Orofacial Lesions Research Articles

Audit of oral neoplasms in children and young adults in Nigeria

BackgroundOrofacial neoplasms in children and young adults may differ significantly from those observed in adults. Our aim was to describe the epidemiological characteristics of histologically diagnosed orofacial neoplasms among children and young adults in Nigeria.MethodsThis was a multicenter cross-sectional study across geopolitical zones in Nigeria. Annual reports of clinical information and surgical biopsies submitted at the Oral Pathology Laboratory, clinic day registries, surgical day case registries and operative theatre registries were retrieved from January 2008 to March 2024. The relevant demographic data were obtained for each patient. The study subjects were categorized by age into children, adolescents and young adults. Tissue involvement was classified as soft tissue involvement, bony involvement or both soft tissue and bony involvement. The site and behaviour of the lesions were subdivided according to the ICD-10 codes. Statistical analysis was performed via the R programming language.ResultsA total of 1889 cases were observed during the period under review, with a mean age of 15 years. Cases were more common in females (52%) and in young adults (47%). Most cases were benign neoplasms (85%), and bony affectation (54%) was slightly predominant. Odontogenic tumours (38%) and fibro-osseous lesions (20%) were the most common category of lesions observed, whereas salivary gland tumours (2.2%) and neoplasms of epithelial origin (2.5%) were the least common. Neoplasms in children involved mostly soft tissues, whereas those in adolescents and young adults had a preference for bone (p < 0.001). In all age groups, benign lesions were mostly observed in the mouth and pharynx. For malignant lesions, in children, the bones of the skull and face were mostly involved, whereas in adolescents, the mandible was the predominant site (p < 0.001). In children, mesenchymal neoplasms were the most prevalent category of lesions, whereas in both adolescents and young adults, odontogenic tumours were more common. The proportion of malignant neoplasms in males was significantly greater than that in females (p < 0.001).ConclusionThis study revealed that although most biopsied orofacial lesions were more often benign, the proportion of malignant neoplasms in this population was greater than that previously reported.

Interdisciplinary management of orofacial lesions in early childhood: paediatric alert system at University of Verona.

Orofacial trauma (OFT) occurs frequently in children and requires thorough evaluation not only by paediatric dentists but also by all specialists involved in emergency services, particularly in cases involving children under 3 years of age, given their inability to directly participate in clinical-anamnestic evaluations. Addressing early childhood orofacial trauma resulting from maltreatment, this study explores the key role played by various healthcare professionals, including paediatric dentists, general dentists, maxillofacial surgeons, dental hygienists, and paediatricians, in the optimal management of these cases. In the event of trauma due to suspected or confirmed mistreatment, it is essential that all healthcare workers involved have precise knowledge of the appropriate course of action from both a clinical and legal point of view, guaranteeing maximum protection for the young patient. This is particularly significant as cases of mistreatment with apparently minor consequences can degenerate into situations of irreparable severity. The latest guidelines from the International Association of Dental Traumatology (IADT) in 2020 continue to emphasise the potential correlation between OFT and cases of abuse or violence. Recent recommendations in the literature highlight the importance of facilitating mandatory reporting of incidents to relevant authorities and improving information sharing between dental healthcare professionals and child welfare services. A new flow diagram, called Paediatric Orofacial Trauma Alert (P.O.T.A.), has been proposed at the University of Verona. This tool is specifically designed to assist specialists dealing with early childhood orofacial trauma cases by assisting them in identifying potential cases of maltreatment. In this innovative approach, the collaborative efforts of general dentists, paediatric dentists, maxillofacial surgeons, dental hygienists and paediatricians play a vital role in cases of abuse. In addition to restoring the oral health of young patients, these professionals can activate a vast network of contacts, ensuring not only optimal oral health care but also providing comprehensive support to victims. The objective is to safeguard not only the physical but also the psychological well-being of these vulnerable subjects.

Odontogenic Cutaneous Fistula: A Zombie Diagnosis.

