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Dive into the research topics where Tjoson Tjoa is active.

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Featured researches published by Tjoson Tjoa.


JAMA Facial Plastic Surgery | 2016

A Comparison of Over-the-Counter Mechanical Nasal Dilators: A Systematic Review

Nicole Kiyohara; Christopher Badger; Tjoson Tjoa; Brian J. F. Wong

IMPORTANCE The internal nasal valve is the narrowest part of the nasal airway and a common site of inspiratory collapse and obstruction of nasal airflow. Over-the-counter mechanical nasal dilators are an alternative to surgical intervention that attempts to improve airflow through the internal nasal valve. OBJECTIVE To determine the efficacy of over-the-counter mechanical nasal dilators and classify these products by mechanism. EVIDENCE REVIEW A database of 33 available over-the-counter mechanical nasal dilators was generated via a PubMed search as well as an internet search via Amazon.com and Google, conducted from April 1, 2013, through December 31, 2015. Products determined to be unavailable or discontinued were excluded from the database. Of the devices examined in published literature, efficacy was based on objective measures, such as measured airflow, the cross-sectional area of the nasal valve, and changes in resistance. Measures of reported sleep quality or patient perception were excluded. FINDINGS An analysis of each products mechanism revealed 4 broad classes: external nasal dilator strips, nasal stents, nasal clips, and septal stimulators. A review demonstrated 5 studies supporting the use of external nasal dilator strips, 4 studies supporting the use of nasal clips, 1 study supporting the use of nasal stents, and no studies supporting the use of septal stimulators. CONCLUSIONS AND RELEVANCE Our findings suggest that external nasal dilator strips and nasal clips effectively relieve obstruction of the internal nasal valve and may be an alternative to surgical intervention in some patients.


JAMA Facial Plastic Surgery | 2016

A Finite Element Model to Simulate Formation of the Inverted-V Deformity

Tjoson Tjoa; Cyrus T. Manuel; Ryan P. Leary; Rani Harb; Dmitriy E. Protsenko; Brian J. F. Wong

IMPORTANCE Computational modeling can be used to mimic the forces acting on the nasal framework that lead to the inverted-V deformity (IVD) after surgery and potentially determine long-range outcomes. OBJECTIVE To demonstrate the use of the finite element method (FEM) to predict the formation of the IVD after separation of the upper lateral cartilages (ULCs) from the nasal septum. DESIGN, SETTING, AND PARTICIPANTS A computer model of a nose was derived from human computed tomographic data. The septum and upper and lower lateral cartilages were designed to fit within the soft-tissue envelope using computer-aided design software. Mechanical properties were obtained from the literature. The 3 simulations created included (1) partial fusion of the ULCs to the septum, (2) separation of the ULCs from the septum, and (3) a fully connected model to serve as a control. Forces caused by wound healing were prescribed at the junction of the disarticulated ULCs and septum. Using FEM software, equilibrium stress and strain were calculated. Displacement of the soft tissue along the nasal dorsum was measured and evaluated for evidence of morphologic change consistent with the IVD. MAIN OUTCOME AND MEASURES Morphologic changes on the computer models in response to each simulation. RESULTS When a posteroinferior force vector was applied along the nasal dorsum, the areas of highest stress were along the medial edge of the ULCs and at the junction of the ULCs and the nasal bones. With full detachment of ULCs and the dorsal septum, the characteristic IVD was observed. Both separation FEMs produced a peak depression of 0.3 mm along the nasal dorsum. CONCLUSIONS AND RELEVANCE The FEM can be used to simulate the long-term structural complications of a surgical maneuver in rhinoplasty, such as the IVD. When applied to other rhinoplasty maneuvers, the use of FEMs may be useful to simulate the long-term outcomes, particularly when long-term clinical results are not available. In the future, use of FEMs may simulate rhinoplasty results beyond simply morphing the outer contours of the nose and allow estimation of potentially long-term clinical outcomes that may not be readily apparent. LEVEL OF EVIDENCE NA.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2018

Antibiotic prophylaxis in clean-contaminated head and neck cases with microvascular free flap reconstruction: A systematic review and meta-analysis

Yarah M. Haidar; Prem B. Tripathi; Tjoson Tjoa; Sartaaj Walia; Lishi Zhang; Yanjun Chen; Danh V. Nguyen; Hossein Mahboubi; William B. Armstrong; Julie A. Goddard

Optimal antibiotic prophylaxis duration in head and neck clean‐contaminated free‐flap cases is unknown.


