Development of Automated Risk Stratification for Sporadic Odontogenic Keratocyst Whole Slide Images with an Attention-Based Image Sequence Analyzer.

(1) Background: The categorization of recurrent and non-recurrent odontogenic keratocyst is complex and challenging for both clinicians and pathologists. What sets this cyst apart is its aggressive nature and high likelihood of recurrence. Despite identifying various predictive clinical/radiological/histopathological parameters, clinicians still face difficulties in therapeutic management due to its inherent aggressive nature. This research aims to build a pipeline system that accurately detects recurring and non-recurring OKC. (2) Objective: To automate the risk stratification of OKCs as recurring or non-recurring based on whole slide images (WSIs) using an attention-based image sequence analyzer (ABISA). (3) Materials and methods: The presented architecture combines transformer-based self-attention mechanisms with sequential modeling using LSTM (long short-term memory) to predict the class label. This architecture leverages self-attention to capture spatial dependencies in image patches and LSTM to capture sequential dependencies across patches or frames, making it suitable for this image analysis. These two powerful combinations were integrated and applied on a custom dataset of 48 labeled WSIs (508 tiled images) generated from the highest zoom level WSI. (4) Results: The proposed ABISA algorithm attained 0.98, 1.0, and 0.98 testing accuracy, recall, and area under the curve, respectively, whereas VGG16, VGG19, and Inception V3, standard vision transformer attained testing accuracies of 0.80, 0.73, 0.82, 0.91, respectively. ABISA used 58% fewer trainable parameters than the standard vision transformer. (5) Conclusions: The proposed novel ABISA algorithm was integrated into a risk stratification pipeline to automate the detection of recurring OKC significantly faster, thus allowing the pathologist to define risk stratification faster.

Building Automation Pipeline for Diagnostic Classification of Sporadic Odontogenic Keratocysts and Non-Keratocysts Using Whole-Slide Images.

The microscopic diagnostic differentiation of odontogenic cysts from other cysts is intricate and may cause perplexity for both clinicians and pathologists. Of particular interest is the odontogenic keratocyst (OKC), a developmental cyst with unique histopathological and clinical characteristics. Nevertheless, what distinguishes this cyst is its aggressive nature and high tendency for recurrence. Clinicians encounter challenges in dealing with this frequently encountered jaw lesion, as there is no consensus on surgical treatment. Therefore, the accurate and early diagnosis of such cysts will benefit clinicians in terms of treatment management and spare subjects from the mental agony of suffering from aggressive OKCs, which impact their quality of life. The objective of this research is to develop an automated OKC diagnostic system that can function as a decision support tool for pathologists, whether they are working locally or remotely. This system will provide them with additional data and insights to enhance their decision-making abilities. This research aims to provide an automation pipeline to classify whole-slide images of OKCs and non-keratocysts (non-KCs: dentigerous and radicular cysts). OKC diagnosis and prognosis using the histopathological analysis of tissues using whole-slide images (WSIs) with a deep-learning approach is an emerging research area. WSIs have the unique advantage of magnifying tissues with high resolution without losing information. The contribution of this research is a novel, deep-learning-based, and efficient algorithm that reduces the trainable parameters and, in turn, the memory footprint. This is achieved using principal component analysis (PCA) and the ReliefF feature selection algorithm (ReliefF) in a convolutional neural network (CNN) named P-C-ReliefF. The proposed model reduces the trainable parameters compared to standard CNN, achieving 97% classification accuracy.

Immunohistochemical expression of paxillin in ameloblastoma and odontogenic keratocyst: An observational study.

Background: Cell adhesion molecules (CAMs) are found on the surface of all cells, where they allow dynamic processes to take place. These include cadherins, integrins, selectins and Immunoglobulin superfamily. Directly associated with ß-integrin tails is a multidomain protein known as paxillin. However, CAMs participate in cell-cell and extracellular matrix-cell interactions during histomorphogenesis in the various phases of odontogenesis. Some tumours or cysts like ameloblastoma (AB) or odontogenic keratocyst (OKC) having odontogenic origin show disturbance in the interaction of these CAMs. Hence, the assessment of paxillin expression in AB and OKC was carried out. Materials and Methods: The present observational study comprised 30 clinically and histologically confirmed cases of AB and OKC. All the slides were stained immunohistochemically using a paxillin antibody. Results: Upon comparison of staining intensity of paxillin among AB and OKC showed statistically significant result, whereas quantitative staining and final summation showed non-significant result. Gender-wise comparison of paxillin staining intensity, quantitative staining and final summation among OKC showed significant result; however, in AB, staining intensity showed non-significant result, whereas quantitative staining and final summation showed significant result. Conclusion: Paxillin has the greatest influence on tissue morphogenesis and development. The regulation of cell mobility is aided by the multiple roles that paxillin plays in a range of cells and tissues. However, further studies using a large sample size, along with other molecular analytical methods, may be essential to draw a definite conclusion about the association of paxillin and its exact function in OKC and AB.

