Recent methods for the diagnosis and differentiation of ameloblastoma: a narrative review

Figures & data

Table 1. Suitable diagnostic technique for clinical diagnosis.

Study	Year	Study contents	Study results
Cardoso LB et al.	2020	Panoramic Radiography (PR) and Cone Beam Computed Tomography (CBCT)	CBCT images revealed that the size and degree of expansion of ameloblastoma are larger than those of odontogenic keratocysts and dentigerous cyst.
Wamasing N et al.	2022	Conventional Magnetic Resonance Imaging (MRI) and diffusion-weighted imaging (DWI)	The apparent diffusion coefficient (ADC) helped distinguish unicystic ameloblastoma from dentigerous cyst and odontogenic keratocysts; however, it cannot be used to distinguish dentigerous cyst from odontogenic keratocyst.
Alves DBM et al.	2018	PR and Computed Tomography (CT)	Although PR is very useful and widely used, CT provides more accurate information on buccolingual expansion, calcification, bone septa, perforation of cortical bones, and tooth resorption.
Apajalahti S et al.	2015	CT and MRI	Enhanced CT and MRI can help distinguish between ameloblastoma and other cyst-like lesions as they enable the visualisation of the mixed cystic and solid content characteristic of non-unicystic ameloblastoma. CT and MRI aid in determining the differential diagnosis of unicystic ameloblastoma.
Wakoh M et al.	2011	PR	The degree of observer reliance on diagnostic elements is more consistent for ameloblastoma than for odontogenic keratocysts in PR. In particular, ‘radicular state adjacent to a lesion' may be a decisive factor for distinguishing ameloblastoma from odontogenic keratocyst.
Cihangiroglu M et al.	2002	CT and MRI	Both CT and MRI show the extent of the tumours.
Crusoe-Rebello I et al.	2009	CT	CT parameters facilitate the evaluation of ameloblastoma and odontogenic keratocysts as well as other lesions.
Shokri A et al.	2017	CBCT	CBCT can clearly visualise the borders and internal structures, cortical expansion, and effect of lesion on adjacent tissues; thus, its use is recommended.
Li D et al.	2018	CBCT	The rotated three-dimensional CBCT images clearly display the exact size, location, and borders of the tumour, as well as the internal changes in the tumour in the jaw cyst and the adjacent tissues. Therefore, CBCT aids clinicians in evaluating lesions and developing better treatment plans.
Surenthar M et al.	2021	CBCT	CBCT plays a crucial role in addressing the diagnostic challenges faced and separating it from other cystic lesions.
Luo J et al.	2014	CBCT	CBCT can provide more information for preoperative radiologic assessment of desmoplastic ameloblastoma compared with PR.
Meng Y et al.	2018	Spiral CT and CBCT	Ameloblastoma, odontogenic keratocyst, and dentigerous cyst are common benign lesions of the maxilla, and the three-dimensional imaging information provided by spiral CT and CBCT facilitates their diagnosis and differential diagnosis.
Saati S et al.	2017	CBCT	CBCT may be beneficial for dentomaxillofacial imaging considering the low radiation dose and high resolution.
Kawai T et al.	1998	CT and MRI	MRI is the optimal method for displaying tumours. MRI is crucial for determining the exact degree of advanced maxillary ameloblastoma.
Heffez L et al.	1988	MRI	MRI is superior to CT in evaluating recurrent diseases as it can distinguish tissues based on their proton composition
Cassetta M et al.	2014	MRI	The acquisition sequence enables us to emphasise the diagnostic efficacy of MRI in characterising the morphology and structure of maxillofacial lesions, and demonstrates the importance of this imaging method as an additional technique to CT in maxillofacial surgery planning, thereby reducing the risk of injury to the inferior alveolar nerve during surgery.
