Author(s)

Hirotoshi Iwai^1*, Takehiro Suzuki², Tomoko Suzuki², Juri Muramori², Hiroyuki Seto², Mitsuko Nakayama², Tadahiko Utsunomiya², Masaaki Suemitsu², Kayo Kuyama², Satoshi Hirayama¹

¹Department of Operative Dentistry, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
²Department of Pathology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.

Background: With transitions in the disease concept of orthokeratinized odontogenic cyst (OOC), the pathogenesis and etiology have not been sufficiently elucidated. Objectives: OOC cases were reclassified and observed to understand the clinico-histopathological characteristics. In addition, literature review of OOC was performed to better organize the pathology. Materials and methods: Subjects with jawbone cysts lined by keratinized stratified squamous epithelium from 2005 to 2018 were reclassified, and clinico-histopathological findings were analyzed. Previous reports of OOC/orthokeratinized-type odontogenic keratocyst (OKC) from 1980 to 2019 were organized. Results: Five cases of OOC were diagnosed, representing 2.1% of odontogenic developmental cysts (total, 239 cases). Mean age was 37.6 years, with a female predominance. The mandibular molar area was the frequent site, and all cysts were solitary. Sixty percent involved an impacted tooth. Mean maximum diameter of the cyst was 2.2 cm. Histopathologically, 4 cases were unilocular, and partial palisading of the basal layer and scattered epithelial islands were observed in 2 cases each and formation of daughter cysts was noted in 3 cases. Previous papers described that most were unilocular and related to impacted teeth. Mean age ranged between 20 and 40 years, and the mandibular molar region was dominant. Recurrence rates were low. Conclusion: OOC shows a different biological attitude to OKC and is closer to dentigerous cyst. Meanwhile, OOC shows a similar histology of epidermoid cysts accompanying the granular layer. We thus surmised that OCC represents an independent concept as an odontogenic developmental cyst.

Orthokeratinized Odontogenic Cyst (OOC), Odontogenic Developmental Cyst, Literature Review

Iwai, H. , Suzuki, T. , Suzuki, T. , Muramori, J. , Seto, H. , Nakayama, M. , Utsunomiya, T. , Suemitsu, M. , Kuyama, K. and Hirayama, S. (2019) Histopathological Examination and Literature Review of Orthokeratinized Odontogenic Cyst. Open Journal of Stomatology, 9, 125-135. doi: 10.4236/ojst.2019.95013.