• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.164-171
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• 2000

Purpose : This study was aimed at measuring the changes in the hyoid bone position, tongue position, and pharyngeal airway space in subjects with mandibular setback osteotomies. Methods : Twenty patients were evaluated retrospectively for their changes in pharyngeal airway space, tongue and hyoid bone positions. All patients underwent surgical mandibular setback using bilateral sagittal split osteotomies. The cephalometric analysis was performed preoperatively, and 1 week, 3-6 months, and 1 year postoperatively. Result : The hyoid bone moved inferiorly and posteriorly immediately after surgery, and it returned to the preoperative position during follow-up period. The nasopharyngeal airway space was not significantly changed after surgery. A considerable decrease in the oropharyngeal and hypopharyngeal airway spaces following mandibular setback surgery was found. The upper and lower tongue was posteriorly repositioned immediately after surgery. During follow-up period, the hypopharyngeal airway space and lower tongue posture returned to the preoperative positions, but the oropharyngeal airway space and upper tongue posture were not significantly changed. The position of pogonion remarkably changed to backward immediately after surgery, but slightly anterior advancement was found during follow-up period. Conclusion : Immediately after mandibular setback surgery, the oropharyngeal and hypopharyngeal airway spaces obviously decreased due to posterior and inferior repositions of the tongue and hyoid bone. During follow-up period, lower tongue and hyoid bone returned to the preoperative positions, it was related to advancement of the pogonion in this period. The narrowing of the oropharyngeal airway space and posterior movement of the upper tongue posture were relatively permanent after mandibular setback surgery. We suspected this phenomenon had an influence on maintaining the total volume of oral cavity against mandibular setback.

• The Journal of the Korean dental association
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• v.56 no.5
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• pp.278-286
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• 2018

Food intake and swallowing are complicated and intriguing series of movements involving voluntary and involuntary activities of cranial and spinal nerves and muscles. They have two most important functions, that is, food passage from the oral cavity to stomach and airway protection. Tongue, buccinators, and hyoid bone and its muscular attachments are anatomic structures for swallowing of special interests. The swallowing process of liquid is commonly divided into oral preparatory, oral propulsive, pharyngeal, and esophageal stages according to the location of the bolus. The movement of the food in the oral cavity and to the oropharynx differs between eating solid food and drinking liquid.

• Speech Sciences
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• v.9 no.4
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• pp.3-14
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• 2002

VPI occurs when the velum and lateral and posterior pharyngeal wall fail to separate the nasal cavity from the oral cavity during deglutition and speech. There are a number of congenital and acquired conditions which result in VPI. Congenital conditions include cleft palate, submucous cleft palate and congenital palatal insufficiency (CPI). Acquired conditions include carcinoma of the palate or pharynx and neurologic disorders. The speech characteristics of VPI is characterized by hypernasality, nasal air emission, decreased intraoral air pressure, increased nasal air flow, decreased intelligibility. VPI can be treated with various methods that include speech therapy, surgical procedures to reduce the velopharyngeal gap, speech aid prosthesis, and combination of surgery and prosthesis. This article describes four cases of VPI treated by speech aid prosthesis and speech therapy with satisfactory result.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.423-429
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• 1998

Human pharynx is unique, acting as a complex interchange between the oral cavity and esophagus, and between the nasal cavity and lungs. It is actively involved in the transport of food and liquid, producing the forces that guide that bolus into the upper esophagus and away from the adjacent larynx and lungs. This study intended to develop a biomechanical model of the human pharynx, utilizing Finite Element Method(FEM). Within each model changes in cross sectional intralumenal area were calculated and compared with the area from the computer-generated FE model. Area matching allowed estimation of intraluminal pressure gradients during swallow. The estimated pharyngeal pressure gradient varies from one region to another. The estimated pharyngeal pressure gradients showed different patterns for upper four levels and lower four levels. The contraction velocity for upper four levels is much higher than lower four levels. The higher contraction velocities and pressure gradients in the upper levels are consistent with the bolus velocities required for efficient swallow.

• Radiation Oncology Journal
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• v.37 no.2
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• pp.134-142
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• 2019

Purpose: The aim is to study the dependence of deformable based auto-segmentation of head and neck organs-at-risks (OAR) on anatomy matching for a single atlas based system and generate an acceptable set of contours. Methods: A sample of ten patients in neutral neck position and three atlas sets consisting of ten patients each in different head and neck positions were utilized to generate three scenarios representing poor, average and perfect anatomy matching respectively and auto-segmentation was carried out for each scenario. Brainstem, larynx, mandible, cervical oesophagus, oral cavity, pharyngeal muscles, parotids, spinal cord, and trachea were the structures selected for the study. Automatic and oncologist reference contours were compared using the dice similarity index (DSI), Hausdroff distance and variation in the centre of mass (COM). Results: The mean DSI scores for brainstem was good irrespective of the anatomy matching scenarios. The scores for mandible, oral cavity, larynx, parotids, spinal cord, and trachea were unacceptable with poor matching but improved with enhanced bony matching whereas cervical oesophagus and pharyngeal muscles had less than acceptable scores for even perfect matching scenario. HD value and variation in COM decreased with better matching for all the structures. Conclusion: Improved anatomy matching resulted in better segmentation. At least a similar setup can help generate an acceptable set of automatic contours in systems employing single atlas method. Automatic contours from average matching scenario were acceptable for most structures. Importance should be given to head and neck position during atlas generation for a single atlas based system.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.45-63
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• 1991