Odontogenic cutaneous fistula (OCF) is a pathologic communication between the cutaneous surface of the face and oral cavity. Majority of oral cutaneous fistulas are reported to arise from chronic dental infection. Delay in treatment may result in chronic tissue injury as well as cosmetic deformities. Lesions are often misdiagnosed, leading to delayed management. Misdiagnosis may be the result of the variability of clinical morphological presentation and location of lesions compounded by the lack of knowledge that these lesions can have dental etiology. It is estimated that half of patients with OCF undergo multiple dermatologic surgical operations, antibiotic regimens, and other excisions and biopsies before a correct diagnosis is made. Herein, we present a systematic review to detail cases of odontogenic cutaneous lesions that had been previously misdiagnosed or managed inappropriately. In addition, we include a case report from our own institution. The aims are to demonstrate various presentations of OCF, increase awareness of plastic surgeons and oral maxillofacial surgeons to this pathological condition, and reinforce the importance of prompt diagnosis and treatment. The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A literature search was conducted in PubMed, Web of Science, and Cochrane databases from January 1, 2013 to July 24, 2023. The following search terms were utilized: "odontogenic cutaneous fistula" OR "odontogenic cutaneous sinus." Twenty-three articles published between 2013 and 2023 were included in this review. In addition, we report a case from our own institution. A total of 28 cases were included in the review. Diagnosis of OCF is challenging for numerous reasons. Misdiagnosis can lead to multiple trials of antibiotics and surgical procedures as well as reoccurrence of the lesion. Cases summarized highlight the importance of communication between oral maxillofacial surgery, plastic surgery, other medical subspecialists, and dentists in the evaluation of patients with head and neck lesions. Physicians should consider dental etiology in the differential diagnosis of orofacial skin lesions, even if teeth appear normal on oral examination.

Orofacial Cysts: A Single Institution Experience of 85 Cases in Enugu, Nigeria.

Orofacial cysts are pathologic cavities that could be symptomatic and may cause facial disfigurement. The only epidemiologic report of such lesions in Southeast Nigeria studied jaw cysts from 1987 to 1996. New studies reflecting recent research findings and classifications on the subject in Southeast Nigeria are lacking. To determine the prevalence and distribution of orofacial cysts in a tertiary hospital in Enugu, Southeast Nigeria. A 10-year retrospective study of patients with orofacial cysts diagnosed by histology was carried out. Orofacial cysts constitute 9.5% (85) of 897 orofacial lesions identified. The male-to-female gender ratio was 1.2:1. The mean age (± standard deviation) at the onset of the cystic lesion was 28.58 (±16.98) years. Developmental odontogenic cysts 52.9% (45) and salivary cysts 18.8% (16) were the most common group of orofacial cysts. The most prevalent orofacial cysts were odontogenic keratocysts at 25.9% (22), mucoceles 16.5% (14), and dentigerous cysts 14.1% (12). Straw-colored aspirates 34.8% (16) and dark brown aspirates 28.3% (13) were the predominant cystic contents. The mandible 45.9% (39) and maxilla 27.1% (23) were the commonest sites for orofacial cysts, while the lip 9.4% (8) was the most frequent soft tissue site. A significant association exists between anatomical site and cyst type at a 95% confidence interval with P = 0.000, X2 = 247.17. Unilocular radiolucency 62.5% (20) and multilocular radiolucency 34.4% (11) were the most common radiographic features. Developmental odontogenic cysts particularly odontogenic keratocysts were most prevalent while mucocele was the most common soft tissue cyst.

Correlation between diffusion-weighted image-derived parameters and dynamic contrast-enhanced magnetic resonance imaging-derived parameters in the orofacial region.

Diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are widely used in the orofacial region. Furthermore, quantitative analyses have proven useful. However, a few reports have described the correlation between DWI-derived parameters and DCE-MRI-derived parameters, and the results have been controversial. To evaluate the correlation among parameters obtained by DWI and DCE-MRI and to compare them between benign and malignant lesions. Fifty orofacial lesions were analysed. The apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudodiffusion coefficient (D*) and perfusion fraction (f) were estimated by DWI. For DCE-MRI, TK model analysis was performed to estimate physiological parameters, for example, the influx forward volume transfer constant into the extracellular-extravascular space (EES) (Ktrans) and fractional volumes of EES and plasma components (ve and vp). Both ADC and D showed a moderate positive correlation with ve (ρ = 0.640 and 0.645, respectively). Ktrans showed a marginally weak correlation with f (ρ = 0.296), while vp was not correlated with f or D*; therefore, IVIM perfusion-related parameters and TK model perfusion-related parameters were not straightforward. Both D and ve yielded high diagnostic power between benign lesions and malignant tumours with areas under the curve (AUCs) of 0.830 and 0.782, respectively. Both D and ve were reliable parameters that were useful for the differential diagnosis. In addition, the true diffusion coefficient (D) was affected by the fractional volume of EES.

