Читать книгу Shear's Cysts of the Oral and Maxillofacial Regions - Paul M. Speight - Страница 66

The mean age of presentation of inflammatory collateral cysts correlates well with the chronological stage of eruption, with lesions most often presenting a few years after the eruption of the associated tooth. The mandibular buccal bifurcation cyst presents in children, but the mean age of presentation depends on the tooth affected (Table 4.3). Lesions on first molars are found at a mean age of about 8 years, with most studies showing a narrow range between 5 and 11 years. Cysts on second molars are found at a mean age of about 13 years. In their review of more than 40 papers, Philipsen et al. (2004 ) found limited demographic data, but showed a wider age range than suggested in the literature. The age range for lesions on first molars and second molars was reported as 5–47 years and 10–40 years, respectively. However, careful reading of their paper shows that there was only one first molar cyst in a patient over 11 years (a male age 47) and this was from their own files. They also found only three cases over the age of 16 on second molars, and two of these were from their own files.

Philipsen et al. (2004 ) also suggested that the ages differ for males and females, with males affected slightly later. They showed that lesions on the first molar affect individuals with a mean age at presentation of 9.0 years for males (range 5–47; n = 24) and 8.1 years for females (range 6–11; n = 12). Lesions on the second molar presented with mean ages of 19.8 years for males (range 10–40; n = 8) and 13.6 years for females (range 12–16; n = 5). These differences were not shown to be significant and the higher mean age in males is almost certainly due to outlying single cases at an older age. Nevertheless, the data show that occasional cysts may persist undetected into later adulthood.

Paradental cysts on third molars present in an older age group (Table 4.2). The mean age of presentation is about 28 years and all studies show a peak in the third decade. Two‐thirds (66.7%) of the cases in Craig's (1976 ) series arose in the third decade. In the study by Ackermann et al. (1987 ), 48 of the 50 cysts occurred between the ages of 10 years and 39 years, with 34 cases (68%) in the third decade. There was only one case in the fifth decade and one patient aged 62 years. Five of the six cases in the study of Fowler and Brannon (1989 ) affected patients in the third decade. In their review of the world literature, Philipsen et al. (2004 ) reported similar age distributions with a peak in the third decade (38% of cases) and a mean age of 27.6 years. The age range of lesions associated with third molars is wide, overall ranging from 11 to 74 years (Table 4.2), again suggesting that occasional lesions may remain undetected and symptomless for long periods.

Inflammatory collateral cysts arising at other sites also reflect the age of eruption of the associated teeth: the four premolar cases reported by Morimoto et al. (2004 ) presented at ages 9 or 10 years, and 7 of the 8 cases reported in the globulomaxillary region were found between the ages of 10 and 19 years (Vedtofte and Holmstrup 1989 ).