The keratocystic odontogenic tumour is classified as a developmental cyst derived from the enamel organ or from the dental lamina. The treatment of keratocystic odontogenic tumour of the jaw remains controversial. The aim of this study was to report the outcome of our conservative treatment protocol for keratocystic odontogenic tumour.
Three patients with different complaints referred to Oral and Maxillofacial Surgery Clinic, Faculty of Dentistry, Selçuk University. Initial biopsy was carried out in all patients and keratocystic odontogenic tumours was diagnosed subsequent to histopathological examination. The patients with keratocystic odontogenic tumours were treated by enucleation followed by open packing. This conservative treatment protocol was selected because of existing young aged patients. The average follow-up duration of the cases was 2 years.
Out of 3 cases, 2 lesions were present in mandible and 1 lesion in maxilla. There was no evidence of recurrence during follow-up. All the cases were monitored continuously with panoramic radiographs, computed tomography and clinical evaluations.
This conservative treatment protocol for keratocystic odontogenic tumours, based on enucleation followed by open packing would be a possible choice with a view of offering low recurrence rate and low morbidity rate particularly in young patients.
The odontogenic keratocyst (OKC) is classified as a developmental cyst derived
from the enamel organ or from the dental lamina [
Treatment of KCOTs remains a controversial subject [
In this present study, 3 cases of keratocystic odontogenic tumour that were treated with enucleation followed by open packing through an intraoral approach and 2 year follow-up period will be presented.
A 26 year old female was referred to Selcuk University, Faculty of Dentistry, Oral and Maxillofacial Surgery Clinic, for the evaluation of swelling and pain located at the posterior body and ascending ramus of the right mandible.
The patient's medical history was unremarkable. In the clinical examination, there was no facial asymmetry. Intraorally, mild swelling was noticed on the right mandibular molar area. The overlying mucosa appeared normal on colour and texture. There was no lympadenopathy.
The patient was evaluated radiographically by panoramic radiography and computed
tomography (CT) imaging. The imaging revealed a multilocular lucency extending from
the neck of the condyle to right canine tooth (
Preoperative panoramic radiograph shows the multilocular lucency extending from the neck of condyle to the right canine tooth (Case 1).
Preoperative computed tomography scan axial image shows the multilocular lucency extending from the neck of condyle to the right canine tooth (Case 1).
Fine needle aspiration yielded yellowish material. Tissue was obtained from the
lesion and submitted for histopathology examination. Microscopic examination revealed
epithelial lining of parakeratinized stratified squamous epithelium. The basal layer
of the epithelium was composed of hyalinised fibrous connective tissue. The basal
cells were either cuboidal or columnar and the basal cell nuclei were hyperchromatic
and arranged in a "picket fence" configuration. The fibrous connective tissue wall
contained sparse chronic inflammatory cells which were composed of lymphocyte and
plasma cells. On the basis of these findings, a diagnosis of a KCOT was made (
Histopathologic view of the lesion shows the basal layer of the epithelium composed of hyalinised fibrous connective tissue (hematoxylin and eosin stain, original magnification x100) (Case 1).
Due to the size of the lesion it was decided to treat it with enucleation followed by open packing. Under local anaesthesia, an incision extending from the mandibular ramus distal to the second molar was carried anteriorly around the crevices of the anteriomandibular teeth and a full thickness mucoperiosteal flap was raised. The cystic cavity was curetted from molar area to the neck of the condyle. The resulting cavity was packed with iodoform gauze impregnated with bacitracin ointment. The packing was replaced during the recall visits biweekly for six months following the initial surgery.
The patient was reviewed radiologically every three months during follow-up period.
At the end of 2 years follow-up period, no evidence of recurrence was noticed (
Computed tomography scan axial image at the end of 2 year follow-up period shows no signs of the recurrence (Case 1).
Panoramic radiograph at the end of 2 year follow-up period shows no signs of the recurrence (Case 1).
A 14 year old female patient presented with complaint of a gradually swelling
extending from the right maxillary canine to molar region. The swelling was slightly
painful; it was first noticed about 5 months previously. The patient's medical history
was unremarkable. Clinical examination revealed a buccal spherical and fluctuant
swelling involving the right lateral incisor, premolars and first molar region.
It was surfaced by normal oral mucosa. The maxillary right lateral incisor was displaced
by the lesion (
Preoperative intraoral view of the lesion shows a buccal spherical and fluctuant swelling involving the right lateral incisor, premolars and first molar region (Case 2).
Evaluation radiographically by panoramic view and CT imaging revealed an expansible
lesion extending from the primary canine tooth to the molar region and superiorly
to the floor of the orbit (
Preoperative computed tomography axial scan image shows an expansible lesion extending from the primary canine tooth to the third molar region and superiorly to the floor of the orbit (Case 2).
Preoperative panoramic radiograph shows an expansible lesion extending from the primary canine tooth to the third molar region and superiorly to the floor of the orbit (Case 2)
Fine needle aspiration yielded thick yellowish "cheesy" material. Biopsy was
taken from the lesion and was consistent with KCOT. Under local anaesthesia, the
impacted right canine tooth was extracted and the lesion was curetted (
Postoperative intraoral view of the patient (Case 2).