Integrating antimicrobial photodynamic therapy into the adjuvant phototherapeutic approach for orofacial manifestations of toxic epidermal necrolysis and Stevens-Johnson syndrome

Characterized by an immune reaction to medications, toxic epidermal necrolysis (TEN) and Steven-Johnson Syndrome (SJS) are potentially fatal mucocutaneous reactions, and their management remains challenging. Considering the promising studies regarding the use of laser in managing orofacial lesions, this study aimed to report two cases in which children presenting with TEN and SJS were treated using a combination of antimicrobial photodynamic therapy (aPDT) and photobiomodulation therapy (PBMT) concurrently with conventional supportive care. The treatment proposed herein resulted in significant clinical improvement of the children's oral condition within a few days, enabling the reintroduction of oral feeding. Within the limitations of the study, the cases reported suggest that the adjuvant combination of PBMT and aPDT may be beneficial for improving the oral condition of children afflicted with oral injuries induced by TEN and SJS.

Prevalence of dengue induced orofacial Lesion in Durg-Bhilai City, Chhattisgarh: A survey

Prevalence of dengue induced orofacial Lesion in Durg-Bhilai City, Chhattisgarh: A survey

USE OF CONE BEAM COMPUTED TOMOGRAPHY GRAY SCALE VALUES FOR DIAGNOSING TUMORS AND CYSTS

The retrospective study was conducted in the Department of Radiology of the hospital from January 2022 to January 2023 to assess the ability of CBCT gray scale value to diagnose tumors and cysts and evaluate differences in bony changes of both. A total of 50 patients were included in the study. CBCT scanner with 68-1073μSv radiation dose was used for obtaining 3D images. Gray scale values were obtained on the tangential section. Radiological diagnosis was made after calculating mean gray values for benign lesions or cysts. Myxoma, odontogenic ghost cell tumor, and the adenomatoid odontogenic tumor had lower grayscale values, and multiple myeloma, cementoblastoma, acanthomatous ameloblastoma, residual cyst, and lateral periodontal cyst had higher values. The mean grayscale value for the tumor was 1468 ± 70.5, and for the cyst was 1292.1 ± 6.5. There was a significant correlation between both (P&lt;0.001). The bone density of normal and pathological maxillofacial regions was compared. The radiolucent area (e.g., axillary sinus) had the lowest, and the radiopaque region (e.g., enamel) had the highest gray scale value. CBCT gray value is a powerful diagnostic tool for tumors, cysts, and other orofacial lesions and has better outcomes than conventional 2-D imaging.

A Herpes Simplex Virus 1 DNA Polymerase Multidrug Resistance Mutation Identified in a Patient With Immunodeficiency and Confirmed by Gene Editing.

Herpes simplex virus 1 can cause severe infections in individuals who are immunocompromised. In these patients, emergence of drug resistance mutations causes difficulties in infection management. Seventeen herpes simplex virus 1 isolates were obtained from orofacial/anogenital lesions in a patient with leaky severe combined immunodeficiency over 7 years, before and after stem cell transplantation. Spatial/temporal evolution of drug resistance was characterized genotypically-with Sanger and next-generation sequencing of viral thymidine kinase (TK) and DNA polymerase (DP)-and phenotypically. CRISPR/Cas9 was used to introduce the novel DP Q727R mutation, and dual infection-competition assays were performed to assess viral fitness. Isolates had identical genetic backgrounds, suggesting that orofacial/anogenital infections derived from the same virus lineage. Eleven isolates proved heterogeneous TK virus populations by next-generation sequencing, undetectable by Sanger sequencing. Thirteen isolates were acyclovir resistant due to TK mutations, and the Q727R isolate additionally exhibited foscarnet/adefovir resistance. Recombinant Q727R mutant virus showed multidrug resistance and increased fitness under antiviral pressure. Long-term follow-up of a patient with severe combined immunodeficiency revealed virus evolution and frequent reactivation of wild-type and TK mutant strains, mostly as heterogeneous populations. The DP Q727R resistance phenotype was confirmed with CRISPR/Cas9, a useful tool to validate novel drug resistance mutations.

Critically Ill Patients With COVID-19: Are Phototherapies Advantageous for Managing Orofacial Lesions? Our Experience With Brazilian Hospitals

Our research group has recently published some case reports on the use of photobiomodulation therapy (PBMT) and antimicrobial photodynamic therapy (aPDT) for managing orofacial lesions in COVID-19 patients, giving a new perspective on the role of laser in daily practice during COVID-19 pandemic. Thus, considering our wide experience with these patients in Brazil, the current commentary paper aimed to briefly present some multicenter cases in which PBMT and aPDT were used concomitantly to manage orofacial lesions in critically ill patients with COVID-19, a condition that has never been addressed in the literature. The proposed laser protocol was effective in wound healing in all the cases; however, the degree of improvement and the period required varied substantially. Given the cases presented, we hope to encourage clinicians to consider using aPDT and PBMT concomitantly for managing COVID-19-related orofacial lesions in intensive care unit patients with respiratory failure requiring mechanical ventilation.