Comparison of blood parameters between periodontitis patients and healthy participants: A cross-sectional hematological study.

Background: Bacteria and their products involved in periodontitis evoke an immunoinflammatory response in the host tissue. Inflammatory diseases, such as periodontitis, are often not just a local event, but may have systemic ramifications, including elevations in the numbers of circulating leukocytes, acute-phase proteins and oxidative stress markers. It is now emerging that also erythrocytes are affected by chronic inflammatory diseases. This phenomenon, named "anemia of inflammation," is not caused by marrow deficiencies or other diseases. The present study aimed to assess whether there was any relation between chronic periodontitis and hematological parameters. Materials and Methods: A total of 80 patients were included in the study and were divided into the healthy and periodontitis groups. Blood sample was obtained from each participant for hematological analysis of leukocytes, erythrocytes, platelets, red blood cell (RBC) distribution width (RDW), mean corpuscular volume (MCV), platelet count and neutrophil-leukocyte ratio (NLR). Further, the values were gathered and subjected to statistical analysis. Unpaired t-test was performed to assess the statistical significance between the groups and P < 0.05 and < 0.001 were considered to be statistically significant. Results: Results show statistically significant difference seen in leukocytes, lymphocytes, RDW, MCV, platelet count and NLR which was higher in patients with periodontitis, all other parameters are nonsignificant. Conclusion: Thus, within limitations, it can be concluded that increased levels of leukocytes, lymphocytes, RDW, MCV, platelet count and NLR depict the inflammatory state and destructive nature of periodontitis.

Immunohistochemical expression of paxillin in potentially malignant disorders and squamous cell carcinoma patients.

Background: Cell adhesion molecules are essential to maintain the integrity of stratified squamous epithelium but their expression has to be dynamic to aid the mobility and turnover of cells. Paxillin is one such multi-domain protein which integrates numerous signals from cell surface receptors, integrins and growth factors. It thus functions as a regulator of various physiological and pathological processes including tissue remodeling, cell motility, gene expression, matrix organization, cell proliferation, metastasis and survival. Hence, the assessment of paxillin expression in normal control, potentially malignant disorders and oral squamous cell carcinoma patients was carried out. Material and Methods: The present retrospective study comprised of 20 each clinically and histologically confirmed case of normal control, potentially malignant disorders, and oral squamous cell carcinomas. All the slides were stained immunohistochemically using Paxillin antibody. Results: The localization, staining intensity and percentage of positivity for paxillin expression was statistically significant among normal control and potentially malignant disorders, whereas oral squamous cell carcinoma showed a non-significant difference. Upon comparison of histopathological grading of potentially malignant disorders, mild versus severe and moderate versus severe epithelial dysplasia showed a statistical significant difference among all the parameters of paxillin expression. However, WDSCC & MDSCC a statistically significant difference among localization and staining intensity of paxillin. Conclusion: Paxillin may play an important role in pathogenesis of oral squamous cell carcinoma by altering the adhesive properties of the tumor cells interacting with the extracellular matrix which in turn affects their invasive behavior and histologic differentiation.

Traumatic ulcerative granuloma with stromal eosinophilia: A puzzle.

Traumatic ulcerative granuloma with stromal eosinophilia (TUGSE) is an ulcerative condition of the oral mucosa amid a chronic course and delayed healing. It is a reactive lesion that usually affects the tongue. TUGSE is a rare mucosal lesion to aid as an ulcer or an indurated submucosal mass and might cause diagnostic problems as it mimics a traumatic or neoplastic ulcer. However, chronic irritation from traumatic agents is well thought out to be a major initiating aspect. Histopathologically, it is categorized by an eosinophilic inflammatory infiltrate penetrating into the underlying muscle. It is significant to make out this mucosal lesion as it mimics malignant ulcers; the condition tends to resolve on its own. Thus, attentiveness of this entity is imperative to emphasize the accurate diagnosis of indurated ulcerated lesions and convey suitable and effective treatment. The present case highlights the clinical aspects, etiopathogenesis and histopathology of this unusual lesion.

