Malignant fibrous histiocytoma of the tongue

A case of malignant fibrous histiocytoma, which developed in the tongue of a 16-year-old girl is presented. Surgical excision with, or without, radical neck dissection is the treatment of choice of this type of lesion.

Capture envelopes of rectangular hoods in cross drafts

The suction fields of the rectangular hoods of various aspect ratios varying from 0.1 to 10 that are subject to the influence of cross drafts were experimentally studied in an apparatus consisting of a hood model/wind tunnel assembly. The velocity field on the symmetry plane was measured with a two-component laser Doppler anemometer. Being under the influence of cross draft, the suction field presents a characteristic capture envelope, which is described by a dividing streamline. The characteristics of the capture envelope were found to be determined by the cross-draft to hood-suction velocity ratio R and the hood-opening aspect ratio AR. The flow characteristics of the hoods with aspect ratios less than unity were dramatically different from those with aspect ratios greater than one. If areas of the hood openings had the same values, the hydraulic-diameter normalized characteristic length scales of the capture zone of the square hood were as same as those of the circular hood. When the diameter of a circular hood was equal to the width of a square hood, the physical dimensions of the capture zones created by these two hoods coincided with each other.

High sequence conservation among cucumber mosaic virus isolates from lily

For classification of Cucumber mosaic virus (CMV) isolates from ornamental crops of different geographical areas, these were characterized by comparing the nucleotide sequences of RNAs 4 and the encoded coat proteins. Within the ornamental-infecting CMV viruses both subgroups were represented. CMV isolates of Alstroemeria and crocus were classified as subgroup II isolates, whereas 8 other isolates, from lily, gladiolus, amaranthus, larkspur, and lisianthus, were identified as subgroup I members. In general, nucleotide sequence comparisons correlated well with geographic distribution, with one notable exception: the analyzed nucleotide sequences of 5 lily isolates showed remarkably high homology despite different origins.

Efficacy of high-level disinfectants for reprocessing GI endoscopes in simulated-use testing

BACKGROUND

There has been recent public concern regarding the adequacy of current practices for flexible endoscope reprocessing. High-level disinfection is defined by the Food and Drug Administration (FDA) as a minimum of 6-log reduction of mycobacteria under a worst-case scenario. Several agents are currently approved by the FDA, but published data on their relative efficacies against mycobacteria are lacking. The objective of this study was to determine the efficacy of these agents for high-level disinfection.

METHODS

In simulated-use testing, video endoscopes (5 colonoscopes and 5 duodenoscopes) were each inoculated with 9.0 x 10(7) colony-forming units of Mycobacterium chelonae. Cleaning was performed by using a standardized protocol. Each endoscope was then subjected to chemical disinfection with Cidex (2.0% glutaraldehyde) at 20 degrees C for 20 minutes, Sporox (7.5% hydrogen peroxide) at 20 degrees for 30 minutes, and Steris 20 (0.2% peracetic acid) at 50 degrees C to 56 degrees C for 12 minutes using the Steris System 1 processor. Although not FDA-approved, tests were also conducted by using 70% isopropyl alcohol at 20 degrees C for 20 minutes. These results were compared with disinfection with ethylene oxide gas. All channels were sampled for M chelonae before and after manual cleaning and after disinfection.

RESULTS

Cleaning alone resulted in an average log reduction of 3. Cidex, Sporox, Steris 20, ethylene oxide gas, and isopropyl alcohol, in combination with manual cleaning, each achieved a 6-log or greater reduction of the mycobacterial inoculum. No organisms were recovered from any channel after reprocessing with ethylene oxide and Steris 20.

CONCLUSIONS

Commercially available high-level disinfectants are equally efficacious for reprocessing flexible GI endoscopes when used in conjunction with cleaning and in accordance with recommended guidelines.

Potent, hydroxyl radical-scavenging effect of apomorphine with iron and dopamine perfusion in rat striatum

In dopaminergic neurons, free radicals are likely produced via dopamine metabolism by monoamine oxidase or via its auto-oxidation, a process facilitated by transition metals. In this study we examined the effect and possible mechanisms of apomorphine to reduce iron- and dopamine-induced 2,3-dihydroxybenzoic acid (2,3-DHBA) formation by microdialysis. We have shown that (1) FeSO(4).7H(2)O reduced both the release of dopamine and the output of dihydroxyphenylacetic acid (DOPAC); (2) apomorphine may reduce FeSO(4).7H(2)O-induced increases of 2,3-DHBA formation; (3) apomorphine has substantially reduced DOPAC output in early phase and blocked dopamine-induced increase of 2,3-DHBA levels. It is concluded that apomorphine is a potent hydroxyl radical scavenger in vivo, especially for the dopamine formation.