35. Head and neck cancers in the emergency department during COVID-19 Pandemic

The impact of COVID-19 pandemic on human life is morbid & unparalleled. During this period, patients with oral lesions were experiencing increased difficulty accessing primary care and being followed up in person in secondary care. This led to a surge of patients with painful orofacial lesions presenting to the emergency department. We attempt to analyse these hospital attendances during the pandemic and its troubling impact on the welfare of these patients.

Simian homologues of human herpesviruses and implications for novel viral introduction to free-living mountain gorillas.

The endangered mountain gorilla (Gorilla beringei beringei) in Rwanda, Uganda, and the Democratic Republic of Congo is frequently in contact with humans through tourism, research activities, and illegal entry of people into protected gorilla habitat. Herpesviruses, which are ubiquitous in primates, have the potential to be shared in any setting where humans and gorillas share habitat. Based on serological findings and clinical observations of orofacial ulcerated lesions resembling herpetic lesions, an alpha-herpesvirus resembling human herpes simplex virus type 1 (HSV-1) has long been suspected to be present in human-habituated mountain gorillas in the wild. While the etiology of orofacial lesions in the wild has not been confirmed, HSV-1 has been suspected in captively-housed mountain gorillas and confirmed in a co-housed confiscated Grauer's gorilla (Gorilla beringei graueri). To better characterize herpesviruses infecting mountain gorillas and to determine the presence/absence of HSV-1 in the free-living population, we conducted a population-wide survey to test for the presence of orally shed herpesviruses. DNA was extracted from discarded chewed plants collected from 294 individuals from 26 groups, and samples were screened by polymerase chain reaction using pan-herpesvirus and HSV-1-specific assays. We found no evidence that human herpesviruses had infected free-ranging mountain gorillas. However, we found gorilla-specific homologs to human herpesviruses, including cytomegaloviruses (GbbCMV-1 and 2), a lymphocryptovirus (GbbLCV-1), and a new rhadinovirus (GbbRHV-1) with similar characteristics (i.e., timing of primary infection, shedding in multiple age groups, and potential modes of transmission) to their human counterparts, human cytomegalovirus, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, respectively.

Photodynamic therapy and Photobiomodulation as adjuvant treatment of oral and facial manifestations in patients with COVID-19 hospitalized in the intensive care unit: a case series

Orofacial injuries resulting from Coronavirus-19 (COVID-19) are reported in the current literature. The etiology of these manifestations is still unknown, but them seem to have an association between the prone position and patient’s immunosuppression. Clinical features range from nonspecific ulcers to vesicles that may mimic viral infections. The search for a clinical protocol for the cure of these lesions is necessary. Thus, some studies about photobiomodulation, a low-level light therapy with regenerative tissue action, associated with antimicrobial photodynamic therapy, as a promising adjuvant treatment. Therefore, the present study aims to report a series of cases where photobiomodulation and photodynamic therapy were used in patients positive for COVID-19 and presented orofacial lesions during the time of hospitalization in the intensive care unit. In all cases, tissue regeneration was complete, demonstrating the effectiveness of photobiomodulation and photodynamic therapy as adjuvant therapy associated with the use of medicines.

Head and neck cancer presentations in the emergency department during the COVID-19 pandemic.

Introduction It is not uncommon to note patients with painful orofacial lesions presenting via the emergency department to the on-call team. However, during the COVID-19 pandemic, we saw a surge in these attendances, prompting a review of our emergency database.Methods The maxillofacial emergency database was retrospectively reviewed in the period between March 2020 and October 2021 (19 months). Data including relevant variables were collected in a standard spreadsheet database and analysed by two clinicians.Results Between March 2020 and October 2021, 34 patients attended with oral ulceration and non-odontogenic neck swellings, out of which nine patients had subsequent diagnosis of oral/oropharyngeal cancer (mean age: 64.2 years). All patients were grouped as stage IV cancers and only one patient was deemed suitable for ablative surgery, which is the primary mode of treatment in oral cancers. Three patients were deemed to have progressive/recurrent disease despite active treatment and two patients unfortunately passed away due to the disease.Conclusion The impact of the COVID-19 pandemic on head and neck cancer diagnoses and management suffered significantly. We present our experience dealing with this vulnerable cohort in the emergency department and their subsequent journey.

