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Dongxu Liu - One of the best experts on this subject based on the ideXlab platform.
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cbct evaluation of the upper airway morphological changes in growing patients of class ii division 1 malocclusion with mandibular retrusion using twin block appliance a comparative research
PLOS ONE, 2014Co-Authors: Hong Liu, Huijua Cheng, Chunling Wang, Yu Che, Jinli Song, Dongxu LiuAbstract:Objective The purpose of this study was to evaluate the morphological changes of upper airway after Twin Block (TB) treatment in growing patients with Class II division 1 malocclusion and mandibular retrusion compared with untreated Class II patients by cone beam computed tomography (CBCT). Materials and Methods Thirty growing patients who have completed TB treatment were recruited into TB group. The control group (n = 30) was selected from the patients with the same diagnosis and without TB treatment. CBCT scans of the pre-treatment (T1) and post-treatment (T2) data of TB group and control data were collected. After three-dimensional (3D) reconstruction and registration of T1 and T2 data, the morphological changes of upper airway during TB treatment were measured. The statistical differences between T1 and T2 data of TB group as well as T2 and control data were accessed by t-test. Results During the TB treatment, the mandible moved advanced by 3.52±2.14 mm in the horizontal direction and 3.77±2.10 mm in the vertical direction. The hyoid bone was in a more forward and inferior place. The upper airway showed a significant enlargement in nasopharynx, oropharynx and Hypopharynx. In addition, the nasopharynx turned more circular, and the oropharynx became more elliptic in transverse shape. However, the transverse shape of the Hypopharynx showed no significant difference. After comparison between T2 and control data, only the horizontal movement of the hyoid bone, the volumetric expansion of the oropharynx and Hypopharynx, and changes of the oropharyngeal transverse shape showed significant difference. Conclusion Compared to the untreated Class II patients, the upper airway of growing patients with Class II division 1 malocclusion and mandibular retrusion showed a significant enlargement in the oropharynx and Hypopharynx as well as a more elliptic transverse shape in the oropharynx, and the hyoid bone moved to an anterior position after TB treatment.
Hong Liu - One of the best experts on this subject based on the ideXlab platform.
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cbct evaluation of the upper airway morphological changes in growing patients of class ii division 1 malocclusion with mandibular retrusion using twin block appliance a comparative research
PLOS ONE, 2014Co-Authors: Hong Liu, Huijua Cheng, Chunling Wang, Yu Che, Jinli Song, Dongxu LiuAbstract:Objective The purpose of this study was to evaluate the morphological changes of upper airway after Twin Block (TB) treatment in growing patients with Class II division 1 malocclusion and mandibular retrusion compared with untreated Class II patients by cone beam computed tomography (CBCT). Materials and Methods Thirty growing patients who have completed TB treatment were recruited into TB group. The control group (n = 30) was selected from the patients with the same diagnosis and without TB treatment. CBCT scans of the pre-treatment (T1) and post-treatment (T2) data of TB group and control data were collected. After three-dimensional (3D) reconstruction and registration of T1 and T2 data, the morphological changes of upper airway during TB treatment were measured. The statistical differences between T1 and T2 data of TB group as well as T2 and control data were accessed by t-test. Results During the TB treatment, the mandible moved advanced by 3.52±2.14 mm in the horizontal direction and 3.77±2.10 mm in the vertical direction. The hyoid bone was in a more forward and inferior place. The upper airway showed a significant enlargement in nasopharynx, oropharynx and Hypopharynx. In addition, the nasopharynx turned more circular, and the oropharynx became more elliptic in transverse shape. However, the transverse shape of the Hypopharynx showed no significant difference. After comparison between T2 and control data, only the horizontal movement of the hyoid bone, the volumetric expansion of the oropharynx and Hypopharynx, and changes of the oropharyngeal transverse shape showed significant difference. Conclusion Compared to the untreated Class II patients, the upper airway of growing patients with Class II division 1 malocclusion and mandibular retrusion showed a significant enlargement in the oropharynx and Hypopharynx as well as a more elliptic transverse shape in the oropharynx, and the hyoid bone moved to an anterior position after TB treatment.
Lori A Deitte - One of the best experts on this subject based on the ideXlab platform.