Gupta A et al.	2018	Fine – needle Aspiration Cytology (FNAC)	FNAC is a simple, rapid, accurate, inexpensive, and minimally invasive procedure for the diagnosis of ameloblastoma.
Günhan O et al.	1989	FNAC	A case of ameloblastoma diagnosed preoperatively as ‘benign tumoural lesion, suggestive of ameloblastoma' using FNAC has been presented.
Uçok O et al.	2005	FNAC	FNAC is used more commonly for the diagnosis of intraosseous and soft tissue lesions in the oral and maxillofacial regions to obtain sufficient material. It is convenient, inexpensive, and non-invasive.
Perić M et al.	2012	FNAC	Adequate sampling patterns and correct cytological and histopathological diagnosis are important factors for FNAC.
Thambi R et al.	2012	^Cytological	Ameloblastoma provides a good cell yield on aspiration and has distinct cytological features. It is almost as effective as histopathology in appropriate clinical and radiological setting.
Desai KM et al.	2023	FNAC	Careful evaluation of FNAC helps diagnose ameloblastoma and must be considered a vital diagnostic tool.
Reid-Nicholson M et al.	2009	FNAC	Although cytological examination is helpful in diagnosing ameloblastoma, it is not helpful in distinguishing conventional ameloblastoma from malignant ameloblastoma. sufficient sampling is necessary to distinguish conventional ameloblastoma from malignant ameloblastoma.
Hallikeri K et al.	2021	FNAC	Compared with FNAC, cell block technology better preserves the structural patterns and morphology of cells.
Zaidi A et al.	2021	FNAC	The cell blocks created from the aspirate can serve as small biopsies that facilitate accurate diagnosis of mandibular ameloblastoma. Moreover, they contribute to the appropriate treatment of the tumour.
Renapurkar SK et al.	2022	Incisional Biopsies	The findings of incision biopsy is not always consistent with the final diagnosis. The possibility of sampling errors should be considered during biopsy.
Chen S et al.	2016	Incisional Biopsy	The diagnosis of incisional oral biopsy was consistent with the final pathological results in 88.9% of cases. Multiple-site biopsy and larger volume samples facilitate more accurate diagnosis.
Perry KS et al.	2015	Incisional Biopsy	Incisional biopsy is an important first step.
Gliddon MJ et al.	2005	Incisional Biopsy and Endoscopy	Endoscopy may prove to be an important tool. This would especially be the case for large cysts that extend into areas that are difficult to inspect and sample through a standard ‘bony window' technique.
Hai HK et al.	1988	Incisional Biopsy	Regression of large ameloblastoma has been observed after performing a biopsy.
Lin Y et al.	2014	Incisional Biopsy and CT	CT-guided percutaneous transthoracic lung biopsy and lymph node biopsy are important methods for confirming metastatic ameloblastoma.
Fahradyan A et al.	2019	Incisional Biopsy	If the biopsy site of ameloblastic carcinoma is not removed from the malignant site, there will be a lack of evidence supporting the presence of a malignant tumour, leading to a lack of diagnosis.
Otsuru M et al.	2008	^18F-Fluorodeoxyglucose Positron Emission Tomography(^18F-FDG PET/CT)	GLUT-1 expression and FDG uptake may serve as indicators of the proliferation and recurrence of ameloblastoma
Nguyen BD et al.	2005	^18F-FDG PET/CT	^18F-FDG PET/CT aided in the early detection of asymptomatic thoracic spine dissemination, which was not conspicuous on CT examination
Niu N et al.	2013	^18F-FDG PET/CT	^18F-FDG PET/CT is an excellent tool for assessing different malignant processes. Multiple organ metastases from ameloblastoma can be detected using ^18F-FDG PET/CT