The capture envelope of a flanged circular hood in cross drafts

The flow patterns of an exterior circular hood subject to the influence of various uniform cross drafts were experimentally studied in an apparatus consisting of hood-model/wind-tunnel assembly. A two-component laser Doppler anemometer was employed to measure the velocity field on the symmetry plane. The streamline patterns were obtained from the measured velocity data. The cross draft caused a characteristic envelope similar to a half Rankine body-of-revolution to form in the flow field. The boundary of the envelope is described by a dividing streamline. All streamlines within the envelope lead to the opening; those outside the envelope evolve to the downstream area. The normalized geometry of the capture envelope is theoretically justified and correlated by modifying the potential theory of point-sink-plus-rectilinear-flow. The domain and shape of the envelope enclosing the hood opening are determined primarily by the velocity ratio between the cross draft and hood suction. The correlated formula is applicable to design the hood parameters, including the sizes of opening and flange as well as the location of contaminant sources.

Characterization of a Virus Infecting Lisianthus

A virus was isolated in Taiwan from imported lisianthus (Eustoma russellianum) plants bearing viruslike symptoms and was biologically, physically, and serologically characterized. Purified virions are isometric and measure 32 to 33 nm in diameter. The virus from Taiwan is morphologically similar to and serologically related to Lisianthus necrosis necrovirus (LNV) reported in Japan. This lisianthus virus does not have the same host range that was reported for LNV from Japan, but inoculation studies show that it is a strain of LNV.

Immunohistochemical expression of inducible nitric oxide synthase in DMBA-induced hamster buccal pouch carcinogenesis

Nitric oxide (NO) plays a key role in the processes of inflammation and carcinogenesis. Three isoforms of NO synthase have been identified: endothelial nitric oxide synthase (NOS), neuronal NOS, and inducible NOS (iNOS). The purpose of this study was to investigate the characteristics of iNOS in 7, 12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. Thirty outbred young (6-week-old) male Syrian golden hamsters were randomly divided into three groups: DMBA (0.5%) painted group (n=10); mineral oil-treated group (n=10); and non-treated group (n=10). The average number of iNOS positive foci per section in the DMBA-treated group was approximately 12.2+/-4.7. Both cytoplasmic and nuclear stainings were observed in the DMBA-treated pouch keratinocytes. No iNOS activity could be detected in the untreated or mineral oil-treated pouches. In conclusion, this study has demonstrated that iNOS is expressed in DMBA-induced hamster pouch carcinomas. This finding suggests that iNOS expression may be associated with the development of chemically induced oral carcinomas.

Recent nonsteroidal anti-inflammatory drug use increases the risk of early recurrence of bleeding in patients presenting with bleeding ulcer

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) use is a well-known risk factor for ulcer formation and ulcer complications. The purpose of this study was to determine whether recent NSAID use increases the risk of early recurrence of bleeding in patients who present with bleeding ulcer.

METHODS

Clinical and endoscopic data were collected prospectively. Dose, frequency, and duration of recent NSAID use were quantified. Recent NSAID use was defined as consumption of over-the-counter or prescription NSAIDs or aspirin for at least 5 days of the 2-week period preceding the index episode of bleeding. Endoscopy was performed within 24 hours of admission to confirm the source of bleeding and endoscopic intervention was applied for stigmata of bleeding. Early recurrence of bleeding was defined as melena, hematochezia or blood per nasogastric tube with a 2 gm or greater decrease in hemoglobin during a period of 48 hours, occurring less than 2 weeks from index episode of bleeding.

RESULTS

One hundred twenty patients (52 NSAID users and 68 nonusers) were enrolled in the study; mean age was 56 years. NSAID users were older than nonusers (p = 0.003); nonusers were more likely to have a history of ulcer disease (p < 0.0005) and higher prevalence of Helicobacter pylori infection (p = 0.05). Recent NSAID use was associated with a significantly higher frequency of early recurrence of bleeding and in-hospital recurrent bleeding compared with nonusers: 19% vs. 6%, p = 0.02, and 17% vs. 6%, p = 0.04, respectively. In multivariate logistic regression analysis, the significant association between recent NSAID use and early recurrence of bleeding persisted (p = 0.0048) while controlling for age and other covariates.