Evaluation Of Histopathological Lesion In Oral And Maxillofacial Department At Tertiary Care Hospital Peshawar

Around the world, maxillofacial disorders are distributed widely. The oral and maxillofacial area is affected by a wide variety of illnesses, from inflammatory lesions to benign and malignant cancers. Objective: This is a base line study that will aid in the diagnosis and management of oral healthcare and also guide recommendations and associated research in the local population in the future. Methods: In this descriptive observational study, 124 patients with orofacial lesions reported at the Hayat Abad medical complex, Department of Oral Maxillofacial and Dental Surgery between 2021 and 2022 were analyzed. Result: A total of 124 orofacial lesions were found, of which 47 were malignant and 57 benign, with the posterior mandible being the most commonly affected area. The pathology that affected most frequently was squamous cell carcinoma. In the fourth, fifth, and sixth decades of life, the soft tissue lesion affected 41% of males and 37% of females. These included squamous cell carcinoma well-differentiated in 32 (25.80%), fibrous epulis in 11 (8.8%), and pyogenic granuloma in 16 (12.90%) of cases. Conclusion: With the posterior mandibular area being the most common site, oral squamous cell carcinoma affects adolescents and the elderly with the most incidence rate.

Clinicopathologic study of 30 fibrous dysplasia of the jaws in Enugu, Nigeria

Background : Fibrous dysplasia (FD) is a genetic-based benign fibro-osseous lesion known to affect the jaws and craniofacial bones. Reports of this entity in Eastern Nigeria are scarce.Objective : To determine the prevalence and clinicopathologic features of fibrous dysplasia.Materials and Methods : A total of 643 clinicopathological records (radiographs, clinical records, and histopathological records) collected between January 2012 and December 2019 were available. The demographic and clinicopathologic records of bone and maxillofacial pathologies were examined and correlated with histological findings to determine the prevalence of FD.Results : A total of 643 orofacial lesions of bone lesions were reviewed. In these, 86 benign fibro-osseous lesions (BFOLs) were identified, of which 30 (34.9%) were FDs. The majority of the BFOLs was ossifying fibromas (OFs). The patients with FD were in the 2nd to 3rd decades of life with a mean age of 19.4 ± 7.9 years.The male to female ratio was 1: 2.8, while the mandible to maxilla ratio was 1: 4.3. There was a statistically significant prevalence of FD on the right-sided jaw, P = 0.000.Conclusion : This study observed a low prevalence of FD of the jaws, mostly observed in young patients, affecting the right side.

Oro-facial mucocutaneous manifestations of Coronavirus Disease-2019 (COVID-19): A systematic review.

We reviewed the prevalence, the likely aetiopathogenesis, and the management of oro-facial mucocutaneous manifestations of Coronavirus Disease-2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2). English language manuscripts searched using standard databases yielded 26 articles that met the inclusion criteria. In total, 169 cases (75 females; 94 males) from 15 countries with a spectrum of COVID-19 severities were reviewed. Gustatory perturbations were prevalent in over 70%. Mucocutaneous manifestations were reported predominantly on the tongue, palate, buccal mucosa, gingivae, and lips and included ulcers, blisters, erosions, papillary hyperplasia, macules, glossitis, and mucositis. Ulcerative lesions, present in over 50 percent, were the most common oral manifestation. Lesions resembling candidal infections, with burning mouth, were prevalent in 19%. Petechiae and angina bullosa were generally seen, subsequent to COVID-19 therapies, in 11%. Ulcerated, necrotic gingivae were documented in severely ill with poor oral hygiene. These manifestations, present across the COVID-19 disease spectrum, were commonly associated with the immunosuppressed state and/ or the concurrent antimicrobial/steroidal therapies. In summary, a wide variety of orofacial mucocutaneous lesions manifest in COVID-19. They are likely to be secondary to the disease-associated immune impairment and/or pharmaco-therapy rather than a direct result of SARS-CoV-2 infection per se.

Pharmacological Inhibition of IRE-1 Alpha Activity in Herpes Simplex Virus Type 1 and Type 2-Infected Dendritic Cells Enhances T Cell Activation.

