Odontogenic keratocysts do not result in the same degree of bony expansion as dentigerous cysts and teeth resorption are less likely to be seen in association with odontogenic keratocysts. In addition, dentigerous cysts are more likely to have smooth periphery and odontogenic keratocysts are more likely to display a scalloped periphery. Unicystic ameloblastomaIt is the most common radiolucent, benign odontogenic tumor that may be unilocular or multilocular. It may result in expansion and destruction of the maxilla and mandible. It is not possible to differentiate unicystic ameloblastomas from dentigerous cysts with clinical and radiographic examinations. Histopathologic examination revealed that the basilar cells in unicystic ameloblastoma become columnar and demonstrate prominent nuclear hyperchromatism. The polarization of nuclei may be away from the basement membrane (reverse polarization). Besides, the superficial epithelial layers may become loosely arranged and resemble the stellate reticulum of the enamel organ. Pindborg tumorIt is a rare odontogenic tumor that is radiolucent with well-defined border and associated calcified radiopaque foci. Adenomatoid odontogenic tumorAdenomatoid odontogenic tumor also shows similar features as dentigerous cyst; however, the  differentiation is by the presence of intra-cystic radio-opaque structures. In younger patients, the periapical radiolucencies associated with deciduous teeth may mimic pericoronal radiolucencies of succedaneous permanent teeth and may result in a false impression of dentigerous cyst. A definitive diagnosis will not be made based on radiographs alone. The diagnosis can only be confirmed by histopathological examination. OdontomaIt is a lytic lesion that is frequently accompanied by amorphous calcification.
Mourshed showed that 33% of ameloblastomas arose from the epithelial lining of a dentigerous cyst. Although undeniably this can occur, the frequency of such neoplastic transformation is low. In addition, a squamous cell carcinoma may rarely arise in the lining of a dentigerous cyst. Transformation from normal epithelial cyst lining to SCC is due to chronic inflammation. It is likely that some intraosseous mucoepidermoid carcinomas develop from mucous cells in the lining of a dentigerous cyst. Malignancy in the cyst wall is usually unexpected at the time of presentation and the diagnosis is usually made following enucleation. Jagged or irregular margins with indentations and indistinct borders are considered to be suggestive of possible malignant change. Due to the potential for occurrence of an odontogenic keratocyst or the development of an ameloblastoma or, more rarely, mucoepidermoid carcinoma, all such lesions, when excised, should be submitted for histopathologic evaluation. Differential Diagnosis
The differential diagnoses of dentigerous cysts are as follows:

Radicular cystIt is an odontogenic cyst that is a sequela of periapical granuloma in a carious tooth. Odontogenic keratocyst(OKC)It is often multilocular and most commonly located in the body or the ramus of the mandible.Histologically, the epithelium is uniform in nature, usually four to eight cells in thickness. The basilar layer consists of a palisaded row of cuboidal to columnar cells that may demonstrate hyperchromatism. Characteristically, a corrugated or wavy layer of parakeratin is produced on the epithelial surface and desquamated keratin may be present in the cyst lumen.