The expression of cytokeratin in keratocystic odontogenic tumor, orthokeratinized odontogenic cyst, dentigerous cyst, radicular cyst and dermoid cyst.

The epithelial lining of odontogenic keratocysts exhibits either parakeratosis or orthokeratosis. In 2005, the WHO classified odontogenic keratocysts with parakeratosis as keratocystic odontogenic tumors (KCOT). Odontogenic keratocysts with orthokeratosis were not classified as odontogenic tumors, but instead referred to as orthokeratinized odontogenic cysts (OOC). To clarify the difference between these two lesions, we investigated their biological characteristics using immunohistochemical studies for cytokeratins (CK) in KCOT and OOC as well as in dentigerous cysts (DC), radicular cysts (RC) and dermoid cysts (DMC). We examined twenty-five cases of KCOT, fifteen cases each of OOC, DC and RC, and ten cases of DMC. We studied the immunohistochemical expression of CK10, 13, 17 and 19. To evaluate the immunohistochemical staining pattern, we divided the epithelial lining of the lesions into three layers (surface layer: su, spinous layer: sp, basal layer: ba). For CK10, most OOC and DMC specimens of su and sp were positive. For CK13 and 19, most KCOT, DC and RC specimens of su and sp were positive. For CK17, most KCOT specimens of su and sp were positive. The percentages of total CK expression of su and sp, and ba of CK19 differed significantly between the lesions (P < 0.001). These results support the hypothesis that OOC originate from not the odontogenic apparatus, but the oral epithelial component.

Evaluation of mandibular condylar movement exercise for patients with internal derangement of the temporomandibular joint on initial presentation.

The aim of the present study was to evaluate mandibular condylar movement in a group of Japanese women who presented with closed lock of the temporomandibular joint. A total of 148 women aged between 19 and 75 years were included in the study. We examined mouth-opening, protrusion, and lateral excursive movements, and divided the patients into two groups (74 experimental cases and 74 controls). The experimental group was treated with exercises of the mandibular condyle, and the median (range) maximum mouth-opening increased from 27 (range 11-34)mm to 38 (24-47)mm. In control cases, it increased from 29 (range 20-35)mm to 30 (20-39)mm without exercise. In the experimental group, the median (range) maximum lateral movement on the opposite (unaffected) side increased from 8 (3-12)mm to 9 (5-13)mm. In the control group it remained similar at 7 (3-12)mm and 7 (3-12)mm. In the experimental group, the median (range) lateral movement on the affected side increased from 6 (2-13)mm to 8 (3-13)mm. In controls it remained similar at 6 (2-12)mm and 6 (2-12)mm. In the experimental group, the median (range) maximum protrusion increased from 6 (3-12)mm to 7 (4-12)mm, and in the control group from 6 (2-10)mm to 7 (2-10)mm. There was a significant difference between the experimental (50/74, 68%) and control groups (3/74, 4%) in the degree of increased mouth-opening. Exercise of the first mandibular condylar seems to be useful in the treatment of closed lock on initial treatment.