Maxillofacial Tumors Research Articles

SARCOID MASQUERADING AS MALIGNANCY ON IMAGING

TOPIC: Imaging TYPE: Medical Student/Resident Case Reports INTRODUCTION: Sarcoidosis is a multi-system inflammatory disease that predominantly affects the lungs and histopathologically characterized by non-caseating granulomas. A comprehensive evaluation must be pursued to diagnose Sarcoidosis as some findings can overlap with other compatible conditions. CASE PRESENTATION: A-44-year-old woman presented with chronic fatigue, shortness of breath, left sided chest pain, and cough. CT chest revealed left hilar, anterior mediastinal, right paratracheal, and subcarinal lymphadenopathy. An 18-F-fluorodeoxyglucose (FDG) positron emission tomography (PET) CT showed extensive mediastinal and hilar PET avid adenopathy. Notable lymph nodes include a 25mm subcarinal node with a Standardized Uptake Value (SUV) of 32.6 and 11mm left hilar node with a SUV of 27.7. The PET CT findings were highly concerning for lymphoma. Patient subsequently underwent an Endobronchial Ultrasound-guided transbronchial needle aspiration of lymph nodes, and forceps biopsy of station 7. Pathology of the lymph nodes was significant for non-caseating granulomas. Ziehl–Neelsen and silver stains were negative for acid fast bacilli and fungi, respectively. Patient was diagnosed with Sarcoidosis and treatment with Methotrexate and folic acid was initiated. Steroids were avoided in the setting of morbid obesity (BMI >40), prediabetes and history of psychiatric disease. DISCUSSION: This case illustrates the potential for misdiagnosis based on high Standardized Uptake Values on FDG PET-CT scan and the value of a comprehensive evaluation involving tissue biopsy. A SUV of >2.5 is suggestive of malignancy however, false positives due to 18-FDG uptake by inflammatory cells in infectious and granulomatous diseases have been reported in a few case series. Sarcoidosis is characterized by non-caseating granulomas that are formed by the recruitment of multiple inflammatory cells such as activated macrophages and lymphocytes which can lead to increased radiotracer uptake. Other causes of granulomatous disease such as fungal and mycobacterial infections, foreign bodies, pneumoconiosis and vasculitis should be explored. Newer nuclear imaging modalities using alternate radio-tracers have been developed to improve specificity however, low accessibility has rendered a paucity of available data. CONCLUSIONS: FDG PET-CT can aid in the detection and monitoring of various pathologies including Sarcoid. Due to the lack of specificity of any one diagnostic evaluation currently, it is important to obtain pathological confirmation in addition to imaging, and rule out other causes of non-caseating granulomas, prior to starting treatment. REFERENCE #1: Anjali Shetty, M., and John D Carter, MD, Sarcoidosis mimicking lymphoma on FDG-PET imaging. Radiology Case Reports 2011. REFERENCE #2: Paul E. Kinahan, P.a.J.W.F., MD, PET/CT Standardized Uptake Values (SUVs) in Clinical Practice and Assessing Response to Therapy. Semin Ultrasound CT MR., 2010. REFERENCE #3: Miyakubo M, Oriuchi N, Tsushima Y, Higuchi T, Koyama K, Arai K, et al. Diagnosis of maxillofacial tumor with L-3-[F-18]-fluoro-alpha-methyltyrosine (FMT) PET: a comparative study with FDG-PET. Ann Nucl Med. 2007. DISCLOSURES: No relevant relationships by Hamna Ahmad, source=Web Response No relevant relationships by Sarah Dubin, source=Web Response No relevant relationships by Ashraf Gohar, source=Web Response No relevant relationships by Sindhuja Palle, source=Web Response

Primary Malignant Tumors of Oral and Maxillofacial Region in Libyan Population: A single institution experience of 171 cases

background: Globally, a significantly high rate of mortality was caused by oral cancer; however, epidemiological data of oral cancer is still scanty, particularly in Arab countries. This retrospective study was designed to provide a systematic analysis of the histological subtypes of oral and maxillofacial malignant neoplasms in Libyan population during two decades, and to compare the results with previous reports from Libya and other countries.
 Method: data were gathered using patients medical record and biopsy files, and the histological slides were revaluated. The tumors were classified according WHO criteria (2017). 
 Results: Carcinoma was found in 145 patients, forming (84.7%) of all the malignant oral and maxillofacial neoplasms, followed by lymphoma and sarcoma (6.4%), and neural crest cell tumours (2.3%). Males were more affected than females at a ratio of 1.3:1. Most of the patients (70.8%) were above the age of 40 with a mean age of 51.7years old at the time of the diagnosis. Only 1% of the malignant neoplasms were odontogenic in origin. Squamous cell carcinoma (67.5%) was the most common epithelial neoplasm, followed by mucoepidermoid carcinoma (9.7%) and adenoid cystic carcinoma (4.1%). The tongue was the most common site for squamous cell carcinoma (41.1%), followed by buccal mucosa (16.8%).
 Conclusion: compared to previous reports from eastern and some western countries; the prevalence of malignant neoplasms of oral and maxillofacial region in Libyan populations is considerably low.