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections are life-long and highly prevalent in the human population. These viruses persist in the host, eliciting either symptomatic or asymptomatic infections that may occur sporadically or in a recurrent manner through viral reactivations. Clinical manifestations due to symptomatic infection may be mild such as orofacial lesions, but may also translate into more severe diseases, such as ocular infections that may lead to blindness and life-threatening encephalitis. A key feature of herpes simplex viruses (HSVs) is that they have evolved molecular determinants that hamper numerous components of the host’s antiviral innate and adaptive immune system. Importantly, HSVs infect and negatively modulate the function of dendritic cells (DCs), by inhibiting their T cell-activating capacity and eliciting their apoptosis after infection. Previously, we reported that HSV-2 activates the splicing of the mRNA of XBP1, which is related to the activity of the unfolded protein response (UPR) factor Inositol-Requiring Enzyme 1 alpha (IRE-1α). Here, we sought to evaluate if the activation of the IRE-1α pathway in DCs upon HSV infection may be related to impaired DC function after infection with HSV-1 or HSV-2. Interestingly, the pharmacological inhibition of the endonuclease activity of IRE-1α in HSV-1- and HSV-2-infected DCs significantly reduced apoptosis in these cells and enhanced their capacity to migrate to lymph nodes and activate virus-specific CD4+ and CD8+ T cells. These findings suggest that the activation of the IRE-1α-dependent UPR pathway in HSV-infected DCs may play a significant role in the negative effects that these viruses exert over these cells and that the modulation of this signaling pathway may be relevant for enhancing the function of DCs upon infection with HSVs.

A necrotic orofacial lesion presenting in an immunocompromised patient in the UK: case review with features of noma

Noma is a gangrenous and destructive orofacial disease. It comes from the Greek word nomein, meaning ‘to devour’. Caused by a rapidly spreading opportunistic infection, noma has a strong affiliation to extreme poverty and is infamously known as the ‘face of poverty’. It is predominantly endemic to children between the ages of two and six who are malnourished, and is incited by disease. However, there is rare precedent of this disease emerging in adulthood in more economically developed countries, with noma-like lesions in the UK doubling since 2015. We report on a 90-year-old patient who initially presented to their general medical practitioner for a necrotic lip ulcer, which was originally thought to be a cold sore. The patient was later admitted to hospital due to reduced mobility and severe anaemia, with underlying features of sepsis, malnutrition, immunosuppression, oral necrosis and progressive ulceration over three weeks. Immediate treatment began following admission, including intravenous antibiotics, oral care and nutritional supplementation, before a definitive clinical diagnosis of noma was made after a biopsy, which ruled out malignancy. The rapid treatment response, albeit before a diagnosis was confirmed, allowed for the disease process to halt. This atypical presentation in a UK hospital highlights the need for periodic review of such lesions, so that current knowledge of their presentation and management is maintained.

A comparison among gamma distribution, intravoxel incoherent motion, and mono-exponential models with turbo spin-echo diffusion-weighted MR imaging in the differential diagnosis of orofacial lesions.

To compare the gamma distribution (GD), intravoxel incoherent motion (IVIM), and monoexponential (ME) models in terms of their goodness-of-fit, correlations among the parameters, and the effectiveness in the differential diagnosis of various orofacial lesions. A total of 85 patients underwent turbo spin-echo diffusion-weighted imaging with six b-values. The goodness-of-fit of three models was assessed using Akaike Information Criterion. We analysed the correlations and compared the effectiveness in the differential diagnosis among the parameters of GD model (κ, shape parameter; θ, scale parameter; fractions of diffusion: ƒ1, cellular component; ƒ2, extracellular diffusion; ƒ3, perfusion component), IVIM model (D, true diffusion coefficient; D*, pseudodiffusion coefficient; f, perfusion fraction), and ME model (apparent diffusion coefficient, ADC). The GD and IVIM models showed a better goodness-of-fit than the ME model (p < 0.05). ƒ1 had strong negative correlations with D and ADC (ρ = -0.901 and -0.937, respectively), while ƒ3 had a moderate positive correlation with f (ρ = 0.661). Malignant entity presented significantly higher ƒ1 and lower D and ADC than benign entity (p < 0.0001). Malignant lymphoma had significantly higher ƒ1 in comparison to squamous cell carcinoma (p = 0.0007) and granulation (p = 0.0075). The trend in ƒ1 was opposite to the trend in D. Malignant lymphoma had significant lower ƒ3 than squamous cell carcinoma (p = 0.005) or granulation (p = 0.0075). The strong correlations were found between the GD- and IVIM-derived parameters. Furthermore, the GD model's parameters were useful for characterising the pathological structure in orofacial lesions.