Anti candidal efficacy of commercially available triphala, neem, denture cleanser and natural aloevera leaf on heat polymerized acrylic resin.

Aim: The aim of the study was to evaluate the anticandidal efficacy of Triphala, aloe vera, Neem, and denture cleanser on heat polymerized acrylic resin. Settings and Designs: In vitro - experimental study. Materials and Methods: In this study, forty denture wearer patients were selected and were divided into four groups consisting of ten patients, namely, Group I, Group II, Group III, and Group IV, in which dentures were cleansed with denture cleanser (tablets), Triphala (churna), aloe vera (leaf), and Neem (tablets), respectively, and stored in copper containers. Swabs were collected from the dentures before and after the use of Denture cleanser, Triphala, aloe vera, and Neem. Thereafter, the swabs were cultured on Sabouraud dextrose agar and the total Candida counts (CFU/4 cm2) were determined. Statistical Analysis Used: One way ANOVA and Tukeys HSD post hoc test were used. Results: The pre- to post-reduction in mean Candida count was found highest in Denture cleanser followed by Neem, Triphala, and aloe vera. Further, both Denture cleaner and Neem showed statistically significant reduction (P < 0.001) in the mean Candida count when compared to Triphala and aloe vera. However, reduction in the mean Candida count of both Denture cleanser and Neem was found statistically similar (P > 0.05). Conclusion: The anticandidal efficacy of denture cleanser was found to be the highest. The cost-effective Neem can be used as anticandidal modality in place of denture cleanser.

Evaluation of titanium-prepared platelet-rich fibrin and leucocyte platelet-rich fibrin in the treatment of intra-bony defects: A randomized clinical trial.

Background. Various treatment modalities, such as leucocyte platelet-rich fibrin (L-PRF), bone grafts, and membranes, have been used for the restoration of lost periodontal tissues. Titanium-prepared platelet-rich fibrin (T-PRF) has attracted attention for its proper haemocompatibility, thick fibrin meshwork, and long resorption time. The present study aimed to evaluate the effectiveness of T-PRF and L-PRF in the management of intra-bony defects based on clinical and radiographic criteria. Methods. Twenty-six subjects with 34 intra-bony 3- walled defects were divided into two groups (n=17) and treated with T-PRF or L-PRF. Clinical and radiographic measurements were recorded at baseline and 6- , 3- and 9- month intervals and tabulated on Microsoft Excel spreadsheets. For intra- and intergroup comparisons, paired and unpaired t-tests were performed. P<0.05 was set as statistically significant Results. Intra-group comparisons revealed statistically significant differences (P<0.05) from baseline in both groups regarding clinical measurements. On intergroup comparison, the T-PRF group exhibited a significantly higher defect fill compared to the L-PRF group (P<0.05). Conclusion. Within the limits of the present study, T-PRF seems to be a better alternative to L-PRF in the treatment of intra-bony defects.

Grub in the mouth: an unusual case with review of literature.

Oral myiasis is a rare disease, identified primarily in non-industrialised nations. It is caused fundamentally by the attack of larvae from Dipteran flies on the human tissues. Predisposing factors for oral myiasis are extraction wounds, destitute oral cleanliness, meagreness, mouth breathing amid rest, suppurative injuries, necrotic tissues, diabetes and perivascular infections primarily within the elderly, extreme halitosis, alcohol addiction, cerebral paralysis and components that favour prolonged mouth opening. Myiasis may have predilection to patients with mental challenges, cerebral palsy and hemiplegia due to unfortunate physical agility. The present case reports an oral myiasis in a 25-year-old woman who was mentally challenged. This condition was treated by topical application of turpentine oil with manual expulsion of hatchlings, taken after by surgical debridement and wide range antimicrobials.

Relative frequency of oral focal reactive overgrowths: An institutional retrospective study.