Effect of hypertension and medication use regularity on postoperative delirium after maxillofacial tumors radical surgery.

The incidence of postoperative delirium (POD) after maxillofacial tumors radical surgery is relatively high. There are a number of evidences showing the relationship between hypertension and decreased cerebral blood flow, as well as the relationship between cerebral ischemia and postoperative cognitive impairment. However, the impact of hypertension in the process of POD and related mechanisms remain unclear.This study included 98 elderly patients who underwent maxillofacial tumors radical surgery in our hospital, from June 2020 to December 2020. We collected the general condition of patients and related research factors before surgery, and also collected related intraoperative factors. After that, we would follow up the patients for POD evaluation.The incidence of POD in the hypertension group was 41%, compared with 12% in the nonhypertension group (P < 0.05). The incidence of POD in the irregular medication group was 62%, compared with 26% in the regular medication group (P < 0.05). Both hypertension (OR = 2.45, 95% CI = 1.11–5.72) and irregular medication use (OR = 2.35, 95% CI = 0.87–5.69) were independent risk factors for POD after this type of surgery in elderly patients.Hypertension and medication use regularity are closely related to POD. This may be related to the delayed postoperative response caused by intraoperative cerebral ischemia.

Incidence of enteral feeding intolerance and its risk factors in patients with oral and maxillofacial malignancies

To explore the incidence of enteral feeding intolerance and its risk factors in patients with malignant oral and maxillofacial tumors. We conducted a retrospective analysis of 122 patients with malignant oral and maxillofacial tumor admitted in a general hospital for enteral nutrition between March, 2018 and March, 2021. The incidence of intolerance to enteral nutrition was analyzed, and the two groups of patients with and without intolerance were compared for age, gender, height, weight, pathological staging, types of enteral nutrition preparations, clinical treatment (physical hypothermia and nasal delivery), drug usage (sedatives, vasoactive drugs, acid suppressant, potassium preparation, antibiotics and hormones) and biochemical parameters (serum total protein, serum albumin, blood glucose and serum potassium concentration). Logistic regression analysis was used to analyze the influencing factors of enteral nutritional feeding intolerance in patients. Of the 122 patients, 52 had enteral feeding intolerance with an incidence rate of 42.6%. Logistic regression analysis showed that potassium preparation (OR=4.125, P=0.027, 95%CI: 1.178-14.444), sedatives (OR=4.125, P=0.000, 95%CI: 2.007-11.765) and hypoproteinemia (OR=3.557, P=0.010, 95%CI: 1.351-9.366) were independent risk factors of feeding intolerance in patients with malignant oral and maxillofacial tumors, while adding dietary fiber was a protective factor (OR= 0.108, P=0.015, 95%CI: 0.018-0.643). The incidence of enteral feeding intolerance is high in patients with malignant oral and maxillofacial tumors. Enteral nutrition preparations with dietary fiber are recommended for these patients. The patients with potassium preparations, sedatives and hypoproteinemia should be closely monitored for enteral feeding intolerance, and timely intervention should be administered to reduce its incidence.

Midfacial Degloving Technique for Free Flap Reconstruction of Nasal and Anterior Skull Base Defects.

Traditionally, surgical access for extirpation and reconstruction of midfacial tumors requires external incisions that can cause a myriad of complications, especially in irradiated patients. The modern midfacial degloving approach involves hidden, sublabial and intranasal incisions that provide reliable access for free flap reconstruction of nasal and maxillofacial tumors. Seven patients with a history of radiation therapy underwent free flap reconstruction of the midface. Five patients underwent the technique in a delayed manner, and the remaining two underwent reconstruction immediately at the time of resection. Five patients underwent free radial forearm fasciocutaneous free flaps and two underwent reconstruction with anterolateral thigh perforator flaps. Bone and/or rib cartilage grafting was used in all patients. All patients underwent successful free flap reconstruction of the midface without external incisions. The most common complication was postoperative infection requiring oral or intravenous antibiotics. No patients sustained loss of their grafts or hardware in the postoperative period. The midfacial degloving technique provides satisfactory exposure to the nasal cavity, midface, orbits, and skull base for free flap reconstruction, without disrupting the external soft tissue. The authors describe a novel use of the midfacial degloving technique to provide safe and reliable results with improved cosmetic outcome.

