreement more effectively than the other processing procedures.

Feasibility Study of Non Local Means Noise Reduction Algorithm with Improved Time Resolution in Light Microscopic Image (광학 현미경 영상 기반 시간 분해능이 향상된 비지역적 평균 노이즈 제거 알고리즘 가능성 연구)

  • Lee, Youngjin;Kim, Ji-Youn
    • Journal of the Korean Society of Radiology
    • /
    • v.13 no.4
    • /
    • pp.623-628
    • /
    • 2019
  • The aim of this study was to design fast non local means (FNLM) noise reduction algorithm and to confirm its application feasibility in light microscopic image. For that aim, we acquired mouse first molar image and compared between previous widely used noise reduction algorithm and our proposed FNLM algorithm in acquired light microscopic image. Contrast to noise ratio, coefficient of variation, and no reference-based evaluation parameter such as natural image quality evaluator (NIQE) and blind/referenceless image spatial quality evaluator (BRISQUE) were used in this study. According to the result, our proposed FNLM noise reduction algorithm can achieve excellent result in all evaluation parameters. In particular, it was confirmed that the NIQE and BRISQUE evaluation parameters for analyzing the overall morphologcal image of the tooth were 1.14 and 1.12 times better than the original image, respectively. In conclusion, we demonstrated the usefulness and feasibility of FNLM noise reduction algorithm in light microscopic image of small animal tooth.

Automatic Registration of Images for Digital Subtraction Radiography Using Local Correlation (국소적 상관계수를 이용한 자동적 디지털 방사선 영상정합)

  • 이원진;허민석;이삼선;최순철;이재성
    • Journal of Biomedical Engineering Research
    • /
    • v.25 no.2
    • /
    • pp.111-117
    • /
    • 2004
  • Most of digital subtraction methods in dental radiography are based on registration using manual landmarks. We have developed an automatic registration method without using the manual selection of landmarks. By restricting a geometrical matching of images to a region of interest (ROl), we compare the cross-correlation coefficient only between the ROIs. The affine or perspective transform parameters satisfying maximum of cross-correlation between the local regions are searched iteratively by a fast searching strategy. The parameters are searched on the 1/4 scale image coarsely and then, the fine registration is performed on the original scale image. The developed method can match the images corrupted by Gaussian noise with the same accuracy for the images without any transform simulation. The registration accuracy of the perspective method shows a 17% improvement over the manual method. The application of the developed method to radiography of dental implants provides an automatic noise robust registration with high accuracy in almost real time.

Chronic Aircraft Noise Exposure and Sustained Attention, Continuous Performance and Cognition in Children (만성 항공기 소음 노출과 아동의 지속주의력과 연속수행능력 및 인지기능)

  • Lim, Myung-Ho;Park, Young-Hyun;Lee, Woo-Chul;Paik, Ki-Chung;Kim, Hyun-Woo;Kim, Hyun-Joo;Rho, Sang-Chul;Kim, Hae-Young;Kwon, Ho-Jang
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
    • /
    • v.18 no.2
    • /
    • pp.145-153
    • /
    • 2007
  • Objectives: This study was focused on the influence of chronic aircraft noise exposure on children's continuous performance, intelligence and reading skill. Methods: We enrolled 586 children in 4-6th grade of 7 primary schools near air base in Korea. Continuous performance was measured using the computerized ADS program. We analyzed 477-512 children on the visual continuous performance test, auditory continuous performance test, intelligence test, and reading and the vocabulary test. Intelligence was measured using vocabulary, digit span, block design, and digit symbol tests of K-WISC-III. Results: The commission error and variability deviation of auditory continuous performance test and reading test were significantly higher among children in schools with the helicopter noise and the fighting plane noise compared to children in the low noised schools. Conclusion: There was a possibility that chronic aircraft noise exposure was associated with impairment of the school performance. The result of our study also shows chronic aircraft noise was associated with reading ability.

  • PDF

A Study on the Temporomandibular Joint Disorder and School Life Stress of High School Student by Department (계열별 남자고등학생의 학교생활스트레스와 측두하악장애에 관한 연구)

  • Lee, Jung-Hwa;Choi, Jung-Mi
    • Journal of dental hygiene science
    • /
    • v.7 no.3
    • /
    • pp.179-185
    • /
    • 2007
  • The purpose of this study targeted on high school student in the department of liberal arts, industry in Daegu metropolitan city, is to get basic data necessary for the development of dental educational program, to discern prevention and treatment of temporomandibular joint disorder by observing the situation temporomandibular joint disorder and contribution element, of relationship of school life stress The results are as follows.: 1. The percentage of occurring temporomandibular joint disorder in the high school resulted in a joint noise at 61.8% and joint dislocation 6.9%, sharp pain 47.5% at time of chewing. 29.8% at the time of the non-chewing, lockjaw 11.3%, a headache appeared at 40.4%.2. In the contribution factor of occurring temporomandibular joint disorder, the cause of joint noise was the clench one's teeth, lip and cheek clench, For the pain at the time of chewing clench one's teeth, one side chewing, over-chewing, lip clench, sideways sleeping showed the difference. (P < 0.01) For the pain at the time of non-chewing, clench one's teeth, bruxism, one side chewing, lip and cheek clench were similar, and for the lockjaw, clench one's teeth, bruxism, sideways sleeping showed the difference. The plum evil thing period at time of the fault writing that statistically showed the difference. For the headache, the contribution factors were the all bad habits mentioned above excluding one side sleeping.(P < 0.01, P < 0.05). 3. The rate of experiencing temporomandibular joint disorder by oral and maxillofacia was 13.4% in industrial department, and 19.6% in liberal arts. And for the factor of wound was that exercise 26.8%, others 24.4%, fall-down 19.5%. And for the industrial, exercise 44.4%, fall-down 22.2%, others 14.9%. The treatment experience appeared at 5.0% in industrial department, 2.9% in liberal arts. And for the medical institutions, liberal arts were dental clinic 50%, orthopedics 50%, and the industrial department orthopedics 40%, oriental medicine clinic 30%, dental clinic 30%. 4. In case of temporomandibular joint disorder, there were no difference by grades or educational background. And at the time of chewing or non-chewing showed similar difference.(P < 0.01). 5. Compared to stress in the high school, it generally showed higher in liberal arts than in industrial department due to school record. Its scope was $3.75{\pm}1.14$ in liberal arts, $3.01{\pm}1.23$ in industrial department. 6. The school record, school life, stress problems by teachers, chewing/non-chewing pain of temporomandibular joint disorder, joint noise had a similar correlation.(P < 0.01, < 0.05).