CONCLUSIONS

Recent NSAID use predisposes bleeding ulcer patients to early and in-hospital recurrent bleeding, probably via its effects on platelet function, mucosal prostaglandins, and ulcer healing.

Glandular odontogenic cyst: a case report

Glandular odontogenic cyst (GOC) is an extremely rare lesion occurring in the jawbones. Sialo-odontogenic cyst was first described as a multicystic lesion resembling a botryoid odontogenic cyst (BOC) or a central mucoepidermoid carcinoma by Padayachee in 1987. In 1988, Gardner used the term "glandular odontogenic cyst" and considered it as a histologic variant of BOC. Most authors agreed that GOC was odontogenic because of the concurrent ball-like epithelial structure, ameloblastoma, squamous odontogenic tumor-like proliferation in its wall, or hyaline bodies in the epithelium lining. Recently, immunohistochemical studies of the cytokeratin profiles have also supported this concept. Its aggressive behavior and the recurrent tendency make it important. A new case of GOC in a 59-year-old male presented as a multilocular radiolucency in the anterior region of the mandible, invading the marrow space by epithelial islands is described with other clinicopathologic features and the literature is briefly discussed.

Structure and genomic organization of porcine RACK1 gene

The cDNA encoding porcine RACK1 protein was isolated from porcine spleen cDNA library. The deduced protein sequence of porcine RACK1 cDNA shows that it contains 317 amino acid residues, and shares nearly 100% identity with its vertebrate counterparts. Noticeably, the RACK1 protein was differentially expressed in various porcine tissues. High expression of RACK1 protein was observed in the tissues including thymus, pituitary, spleen and liver, whereas there was no detectable expression in muscle. The genomic DNA of porcine RACK1 with approximate 7.5 kb was constructed by both polymerase chain reaction amplification and genomic library screening. It consists of eight exons intervened by seven introns, and most of the intron/exon splice sites conform to the GT/AG rule. The promoter region contains functional serum response element, YY1-like binding site and AP1 site, which is supported by the finding that the expression of RACK1 gene in cultured porcine ST cells has a serum response as well as a TPA response.

Rate and extent of digestion of the ethanol-soluble and neutral detergent-insoluble fractions of corn grain

The objectives of this study were to partition corn grain into three digestible fractions and to measure the rate of disappearance of these fractions in vitro. Seventeen corn grain samples with varied fiber concentrations were extracted with either 80% ethanol or neutral detergent to obtain estimates of the pool size and digestion kinetics of the A, B1, B2, and C fractions. The carbohydrate soluble in 80% ethanol averaged only 2.6+/-.3% of the DM, although 80% ethanol extracted 7.1+/-1.2% of DM of corn grain. The ethanol-soluble fraction of corn grain contained protein, ether-extractable compounds, and a small amount of ash in addition to carbohydrate. Because of this chemical heterogeneity and because of the small size of the ethanol-soluble fraction, it was not possible to determine the digestion rate of this fraction by measuring gas production. The NDF content of the corn grain was 10.6+/-.7% of DM and was highly digestible (94.6+/-1.4%). The digestible NDF contributed 9.5% of the total gas production from corn grain. Because the size, digestibility, and digestion rate of the digestible NDF fraction varied little among corn grain samples, it is not necessary to routinely analyze the digestion kinetics of the digestible NDF fraction of dried corn grain. An average gas production curve of this fraction can be used as a base to subtract from the total gas production curve to generate the gas production curve of the neutral detergent-soluble fraction for dried, ground corn grain samples.

Adenomatoid hyperplasia in the mandibular retromolar area. Case report

This paper reports a case of adenomatoid hyperplasia of minor salivary glands in the retromolar area, with a unique symptom of painful swelling. This appears to be the first reported case in the Chinese population. It would be useful for clinical dentists to be aware of this tumour.