Results of Dynamic Contrast-Enhanced Ultrasound Correlate With Treatment Outcome in Canine Neoplasia Treated With Electrochemotherapy and Interleukin-12 Plasmid Electrotransfer.

Electrochemotherapy (ECT) and/or gene electrotransfer of plasmid DNA encoding interleukin-12 (GET pIL-12) are effective treatments for canine cutaneous, subcutaneous, and maxillofacial tumors. Despite the clinical efficacy of the combined treatments of ECT and GET, data on parameters that might predict the outcome of the treatments are still lacking. This study aimed to investigate whether dynamic contrast-enhanced ultrasound (DCE-US) results of subcutaneous tumors differ between tumors with complete response (CR) and tumors without complete response (non-CR) in dogs treated with ECT and GET pIL-12. Eight dogs with a total of 12 tumor nodules treated with ECT and GET pIL-12 were included. DCE-US examinations were performed in all animals before and immediately after therapy as well as 8 h and 1, 3, and 7 days later. Clinical follow-up examinations were performed 7 and 14 days, 1 and 6 months, and 1 year after treatment. Numerous significant differences in DCE-US parameters were noted between tumors with CR and non-CR tumors; perfusion and perfusion heterogeneity were lower in CR tumors than in non-CR tumors. Therefore, studies with larger numbers of patients are needed to investigate whether DCE-US results can be used to predict treatment outcomes and to make effective decisions about the need for repeated therapy or different treatment combinations in individual patients.

Perioperative Albumin Supplementation is Associated With Decreased Risk of Complications Following Microvascular Head and Neck Reconstruction

Studies have demonstrated that low serum albumin levels are associated with a high postoperative complication rate after microvascular free flap reconstruction. The aim of this study was to investigate whether perioperative albumin supplementation reduced the postoperative complications of microvascular free flap reconstruction in oral and maxillofacial tumor resections. Patients who underwent microvascular free flap reconstruction during oral and maxillofacial tumor resections from January 2012 to December 2017 were enrolled in this retrospective study. The predictor variable was perioperative albumin supplementation. The primary outcome variables were surgery-associated postoperative complications, including local and systemic complications. The secondary outcome variables were the total duration of hospital stay, postoperative ICU admission rate, duration of ICU stay, and mortality during hospitalization. In total, 315 patients met the criteria. Patients with serum albumin supplementation showed a lower rate of surgery-associated local complications (6.5 vs 21.6%) with an adjusted odds ratio (OR) of 0.24 (95% confidence interval (CI), 0.12 to 0.49, P < .001). The average postoperative hospital stay was significantly shortened for patients with albumin supplementation (12.56 ± 4.23 vs 15.34 ± 5.24 days, P < .001). However, albumin supplementation had no effect on systemic complications. The results of this study suggest that perioperative albumin supplementation is associated with a decreased risk of local complications, shortened hospital stay, and decreased need for crystalloid infusion in patients who underwent oral and maxillofacial tumor resections with microvascular free flap reconstruction.

Calcifying Odontogenic Cyst: Reappraisal and Case Report

The fourth edition of the World Health Organization classification of head and neck tumours summarizes changes in odontogenic and maxillofacial tumours and reintroduces a chapter on odontogenic cysts that reclassifies calcifying odontogenic cystic tumours as calcifying odontogenic cysts based on lack of evidence to substantiate them as true neoplasms. This article presents an unusual case report of a calcifying odontogenic cyst treated successfully with enucleation in support of the view of recent classification. CPD/Clinical Relevance: Calcifying odontogenic cysts are rare entities that can be managed successfully by enucleation, supporting the WHO position that these cysts are not neoplasms.

Optimization of provision of specialized medical care for patients with maxillofacial neoplasms in the Penza region of Russia

Recent years are characterized by the active development and advancement in clinical practice of the method of photodynamic therapy (PDT). PDT shows high effectiveness in the treatment of skin tumors, digestive, nervous, respiratory systems, in gynecology, ophthalmology. Antimicrobial PDT is successfully used in the treatment of purulent wounds and infectious diseases. One of the most actively developing applications of antitumor PDT is the treatment of maxillofacial tumors.The study assessed the organization of medical care for patients with malignancies of the maxillofacial region (MNMR) in the Penza region and the provision of oncologists, maxillofacial surgeons specializing in the treatment of tumor pathology. In the course of the study, the incidence of MNMR of the population of the Penza region and the gender and age structure were determined. The shortcomings of the organization of medical care for patients with MNMR are indicated.

