The odontogenic keratocyst (OKC) was originally classified as a developmental cyst, and OKCs were histologically divided into orthokeratotic (O-OKCs) and parakeratotic (P-OKCs) types. Clinical features differ between O-OKCs and P-OKCs with P-OKCs having a tendency to recur after surgical treatment. According to the revised histopathological classification of odontogenic tumors by the World Health Organization (2005) , the term keratocystic odontogenic tumor (KCOT) has been adopted to describe P-OKCs. In this retrospective study, we examined 186 KCOTs treated at the Maxillofacial Surgery Department of the Tokyo Medical and Dental University Hospital from 1981 through 2005. The patients ranged in age from 7 to 85 years (mean, 32.7) and consisted of 93 males and 93 females. The most frequently treated areas were the mandibular molar region and ramus. The majority of KCOTs in the maxillary region were treated by enucleation and primary closure. The majority of KCOTs in the mandibular region were enucleated, and the wound was left open. Marginal resection was performed in the 4 patients with large lesions arising in the mandible. In patients who were followed for more than a year, recurrences were observed in 19 of 120 lesions (15.8%) . The recurrences were found at the margins of the primary lesion in contact with the roots of the teeth or at the upper margins of the mandibular ramus. Clinicians should consider aggressive treatment for KCOTs because the recurrence rate of P-OKCs is higher than that of other cyst types such as O-OKCs, dentigerous cysts, primordial cysts that were non-keratinized, and slightly keratinized stratified squamous epithelium. Although more aggressive treatment is needed for KCOTs as compared to other cystic lesions, it is difficult to make a precise diagnosis preoperatively on the basis of clinical features and X-ray imaging. Therefore, preoperative biopsy is necessary for selecting the appropriate treatment for patients with cystic lesions.
Biopsy ; Dentigerous Cyst ; Epithelium ; Female ; Humans ; Keratins ; Male ; Mandible ; Molar ; Odontogenic Cysts ; Odontogenic Tumors ; Recurrence ; Retrospective Studies ; Surgery, Oral ; Tokyo ; Tooth ; World Health Organization

Regional cooperation in palliative medicine involves multidisciplinary team care. It is very important for cancer patients to choose an appropriate place of stay during their end-of-life period. As the Nagoya Memorial Hospital does not have a palliative care ward, collaborating with other facilities offering palliative care and home care becomes pivotal. Therefore the Higashi-Nagoya home care social gathering was organized to improve communication and cooperation among regional health care professionals. Through discussions during this social gathering, the communication tools for cooperation in palliative care were outlined in November, 2015. We reviewed the outcome of 35 patients referred from our hospital using the communication tools for cooperation in palliative care: 25 patients were referred to chronic care hospitals including palliative care facilities, and 10 patients received palliative care at home; 23 died in the palliative care ward, 6 died at home, and 4 died at our hospital. A questionnaire survey conducted among the community health care professionals revealed that the introduction of this tool would be useful in providing accurate information on the prognosis of patients, level of understanding between the patients and their family, and patients’ views on life and death. Using the communication tool for communication would contribute to realizing seamless palliative care in the region surrounding our hospital, which would in turn lead to local team work and shared responsibilities to provide optimal palliative care.