CONTEXT: Focal fibrous hyperplasia, peripheral ossifying fibroma, pyogenic granuloma, peripheral giant cell granuloma, giant cell fibroma and focal reactive overgrowth (FROGs) are one of the foremost numerous benign soft-tissue growths in the oral cavity. Chronic irritation or trauma is with identified as the causative aspect. It may develop up to few centimeters in diameter, pedunculated or sessile and may arise on the gingiva or buccal mucosa. Treatment involves surgical excision, and recurrences are infrequent. AIMS: The aim of this study was to assess the prevalence of FROGs of oral mucosa in an institutional setup. SUBJECTS AND METHODS: All the histopathologically diagnosed cases of FROGs within a period of 10 years (January 2008-December 2017) were retrieved from the archives of the Department of Oral Pathology. The information such as age, sex, site, anatomical side and its prevalence were recorded on customized case history performa. STATISTICAL ANALYSIS USED: The significance of difference was assessed using the Chi-square test and Fisher's exact test. RESULTS: A total of 2849 cases were identified, of which 449 (15%) were FROGs. The most prevalent lesion amid them were focal fibrous hyperplasia (277, 62%), followed by pyogenic granuloma (92, 20%), whereas the least common was giant cell fibroma with 2 (0.5%) cases. All the FROGs were distributed among 21-40 years of age showing female predominance. The commonly affected site was the right buccal mucosa. CONCLUSIONS: Nevertheless, information of the frequency and distribution of these lesions is favorable when establishing a diagnosis and treatment plan in clinical practice.

Novel method of determining the periodontal regenerative capacity of T­PRF and L­PRF: An immunohistochemical study.

BACKGROUND: Platelet-rich fibrin (PRF) plays an important role in the regeneration of the lost periodontal tissues. Immunohistochemistry (IHC) is the most sensitive staining technique for the identification and localization of specific cells. There are few studies in the available literature which use IHC to compare PRF prepared from titanium and silica glass tubes. OBJECTIVES: The aim of the study was to use IHC to evaluate and compare cells present in the PRF membrane prepared from titanium and silica glass tubes. MATERIAL AND METHODS: Blood was drawn from 10 healthy volunteers and PRF was prepared from titanium and silica glass tubes. Immunohistochemical staining for the localization, distribution and pattern of cells present in PRF with the CD 3, CD 15, CD 20, CD 34, CD 61, and CD 163 antibodies was carried out. A statistical analysis including the χ2 test, independent t-test and unpaired t-test was performed to determine significant differences. RESULTS: There were significantly more T cells, B­lymphocytes and platelets, with a strongly positive staining in terms of the cell distribution and the labeling index in the T-PRF group in comparison with the L-PRF group. However, in terms of localization, a stronger positive staining was obtained with platelets in the T-PRF group and stem cells in the L-PRF group. In terms of the cell pattern, a significantly stronger positive staining was obtained by neutrophils in the L-PRF group and B­lymphocytes in the T­PRF group. CONCLUSIONS: Titanium PRF has the edge over PRF prepared from silica glass tubes, and emerged as a better alternative for use in the field of periodontal regeneration.

Oral mucocele in infant with an unusual presentation.

Mucocele is a benign lesion characterised by an extravasation or retention of mucous secretion in submucosal tissue from minor salivary glands. The occurrence of mucocele is common in the oral cavity, with more than 70% of cases on lower labial mucosa. The occurrence of mucocele on the tongue is considered rare and accounted for only 2.25% in the previous literature. Histopathological examination plays a great role in the confirmation of the clinical diagnosis. Management of mucocele is at times challenging. This paper highlights a rare case of mucocele in a 5-month-old infant who was successfully managed under day-care anaesthesia.

Evaluation of candidal species among individuals with oral potentially malignant disorders and oral squamous cell carcinoma.

CONTEXT: Cancer afflicts almost all communities worldwide. Although it arises de novo in many instances, a significant proportion of oral squamous cell carcinoma (OSCC) develops from potentially malignant disorders (PMDs). Further, the association of Candida with various potentially malignant and malignant lesions has been reported as a causative agent. AIMS: The aim of the study is to evaluate and intercompare the predominant candidal species among individuals with PMD and OSCC. SUBJECTS AND METHODS: The swab samples were collected for the microbiological culture followed by incisional biopsy for histopathological confirmation. The swab samples were streaked and incubated on Sabouraud-dextrose agar medium and positive candidal colonies were incubated on CHROM agar for speciation. SETTINGS AND DESIGN: A total of clinically diagnosed 95 subjects of which 25 as normal controls, 30 as PMDs and 40 as OSCC were included. The collected swab samples were initially streaked and incubated on Sabouraud dextrose agar (SDA) medium, and later, only positive candidal colonies were incubated on CHROM agar for speciation. STATISTICAL ANALYSIS: Chi-square test was utilized. RESULTS: Positive candidal growth on SDA medium was seen in 24%, 43% and 82% and negative in 76%, 57% and 18% individuals of normal controls, PMDs and OSCC, respectively. On evaluation on Chromagar medium, Candida species was present in 20%, 40% and 77% and absent in 80%, 60% and 23% individuals among controls, PMDs and OSCC group, respectively. On speciation of Candida in CHROMagar among the controls, PMDs and OSCC, Candida albicans species was present in 4 (16%), 7 (23%) and 4 (10%); Candida krusei in 1 (4%), 5 (17%) and 10 (25%); Candida glabrata in nil, nil and 6 (20%) and Candida tropicalis in nil, nil, and 2 (5%) cases, respectively. CONCLUSION: There was predominant carriage of candidal species in PMDs and OSCC, but whether Candida has specific establishment in PMDs or in malignancy is still a matter of debate.