Placental glutathione S-transferase isoenzyme expression during promotion of two-stage hamster cheek-pouch carcinogenesis

Glutathione S-transferases (GSTs) are the products of a multigene family. A well-established function of GSTs is to metabolize carcinogens by catalysing the conjugation of electrophilic substrates to glutathione. Whether placental GST (GST-P) is expressed during the promotion of two-stage hamster buccal-pouch mucosa (HBPM) carcinogenesis was investigated here, using 7,12-dimethylbenz[a]anthracene (DMBA) as the initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as the promoter. Cytoplasmic and nuclear staining for GST-P was seen in pouches treated with DMBA for 4 or 16 weeks, as well as in those treated with DMBA for 4 weeks and then TPA for 12 weeks. No GST-P positivity was seen in any pouches treated with only TPA or with mineral oil for either 4 or 16 weeks. The average number of GST-P-stained foci in the groups treated with DMBA for 16 weeks (246 +/- 96; mean +/- SD) or DMBA for 4 weeks followed by TPA for 12 weeks (186 +/- 67) was significantly higher than in pouches treated with only DMBA for 4 weeks (97 +/- 24). These results demonstrate that TPA alone is not sufficient for GST-P expression in hamster buccal pouch mucosa. However, after being initiated with DMBA, then promoted with TPA, GST-P activity is induced in hamster buccal pouch mucosa during squamous-cell carcinogenesis. This underpins the suggestion that GST-P may play an important part during the promotion stage of oral carcinogenesis.

High-level disinfection of gastrointestinal endoscopes: are current guidelines adequate?

OBJECTIVE

For a germicide to obtain a high level disinfection (HLD) claim, FDA requires demonstration of a 6-log reduction of mycobacterial inoculum under worst case conditions. The purpose of this study was to assess the adequacy of current guidelines for high level disinfection of GI endoscopes using alkaline glutaraldehyde in simulated-use testing.

METHODS

Various gastrointestinal endoscopes were contaminated with Mycobacterium chelonae in 46 experiments. Quantitative cultures were obtained from each endoscope channel separately after each step: inoculation, standardized manual cleaning, immersion in 2% glutaraldehyde (Cidex) for 10, 20, or 45 min at room temperature, 70% isopropanol rinse, and drying.

RESULTS

Manual cleaning alone achieved a 4-log reduction. After 10 min of glutaraldehyde exposure, but before alcohol rinse, two of 10 experiments failed to achieve a 6-log reduction. However, after alcohol rinse, all 10 experiments achieved HLD. After 20 min of glutaraldehyde exposure, but before alcohol rinse, one of 18 experiments failed to achieve a 6-log reduction. After alcohol rinse, all 18 experiments achieved HLD. After 45 min of glutaraldehyde exposure, but before alcohol rinse, one of 18 experiments failed to achieve a 6-log reduction. After alcohol rinse, all 18 experiments achieved HLD. Thus, if the entire reprocessing protocol including manual cleaning, glutaraldehyde exposure, alcohol rinse, and drying was taken into account, the required 6-log reduction of mycobacteria was achieved with a minimum of 10 min of glutaraldehyde exposure at room temperature.

CONCLUSIONS

Current guidelines for high level disinfection using glutaraldehyde are appropriate. Alcohol rinse is a valuable adjunctive step for drying and for its bactericidal effects.

Impact of flumazenil on recovery after outpatient endoscopy: a placebo-controlled trial

BACKGROUND

Flumazenil is an imidazobenzodiazepine that blocks the central effects of benzodiazepines by competitive interaction at the receptor level. In this study we assessed the impact of flumazenil use on postsedation observation time in outpatients undergoing endoscopy.

METHODS

Sixty outpatients received midazolam for conscious sedation and were randomized after endoscopy to receive intravenous flumazenil (0.1 mg/mL) or placebo until awake or a total of 10 mL was given. All patients were assessed using various psychomotor and cognitive tests at baseline and at 5, 15, 30, 45 and 60 minutes after flumazenil or placebo was administered.

RESULTS

The two groups were similar in age, gender, midazolam dose (mg/kg), vital signs, and baseline parameters. The average dose of flumazenil given was 0.41 mg. Sedation scores returned to presedation levels earlier in the flumazenil group, with significant differences compared to placebo at 5 minutes (84.6% vs. 24.2%), 15 minutes (88. 5% vs. 57.6%) and 30 minutes (96.2% vs. 66.7%). Other parameters tested were not significantly different for patients receiving placebo compared to those given flumazenil. Sedation scores returned to baseline earlier than other psychomotor and cognitive tests in both groups. Flumazenil reduced the mean observation time from 23.5 minutes to 8.3 minutes (p < 0.0005), a difference of 15.2 minutes (64.7%) based on sedation score.

CONCLUSIONS

Flumazenil significantly reduces postsedation observation time. Actual cost savings will vary depending on staff and facility capacity, patient volume, flumazenil cost, and unit cost of observation time.

