Instrumentation of curved root canals: a comparison study.

Flex-R, Flex-O, and K-Flex files were compared using a circumferential filing technique on 30 extracted human molars. The buccal canals of maxillary molars and mesial canals of mandibular molars were utilized. The minimal initial curvature was 18 degrees. Canal curvature was measured before and after filing, and changes were analyzed statistically. Analysis showed that, no matter which of the instruments was used, the angle of curvature was maintained with a high degree of accuracy.

Cancrum oris--a 35-year retrospective study.

OBJECTIVES: To determine the factors predisposing to cancrum oris and its frequency, clinical features, treatment and outcome. Cancrum oris is a gangrenous condition of the face usually occurring in poorly nourished children in a Third-World setting. DESIGN: Retrospective review of clinical data on children with cancrum oris. SETTING: All children with cancrum oris seen over a 35-year period, from 1960 to 1995, at Red Cross War Memorial Children's Hospital (RXH) in Cape Town. SUBJECTS: Twenty-six patients (16 female and 10 male) with cancrum oris. Their average age at presentation was 4 years and 4 months (range 1-15 years). RESULTS: The peak incidence was between 1971 and 1975 (11 cases); subsequently only 1 new case was seen at RXH in every 5-year period. Most children were referred from rural areas. Associated conditions could only be determined in 11 of the 26 patients. In order of frequency, these were malnutrition, gastro-enteritis, measles and anaemia. Twenty-three of the 26 children had soft-tissue involvement affecting the lips, cheek, chin, nose or other structures. Eighteen had bony or cartilaginous involvement; the maxilla was affected in 15, the palate in 7, the vomer in 5, the mandible in 3 and the nasal septum in 7. Three children had bony involvement only, the soft tissues being spared. Operative records were available for 18 children. These 18 children had a total of 84 operations, with an average of 4.7 per child (range 0-12). CONCLUSIONS: Cancrum oris is a devastating condition affecting malnourished children. Reconstruction is complex and demanding, involving both soft tissue (23 of 26 cases) and bone (18 of 26 cases). Most children require multiple procedures. Prevention is best effected by comprehensive primary health care.

The role of suprahyoid block dissection in carcinoma of the floor of the mouth.

The efficacy of suprahyoid block dissection combined with radiotherapy, in the management of neck nodal disease was evaluated in 15 patients with carcinoma of the floor of mouth (abutting on the mandible) between 1983 and 1989. Ten males and 5 females had a mean age of 60.3 years. Suprahyoid block dissection was performed in 10 patients as initial treatment. Nine of these presented with a submandibular mass and one patient with a T4NO lesion had a prophylactic block performed. Suprahyoid block dissection was performed in five patients who developed a submandibular mass after completion of surgery and radiotherapy. Wound sepsis occurred in three patients, but resolved with conservative treatment. Clinical assessment of the suprahyoid mass was accurate in 65% of patients. Nodal recurrence occurred in one patient. Seven patients are alive and disease free after a mean of 64.5 months. Two other patients are alive, one with lung metastases, and one with a supraclavicular mass. Six patients have died, two of whom developed local recurrence, one who developed a supraclavicular mass, one after nodal recurrence, one with lung metastases, and one of an unrelated cause. Suprahyoid block dissection combined with radiotherapy is effective treatment for nodal control of patients with carcinoma of the floor of mouth. This procedure is associated with a low morbidity.