a Frequency as a proportion of inflammatory collateral cysts.
b Frequency as a proportion of all odontogenic cysts.
Table 4.1 Selected papers, with a wide geographical distribution, showing the frequency of inflammatory collateral cysts as a proportion of total odontogenic cysts. Based on Philipsen et al. (2004).
| Country | n | ICC (%) | |
|---|---|---|---|
| Data from references in Table 1.3 | |||
| Meningaud et al. (2006 ) | France | 695 | 0 |
| Tortorici et al. (2008 ) | Italy (Sicily) | 1273 | 0 |
| Ali (2011 ) | Kuwait | 196 | 0 |
| Ramachandra et al. (2011 ) | India | 252 | 0 |
| Manor et al. (2012 ) | Israel | 285 | 0 |
| Bhat et al. (2019 ) | India | 125 | 0 |
| Soluk Tekkeşin et al. (2012b ) | Turkey | 5003 | 0.2 |
| Daley et al. (1994 ) | Canada | 6847 | 0.5 |
| Grossmann et al. (2007 ) | Brazil | 2812 | 0.7 |
| Tamiolakis et al. (2019 ) | Greece | 5165 | 1.1 |
| Mosqueda‐Taylor et al. (2002 ) | Mexico | 856 | 1.4 |
| Aquilanti et al. (2021 ) | Italy | 2150 | 1.5 |
| Sharifian and Khalili (2011 ) | Iran | 1227 | 1.8 |
| Ochsenius et al. (2007 ) | Chile | 2944 | 3.8 |
| Jones et al. (2006 ) | UK | 7121 | 5.6 |
| Kammer et al. (2020 ) | Brazil | 406 | 13.6 |
| Data from references in Table 4.2 | |||
| Ackermann et al. (1989) | South Africa | 1852 | 3.0 |
| Craig (1976 ) | UK | 1051 | 4.7 |
| De Sousa et al. (2001 ) | Brazil | 1256 | 4.3 |
ICC, inflammatory collateral cysts; n, total number of odontogenic cysts in each study.
Few studies have determined separately the frequencies of paradental cysts and mandibular buccal bifurcation cysts. Tamiolakis et al. (2019 ) reviewed 5165 odontogenic cysts and found only 57 (1.1%) inflammatory collateral cysts. Of these, 53 were paradental cysts on third molars and only 4 were mandibular buccal bifurcation cysts in children, suggesting frequencies of 1.0% and 0.1%, respectively. Jones et al. (2006 ) used the term paradental cyst to encompass both types of inflammatory collateral cyst, but found only 15 cases in their paediatric population (patients ≤16 years), representing 2.7% of odontogenic cysts in children (n = 553) and only 0.2% of all odontogenic cysts (n = 7121). Paradental cysts in adults comprised 376 cases, representing 5.2% of odontogenic cysts. These data suggest that paradental cysts are about 10–20 times more common than mandibular buccal bifurcation cysts.
Overall, the data from these studies (Table 4.1) suggest that inflammatory collateral cysts represent about 4% of odontogenic cysts. It is probable, however, that they are under‐reported, because many cases received within pathology departments may have insufficient clinical or radiological information to establish the diagnosis and many may have been diagnosed as inflamed dentigerous cysts, pericoronitis, or inflamed follicles. In departments where the diagnosis is made on a regular basis, the paradental cyst appears to be a common lesion. In the series of Colgan et al. (2002 ), paradental cysts comprised 15 of 60 (25%) cystic lesions associated with lower third molars. This was the second most common diagnosis after dentigerous cyst (30%).
In an analysis of pericoronal tissues from extracted third molars, Costa et al. (2014 ) found that 73.5% (83 of 113) showed pathological changes and of these, 55 (66.2%) were diagnosed as paradental cysts and 21 (25.3%) as dentigerous cysts. It should be noted, however, that the majority of lesions were associated with erupted or partially erupted teeth (85.5%), and only seven teeth were unerupted, suggesting that a number of dentigerous cysts were diagnosed in association with partially erupted impacted third molars. Mohammed et al. (2019 ) undertook a similar