Otolaryngology-Head and Neck Surgery | 2017

The Role of In-Office Ultrasound in the Diagnosis of Neck Masses:

Omid Moshtaghi; Yarah M. Haidar; Amin Mahmoodi; Tjoson Tjoa; William B. Armstrong

To evaluate the efficacy of otolaryngologist-performed in-office ultrasound (US) in the clinical assessment of lateral neck masses, we performed a retrospective review of patients with lateral neck masses who had both a surgeon-performed US and US-guided fine-needle aspiration (USGFNA) at our tertiary academic center from 2012 to 2015. Fifty-nine patients were included. USGFNA results included 32 (54%) malignant lesions, 23 (39%) benign lesions, and 4 (6%) nondiagnostic lesions. USGFNA demonstrated 85% accuracy. In 22 (37%) patients, in-office US revealed additional findings that were not identified on physical examination (eg, nonpalpable lymph nodes or elucidated anatomical structures), which either assisted in surgical planning or altered treatment. In-office US and USGFNA on initial evaluation by the otolaryngologist augment physical examination and have potential value as the primary imaging and diagnostic modality in the workup of lateral neck masses.


Laryngoscope | 2015

Long‐term in vivo electromechanical reshaping for auricular reconstruction in the New Zealand white rabbit model

Karam W. Badran; Cyrus T. Manuel; Anthony Chin Loy; Christian Conderman; Yuk Yee Yau; Jennifer Lin; Tjoson Tjoa; Erica Su; Dmitriy E. Protsenko; Brian J. F. Wong

To demonstrate the dosimetry effect of electromechanical reshaping (EMR) on cartilage shape change, structural integrity, cellular viability, and remodeling of grafts in an in vivo long‐term animal model.


Otolaryngology-Head and Neck Surgery | 2017

Tympanic Membrane and Ossicular-Sparing Modified Lateral Temporal Bone Resection

Yaser Ghavami; Yarah M. Haidar; Marlon Maducdoc; Tjoson Tjoa; Omid Moshtaghi; Harrison W. Lin; Hamid R. Djalilian

A modified lateral temporal bone resection (mLTBR) is a unique technique that spares the tympanic membrane (TM) and ossicles in select patients with squamous cell carcinoma (SCCa). The records of 5 patients with SCCa of the temporal bone with negative frozen-section biopsy at the tympanic annulus were reviewed. The mean follow-up time for the patients was 29.2 months. One patient received postoperative radiation due to cervical nodal extracapsular spread. All patients were recurrence free as of the most recent follow-up (range, 8-50 months). Postoperative audiometry demonstrated an average conductive hearing loss of 9 dB (range, 0-17 dB). The mLTBR with sparing of the TM can be an effective alternative to the traditional lateral temporal bone resection (LTBR) with better hearing results for patients with SCCa involving the bony external auditory canal. In the short term, oncologic results of mLTBR appear equivalent to the LTBR. However, long-term follow-up is needed for >5-year outcomes.


Archive | 2016

Transoral Laser Microsurgery for Laryngeal Cancer

Tjoson Tjoa; William B. Armstrong

Historically, treatment of laryngeal cancer has been in the form of open transcervical surgery, endoscopic transoral surgery using cold steel instrumentation, and external beam radiation therapy. The advances of direct laryngoscopy, microscopic instrumentation, and lasers in the twentieth century have paved the way for transoral laser microsurgery (TLM), which now competes with, and often replaces, the traditional modalities to treat laryngeal cancer. Currently, TLM is a proven, minimally invasive alternative to open surgery for T1, T2, and selected T3 tumors of the glottis and supraglottis. The results of TLM are comparable to open partial laryngectomy procedures and RT in terms of local control and survival rates. With its low postoperative morbidity, TLM represents an attractive means to surgically remove cancer while preserving the laryngeal framework.


JAMA Facial Plastic Surgery | 2016

Optimal Electromechanical Reshaping of the Auricular Ear and Long-term Outcomes in an In Vivo Rabbit Model.