Advances in the application of three-dimensional photothermal functionalized scaffold for bone repairation after maxillofacial tumor surgery

The traditional treatment of maxillofacial tumors includes surgery and chemoradiotherapy. Surgery carries a high risk,and large bone defects are difficult to repair themselves. Besides, chemoradiotherapy can bring serious side effects. Therefore, how to repair the bone defects after maxillofacial tumor surgery and prevent tumor recurrence has become a major clinical challenge. In recent years, photothermal therapy has attracted much attention because of its low invasion, high efficiency, and no side effects. More and more photothermal materials have emerged and been applied in photothermal therapy. In order to treat tumor-related bone defects, many studies use three-dimensional printing technology to prepare photothermal functionalized scaffold to repair bone defects and prevent the recurrence of tumors. Based on photothermal therapy, the review states the photothermal materials, bone repair materials and photothermal functionalized scaffolds in the treatment of maxillofacial tumors at home and abroad, and provides a new way to solve the clinical challenge of bone defect and tumor recurrence after maxillofacial tumor surgery.

Application of the posteromedial thigh flap for oral and maxillofacial defect reconstruction

To explore the feasibility of using the posteromedial thigh flap as an alternative source for oral and maxillofacial reconstruction. During January 2019 to January 2020, twenty-three patients underwent oral and maxillofacial tumor ablation and defect reconstruction with 23 posteromedial thigh flaps were enrolled in the Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University. Thirteen of the patients were male and ten were female, with age of (54.5±9.7) years (33-72 years). The numbers and types of perforators, the dimension of flap and the vascular pedicle length were measured. The outcomes of flaps and donor-site complication were recorded. The patients' satisfaction with donor-site cosmesis were evaluated by the visual analogue scale (VAS). More than one sizable perforators was found in each case and the median number of perforators was 2 (range, 1 to 4), and all of the perforators were musculocutaneous. The pedicle length was (9.8±1.5) cm (range, 7.3 to 13.4 cm). The diameters of artery and the larger vein were 2.0 mm (range, 1.5 to 2.5 mm) and 2.0 mm (range, 1.5 to 3.0 mm), respectively. The dimension of the flaps ranged from 8 cm×6 cm to 12 cm×8 cm, and the donor sites were all closed primarily. All of the flaps were clinically survived, only one patient experienced partial wound dehiscence of donor site 14 days postoperatively and no donor site infection or permanent muscular weakness was reported. The VAS scores of the patients' satisfaction with donor-site cosmesis were all more than 8. The perforators of the posteromedial thigh flap is consistent and the donor-site scar is well concealed, which make the posteromedial thigh flap an excellent option for oral and maxillofacial reconstruction.

Clinical analysis and countermeasures of 739 cases treated in the emergency department of stomatology in general hospital during COVID-19 epidemic

Purpose In this paper, based on the age, sex, disease type, and consultation time of dental emergency during COVID-19 epidemic, a comprehensive analysis of dental emergency management and prevention and control of COVID-19 was conducted. Methods A total of 739 emergency dental cases were collected from January 29 2020 to February 28 2020. They were divided into 3 groups，including adolescents (≤18 years), young adults (18 ~ 60 years), and elderly ( ≥60 years old). The data was analyzed using SPSS 21.0 software package. Results The ratio of male to female was 1.24∶1. There were 655 emergency cases during the day and 84 cases during the night. The types of diseases included pericoronitis (15.83%), apical periodontitis (14.21%), pulpitis (13.40%), periodontitis (12.31%), oral mucosal disease (12.18%), Oral and maxillofacial trauma (10.55%), oral and maxillofacial space infection (8.39%), dental disease in children (5.41%), oral and maxillofacial tumors (2.84%), temporomandibular joint dislocations and disorders (1.76%), and others (3.11%). Conclusions Under the epidemic situation of the new coronavirus, as one of the high-risk departments, it is of great significance to enhance the clinical emergency skills and ability of emergency treatment, improve patients' oral health awareness, address the diagnosis and treatment of essential diseases, for the improvement the quality of dental medical care and the prevention and control of COVID-19 epidemic.