Oral malignant melanoma of alveolar ridge.

Malignancy of melanocytes, a pigment-producing cell, is referred as malignant melanoma (MM) which occur basically on skin and oral mucous membrane, but as well found in ears, eyes, gastrointestinal tract and genital mucosa. Oral melanomas has propensity to metastasise and invade more voluntarily than other malignant counterparts. Here we present a case of 52-year-old male patient with a chief symptom of blackening of gums in the upper front tooth region. In dental history, the patient revealed history of faulty artificial prosthesis fixed in the same region since 6 months. On the basis of a through clinical assessment, a provisional opinion of oral malignant melanoma, was prepared. On histopathological and immunohistochemical analysis with S-100 and homatropine methylbromide 45 the diagnosis of MM was confirmed.

Racial predilection of C-shaped canal configuration in the mandibular second molar.

AIM: The purpose of this article is to determine the racial predilection of C-shaped canal configuration in a mandibular second molar. BACKGROUND: Unusual root canal anatomy always poses a diagnostic and treatment challenge. Identification of such variation is important for the success of root canal treatment outcome. C-shaped canal configuration is such an aberrant morphology of molar teeth that vary in different population and is commonly seen in a mandibular second molar. Thus, knowledge of racial predilection of C-shaped canal configuration in different population for early diagnosis is obligatory. MATERIALS AND METHODS: An exhaustive search was undertaken to identify published research articles related to C-shaped canal configuration in mandibular second molars. Forty-three research articles were analyzed which included 12,481 mandibular second molars. Chi-square test using value of P < 0.05 was performed to assess the statistical significance of this anomalous anatomic variation among the different population. RESULTS: Statistical test revealed a significant variation between the Asian and nonAsian population. The highest incidence of racial predilection was observed in China (Asia) with 93.1%, and the minimum was observed in America with 2.7%. CONCLUSION: This research reported that racial predilection of C-shaped canal configuration in mandibular second molar varies significantly.

Ewing's sarcoma in maxilla.

Ewing sarcoma is a lesion of bone, described in small round cell neoplasm. This tumour resembles primitive neuroectodermal tumour both clinically and histologically. Major difference between these two is that the former arises in the bone and the later in soft tissue. It appears most frequently in males at the age range of of 5-25 years, 80% of which occurs within first two decades of life. Males are more commonly affected than females. Present paper reported with a case report of male patient with 24-year-old showing Ewing's sarcoma of right maxilla.

Candidal carriage in diabetic patients: a microbiological study.

OBJECTIVE: Candida yeast species are widespread opportunistic microbes and incidence of its carriage in diabetic patients compared with non-diabetic controls is not clearly defined. The present study was carried out to isolate and identify the candida species in type I, type II diabetes mellitus patients and in controls. Study comprised of 60 subjects in the age range of 20 to 65 years, consisting of two groups of diabetes patients with controlled diabetic status (20 subjects each with type I and type II) and 20 age and sex matched controls. Saliva samples were collected from all groups and inoculated on Sabouraud's Dextrose Agar (SDA) to check for the fungus growth. The confirmed candidal colonies were further inoculated on CHROMagar for different colour differentiation. Out of 60 samples, 40 (66.67%) showed a positive fungal prevalence. Out of 40 positive fungal prevalence 82.50% were representative of candida. The positive fungal prevalence for candida I was 48.48%, in group II was 30.30%, in group III was 21.21 %. Further speciation in CHROMagar revealed different species of candida predominantly of candida albicans 20% and few mixed culture of candida albicans with candida krusei 5% and candida albicans with candida tropicalis 5% in group I. In group II, candida albicans was 35% and mixed culture of candida albicans with candida glabrata was 5%. In group III, candida albicans was 25% and candida tropicalis was 5%. The findings confirm that diabetic patients harbor yeast in their oral cavity and are more susceptible to oral candidiasis and also that CHROMagar medium is a satisfactory isolation medium for oral cavity specimens, allowing rapid and accurate identification of yeast colonies with easy recognition of mixed culture and is easy to use.

