Michael C. F. Tong
The Chinese University of Hong Kong
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International Journal of Pediatric Otorhinolaryngology | 1996
Michael C. F. Tong; Shun Yuen Ying; Charles Andrew van Hasselt
This study investigates the pattern of pediatric nasal foreign body impaction and its management in a metropolitan area. Data was obtained from 147 children presenting to the Accident and Emergency Department over a 4-year period. The majority of foreign bodies were toys and household products. Complications which occurred, such as ingestion of the foreign body or epistaxis were usually related to attempts at removal. Fourteen cases of local complications resulted from button battery impaction. Most of these patients can successfully be managed without complication if correct procedures are adopted.
Journal of Laryngology and Otology | 1996
Michael C. F. Tong; John K. S. Woo; C. Andrew van Hasselt
Active chronic suppurative otitis media poses a management problem when patients are being considered for surgical treatment. Topical antibiotics have demonstrated varying degrees of success in the management of discharging ears. The introduction of quinolones has revived interest in these topical agents. This double-blind study compares two antibiotics, namely ofloxacin and neomycin-polymyxin B, with similar in vitro sensitivities to Gram positive and Gram negative organisms. Fifty-two patients were selected randomly and the results show that ofloxacin eardrops have marginal benefits in symptomatic improvement (89 per cent versus 79 per cent, p = 0.27) and bacterial eradication (81 per cent versus 75 per cent, p = 0.81) in active chronic suppurative otitis media. Significantly fewer patients (seven per cent versus 29 per cent, p = 0.04) in the ofloxacin group had active disease at the end of the two-week treatment. We recommend the use of ofloxacin eardrops in managing active chronic suppurative otitis media since it has high clinical efficacy, contains no steroid component and has no demonstrated risk of ototoxicity.
American Journal of Rhinology & Allergy | 2009
Sham Cl; John K. S. Woo; C. Andrew van Hasselt; Michael C. F. Tong
Background This article reviews our treatment results of sinonasal inverted papilloma (SNIP) over the past 18 years. A retrospective observational study was performed. Methods Fifty-six patients with SNIP seen between 1990 and 2008 with follow-up of >2 years were retrospectively analyzed. Results Forty patients (71%) had primary endoscopic resection and 16 patients (29%) had endoscopic-assisted external approaches. Ten patients (18%) had small nasoethmoid residual disease resectable under local anesthesia in the outpatient department. Eight patients (14%) had recurrences requiring revision under general anesthesia, most of which were maxillary and frontal disease requiring additional external approaches. Comparing patients with and without a history of previous surgery (36% versus 64% of all patients), the former had a higher chance of requiring external approaches during the primary resection (45% versus 29%), a higher recurrence rate (45% versus 25%), and a higher chance of external approaches for revision (44% versus 22%). All the first recurrences were at the original tumor site. Eighty-nine percent of the first recurrences were diagnosed within the first 2 years postoperation. Conclusion Thirty-two percent of our patients had recurrence after their primary resection. Recurrences in the nasoethmoid area are usually small and resectable endoscopically under local anesthesia in the outpatient department whereas those inside the maxillary and frontal sinuses are likely to require additional external approaches under general anesthesia. A minimum of 2 years of follow-up is recommended for the preliminary report on the treatment results of this condition. Lifelong follow-up is recommended for possible late recurrences and metachronous multifocal disease.
The Cleft Palate-Craniofacial Journal | 2011
Wendy M.Y. Kwan; Victor J. Abdullah; Kelvin K.W. Liu; C. Andrew van Hasselt; Michael C. F. Tong
Objective To determine the incidence of otitis media with effusion and the associated hearing loss, the rate of ventilation tube insertion, and complications of ventilation tube insertion in Chinese cleft palate patients. Design Retrospective review in a tertiary care hospital in Hong Kong. Patients A total of 104 consecutive patients with cleft lip and/or cleft palate who were born between January 1996 and January 2006. Results The incidence of otitis media with effusion in Chinese cleft palate patients for the first 2 years after birth was 76.1%. Of these patients, 16.9% had otitis media with effusion associated with a moderate hearing loss (40 decibels hearing level [dBHL]). Approximately half (53.2%) of our patients had ventilation tube insertion. Complications including retraction, tympanosclerosis, and perforation of the tympanic membrane were found in 15.7% of all ears with otitis media with effusion and ventilation tube insertion. Conclusions The high incidence of otitis media with effusion in cleft palate infants found in this study is consistent with that reported in the Western literature. A small but significant proportion of otitis media with effusion was associated with moderate hearing loss that truly required surgical treatment. Cleft palate children are much more likely to develop otitis media with effusion than normal children, and they develop the condition at an earlier age. A protocol for the treatment of otitis media with effusion in cleft palate patients and further prospective studies are warranted.