  • PDF

Safe and Effective Reduction Malarplasty (안전하고 효과적인 광대축소술)

  • Kang, Young Ho
    • The Journal of the Korean dental association
    • /
    • v.58 no.2
    • /
    • pp.103-113
    • /
    • 2020
  • Background: Reduction malarplasty is one of the most popular facial contouring surgeries in east Asia for making patients' faces smaller. Currently in Korea, reduction malarplasty surgeries are performed mostly at plastic surgery clinics, but few cases are done at oral and maxillofacial surgery clinics. The reason might be because of post-operative complications after reduction malarplasty, such as undercorrection, overcorrection, asymmetry, cheek drooping, malunion, pain and noise. Those complications should be uneasy to be handled by oral and maxillofacial surgeons, however, they can be prevented by knowing the effective and safe reduction malarplasty techniques. Therefore, in this article the author as an oral and maxillofacial surgeon, would like to suggest safe and effective surgical methods for reduction malarplasty customized for Korean patients. Method: L- shape osteotomy of zygomatic body was performed with intraoral approach via vestibular incision, and the zygomatic arch was osteotomized with extraoral approach via sideburn incision. Then zygomatic complex was separated and rotated mesio-superiorly without removal of a bony strip and fixed with miniplates and microplates without making a bony gap. Conclusion: Surgical results were favorable and satisfied by the patients without cheek drooping, malunion, undercorrection and asymmetry.

  • PDF

Clinical characteristics and treatment plan for patients with snoring and obstructive sleep apnea (코골이와 수면무호흡증 환자의 임상적 특징과 치료계획)

  • Jung, Jae-Kwang;Kim, Ki-Rim;Byun, Jin-Seok;Choi, Jae-Kap
    • The Journal of the Korean dental association
    • /
    • v.53 no.4
    • /
    • pp.249-258
    • /
    • 2015
  • Snoring and obstructive sleep apnea are the representative sleep disordered breathings, caused by the temporary and repetitive constriction or obstruction of upper airway during sleep. They present with excessively vibratory noise and repetitive cease of respiration. These disorders commonly result in sleep disturbance and the subsequent daytime sleepiness, chronic fatigue. Furthermore, they can cause the serious and extensive complications including increased risk of hypertension, cardiac arrhythmia, cardiovascular disease, cerebrovascular accident, neurocognitive disturbance, traffic and occupational accidents, type II diabetes, childhood growth interruption, awakening headache and finally, relatively increased mortality rate. Because appropriate therapeutic intervention is best way for patients to relieve their symptoms and prevent their possible complications, it is very important for dentists to recognize their own role and responsibility in diagnosis and treatment of these disorders. For this, the present article provides the understanding of the clinical features, possible complications, various treatment modalities, and suitable treatment strategies for snoring and obstructive sleep apnea.

Does the metal artifact reduction algorithm activation mode influence the magnitude of artifacts in CBCT images?

  • Fontenele, Rocharles C.;Nascimento, Eduarda H.L.;Santaella, Gustavo M.;Freitas, Deborah Queiroz
    • Imaging Science in Dentistry
    • /
    • v.50 no.1
    • /
    • pp.23-30
    • /
    • 2020
  • Purpose: This study was conducted to assess the effectiveness of a metal artifact reduction (MAR) algorithm activated at different times during cone-beam computed tomography (CBCT) acquisition on the magnitude of artifacts generated by a zirconium implant. Materials and Methods: Volumes were obtained with and without a zirconium implant in a human mandible, using the OP300 Maxio unit. Three modes were tested: without MAR, with MAR activated after acquisition, and with MAR activated before acquisition. Artifacts were assessed in terms of the standard deviation (SD) of gray values and the contrast-to-noise ratio (CNR) in 6 regions of interest with different distances (10 to 35 mm, from the nearest to the farthest) and angulations(70° to 135°) from the implant region. Results: In the acquisitions without MAR, the regions closer to the implant(10 and 15mm) had a higher SD and lower CNR than the farther regions. When MAR was activated (before or after), SD values did not differ among the regions (P>0.05). The region closest to the implant presented a significantly lower CNR in the acquisitions without MAR than when MAR was activated after the acquisition; however, activating MAR before the acquisition did not yield significant differences from either of the other conditions. Conclusion: Both modes of MAR activation were effective in decreasing the magnitude of CBCT artifacts, especially when the effects of the artifacts were more noticeable.