Table 2. Advanced imaging techniques and molecular techniques suitable for experimental use.

Study	Year	Study contents	Study results
Poedjiastoeti W et al.	2018	Convolutional Neural Network (CNN)	CNN can be used to distinguish ameloblastoma from odontogenic keratocyst. Its accuracy is comparable with that of manual diagnosis of oral and maxillofacial surgeons. CNN can screen for ameloblastoma and odontogenic keratocysts in a shorter period of time.
Yang H et al.	2020	CNN	Automatic detection convolution network aids in pathological detection and incidence rate prevention in the field of oral and maxillofacial surgery.
Kwon O et al.	2020	CNN	CNN can automatically diagnose odontogenic cysts and tumours of both jaws on PR using data augmentation with high sensitivity
Ariji Y et al.	2019	CNN	Radiolucent lesions of the mandible can be detected with high sensitivity using deep learning.
Lee A et al.	2021	Deep learning neural networks	The present algorithm is expected to be a useful tool for clinicians, as it can be used to diagnose Stafne bone cavity in PR to prevent unnecessary examinations for patients.
Liu Z et al.	2021	CNN	This algorithm improves the diagnostic accuracy of ameloblastoma and odontogenic keratocyst, thereby providing reliable recommendations before surgery.
Vanagundi R et al.	2020	Diffusion-weighted MRI	Addition of diffusion-weighted sequences to MRI jaw protocols can assist in the characterisation of odontogenic keratocyst, unicystic ameloblastoma, and dentigerous cyst.
Oda M et al.	2019	Texture Analysis	CT texture analysis can be used as a non-invasive method to obtain additional quantitative information to differentiate cystic and cystic-appearing odontogenic lesions of the jaw.
Chai ZK et al.	2021	CNN	CNN may provide assistance for clinical diagnosis, especially for inexperienced surgeons.
Yuan XP et al.	2008	Spiral CT	Multi-layer spiral CT can clarify the scope of jaw tumour and changes in the bone. It aids in the qualitative diagnosis and differential diagnosis of diseases. Moreover, it aids in the selection of appropriate treatment options.
Hayashi K et al.	2002	Dynamic Multi-slice Helical CT	Dynamic multi-slice Helical CT distinguishes ameloblastoma and odontogenic keratocyst based on the contrast enhancement values of intra-tumoural vascularities during the arterial phase.
Hisatomi M et al.	2011	Dynamic contrast-enhanced MRI (DCE-MRI)	CE-T1WI and DCE-MRI were helpful in the differential diagnosis of unilocular cystic-type ameloblastoma with homogeneously bright high signal intensity on T2WI or STIR
Hisatomi M et al.	2006	MRI and DCE-MRI	They retrospectively evaluated MRI and DCE-MRI of ameloblastoma.
Sumi M et al.	2008	Diffusion-Weighted MRI	ADC values can be used as an adjunct tool for differentiating ameloblastoma from odontogenic keratocysts.
Han Y et al.	2018	Diffusion-Weighted MRI	Diffusion weighted imaging (DWI) and ADC determination can be used as a tool to differentiate unicystic ameloblastoma from odontogenic keratocyst.
Asaumi J et al.	2005	Contrast-Enhanced MRI(CE-MRI)	CE-MRI is considered useful for diagnosing unicystic ameloblastoma, as only CE-MRI can detect thick enhancement of the tumour wall and small intraluminal nodules.
Gomes JPP et al.	2022	Texture Analysis	MRI texture analysis has the potential to differentiate ameloblastoma from odontogenic keratocyst. MRI texture analysis can be an additional tool to differentiate ameloblastoma from odontogenic keratocyst.
Sant'Ana MSP et al.	2021	BRAF p.V600E	BRAF V600E may aid in establishing the correct diagnosis in cases that microscopically resembling other odontogenic lesions
Pereira NB et al.	2016	BRAFV600E	BRAFV600E may aid in the differential diagnosis of unicystic ameloblastoma with dentigerous and radicular cyst, in conjunction with clinical, radiologic, and histopathological features.
Mendez LD et al.	2022	BRAF VE1	BRAF VE1 is an excellent tool for the diagnosis of mandibular ameloblastoma but of limited utility in the maxilla, where BRAF VE1 and BRAFV600E mutation occur less commonly
Duarte-Andrade FF	2019	BRAF V600E	BRAF-V600E may contribute to metabolic alterations in ameloblastoma. Metabolic alterations might play a role in tumour pathogenesis.
Joshi J et al.	2015	Immunohistochemical markers	Immunohistochemical markers play a very vital role in diagnosingcases
Coleman H et al.	2001	Calretinin	Calretinin appears to be a specific immuno-histochemical marker for neoplastic ameloblastic epithelium and it may be an important diagnostic aid in the differential diagnosis of cystic odontogenic lesions and ameloblastoma.
Kubota Y et al.	2001	Cytokine levels and gelatinase species of the intracystic fluids	Ameloblastoma can be aid in distinguishing it from odontogenic keratocysts by measuring the IL-1a and IL-6 levels, as well as the gelatinase species, in the fluids.
Lu L et al.	2009	Ultrasonography	Ultrasonography can be an effective auxiliary diagnostic method for mandibular ameloblastoma.
Shinohara EH et al.	2013	Ultrasonography	Ultrasonography is the preferred diagnostic tool for evaluating soft tissue lesions in the head and neck region
Beier M et al.	2020	Tomoelastography	Stiffness and fluidity measured by tomoelastography can sensitively detect the presence and extent of bone tumours and metastatic spread to cervical lymph nodes.
Delarue M et al.	2021	Medical infrared thermography (MIT)	MIT can monitor whether there is any diseased tissue passing through the resection edge at the end of the surgery to minimize the risk of recurrence.