This comparative study was designed to ascertain whether any differences existed between skeletal class Ⅱ malocclusion (

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.517-523
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• 2000

Nasopharyngeal closure is a sphincter mechanism between the activities of the soft palate, lateral pharyngeal wall and the posterior pharyngeal wall, which divides the oral cavity and the nasal cavity. It participates in physiological activities such as swallowing, breathing and pronunciation. In case of an error in this mechanism, it is called a nasopharyngeal incompetence. The causes of this error are defects in (1) length, function, posture of the soft palate (2) depth and width of the nasopharynx, (3) activity of the posterior and lateral pharyngeal wall. The purpose of this study is to analyze the nasopharynx of cleft palate patients using lateral cephalograms and at the same time, evaluate the degree of hypernasality of each vowels to find its relationship with nasopharyngeal incompetence. The following results were obtained: 1. The length of the soft palate was markedly short than normal. 2. The adequate ratio was smaller than the normal value. 3. As the adequate ratio decreased, when articulating vowels, anatomic mVPI increased. 4. When articulating each vowels, anatomic VPI was in proportion with the degree of hypernasality. 5. The degree of hypernasality was greater in high vowels(/i/, /u/) than low vowel(/a/). From the above results, it can be concluded that in cleft palate patients, lateral cephalograms can be used effectively in diagnosing and evaluating nasopharyngeal incompetence. The anatomic structure of the nasopharynx has close relation to the degree of hypernasality.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.401-406
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• 2011

Purpose: The purpose of this study was to investigate changes in the position of the hyoid bone and soft palate and the amount of airway space after bilateral sagittal split ramus osteotomy (B-SSRO). Methods: This study is a review of lateral cephalometric tracings of 30 patients who underwent B-SSRO with setbacks at Kyunghee Dental Hospital from 2005 to 2009. Lateral cephalograms were taken before (T0), within one month (T1), and more than six months after the surgery (T2). Results: The hyoid bone at T1 changed significantly towards the inferoposterior position. At T2, it had significantly moved superiorly, but not anteriorly. At T1, the nasopharyngeal space, extending from the posterior nasal spine to the posterior pharyngeal space, decreased significantly, but did not show a significant increase at T2. The nasopharyngeal space, extending from the middle of soft palate to the posterior pharyngeal space, decreased significantly at T1, but did not show a significant decrease at T2. The oropharyngeal airway space decreased significantly at T1 and did not return to its original position at T2. The hypopharyngeal space, extending from the anterior to the posterior pharyngeal space at the level of the most anterior point of the third cervical vertebrae, slightly decreased at T1, but the amount was insignificant; however, the amount of decrease at T2 was significant. The hypopharyngeal space extending from the anterior to the posterior pharyngeal space at the level of the lowest point of the third cervical vertebrae, decreased significantly at T1 but returned to its original position at T2. Conclusion: B-SSRO changes the position of the hyoid bone and muscles inferoposteriorly. These change allows enough space for the tongue and prevent airway obstruction. Airway changes may be related to post-operative edema, posterior movement of the soft palate, anteroposterior movement of the hyoid bone, or compensation for decreased oral cavity volume. The position of the pogonion which measures anterior relapse after surgery did not show significant differences during the follow-up period.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.454-458
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• 2010

Velopharyngeal insufficiency is defined as a status in which nasal cavity and oral cavity can not be sepa-rated when speaking, swallowing by any reason. It has been treated by palatorrhaphy, pharyn-geal flap, local flap, free flap etc. When the size of the defect is small, it can be restored by palatorrhaphy, pharyngeal flap etc. But they are not proper for treatment of the large size of defect. In that case, local flap and free flap are more beneficial. Although large defect can be restored by free flap technique, but it is very complex, time-consuming and may bring about esthetical, functional complications of donor site. Buccinator myomucosal flap is a kind of local flap and reported for the first time by Bozola et al in 1989 and it has become a useful way for reconstruction of large intraoral defect. Authors experienced the use of buccinators myomucosal flap for treating secondary velopharyngeal insufficiency with large soft palate defect and obtained good result. So we report the case with literature reviews.

• 대한두경부종양학회:학술대회논문집
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• 2007.05a
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• pp.80-84
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• 2007

Background and Objectives : The radial forearm free flap is a useful reconstructive method of surgical defects after oral and oropharyngeal tumor resection. We evaluated the swallowing and speech outcomes of radial forearm free flap reconstruction for oral and oropharyngeal cancers. Materials and Methods : We retrospectively reviewed clinical data of 84 patients who underwent reconstructive surgery for oral or oropharyngeal cancer using radial forearm free flap from August 1994 to January 2007. Modified barium swallowing (MBS) was done in 100 patients and speech-language assessment was done in 23 patients by a speech-language pathologist. Results were analyzed according to the swallowing functions and the speech-language assessments. Results : According to the results of MBS which was done postoperatively, aspiration occurred in three patients and velopharyngeal insufficiency occurred in four patients who had been reconstructed with multilobed free flap due to large mucosal defects. There was one patient who exhibited severe articulation impairment out of 23 patients. However, 19 patients out of 23 patients showed excellent intelligibility in speech. Conclusion : We concluded that the radial forearm free flap technique is an excellent reconstructive method for the restoration of palatal and pharyngeal function in oral and oropharyngeal cancer patients.