Corrupted incorruptible saints according to Catholicism?
Why does the Catholic Church promote the bodies of certain individuals as "incorruptibles" when their bodies have clearly corrupted?
Do you have any examples to support your statement?
If a body shows signs of corruption, the Church would not hold it to be incorruptible. That is basic evidence, the Church can not ignore.
As for your question about Padre Pio’s face, his face was covered with a lifelike silicone mask in order to help the skin from getting damaged from sunlight and from individuals cleaning the face for public viewing. This type of thing has happened to the face of St. Bernadette.
Not every saint is expected to have an incorruptible corpse. Although incorruptibility is recognized as supernatural, it is no longer counted as a miracle in the recognition of a saint (The Incorruptibles).
Embalmed bodies were not recognized as incorruptibles. For example, although the body of Pope John XXIII remained in a remarkably intact state after its exhumation, Church officials remarked that the body had been embalmed and additionally there was a lack of oxygen in his sealed triple coffin.
Incorruptibility is seen as distinct from the good preservation of a body, or from mummification. Incorruptible bodies are often said to have the odour of sanctity, exuding a sweet or floral, pleasant aroma.
Incorruptibilty is not reserved to the Catholic Church alone. There are a number of Orthodox Saints who have incorrupt bodies.
Nowadays the Catholic Church is striving to better understand why some Saints are preserved from corruption, thus seeing if the preservation is indeed miraculous or not. "These saints are in a class by themselves. Even though incorruptibility does not automatically confer sainthood upon the subject, it is still properly appreciated by the Church as a supernatural occurrences. The Church thus seeks the help of scientists and other professional to understand this question in a more modern light!
The lack of formal explanations on this subject seems to stem from the fact that this is an area of expertise for the scientific (professional) community and not the Church to investigate.
"Over the last 15 years, however, a new view of the Incorruptibles has begun to emerge. At the Vatican's request, Italian pathologists, chemists, and radiologists have been poring over the bodies of the ancient men and women interred in church reliquaries. Charged with gleaning new information about the lives of the saints and assisting in the conservation of sacred remains, they have also brought science to the altars of Europe's cathedrals. Already, they have examined more than two dozen saints and beati, shedding light on the mystery of their preservation. While some saints were clearly mummified by their devout followers, others were protected from decay by environmental conditions, raising new questions about incorruptibility. "What is a miracle?" asks Ezio Fulcheri, a pathologist at the University of Genoa and one of the leading researchers on the Incorruptibles. "It's something unexplainable, a special event that may occur in different ways." The causes may seem mysterious "but don't exclude [rare] natural processes that are different from the normal course of things." - The Incorruptibles.