Oral focal mucinosis in adolesence: a sparingly diagnosed clinicopathologic entity.

OBJECTIVE: Oral focal mucinosis an oral counterpart of cutaneous focal mucinosis, is a rare disease of unknown etiology. Its pathogenesis may be due to the overproduction of hyaluronic acid by a fibroblast, at the expense of collagen production, resulting in focal myxoid degeneration of the connective tissue, primarily affecting the mucosa overlying the bone. Oral focal mucinosis occurs predonderantly in adults during the fourth and fifth decade of life, although it has been reported sparingly in children and adolescents. It has no distinctive clinical features, as the diagnosis is solely based on the histopathological features and treatment involves complete surgical excision. Recurrence is unreported. This case report put forward the clinical and histological presentation and consequent management of Oral focal mucinosis in an adolescent female patient.

Prevalence of oral squamous cell carcinoma in Bareilly Region: A seven year institutional study.

BACKGROUND: Oral squamous cell carcinoma is a major contributor to disability and death caused by malignant tumors. Variations in social, cultural, and geographic factors affect the tumor behavior and response to treatment. In this study, we undertake a seven years institutional review and analysis of Oral squamous cell carcinoma cases in Bareilly. MATERIALS AND METHODS: A total of 1938 histologically diagnosed cases during the period of seven years i.e. from 2010 to 2016 were extracted from the archives of Department of Oral & Maxillofacial Pathology, Institute of Dental Sciences, Bareilly and evaluated to know the prevalence of Oral squamous cell carcinoma. The details like age, sex, habits and anatomical site were also recorded from the archived patient's case sheets. RESULTS: Out of the total 1938 cases, 318 were found to be Oral squamous cell carcinoma of which 232 were males and 86 were females. Incidence was highest in 40-49 year age group. The most common site was buccal mucosa (190 cases), followed by tongue (68 cases). Most lesions were well differentiated Oral squamous cell carcinoma (230 cases). Patients with poorly differentiated lesions had a comparatively lower mean age than their counterparts with other histological varieties. CONCLUSION: The pattern of Oral squamous cell carcinoma differs from that of previous studies in relation to incidence and age correlation with the grade of carcinoma. The majority of the lesions were well differentiated. There is a need for intensive oral health awareness to encourage early presentation to cancer center as early detection will further enhance prognosis.

Morphology and prevalence of middle canals in the mandibular molars: A systematic review.

OBJECTIVES: The purpose of this paper is to systematically review the various studies and case reports on the morphology and prevalence of middle canals in the mandibular molars. METHODOLOGY: Electronic databases such as MEDLINE, PubMed, EBSCOhost, ScienceDirect and various journals were screened to identify published literature till March 2017 and earlier for articles related to middle canals in the human permanent mandibular molars. Obtained articles were categorized as original researches, case reports and review articles. Well-defined review questions were developed using the patient population, intervention, comparison and outcome framework to summarize the objectives: "Does middle canal vary in morphology and anatomic location? What is the prevalence of middle canals in mandibular molars? Does ethnicity affect the prevalence of middle canals in mandibular molars?" Morphology was studied and prevalence rates were determined from the evaluation of data extracted from the articles. RESULTS: The search strategy resulted in 87 articles, of which 36 were original research papers and 51 were case reports. The prevalence of middle canals in the various populations ranged from 0.26% to 53.8%. Middle canals were reported in Europeans, Asians, Africans and South and North American populations. The prevalence of middle mesial canal and middle distal canal in various races was reported as up to 53.8% and 10%, respectively. The orifice of middle canal exists below a dentinal projection in the groove between the two main canals. They were observed in fin, confluent and independent configuration. Out of these, confluent configuration was more prevalent. CONCLUSION: Middle canal varies in morphology and anatomic location. Ethnicity affects the prevalence of middle canals in the mandibular molars.