American Journal of Rhinology & Allergy | 2010
Sham Cl; Lee Dl; Van Hasselt Ca; Michael C. F. Tong
BACKGROUND The etiology of sinonasal inverted papilloma (IP) is unknown. This study was designed to evaluate the possible risk factors associated with IP Methods: This is a case-control epidemiology study in a tertiary referral center. Fifty patients with IP and 150 matched controls were interviewed using a questionnaire on suspected risk factors. Univariate analysis of the risk factors and calculation of the matched odds ratios, the corresponding 95% CIs, and p values was performed. Significant risk factors were further studied using conditional logistic regression analysis. RESULTS Outdoor and industrial occupations were associated with IP. Tobacco smoking, drinking alcohol, history of allergic rhinitis, sinusitis, nasal polyp, non-sinonasal papilloma and non-sinonasal malignancy were not significant factors. CONCLUSION Outdoor and industrial occupations were associated with IP and may be potential risk factors. Future studies are warranted to further evaluate the individual type of occupation and chemical involved.Background The etiology of sinonasal inverted papilloma (IP) is unknown. This study was designed to evaluate the possible risk factors associated with IP Methods This is a case-control epidemiology study in a tertiary referral center. Fifty patients with IP and 150 matched controls were interviewed using a questionnaire on suspected risk factors. Univariate analysis of the risk factors and calculation of the matched odds ratios, the corresponding 95% CIs, and p values was performed. Significant risk factors were further studied using conditional logistic regression analysis. Results Outdoor and industrial occupations were associated with IP. Tobacco smoking, drinking alcohol, history of allergic rhinitis, sinusitis, nasal polyp, non-sinonasal papilloma and non-sinonasal malignancy were not significant factors. Conclusions Outdoor and industrial occupations were associated with IP and may be potential risk factors. Future studies are warranted to further evaluate the individual type of occupation and chemical involved.
Archives of Otolaryngology-head & Neck Surgery | 2010
Siu Kwan Ng; Dennis Lee; Albert M. Li; Yun Kwok Wing; Michael C. F. Tong
OBJECTIVE To determine the reproducibility of the Brodsky grading scale and the modified 3-grade and 5-grade scales in reporting the size of the tonsils. DESIGN Retrospective review of 60 video recordings of tonsil examination by 12 independent observers with different clinical backgrounds and various levels of training. The sizes of the tonsils were graded using different grading scales. SETTING Tertiary care university hospital. PARTICIPANTS The video recordings were chosen from an ongoing epidemiologic study of sleep-related breathing disorder in children in Hong Kong. Main Outcomes Measures The intraobserver and interobserver reproducibility of each grading scale was determined using intraclass correlation. An intraclass correlation coefficient (ICC) exceeding 0.75 was set a priori to indicate an acceptable level of reliability. RESULTS The mean intraobserver ICCs for the Brodsky grading scale and the modified 3-grade and 5-grade scales were 0.858, 0.830, and 0.865, respectively. The mean interobserver ICCs for the Brodsky grading scale and the modified 3-grade and 5-grade scales were 0.763, 0.739, and 0.783, respectively. CONCLUSION The Brodsky grading scale and the modified 5-grade scale achieved acceptable intraobserver and interobserver reproducibility.
Anesthesia & Analgesia | 1998
Peter K. M. Ku; Michael C. F. Tong; K. M. Ho; Anne Kwan; Charles Andrew van Hasselt
E sophageal perforation due to a traumatic intubation is exceedingly rare. If not noticed immediately or treated promptly, however, the morbidity and mortality is significant. Most cases present within 24 h after the event. A delay in symptoms that signal esophageal perforation after a traumatic endotracheal intubation has serious clinical implications. We report a case of traumatic esophageal perforation due to endotracheal intubation for elective sinus surgery under general anesthesia with a delay in onset of symptoms and signs. The diagnosis and management of this complication are discussed.
Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2012
Sham Cl; Kin-Wang To; Paul K.S. Chan; Dennis Lee; Michael C. F. Tong; C. Andrew van Hasselt
The purpose of this study of human papillomavirus (HPV), Epstein–Barr virus (EBV), p21, and p53 in sinonasal inverted papilloma (IP) was to help elucidate its pathogenesis.
Journal of Laryngology and Otology | 1999
Peter K. M. Ku; Michael C. F. Tong; C. Y. Leung; Martin Wai Pak; C. Andrew van Hasselt
Two cases of Rosai-Dorfman disease with polypoid nasal infiltration mimicking nasal tuberculosis and malignant lymphoma are reported. This rare benign disease was first described by Rosai and Dorfman in 1969 and is characterized by histiocytic proliferation. It is seldom considered in the differential diagnosis of granulomatous diseases due to its rarity and histological similarity to other diseases. Extranodal manifestations of this disease are uncommon. Although no specific treatment can guarantee a sustained remission of this disease, surgery for loco-regional lesions can result in long-term symptomatic control and restoration of function. Both patients underwent endoscopic resection of the nasal polypoid lesions and have subsequently been free of recurrence. Loco-regional infiltration of the nasal cavity by Rosai-Dorfman disease is effectively managed by endoscopic resection.
Journal of the Acoustical Society of America | 2009
Meng Yuan; Tan Lee; Kevin C. P. Yuen; Sigfrid D. Soli; Charles Andrew van Hasselt; Michael C. F. Tong
This study investigated the contributions of temporal periodicity cues and the effectiveness of enhancing these cues for Cantonese tone recognition in noise. A multichannel noise-excited vocoder was used to simulate speech processing in cochlear implants. Ten normal-hearing listeners were tested. Temporal envelope and periodicity cues (TEPCs) below 500 Hz were extracted from four frequency bands: 60-500, 500-1000, 1000-2000, and 2000-4000 Hz. The test stimuli were obtained by combining TEPC-modulated noise signals from individual bands. For periodicity enhancement, temporal fluctuations in the range 20-500 Hz were replaced by a sinusoid with frequency equal to the fundamental frequency of original speech. Tone identification experiments were carried out using disyllabic word carriers. Results showed that TEPCs from the two high-frequency bands were more important for tone identification than TEPCs from the low-frequency bands. The use of periodicity-enhanced TEPCs led to consistent improvement of tone identification accuracy. The improvement was more significant at low signal-to-noise ratios, and more noticeable for female than for male voices. Analysis of error distributions showed that the enhancement method reduced tone identification errors and did not show any negative effect on the recognition of segmental structures.