are frequently discovered during routine dental radiographic examination. They vary in radiographic appearance. When they are of the monocystic type the prognosis is always better than when they have many compartments. Sometimes these lesions appear as radiolucent areas with dividing radiopaque septa, while ot,hers show both radiopaque and radiolucent areas of varying density. The following is an analysis of casesreported in the literature’ : Cases 1,036 Total number reported Sex (987 cases) <514 Male (52 per cent) 473 Female (48 per cent) Race (594 cases) 371 Caucasian 121. Negro 7s Chinese 15 Egyptian 15 Indian 1 Filipino 858 38.9 years Average age at time of rcport-708 5.8 years Average duration of tumor 621. Average age at time of discovery-32.7 years Site of growth (925 cases) 752 Mandible (81 per cent) 173 Maxilla (19 per cent) Structural characteristics (465 cases) 365 Cystic, including those called cystic and solid (78 per cent) 100 Solid (22 per cent) Location (mandible) 170 Molar and ramus area (70 per cent) 49 Premolar area (20 per cent) 27 Symphysis area (10 per cent) Location (maxilla) Molar area (47 per cent) ?: Antrum and floor of nose (33 per cent) 4 Premolar area (9 per cent) 4 Canine area (9 per cent,) 1 Palate (2 per cent) MELOBLASTOMAS
This Division
of
article the
was written while the American Cancer Society
author at
was Roswell
on
a fellowship Park Memorial
from the Institute.
New York Buffalo,
State N. Y.
Volume 16 Number 9
STATISTICAL
ANALYSIS
Duration of tumor 0 to 11 months 1 years 2 years 3 years 4 years 5 years 6 years 7 years 8 years 9 to 15 years 16 to 50 years Another study2 has given the following
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AMELOBLASTOMA
results :
Cases 379 Total number of cases Sex (311 cases) 142 Male (45 per cent) 169 Female (34.3 per cent) 248 Average age at time of report------u ‘?‘7.6 years 232 8.5 years Average duration of tumor 222 30.1 years Average age at time of discoverySite of growth (295 cases) 247 Mandible (83.7 per cent) 48 Maxilla (16.3 per cent) Structural characteristics (219 cases) 124 Cystic (57.5 per cent) 53 Cystic and solid (24.2 per cent) 42 Solid (19.1 per cent) It is obvious that there are similarities between these two sets of data. The main incidence is in the mandibular molar areas of men approximately 38.3 years of age. REFERENCES
1. Small,
I. A., and Waldron, C. A.: ORAL PATII. 8: 281, 1951. 2. Robinson, H. B. G.: Ameloblastoma; Path. 23: 831, 1937. 1501