Photograph shows the totally excised lesion (Case 2).
Patient was seen for clinical and radiological evaluation regularly after treatment.
The bony cavity has healed clinically and radiographically approximately 16 months
after treatment (
Postoperative intraoral view of the patient shows no signs of the recurrence (Case 2).
Computed tomography scan axial image at the end of 2 year follow-up period shows no signs of the recurrence (Case 2).
Postoperative panoramic radiograph at the end of 2 year follow-up period shows no signs of the recurrence (Case 2).
A 29 year old man was referred to our clinic with a complaint of swelling and
pain from the mandible. Based on the history obtained from the patient, pain and
swelling were first noticed 3 years ago. He was evaluated by his general dentists
and then referred for treatment to our department. The radiographic examination
revealed a lesion involving the entire mandible from second molar on the right to
second molar on the left (
Preoperative panoramic radiograph shows a lesion involving the entire mandible from second molar on the right to second molar on the left (Case 3).
The incisional biopsy obtained by the general practitioner revealed presence of a KCOT.
His medical history was unremarkable. Extraoral examination revealed that there was a swelling and expansion at mandibular basis at both sides of the mandibular molar region. Radiologic examination revealed that the right mandibular canine tooth was impacted at the symphysis region, and there was a multilocular radiolucent cystic lesion related to this tooth.
A yellow serous liquid or semi-solid content was obtained as a fine needle aspiration material, matching the typical description of a cystic lesion. Biopsy was performed and impacted canine tooth was extracted at the same time. Biopsy result was KCOT.
Endodontic treatment was performed for all teeth related to a lesion. Enucleation
followed by open packing treatment was performed. After the operation, the resulting
bony cavity was packed with iodoform gauze impregnated with bacitracin ointment
which again was changed biweekly for the following six months. There was no sign
of recurrence at a postoperative 2 years period (
Panoramic radiograph at the end of 2 year follow-up period shows no signs of the recurrence (Case 3).
The KCOT is one of the most aggressive odontogenic tumours due to its relatively
high recurrence rate, its relatively fast growth, and its tendency to invade adjacent
tissues; it has even been reported to penetrate the skull base [
Y. Kubota et al. [
However, the most important evidence that KCOT is a neoplasm comes from genetic
studies demonstrating loss of heterozygosity of the tumour suppressor genes in KCOT
cases [
Grachtchouk et al. [
de Vicente et al. [
A review of the biological KCOT behavior of this recognized aggressive pathological
entity of the jaws and a contemporary outline of the molecular (growth factors,
p53, PCNA and Ki-67, bcl-2) and genetic (PTCH, SHH) alterations associated with
this odontogenic neoplasm, provides a better understanding of the mechanisms involved
in its development and strengthen the current concept that the KCOT should, indeed,
be regarded as a neoplasm. Furthermore, markers known to be rapidly induced in response
to growth factors, tumour promoters, cytokines, bacterial endotoxins, oncogenes,
hormones and shear stress, such as COX-2, may also shed a new light on biological
mechanisms involved in the development of these benign but sometimes aggressive
neoplasms of the jaws [
KCOT comprises approximately 11% of the all cysts of the jaws [
On the radiography KCOTs appear as well-defined radiolucencies, which can be
either unilocular or multilocular. Large unilocular KCOTs can be indistinguishable
from cystic ameloblastoma [
Microscopically KCOT is characterized by epithelial lining of parakeratinized
stratified squamous epithelium. The basal layer of the epithelium is composed of
hyalinised fibrous connective tissue. The basal cells are either cuboidal or columnar
and the basal cell nuclei are hyperchromatic and arranged in a "picket fence" configuration.
Furthermore, it has a corrugated parakeratinized luminal layer and a prominent basal
cell layer [
Treatment of KCOTs remains a controversial subject [
Resection offers a high cure rate, but produces significant morbidity such as
the loss of jaw continuity or facial disfigurement. It should, therefore be reserved
only for aggressive or recurrent lesions, or for the patients who cannot be closely
followed-up after conservative treatments [
The one technique used in the treatment of the KCOT, as described in the reports
of Brondum and Jensen [
Cytokeratin-10 expression by cystic epithelium has been shown in the suprabasilar
layers of odontogenic keratocyts. Cyst decompression and irrigation result in the
loss of keratinisation [
Currently, a total enucleation, with or without a "peripheral ostectomy" presents
the most common surgical procedures used to treat most of the KCOTs [
Enucleation of the KCOTs followed by open packing has been suggested as another
conservative method of surgical treatment [
Different views on the recommended duration of radiologic and clinical follow-up
are reported in the literature. According to Forssell [
Extraction of the teeth affected by the lesion, as well as a generous removal
of partially eroded bone and overlying soft tissues, may contribute to lower recurrence
rates. Bataineh and Al Qudah [
Enucleation followed by open packing can be suggested as a choice of conservative treatment with low recurrence rate for large keratocystic odontogenic tumours. However, due to the clinical behaviour of keratocystic odontogenic tumours, in case of possible risk of recurrence requirement for further operations should not be disregarded. Therefore, the patients should have control radiographic and clinical examinations for indefinite prognosis regardless of the treatment protocol.
The authors report no conflicts of interest related to this study.