Successful reversal of Barrett's esophagus with multipolar electrocoagulation despite inadequate acid suppression

BACKGROUND

Barrett's epithelium is a risk factor for esophageal cancer. In this study we attempted to reverse Barrett's epithelium in an acid-reduced environment by using multipolar electrocoagulation.

METHODS

All patients had specialized columnar epithelium of at least 2 cm in length. Patients with dysplasia on successive screening examinations were excluded. Esophageal motility and 24-hour pH studies were performed before therapy and at 9 and 18 weeks. All patients received lansoprazole 30 mg twice a day regardless of pH study results. Multipolar electrocoagulation was applied to one side of the esophagus (2 to 3 cm per session) with the contralateral side serving as control. Biopsies were obtained from each 2 cm length at each endoscopy and reviewed by a single, blinded pathologist. At the 9-week evaluation of the treatment side, all patients elected to undergo multipolar electrocoagulation therapy for the control side.

RESULTS

Twenty-seven patients completed the study: 21 men and 6 women, ages 33 to 81 years, length of specialized columnar epithelium 2 to 10 cm. Endoscopy at the 18-week follow-up showed normal mucosa (n = 16), residual small (< 3 mm) islands or tongue-shaped extensions of apparent specialized columnar epithelium (n = 7), untreated distal strips (< 5 mm) of apparent specialized columnar epithelium at the gastroesophageal junction (n = 3), and persistent specialized columnar epithelium (n = 1). Histologically, only 5 of 27 patients had residual specialized columnar epithelium at week 18. Of 16 patients with a normal endoscopic appearance, one still had specialized columnar epithelium on biopsy. While on lansoprazole, pH studies were normal in 15 of 26 patients at 9 weeks. Of 22 patients with histologic evidence of specialized columnar epithelium reversal, 10 had persistently abnormal 24-hour pH studies (pH < 4, 6.1% to 33.7% of total time). Four of five patients with residual specialized columnar epithelium on biopsy had persistent reflux. Side effects of multipolar electrocoagulation were transient, and treatment did not adversely alter motility patterns.

CONCLUSIONS

Multipolar electrocoagulation therapy can induce re-epithelialization with normal squamous mucosa in most patients with specialized columnar epithelium and does not adversely affect esophageal motility. Adequate acid suppression is not mandatory for therapy to be effective in the short term.

Primary oral squamous cell carcinoma: an analysis of 703 cases in southern Taiwan

We retrospectively analyzed the records of 703 cases of oral squamous cell carcinoma (SCC) collected from 1 January 1985 to 31 December 1996 at a teaching hospital in southern Taiwan, to identify the characteristics of patients and factors associated with survival. There was an overwhelming male predominance (male:female = 15:1). The mean age of the patients was 52. The peak age of oral SCC patients declined from 50 to 59 years in the first six years (1985-1990) and 40-49 years in the last six years (1991-1996). The most common site of oral SCC was the buccal mucosa with 263 patients (37.4%). Most patients (346/703 patients; 49.2%) had stage III cancer. The most common site of occurrence of SCC was the buccal mucosa (263/703 patients; 37.4%), both overall and in patients who chewed betel quid alone or in combination with cigarette smoking and/or alcohol consumption; the tongue was the most common site among patients without any oral habits (18/48 patients; 37.5%). Furthermore, the age of occurrence was on average 6-12 years younger among patients who chewed betel quid than in those who did not. Of the 703 patients, 496 received treatment with surgery, chemotherapy, and/or radiation therapy. Of these, 209 (42.1%) died. The cancer stage significantly influenced mortality: the 5-year survival rate in patients treated from 1985 to 1991 was 72% in those with stage I, 38.9% in those with stage II, 26.7% in those with stage III, and 11.8% in those with stage IV cancer. Six variables were found to significantly affect survival: tumor size, lymph node involvement, surgery, betel quid chewing, staging, and histological differentiation (all p < 0.05, Kaplan-Meier analysis with log rank test). Of these, surgery and cancer stage independently affected survival in a proportional hazards model (both p < 0.0001). Therefore, the early surgical intervention, and the withdrawal from oral habits, especially betel quid chewing, will be advantageous to patients' survival.

