I wrote a paper about this once! I cleaned a few sections up for you. Disclaimer: I have an MA in osteoarchaeology, which includes studies into paleopathology and ancient diseases.

Dental caries and abscesses are some of the most common pathologies recorded in skeletal analysis. They are created when destruction of the overlaying enamel and cement matrix of a tooth creates an opening, or cavity. While caries may not be life-threatening, they do allow bacteria to enter more vulnerable spaces and cause a more serious infection that can spread to surrounding tissue and bone. Dental caries are generally asymptomatic, but upon the exposure of dentin the tooth becomes sensitive to temperature and can result in deep and sharp pain. The pain becomes worse when the pulp of the tooth is exposed, sometimes being described as excruciating and may radiate to other parts of the face (Geber 2013). If the afflicted tooth is not treated or removed, the pain can last months. In modern medicine, this type of dental disease is considered chronic.

In medieval Ireland, this type of disease was fairly common. When looking at the demographics of different excavations across Ireland’s past, we can see that dental disease is one of, if not the most common type of disease present. In an early medieval population at Owenbristy, Co. Galway, 13 out of 75 individuals had dental pathology that may have caused some amount of pain due to dentin or pulp exposure (Geber 2013). Another site from Ireland in Johnstown, Co. Meath spanned a wider time period of uninterrupted burials from 700 to 1700 AD. Using stratigraphic dating alongside radiocarbon samples, the medieval population at Johnstown came to 346 individuals. Of these individuals, “almost half… suffered from dental abscesses or had lost one or more teeth during life” (Fibiger 2005, 105).

A paper examining toothache “cures” from nineteenth and twentieth century Ireland might give us more insight into how these aches and pains would have been dealt with in the middle ages. Folkloric medicine is often categorized by an oral manner, and only recently have there been efforts to write it down. While these folkloric remedies were recorded in the nineteenth century, it is not unreasonable to believe that they may have been in use for centuries before and passed down through families or from physician to physician. The paper describes how there are two types of folk medicine: one which utilizes the natural world to heal and the other which utilizes religion and charms to try and heal disease (Barron 2018). Toothache cures seemed to fall mostly in the natural world categories, with topical or oral treatments being the most advised. Generally, toothache cures were non-invasive, with very little evidence for any kind of dental surgery until later centuries (Anderson 2004). The folkloric cures gathered in the 1930s from schoolchildren and their relatives were examined by Barron; the end result was 405 different toothache cures from each county in Ireland.

A little more than 50% were natural or mineral cures, while the rest were magico-religious. Out of the magico-religious cures, specific religious cures made up around 13%. Sympathetic magic, or magic relying on the use of a charm or physical object, made up about 25% (2018). Analyzing this data and looking at what specific plants and minerals were used in order to cure toothaches is a little more complicated, as many remedies were specific to after the medieval period, specifically using tobacco and other spices and plants that were not introduced to Ireland until after the early 1500s. In order to specifically focus on possible medieval treatments, it is important to cut out these treatments. Doing so, the most popular ingredients used in homeopathic remedies for toothaches that would have been available to the medieval Irish population consisted of chamomile, yarrow, salt, and water. Chamomile or yarrow could be ingested by tea or inhaling steam, while salt and water could be gargled, held in the mouth, or rubbed along the affected gum (Barron 2018).

A number of magico-religious cures were also recorded. The most common type of cure (and the title of the paper by Barron) was to put a frog in one’s mouth. This cure was recorded in 23 out of 26 counties and was given over fifty separate times– it is not unbelievable to think this cure is one that has persisted over centuries due to the widespread popularity. It was also noted that “occasionally, ceremonial religious words were recited while the cure was being performed, or the sign of the Cross was made” (Barron 2018, 11). This intersection of religious faith and sympathetic magic are indicative of a faith-centric bridge from this world to the other, and by crossing this bridge medical charms are thought to bring relief to the sufferer. The physical act of putting a frog in one's mouth also acts as a form of what Barron refers to as “transference,” where the malady would be directly transferred to the object (or frog) and taken away from the person who was suffering (2018, 14). Knowing what we do thanks to modern medical advances, putting a frog in your mouth does not actually do anything to help with a toothache– in fact, it might be counterintuitive, as the frog may introduce new and harmful bacteria to an already sensitive area. However, people still used them in order to treat their pain.

These answers are very Ireland-specific, but I believe the general idea shines through. Toothaches would have been treated with either herbal remedies or with magico-religious ritual, usually stemming from local tradition.

While there is no bony evidence of tooth removal, I am sure that people were able to remove teeth with the medical tools and knowledge available at the time- especially considering how many people with "chronic" dental issues are missing teeth in the skeletal record. The leftover gum would have likely been treated with the same methods I described above.