原文題目

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口腔病理科 On-Line KMU Student Bulletin

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原文題目(出處)： Primary oral myiasis: A case report. Case Rep Dent; 2012, Article ID 734234

原文作者姓名： Bhola N, Jadhav A, Borle R, Adwani N, Khemka G, Jadhav P

通訊作者學校： Department of Oral and Maxillofacial Surgery &

Periodontology and Implantology, Sharad Pawar Dental College and Hospital, Maharastra, Wardha, India

報告者姓名(組別)：蕭智謙 Intern C組

報告日期： 101/11/9

內文：

1. Introduction

 Human race has been plagued with parasitic infection since the time immortal.

One of the most daunting infestations amongst them through common flies is myiasis

 Myiasis, introduced by Hope (1940), refers to invasion of tissues, organs, and certain body cavities of vertebrate species by the dipteran eggs or larvae

 Zumpt defined Myiasis as an infestation of live human and vertebrate animals by dipterous larva, which at least for certain period of its lifecycle feeds on host’s dead or living tissue

 Higher incidence is reported in tropical, subtropical regions of Africa, America, and South East Asia, where warm, humid climate prevail almost throughout the year

 Commonly seen amongst people where personal hygiene is often ignored and close association with domestic pets exists

 Infestations are common phenomenon in skin, nose, eye, lung, ear, anus, and vagina but oral manifestation is exceptional ( the oral tissues are not exposed to the external environment )

 Oral myiasis is more commonly at the conditions where oral cavity is being exposed to external environment for a prolonged time, mouth breathing, anterior open bite, incompetent lips, cerebral palsy, following tooth extractions, and oral malignancies

2. Case Report

 General data : 12-year-old male child with neurological deficit

 Chief complains : swelling of upper lip and jaw, discomfort with upper front teeth region since 4-5 days

 Extra oral examination revealed incompetent lips, a solitary, large, diffuse, swelling of size approximately 4 × 3 cm in size associated with upper lip with overlying skin tense, and shiny. The swelling was tender to palpation, soft, and edematous

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 Intraoral examination revealed labial gingiva in the region of the maxillary incisors with multiple fenestrations. The anterior labial gingiva showed a poorly defined swelling measuring 3×1 cm with detachment and exposure of underlying bone. Deep burrowing, with multiple cavitations, was seen. Multiple larvae were noted crawling within the gingival lesion. The surrounding mucosa was inflamed and tender to palpation but bleeding and discharge were not evident. Based on clinical findings and presence of maggots, a provisional diagnosis of oral myiasis was made

 Treatment plan : Cotton bud impregnated with turpentine oil was placed at the orifice of the socket for approximately 10 minutes.14–16 maggots were manually removed with the help of hemostats. Patient administered Inj Amoxycillin + Potassium Clavulanate and Inj Metronidazole IV for 3 days. The larvae were mechanically removed for next three consecutive days with exploration, curettage, and warm saline irrigations till no further larvae could be found. No attempt was made to administer antiparasitic drug

3. Discussion

 Myiasis of orodental complex is caused by common Indian housefly Musca Nebulo, found commonly in human habitats with poor hygiene especially

 Clinically, myiasis can be classified as primary or secondary

 Primary myiasis is caused by larvae that feed on living issue

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(biophagous).This form of myiasis is commoner in cattle and rare in humans

 Secondary myiasis is caused by flies that feed on dead tissue (necrobiophagous). This is the more common type and infests patients with lesions that have necrotic cavities

 The lifecycle of a fly commences with egg stage followed by the larval stage, the pupal stage, and finally the adult fly. The requisites for egg laying and survival of the larvae are moisture, necrotic tissue, and suitable temperature. Thus wounds contaminated with discharges make possible way for the same

 Modes of infestation in humans may occur in two ways, either accidentally with direct inoculation by the fly or by ingestion of infected material such as meat

 Larvae are photophobic and tend to hide deep into the tissues

 Standard guidelines for management of oral myiasis do not exist, but more than a few authors note that the ideal approach is to remove all larvae and perform surgical debridement. The treatment incorporated in our case was simple and involved usage of antilarval measures(turpentine oil) followed by removal of the larvae

 Other treatment include occlusion and administration of larvacides. These techniques can be used in addition to manual removal, or if manual removal is not possible

 By depriving larvae of oxygen, occlusion of an infested wound either kills the larvae or induces them to move more superficially where they can be removed more easily. Occlusion of infested wounds with a variety of substances has been described, including petroleum, nail polish, animal fat, beeswax , and mineral oil with varied success

 Early diagnosis, with adequate and careful surgical exploration of the lesion, seems to forestall extensive tissue damage and morbidity, Early surgical treatment of oral myiasis is also important where esthetics is an issue

 4. Conclusion

Oral myiasis is a rare and preventable disease. It can be prevented by controlling fly population, maintaining good oral and personal hygiene such as reducing the decomposition odor, cleaning and covering the wounds, and educating the susceptible population where basic sanitation is of low standard

題號題目

1 The reason leads to the higher incident rate of myiasis. Which one is incorrect?

(A)poor personal hygiene

(B)Wound exposed to the external environment for a long time (C)Child

(D)Warm & humid climate 答案(C) 出處：本Journal

題號題目

2 What is the main difference between primary and secondary myiasis?

(A)different species of host (B)different kind of fly

(C)different stage of lifecycle of fly when infestation (D)different origin of nutrition that larvae feed on 答案(D) 出處：本Journal