Comparison of the characteristics of double-pass erbium-doped superfluorescent fiber sources obtained from different flattening techniques

We investigate and compare the characteristics of erbium-doped superfluorescent fiber sources (SFS's) obtained from the use of different flattening techniques in double-pass forward (DPF) and double-pass backward (DPB) configurations. The intrinsic flattening technique consists of optimizing the length of the erbium-doped fiber. The extrinsic flattening methods include the addition of a samarium-doped fiber (SDF) and a fiber-Bragg-grating (FBG) notched filter at the output end separately to shape the SFS spectrum. Although intrinsically flattened DPF and DPB SFS's have a large output power of >34 mW, they are accompanied by an approximately 3-dB ripple. The FBG-flattened DPF and DPB SFS's can achieve a wide linewidth of 35 nm with a small ripple of approximately 1.7 dB and better pump-power-dependent mean-wavelength stability; SDF-flattened DPF and DPB SFS's are inferior because of the SDF's lossy spectrum.

Efficacy of various disinfectants in killing a resistant strain of Pseudomonas aeruginosa by comparing zones of inhibition: implications for endoscopic equipment reprocessing

OBJECTIVE

Previous studies have shown that high-level disinfection of GI endoscopes may not be reliably achieved using glutaraldehyde at room temperature. In our laboratory, we have isolated a strain of Pseudomonas aeruginosa that is resistant to disinfection with glutaraldehyde. We compared the bactericidal activity of various disinfectants against this organism.

METHODS

One hundred microliters of an overnight culture of this organism was spread onto blood agar plates. Twenty microliters of a disinfectant was placed on a sterile 7-mm filter paper, placed on the blood agar plate, and incubated overnight at 37 degrees C to determine the zone of inhibition for each disinfectant tested. Disinfectants included Cidex, Dispatch, Virahol, OMNI II, Lysol, IodoFive, Lysol I.C. Spray, and Chlorox. The zone of inhibition (i.e., clearing) roughly correlates with the bactericidal strength of the disinfectant.

RESULTS

Compared with the glutaraldehyde-containing solution Cidex, the alcohol-containing disinfectants Lysol I.C. Spray and Virahol had the largest mean zones of inhibition (11.33 vs 20.60 and 20.55 mm; p = 0.0001). The hypochlorite compounds Chlorox (1:10 dilution) and Dispatch had mean zones of inhibition similar to that of Cidex (11.08 and 11.25 mm vs 11.33 mm; p = not significant). The phenolic compounds OMNI II and Lysol had mean zones of inhibition smaller than that of Cidex (10.50 and 10.35 mm vs 11.33 mm; p < 0.006), and the phosphoric acid and iodine-containing IodoFive had the smallest mean zone of inhibition (9.70 vs 11.33 mm; p = 0.0001).

CONCLUSIONS

The alcohol-containing disinfectants had the largest zones of inhibition against resistant P. aeruginosa. These compounds may be more effective than glutaraldehyde for endoscopic equipment reprocessing.

Osseous choristoma of oral cavity--report of two cases and review of the literature

Osseous choristoma of the oral cavity is an extremely rare lesion. Two cases of osseous choristomas of oral cavity, representing two different natures of such lesions are reported. One was situated on the dorsal surface of posterior tongue just anterior to the circumvallate papillae and the other on the right buccal mucosa just below the orifice of the Stensen's duct. To date, about 73 cases of oral osseous choristoma have been reported in the literature including the two present cases, of which, 61 and 8 cases occurred in the tongue and buccal mucosa, respectively. The clinical and microscopic characteristics, and their common sites of these peculiar lesions are presented. The origin and pathogenesis of the lesion are discussed and the literature on the subject is reviewed.

A retrospective study of oral and maxillofacial biopsy lesions in a pediatric population from southern Taiwan

This is a retrospective study of biopsied oral lesions (N = 534) in a pediatric population (0-15 years old) in southern Taiwan. In this study, we included 6% of the 9672 biopsies performed from 1985 through 1996. The lesions were divided into three groups according to patients' ages, 0-5 years old; 6-10 years old; and 11-15 years old The majority of the samples were from the oldest age group (273/518). With the exclusion of normal tissues (N = 26), 518 samples were classified into four categories: inflammatory lesions, cystic lesions, tumor or tumor-like lesions, and other lesions. The largest number of lesions occurred in the inflammatory lesion group (46%). The 12 most frequently occurring lesions contributed about 78% of all the biopsies in the three age groups (0-15 years old). Frequencies of the lesions of mucous extravasation phenomenon, dentigerous cyst, fibrous dysplasia, and odontonia in our three pediatric age groups showed a significant proportion in the biopsies of the same lesions in the group of patients of all ages. These information may be valuable for both epidemiology and teaching.