• 음성과학
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• 제5권1호
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• pp.105-119
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• 1999

Cleft palate patients have general speech problems with resonance disorders and articulation disorders. The aim of this study is to find the aerodynamic and acoustic characteristics of the nasalization in cleft palate speakers. Thirteen control groups and three cleft palate patients pre- and post operation were selected for these studies. The test words are composed by polysyllabic words: consonants between high vowel /i/ analysis. The cleft palate patients repeated test words pre- and post-operation from one, three and six month periods. The subjects repeated test words on Macquirer and on Nasometer Model 6200-3. The aerodynamic and acoustic results of nasalization show as follows: (1) The nasal rate in overall airflow of aspirated consonant for cleft palate patients shows higher levels than that of the control group. It had decreased since one month after operation. (2) The overall airflow of cleft palate patients is higher than in the control group, however oral air pressure is lower than control group. (3) The nasal airflow and the nasal rate in overall airflow of cleft palate patients has higher than the control group, however its decreased after operation. (4) The nasalance scores of cleft palate patients were 40% higher than that of the control group. The scores did not decrease after operation. The nasalance score of lateral and fricative sounds did not decrease after operation.

• 대한치과교정학회지
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• 제47권6호
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• pp.353-364
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• 2017

Objective: The objective of this study was to investigate the effects of miniscrew-assisted rapid palatal expansion (MARPE) on changes in airflow in the upper airway (UA) of an adult patient with obstructive sleep apnea syndrome (OSAS) using computational fluid-structure interaction analysis. Methods: Three-dimensional UA models fabricated from cone beam computed tomography images obtained before (T0) and after (T1) MARPE in an adult patient with OSAS were used for computational fluid dynamics with fluid-structure interaction analysis. Seven and nine cross-sectional planes (interplane distance of 10 mm) in the nasal cavity (NC) and pharynx, respectively, were set along UA. Changes in the cross-sectional area and changes in airflow velocity and pressure, node displacement, and total resistance at maximum inspiration (MI), rest, and maximum expiration (ME) were investigated at each plane after MARPE. Results: The cross-sectional areas at most planes in NC and the upper half of the pharynx were significantly increased at T1. Moreover, airflow velocity decreased in the anterior NC at MI and ME and in the nasopharynx and oropharynx at MI. The decrease in velocity was greater in NC than in the pharynx. The airflow pressure in the anterior NC and entire pharynx exhibited a decrease at T1. The amount of node displacement in NC and the pharynx was insignificant at both T0 and T1. Absolute values for the total resistance at MI, rest, and ME were lower at T1 than at T0. Conclusions: MARPE improves airflow and decreases resistance in UA; therefore, it may be an effective treatment modality for adult patients with moderate OSAS.

• 음성과학
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• 제15권4호
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• pp.135-146
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• 2008

Breath group generally refers to one of units of speech production. It is an integral component of structural and contextual features of utterances with some responsibility for fluctuations in speech intelligibility. The purpose of this study was to know the characteristics of breath group in reading passages spoken by healthy speakers, specifically in view of aerodynamic aspects. Eighteen female speakers aged from 20 to 30 years old without communication problems and in healthy condition were participated in this study. PAS (Phonatory Aerodynamic System) was used for aerodynamic measurement of breath group. Results showed that the mean value of breath group in reading tasks was 16.03 per minute (SD=3.1), and the spoken syllables per one breath group were 17.95. And the mean time (m) of breath group was 3.06 (SD=0.62), and the ratio of exhalation and inhalation was appeared in the 1:5. The results need to be discussed in values of normality of breath group and clinical viewpoint, especially their potential implication from speech intelligibility caused by brain damage.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.21-24
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• 2008