Osteosarcoma: A case report and evaluation.

Osteosarcoma (OS) comprises 2.1% of all malignant oral and maxillofacial tumors. OS arising from the jaw OS differs from OS of the long bones in its biological behavior, presenting a lower incidence of metastasis and a better prognosis. The morphologic and behavioral heterogeneity observed in OS and the perplexity of the varied histological features mimicking other primary and metastatic bone tumors has emphasized the need of advanced molecular techniques in its diagnosis. Hereby, we present a case of OS which was diagnosed by immunohistochemical analysis, aiding in establishing its histogenetic origin.

Neochlorogenic acid enhances the antitumor effects of pingyangmycin via regulating TOP2A.

Neochlorogenic acid (NCA), a natural compound found in honeysuckle, possesses prominent anti‑inflammatory and antitumor effects. Pingyangmycin (PYM) induces DNA damage and has been used for the treatment of oral and maxillofacial tumors. Oral care serves an important role in promoting wound healing during chemotherapy in patients with oral squamous cell carcinoma (OSCC). Therefore, the present study aimed to analyze the effects of NCA and PYM on OSCCcells and to investigate the potential underlying mechanism. Reverse transcription‑quantitative PCR and western blotting were conducted to analyze the expression levels of DNA topoisomeraseIIα (TOP2A) in different OSCC cell lines. TOP2A‑overexpression cells were constructed via transfection of TOP2A‑overexpression plasmids. Following NCA or PYM treatment, cell proliferation was assessed using Cell Counting Kit‑8 and colony formation assays, whereas cell apoptosis and the cell cycle distribution were assessed via TUNEL staining and flow cytometry, respectively. In addition, the expression levels of apoptosis‑ and cell cycle‑related proteins were detected via western blotting. Moreover, co‑immunoprecipitation (Co‑IP) was conducted to determine whether TOP2A interacted with CDK1. The results of the present study indicated that NCA treatment significantly enhanced the suppressive effects of PYM on OSCC cell proliferation and apoptosis. The results also indicated that PYM arrested the cell cycle in the G0/1 by regulating cyclin dependent kinase1 (CDK1)/cyclinB1, which was enhanced by the cotreatment of NCA and PYM. In addition, NCA and PYA treatment altered the expression levels of apoptosis‑related proteins. The Co‑IP assay indicated that TOP2A interacted with CDK1. Moreover, TOP2A overexpression significantly reversed the effects of NCA and PYM treatment on OSCC cell proliferation and apoptosis. In addition, NCA significantly decreased PYM‑induced toxicity in normal oral epithelial cells. In conclusion, the results of the present study suggested that NCA may promote the inhibitory effects of PYM in OSCC via TOP2A.

MR-guided 125I seed implantation treatment for maxillofacial malignant tumor.

PurposeThis study assessed the therapeutic efficacy of postoperative magnetic resonance (MR)‐guided interstitial 125I seed implantation for treatment of oral and maxillofacial malignant tumors.Methods and MaterialsA total of 127 patients with oral or maxillofacial malignant tumors were included in this study who received interstitial 125I treatment after the surgery resection. Before implantation, all the patients received MR scans to assess the lesion scope, extent, and nature. 125I implantation target regions were based on the pre‐operative imaging. 125I seeds were delivered to target regions via puncture needles under the real‐time guidance of MR. Computed tomography (CT)or MR was performed immediately after implantation and again every 3 months later.ResultsAfter successful 125I implantation, all patients were also examined regularly to detect tumor recurrence, lymphatic, and distant metastases. To date, CT or MR verification showed that 13/127 patients experienced tumor recurrence or lymphatic metastasis or distant metastasis. No seeds migration was observed, no serious treatment‐related complications affected patient quality of life, and no important organ (such as major cervical vessels, spinal cord, etc.) injuries were observed.ConclusionOur results show that MR‐guided 125I implantation is an effective approach to site‐specific treatment for oral and maxillofacial tumor, which could potentially reduce postoperative complications and tumor recurrence rates, increase patient survival, and improve quality of life.

Multimodal image fusion: applications in the diagnosis and treatment of oral and maxillofacial tumors

Multimodal image fusion: applications in the diagnosis and treatment of oral and maxillofacial tumors

Electroporation-Based Treatments in Small Animal Veterinary Oral and Maxillofacial Oncology.

