1

Introduction

The presentation of oral pathology in the paediatric patient is significantly different to that of the adult patient. It has been speculated that thinner, less keratinized attached gingiva, greater vascularity and less differentiated pattern of collagen fibers in the primary dentition render the tissues less susceptible to inflammation . In addition, increased turnover of cells due to active growth in the developing child and varying immune cell profile could be some of the other underlying factors to explain the stark contrast in the presentation of oral pathology between these groups. The occurrence of oral pathology in the paediatric population, is reported to be in the range of 5–15%, with malignant pathology in less than one percent of the paediatric population . Developmental anomalies commonly diagnosed in the mouth of newborns include Epstein pearls, Bohn’s nodules, dental lamina cysts, and natal teeth. These anomalies are usually of little concern as they are commonly regarded as normal . There is however an increase in the incidence of pathosis with increasing age, with mucous extravasation cysts and periapical pathology being the most commonly diagnosed lesions in children under 16 years of age .

To date, only a few epidemiological studies have been published worldwide, that investigate oral pathology in the pediatric population. There is however, a large variance in the reporting and classification of demographic data, making comparison between studies difficult. Majority of the scientific literature worldwide, shows approximately ten percent of specimens submitted for histopathological analysis are from children under 16 years of age, with a large proportion of lesions being benign and warranting further intervention. Though the risk of malignancy in children is low, it is important for the clinician to be able to diagnose them correctly so that appropriate timely treatment may be provided, helping reduce aesthetic and functional morbidity in the developing child. There have been only two previously published studies looking at paediatric oral pathology in the Australian cohort with the most recent one investigating 676 biopsied oral lesions over a 16-year study period.

Our study aimed to evaluate specimens from 1 to 16-year old children over a 23-year period, with the vast majority of referring clinicians being dentists or dental specialists and histopathological reporting being carried out by oral pathologists. To date there has been no published literature for the paediatric population in the state of New South Wales.

The data for our study was obtained from records of patients presenting to the Department of Paediatric Dentistry and Orthodontics at the Westmead Centre for Oral Health, a major tertiary referral center and a state-wide specialist oral health service provider for New South Wales. Westmead Hospital serves a population of over 1.85 million people and is located on the largest health and hospital campuses in Australia. The purpose of this study was to analyze data from paediatric oral biopsy reports received over a period of 23 years at the Institute for Clinical Pathology and Medical Research (ICPMR), and report on the frequency of oral pathology in the Australian pediatric population to enable comparison with worldwide data.

2

Methods

A total of 15,691 oral biopsy specimens for patients of all ages were received by the Institute for Clinical Pathology and Medical Research (ICPMR) at the Westmead Centre for Oral Health, between the years 1993–2015 (inclusive). The specimens were processed and reported by oral pathologists. The data and records were extracted and stored using a Microsoft® Excel spreadsheet (Microsoft, Inc, Redmond, Wash., USA). The data was categorized using a classification initially proposed by Jones and Franklin , which in the authors opinion remains the most exhaustive and optimally devised classification system to date.

3

Results

A total of 15,691 biopsies were received at the ICPMR during the 23-year study period, of which 935 belonged to our study population. There were 460 specimens from males and 469 from females (M: F ratio = 0.98), with six specimens of unspecified gender. There was a consistent increase in the number of biopsies received with increasing age ( Fig. 1 ).

Distribution of Paediatric biopsies in relation to age and gender.

The diagnostic category with the largest number of specimens was salivary gland pathology ( Table 1 and Fig. 2 ). Of the 196 cases in this group (21.1% of the total samples), 88.2% ( Table 2 ) were mucoceles, which also was the most likely reason why this diagnostic category was most prevalent. There were four pleomorphic adenomas and two salivary carcinomas, which although malignant were classified into the salivary gland category.

Distribution of results based on categories.

Mucosal pathology was the second largest category, with the giant cell fibroma comprising 46 specimens (31.5%) of the 146 cases in this group. Squamous cell papillomas were the next largest group of lesions within this category, comprising 33 cases (22.6%). There were four cases (2.7%) of lichen planus, all in patients between the ages of 14 and 15.

Miscellaneous pathology constituted the third largest group. Forty-six (33%) cases were reported as normal tissue, with one case of orofacial granulomatosis.

Dental pathology was the fourth largest group comprising 125 (13.4%) of the total number of specimens, of which periapical granuloma constituted 54 cases (43.2%). Twenty-three specimens (18.4%) were that of dental follicles, majority (86.9%) of which were reported as hyperplastic. There were two specimens diagnosed as supernumerary teeth and five cases of amelogenesis imperfecta.

In the gingival pathology group, pyogenic granuloma and fibrous epulis constituted 35 specimens (28%) each. There were seven cases (5.6%) of peripheral giant cell granuloma of which five cases were seen in females.

Cysts of odontogenic, non-odontogenic and unknown origin comprised 140 cases (14.9%) of all oral biopsies. The ratio of odontogenic cysts to non-odontogenic cysts was 9.3:1. Among the 10 cases of non-odontogenic cysts there were two dermoid cysts and one case each of nasopalatine duct cyst and solitary bone cyst.

In diseases of connective tissue origin, over 30% of cases were hemangiomas with most being diagnosed as capillary hemangiomas. Neuronal tumours such as neurofibroma (three cases), neuroma (one case) and schwannoma (three cases) comprised 30% of cases with similar numbers in males and females.

Tumours as a group only accounted for 23 (2.4%) of the oral specimens in this age cohort, with 10 lesions being diagnosed as ossifying fibroma. Malignancies constituted nine cases (0.9%), with four cases of Langerhans cell histiocytosis and one case of neuroblastoma.