Cyrus T. Manuel; Tjoson Tjoa; Tony D. Nguyen; Erica Su; Brian J. F. Wong

IMPORTANCE The prominent ear is a common external ear anomaly that is usually corrected through surgery. Electromechanical reshaping (EMR) may provide the means to reshape cartilage through the use of direct current (in milliamperes) applied percutaneously with needle electrodes and thus to reduce reliance on open surgery. OBJECTIVE To determine the long-term outcomes (shape change, cell viability, and histology) of a more refined EMR voltage and time settings for reshaping rabbit auricle. DESIGN, SETTING, AND SUBJECTS The intact ears of 14 New Zealand white rabbits were divided into 2 groups. Group 1 received 4 V for 5 minutes (5 ears), 5 V for 4 minutes (5 ears), or no voltage for 5 minutes (control; 4 ears). Group 2 received an adjusted treatment of 4 V for 4 minutes (7 ears) or 5 V for 3 minutes (7 ears). A custom mold with platinum electrodes was used to bend the pinna and to perform EMR. Pinnae were splinted for 6 months along the region of the bend. Rabbits were killed humanely and the ears were harvested the day after splint removal. Data were collected from March 14, 2013, to July 8, 2014, and analyzed from August 29, 2013, to March 1, 2015. MAIN OUTCOMES AND MEASURES Bend angle and mechanical behavior via palpation were recorded through photography and videography. Tissue was sectioned for histologic examination and confocal microscopy to assess changes to microscopic structure and cell viability. RESULTS Rabbits ranged in age from 6 to 8 months and weighed 3.8 to 4.0 g. The mean (SD) bend angles were 81° (45°) for the controls and, in the 5 EMR groups, 72° (29°) for 4 V for 4 minutes, 101° (19°) for 4 V for 5 minutes, 78° (18°) for 5 V for 3 minutes, and 126° (21°) for 5 V for 4 minutes. At 5 V, an increase in application time from 3 to 4 minutes provided significant shape change (78° [18°] and 126° [21°], respectively; P = .003). Pinnae stained with hematoxylin-eosin displayed localized areas of cell injury and fibrosis in and around electrode insertion sites. This circumferential zone of injury (range, 1.3-2.1 mm) corresponded to absence of red florescence on the cell viability assay. CONCLUSIONS AND RELEVANCE In this in vivo study, EMR produces shape changes in the intact pinnae of rabbits. A short application of 4 V or 5 V can achieve adequate reshaping of the pinnae. Tissue injury around the electrodes is modest in spatial distribution. This study provides a more optimal set of EMR variables and a critical step toward evaluation of EMR in clinical trials. LEVEL OF EVIDENCE NA.


Proceedings of SPIE | 2014

Temporal correlation of optical coherence tomography in-vivo images of rabbit airway for the diagnosis of edema

DongYel Kang; Alex Wang; Tjoson Tjoa; Veronika Volgger; Ashley Hamamoto; Erica Su; Joseph Jing; Zhongping Chen; Brian J. F. Wong

Recently, full-range optical coherence tomography (OCT) systems have been developed to image the human airway. These novel systems utilize a fiber-based OCT probe which acquires three-dimensional (3-D) images with micrometer resolution. Following an airway injury, mucosal edema is the first step in the body’s inflammatory response, which occasionally leads to airway stenosis, a life-threatening condition for critically ill newborns. Therefore, early detection of edema is vital for airway management and prevention of stenosis. In order to examine the potential of the full-range OCT to diagnose edema, we investigated temporal correlation of OCT images obtained from the subglottic airway of live rabbits. Temporally correlated OCT images were acquired at fixed locations in the rabbit subglottis of either artificially induced edema or normal tissues. Edematous tissue was experimentally modeled by injecting saline beneath the epithelial layer of the subglottic mucosa. The calculated cross temporal correlations between OCT images of normal airway regions show periodicity that correlates with the respiratory motion of the airway. However, the temporal correlation functions calculated from OCT images of the edematous regions show randomness without the periodic characteristic. These in-vivo experimental results of temporal correlations between OCT images show the potential of a computer-based or -aided diagnosis of edema in the human respiratory mucosa with a full-range OCT system.


Laryngoscope | 2018

Risk factors for thirty-day readmission following flap reconstruction of oncologic defects of the head and neck

Heather A. Osborn; Vinay K. Rathi; Tjoson Tjoa; Neerav Goyal; Bharat B. Yarlagadda; Debbie L. Rich; Kevin S. Emerick; Derrick T. Lin; Daniel G. Deschler; Marlene L. Durand

Unplanned 30‐day readmission rate following hospital discharge is an important metric of healthcare quality. This study sought to characterize the rate, risk factors, and common causes of readmission in head and neck cancer patients following free or pedicled flap reconstruction.

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Julie A. Goddard

University of Colorado Denver

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Edward C. Kuan

University of California

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Erica Su

University of California

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Daniel G. Deschler

Massachusetts Eye and Ear Infirmary

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Derrick T. Lin

Massachusetts Eye and Ear Infirmary

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