Table 3. Advantages and disadvantages of various methods.

	Advantage	Disadvantage
Panoramic Radiography	Simple technique	Two-dimensional imaging
	Lower radiation dosage	Overlap of structures
	Wide inspection scope
	Low cost
Conventional computed tomography (CT)	Three-dimensional imaging	High cost
	Clearer anatomical structure	High radiation dose
	Provide more information	Technique is more difficult than panoramic radiography
		Poor resolution of soft tissue
Cone Beam Computed Tomography (CBCT)	Three-dimensional imaging	Cost and radiation dose are higher than those of panoramic radiography
	Higher spatial resolution.	Poor resolution of soft tissue
	Cost and radiation are lower than those of traditional computed tomography.
	Presents the boundaries, internal structure, and relationship with surrounding structures of the tumour
Spiral CT	Three-dimensional imaging	Low resolution in dental lesions
	Display lesions from multiple directions, such as cross-section	High cost and radiation dose
	High accuracy	The quality of multi-slice spiral CT for fine structures is lower than that of cone beam computed tomography
Conventional magnetic resonance imaging (MRI)	High soft-tissue resolution	High radiation and high cost
	Displays the internal and wall components of the solid cavity
	More suitable for recurrent tumours.
	Effectively images the soft tissue around the lesion, especially distinguishing the surrounding nerves
Diffusion-weighted MRI	ADC values provide valuable information for the differentiation of ameloblastoma
Dynamic contrast-enhanced MRI	Provide diagnostic features for single cyst ameloblastoma (Thick enhancement, intramural nodules)
Fine needle Aspiration Cytology (FNAC)	Simple, fast, safe, minimally invasive, and cost-effective	The sample size is small and sufficient material must be aspirated
	Patient comfort level is good	Requires the assistance of cytologists
	No special equipment required	The sensitivity and specificity of its diagnosis depend on the type of facility and the experience of the cytologists
	Safe for pregnant women, children, and other at-risk patients
Gene mutation	BRAF V600E mutation has certain specificity and frequency, and can be used as a supplementary diagnosis	BRAF V600E mutations are not detected in all patients with ameloblastoma, and this method requires laboratory personnel and special equipment
Biopsy	Appropriate organizational size and depth provide valuable information, which could aid in improving diagnostic consistency	Reliant on the professionalism of pathologists
		Sampling errors, insufficient tissue removal, and the presence of inflammation can affect diagnosis
Ultrasonography	Economical, non-invasive, easy to use, and provides real-time images	If the tumour is small or the cortical bone is not damaged, ultrasound cannot penetrate the bone tissue and can only detect the appearance of the bone tissue
	Can be used without contrast agents and is not subject to ionizing radiation
	Can also provide blood flow information to distinguish between cystic and solid lesions	Large tumours cannot be evaluated
^18F-Fluorodeoxyglucose Positron Emission Tomography (^18F-FDG PET/CT)	Can identify recurrence and metastasis of ameloblastoma
Tomoelastography	Can detect the presence, range, and neck lymph node metastasis of bone tumours, owing to its excellent mechanical parameters (stiffness and fluidity)
Medical Infrared Thermography	Non-invasive, non-ionising, real-time imaging, thermal imaging
	Effectively demonstrates the extension of lesions in soft tissue
Convolutional Neural Network	As a feature extractor, especially for two-dimensional images, it greatly improves diagnostic accuracy
Texture Analysis	Can be applied to computer tomography and magnetic resonance imaging
	As it is based on different texture features, it can differentiate lesions non-invasively and accelerate biopsy and treatment.
Markers	Can identify the levels of cytokines and gelatinase types in the cyst-fluid or the calretinin

Data availability statement

Data sharing is not applicable to this article as no new data were created or analysed in this study.