The present study numerically investigates the glottal airflow characteristics as well as acoustic features of phonation fully coupled with dynamic behavior of vocal folds. The vocal folds are described by a low-dimensional body-covered model characterized by bio-mechanical parameters such as glottal width, vocal folds stiffness, and subglottal pressure. The flow in the vocal tract is modeled as an incompressible, axisymmetric form of the Navier-Stokes equations (INS), while the acoustic field is predicted by the linearized perturbed compressible equations (LPCE). The computed result shows that a two-mass model of vocal folds is sufficient to reproduce temporal variations in oral airflow and glottis motion produced by female speakers. It is also found that i) the glottal width has a significant effect on the amplitude of glottal flow, and thus on the amplitude of acoustic wave in the vocal tract, ii) the vocal fold tension is the main control parameter for the fundamental frequency of phonation, iii) the subglottal pressure plays an appreciable role on reproduction of the self-sustained oscillation of vocal folds, and iv) the strength of pulsating airflow and vortical structures are primarily affected by glottal width and subglottal pressure, and are closely related to pitch, loudness, and voice quality. Finally, more comprehensive explanation about the difference between one- and two-mass models is presented with discussion of effectiveness of vocal folds oscillation and voice quality.

• 대한기계학회논문집 C: 기술과 교육
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• 제2권2호
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• pp.73-80
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• 2014

상기도 내의 약물 전달을 알아보기 위하여 구강 호흡 시 공기유동에 대한 수치해석을 수행하였다. 상기도는 구강과 후두, 기관과 기관지로 구성되어 있다. 정밀 촬영한 CT 데이터로부터 의료영상 소프트웨어(Mimics)를 이용한 구분(segmentation)과 세심한 표면처리를 통하여 해부학적으로 정확한 모델을 만들 수 있었다. 이 3차원 컴퓨터 모델을 이용하여, 구강에서 기관지의 2번째 분지까지 이르는 유로의 수치 모델을 제작하였다. 수치해석은 상용 소프트웨어인 ANSYS/Fluent를 이용하여 계산하였다. 본 연구에 사용된 모델은 노즐이 부착되지 않은 상태에서 초당 250 mL를 흡입하는 정상 구강호흡 모델과 입구에 각각 20 mL/s, 40 mL/s, 60 mL/s의 유량을 갖는 노즐을 장착한 모델을 사용하였다. 전산 유동가시화 결과로부터, 노즐의 유량을 증가시킬수록 선회류의 발생 정도가 증가하여 구강 내 약물의 잔류 량은 증가하지만, 기관/기관지에 약물 도표는 균일하게 나타났다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권4호
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• pp.321-328
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• 2007

If there are problems for us to sleep, we are faced with fatigue and dizziness in the day. Snoring and OSAS (obstructive sleep apnea syndrome) during sleeping are the main cause of sleep disorder. Treatments through surgical method and sleep splint can be performed to treat snoring and OSAS. Relapse of snoring and OSAS is common after treatment by surgical method. But, Recently sleep splint is frequently applied to treat snoring and OSAS with surgical treatment, because it is convenient and conservative. Sleep splint treat snoring and OSAS by ensuring airway through nose. As first step of fabrication occlusal bite is gained at a point that patient get feeling of increased nasal breathing in supined position, and next, the bite is transfered to sleep splint. This study surveyed the effect of sleep splint by questionnaire to the out-patients (the Dept. of Oral and Maxillofacial Surgery, Chonbuk National University Hospital) weared sleep splint and their partners, secondarily measured airflow through nose by aerophone II after wearing sleep splint and finally evaluated the effect of treatment of snoring and OSAS by sleep splint. The obtained result were as follows; 1. Though 'sleep splint' couldn't eliminate fundamental problems of snoring, it could improve the symptoms when patients were selected could using the 'Nakagawa's respiration method'. 2. Patients who used the sleep splint could breathe stably when patients are sleeping stably. Wearing a 'sleep splint' improved airflow by expanding the upper airway. 3. Even though sleep splint can be made with variable materials, the patients expressed the most satisfaction on the splint with '0.75mm hard shell'. 4. The 'Herbst' may allows the mandible to move the TMJ to relax. Nevertheless, some patients experienced a discomfort or irritation. 5. In Snoring and OSAS cases, it is recommended that patients should first explore non-surgical options prior to choosing a surgical treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권3호
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• pp.267-275
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• 2005