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cricoid pressure results in compression of the postcricoid Hypopharynx the esophageal position is irrelevant
Obstetric Anesthesia Digest, 2011Co-Authors: Mark J Rice, Anthony A Mancuso, Charles P Gibbs, Timothy E Morey, Nikolaus Gravenstein, Lori A DeitteAbstract:BACKGROUND: Sellick described cricoid pressure (CP) as pinching the esophagus between the cricoid ring and the cervical spine. A recent report noted that with the application of CP, the esophagus moved laterally more than 90% of the time, questioning the efficacy of this maneuver. We designed this study to accurately define the anatomy of the Sellick maneuver and to investigate its efficacy. METHODS: Twenty-four nonsedated adult volunteers underwent neck magnetic resonance imaging with and without CP. Measurements were made of the postcricoid Hypopharynx, airway compression, and lateral displacement of the cricoid ring during the application of CP. The relevant anatomy was reviewed. RESULTS: The Hypopharynx, not the esophagus, is what lies behind the cricoid ring and is compressed by CP. The distal Hypopharynx, the portion of the alimentary canal at the cricoid level, was fixed with respect to the cricoid ring and not mobile. With CP, the mean anterioposterior diameter of the Hypopharynx was reduced by 35% and the lumen likely obliterated, and this compression was maintained even when the cricoid ring was lateral to the vertebral body. CONCLUSIONS: The location and movement of the esophagus is irrelevant to the efficiency of the Sellick’s maneuver (CP) in regard to prevention of gastric regurgitation into the pharynx. The Hypopharynx and cricoid ring move together as an anatomic unit. This relationship is essential to the efficacy and reliability of Sellick’s maneuver. The magnetic resonance images show that compression of the alimentary tract occurs with midline and lateral displacement of the cricoid cartilage relative to the underlying vertebral body. (Anesth Analg 2009;109:1546‐52)
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the anatomy of the cricoid pressure unit
Surgical and Radiologic Anatomy, 2010Co-Authors: Mark J Rice, Anthony A Mancuso, Timothy E Morey, Nikolaus Gravenstein, Lori A DeitteAbstract:We read with interest the article by Benkhadra et al. [1] describing the relationship of the cricoid cartilage and the esophagus during neck Xexion and extension. As the authors correctly point out, the bond between the cricoid ring and esophagus is vital to the clinical eYcacy of cricoid pressure performed to prevent regurgitation of stomach contents during the induction of general anesthesia. Our group recently reported a magnetic resonance imaging (MRI) study investigating the relationship of the cricoid cartilage and the esophagus, with and without cricoid pressure, in the typical anatomic positions for endotracheal intubation [2]. As similarly reported by Schmalfuss et al. [3], we also did not observe the esophagus at the level of the cricoid as is commonly believed, but found the postcricoid Hypopharynx. This is more than just a curiosity of nomenclature. The postcricoid Hypopharynx is Wxed in relationship to the cricoid cartilage in what we have named the cricoid pressure unit [2]. “It is the constant relationship of the cricoid cartilage to the laryngeal cartilages, maintained by their connecting ligaments and muscles, which laterally stabilizes the cricoid relative to the thyroid lamina and cornua. Because the cricoid cartilage and the postcricoid Hypopharynx are constantly related by a subset of these muscular attachments, the cricoid cartilage and postcricoid Hypopharynx behave as a unit when they are compressed together posteriorly against the cervical spine or the deep neck muscles. This cricoid pressure unit also has built-in constraints to lateral displacement of the cricoid cartilage relative to the postcricoid Hypopharynx with compression [2].” We agree with Benkhadra et al. [1] that wall thickness must play a role in the eYcacy of cricoid pressure. Schmalfuss and colleagues [3] made precise wall thickness measurements, which we used to bolster our case that the alimentary tract lumen was occluded because our observed total antero-posterior diameter of the postcricoid Hypopharynx was much less with cricoid pressure than the total of the two walls in the non-occluded state [2]. The Wnal words on the eYcacy of cricoid pressure, Wrst described by Dr. Brian Sellick [4], have not yet been written. Continued dialogue between investigators and across disciplines, as Benkhadra et al. have demonstrated, will help us further reWne our thinking about the role for and eYcacy of cricoid pressure in clinical practice.
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cricoid pressure results in compression of the postcricoid Hypopharynx the esophageal position is irrelevant
Anesthesia & Analgesia, 2009Co-Authors: Mark J Rice, Anthony A Mancuso, Charles P Gibbs, Timothy E Morey, Nikolaus Gravenstein, Lori A DeitteAbstract:BACKGROUND: Sellick described cricoid pressure (CP) as pinching the esophagus between the cricoid ring and the cervical spine. A recent report noted that with the application of CP, the esophagus moved laterally more than 90% of the time, questioning the efficacy of this maneuver. We designed this study to accurately define the anatomy of the Sellick maneuver and to investigate its efficacy. METHODS: Twenty-four nonsedated adult volunteers underwent neck magnetic resonance imaging with and without CP. Measurements were made of the postcricoid Hypopharynx, airway compression, and lateral displacement of the cricoid ring during the application of CP. The relevant anatomy was reviewed. RESULTS: The Hypopharynx, not the esophagus, is what lies behind the cricoid ring and is compressed by CP. The distal Hypopharynx, the portion of the alimentary canal at the cricoid level, was fixed with respect to the cricoid ring and not mobile. With CP, the mean anterioposterior diameter of the Hypopharynx was reduced by 35% and the lumen likely obliterated, and this compression was maintained even when the cricoid ring was lateral to the vertebral body. CONCLUSIONS: The location and movement of the esophagus is irrelevant to the efficiency of the Sellick's maneuver (CP) in regard to prevention of gastric regurgitation into the pharynx. The Hypopharynx and cricoid ring move together as an anatomic unit. This relationship is essential to the efficacy and reliability of Sellick's maneuver. The magnetic resonance images show that compression of the alimentary tract occurs with midline and lateral displacement of the cricoid cartilage relative to the underlying vertebral body.