Electroporation is a method of inducing an increase in permeability of the cell membrane through the application of an electric field and can be used as a delivery method for introducing molecules of interest (e.g., chemotherapeutics or plasmid DNA) into cells. Electroporation-based treatments (i.e., electrochemotherapy, gene electrotransfer, and their combinations) have been shown to be safe and effective in veterinary oncology, but they are currently mostly recommended for the treatment of those solid tumors for which clients have declined surgery and/or radiotherapy. Published data show that electroporation-based treatments are also safe, simple, fast and cost-effective treatment alternatives for selected oral and maxillofacial tumors, especially small squamous cell carcinoma and malignant melanoma tumors not involving the bone in dogs. In these patients, a good local response to treatment is expected to result in increased survival time with good quality of life. Despite emerging evidence of the clinical efficacy of electroporation-based treatments for oral and maxillofacial tumors, further investigation is needed to optimize treatment protocols, improve clinical data reporting and better understand the mechanisms of patients' response to the treatment.

Pain relief in a patient with massive sino-nasal tumor

Maxillofacial neoplasms, though relatively rare, are potentially devastating tumors, that may require medical or surgical intervention. Among all the head and neck tumors, sino-nasal tumors make up 3%. Such tumors can be very vascular as well as extremely painful. Conventional analgesic treatment in a cascading manner usually proves to be inadequate and unsatisfactory

Role of craniofacial surgery in oral and maxillofacial tumors involving the skull base: A retrospective analysis of 126 patients

Oral and maxillofacial tumors involving the skull base (SB) are rare and complex, making treatment difficult and controversial. The purpose of the present study was to evaluate the treatment efficacy of craniofacial surgery (CFS). Patients who underwent CFS for these tumors between May 2000 and November 2017 were retrospectively analyzed. Clinicopathologic and treatment modality data were collected and follow-up was recorded. Kaplan-Meier and log-rank tests and Cox-regression model were used for survival analysis. In total, 126 patients were enrolled (70 males and 56 females; 97 malignant tumors). Squamous cell carcinoma accounted for the majority of tumors. The lip-submandibular-neck approach was most frequently applied. Through-and-through SB bone or partial dura resection was performed in 42 cases. A pathologic positive margin was found in 18 cases. Of the included patients, 80 underwent simultaneous craniofacial reconstruction. The postoperative complications rate was 11.1%. Estimated 1-year, 3-year, and 5-year overall survival rates were 78.8%, 68.2%, and 54.4% respectively; and the 1-year, 3-year, and 5-year recurrence-free survival rates were 77.4%, 66.8%, and 63.8%, respectively. Multivariate analysis indicated postoperative complications, radiotherapy, recurrence, and metastasis status had a negative impact on survival (P < .05). Although tumors involving the SB had various clinicopathologic characteristics, with interdisciplinary cooperation, CFS is an optimal option.

Accuracy of multimodal image fusion for oral and maxillofacial tumors: A revised evaluation method and its application

ObjectiveTo develop a revised evaluation method for accuracy of multimodal image fusion for oral and maxillofacial tumors and explore its application for comparing the accuracy of three commonly used fusion algorithms, automatic fusion, manual fusion, and registration point–based fusion. Materials and methodsImage sets of patients with oral and maxillofacial tumor were fused using the iPlan 3.0 navigation system. Fusion accuracy included two aspects: (1) overall fusion accuracy: represented by the mean value of the coordinate differences along the x-, y-, and z- axes (Δx, Δy, and Δz), mean deviation (MD), and root mean square (RMS) of six pairs of landmarks on the two image sets; (2) tumor volume fusion accuracy: represented by Fusion Index (FI), which was calculated based on the volume of tumor delineated on the two image sets. ResultsEighteen pairs of image sets of 17 patients were enrolled in this study. The Δx and Δy values for the three algorithms were less than 1.5 mm. The Δz values for automatic fusion, manual fusion and registration point–based fusion was 1.049 mm, 1.864 mm and 1.254 mm. The MD for automatic fusion, manual fusion and registration point–based fusion was 1.978 mm, 2.788 mm and 1.926 mm. Significant differences existed in Δz for manual fusion and that for automatic fusion (P = 0.058), in MD for manual fusion and that for automatic fusion (P = 0.087), and in MD for manual fusion and that for registration point–based fusion (P = 0.069). The FI for automatic fusion, manual fusion, and registration point–based fusion was 0.594, 0.520, and 0.549; the inter-algorithm differences were not significant (P = 0.290). ConclusionThe automatic fusion and the registration point–based fusion were more accurate than manual fusion, and therefore were recommended to be used in multimodal image fusion for oral and maxillofacial tumors.