Obstructive sleep apnea syndrome (OSAS) is characterized by sleep-induced obstruction of the upper airway that results in cessation of airflow. Obstruction can occur at a number of points in the airway, but frequently in the oropharynx. A diagnostic evaluation includes cephalometry, computed tomography, magnetic resonance imaging, acoustic reflection technique, polysomnography and fibroptic endoscopy. Cephalometric measurements of the patients with obstructive sleep apnea have revealed that posterior airway anatomy has strong relations with the symptoms of them. A lateral cephalogram is routinely obtained in the radiologic evaluation of sleep apnea patients. The purpose of this study is to provide a the lateral cephalometric korean norms for the diagnosis and treatment of the patients with obstructive sleep apnea by analyzing the abnormal occlusion of Korean adults.

• 한국가시화정보학회지
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• 제19권3호
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• pp.115-122
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• 2021

Oral cancer surgery typically consists of resection of lesion, neck dissection and reconstruction, and it has an impact on the position of hyoid bone. Therefore, morphological change of airway can occur since the geometric parameter of airway is correlated with the hyoid bone. Airflow is affected by geometry of the airway. In this study, flow characteristics were compared between pre- and post-surgery models by both particle image velocimetry (PIV) and numerical simulation. 3D model of upper airway was reconstructed based on CT data. Velocity is accelerated by the reduced channel area, and vortex and recirculation region are observed in pre- and post-surgery models. For the post-surgery model, high pressure distribution is developed by significantly decreased hydraulic diameter, and the longitudinal flow stream is also interrupted.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권2호
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• pp.157-161
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• 2001

The purpose of this study cephalometrically evaluated changes in the posterior airway space for patients with obstructive sleep apnea syndrome(OSAS) before and after surgical advancement of the maxilla and mandible. The change in calculated airway resistance was correlated with the respiratory disturbance index(RDI). Twenty cephalometric radiographs were traced before and after surgery to determine the posterior airway area and calculate resistance. Polysomnograms of each patient were obtained before and after surgery. All patients had a decrease in calculated airflow resistance in the airway. The mean amount of resistance was 865.15 before surgery, decreasing to 192.65 after surgery (p<0.01). Eighty-five percent of the patients experienced improvement in their RDI. Reduction in the RDI appears to be due to an increase in the posterior airway space and decrease in flow resistance.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권3호
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• pp.338-345
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• 1991

선천성 혹은 술후성 기형으로 발생하는 구개인두 부전증은 구강과 비강사이의 부적절한 폐쇄기능으로 인해 과비음 등의 발음장애를 초래한다. 그 원인으로는 구개파열, 인두비대증, 편도선절제술후의 구개와 인두의 비율 부조화, 구개인두 괄약근의 기형, 구래부전마비, 연구개 결손, 상악골 전진 절단술 등이 있다. 구개인두 부전증의 진단에는 임상적, 방사선학적 검사와 더불어 섬유광학 비내시경을 이용한 구개인두의 기능검사가 강조된다. 수술방법으로는 구개성형술, 인두증강술, 인두성형술, 인두피판술 등이 있다. 근자에는 상부기저형 인두피판술이 널리 사용되고 있는데, Hogan등이 개선시킨 술식에 의하면, 넓고 긴 피판을 얻을 수 있고 피판의 Raw surface를 연구개의 비강측 점막으로 덮을 수 있으며 측방 통로를 조절할 수 있다는 장점이 있다. 이에 저자등은 본인에 내원한 구개인두 부전증 환자 7례에서 상부기저형 인두피판을 이용하여 구강과 비강 사이의 측방 통로를 적절히 조절함으로서 발음을 개선시켜 본 바 양호한 임상성적을 얻었기에 보고하는 바이다.