Jatin P Shah - One of the best experts on this subject based on the ideXlab platform.
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combined surgery and radiation therapy for squamous cell carcinoma of the Hypopharynx
Otolaryngology-Head and Neck Surgery, 1997Co-Authors: Dennis H Kraus, Michael J Zelefsky, Heidi A J Brock, Jerry Huo, Louis B Harrison, Jatin P ShahAbstract:Squamous cell carcinoma of the Hypopharynx remains a highly lethal disease. This article documents our experience with 132 patients undergoing surgical management of squamous cell carcinoma of the Hypopharynx, of whom 80% received postoperative radiation therapy. Local-regional control was obtained in 61% of the patients. Five-year overall and disease-free survival rates were 30% and 41%, respectively. Prognosis was better in patients with limited disease: local disease permitting larynx-sparing surgery, N0/N1 clinical neck, and stage I/II/III disease. Cancer of the Hypopharynx remains an aggressive entity associated with poor prognosis. Novel strategies stressing improved local-regional control with prevention of distant metastasis are warranted.
Robert J Amdur - One of the best experts on this subject based on the ideXlab platform.
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sparing the larynx and Hypopharynx with radiation therapy for squamous cell carcinoma of unknown primary site and predominant adenopathy in level iia
Practical radiation oncology, 2021Co-Authors: Alexandra N De Leo, Christopher G Morris, William M Mendenhall, Roi Dagan, Kathryn E Hitchcock, Peter T Dziegielewski, Robert J AmdurAbstract:Abstract Purpose There is controversy about the need to target the mucosa of the larynx and Hypopharynx during radiation therapy (RT) for squamous cell carcinoma of an unknown primary site (SCCA-UP). By 1997, the policy in our department was to target only the oropharynx and nasopharynx in patients with SCCA-UP metastatic to the level II cervical nodes. The purpose of this study was to report the rate of cancer recurrence in the larynx or Hypopharynx using an approach that excluded these areas from the RT target volumes. Methods and Materials The inclusion criteria for this study were RT in our department for SCCA-UP between January 1, 1997, and December 31, 2019; no history of surgery that could disrupt the cervical lymphatics; predominant adenopathy in level IIA; and neck stage N1-2c. We excluded N3 because the incidental dose to the larynx and Hypopharynx is usually high in patients with a >6-cm nodal conglomerate. Results The study population was comprised of 50 patients with a median follow-up after RT of 7.1 years. No patient developed recurrent cancer in a mucosal site (0/50), 2% (1/50) developed a neck recurrence in a high-dose area with synchronous distant metastases, and 2% (1/50) developed distant metastases with no evidence of local or regional recurrence. Conclusions When delivering RT for SCCA-UP metastatic predominantly to level IIA, it is not necessary to target the mucosa of the larynx or Hypopharynx. The extent to which the incidental RT dose to these areas contributes to cancer control is not evaluated in this study.
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surgery and postoperative radiotherapy for squamous cell carcinoma of the larynx and pharynx
American Journal of Clinical Oncology, 2006Co-Authors: Russell W Hinerman, Christopher G Morris, Robert J Amdur, Christopher D Lansford, John W Werning, Douglas B Villaret, William M MendenhallAbstract:Objective: To determine the rates of local-regional control, survival, and complications for patients treated with postoperative radiation for squamous carcinomas of the larynx, Hypopharynx, and oropharynx. Methods: There were 295 patients with previously untreated squamous cell carcinomas of the larynx (n = 199), Hypopharynx (n = 80), and oropharynx (n = 16) treated postoperatively with radiotherapy (RT). Results: Five-year local-regional control rates according to site and pathologic American Joint Committee on Cancer (AJCC) stage were: stage III larynx, 89% versus stage IVA larynx, 85% (P = 0.33); stage III oropharynx/Hypopharynx, 76% versus stage IVA oropharynx/Hypopharynx, 79% (P = 0.72). Local-regional control rates steadily declined as the number of indications for administering postoperative RT increased. Five-year absolute survival rates versus pathologic AJCC stage for the entire group were: stage III 59% and stage IVA 40% (P = 0.40). Conclusion: Rates of local-regional control, survival, and complications support the use of postoperative radiation in selected patients. Tumor control and survival will hopefully improve further with the addition of chemotherapy to postoperative radiation.