The shrine comprises a wooden case lined with bronze and decorated with gold, silver and amber fittings, and was built in two phases.

Its basic structure and the central ringed crosses on either side are 12th century, while the purse-shaped form and most of the metal work, including the saints, were added in the 1370s when the object was substantially refurbished.

According to this hagiography, Patrick began to lose his teeth late in life, and a number that fell out during his final travels across the west coast were collected by clerics and as corporal relics became the basis for new or renamed churches.

[7] In most tellings the local bishop, Bron in Ui Fiachrach, held onto the tooth and much later commissioned a wooden case to protect it from loss or damage.

[8][6] The linen insert on the lower part of the front once contained a fragment of cloth and is usually assumed to have been the container for the relic,[9][10] The shrine is roughly shaped like a tooth, modified to also resemble a burse (a bag and purse combination), crest or shield, with a flat horizontal top and crest.

[11] Its form is unique in medieval art; its closest counterpart is a satchel worn on the neck of a figure on the Cross of Scriptures at Clonmacnoise, County Offaly.

[1] It is constructed from a wooden case decorated with attachments in bronze, gilt-silver, gold filigree, rock crystal, amber and glass.

[13][9] During the late 14th-century refurbishment, the top was lined with an openwork crest, containing a series of bas-relief (with a shallow depth) figures, filigree decorations, friezes of animals, and tracery of Gothic windows.

[15] The dating of the second phase is based on the Latin inscription that records the object was decorated for Thomas de Bermingham (d. 1376), the 6th Lord of Athenry, and his wife Isabel.

[22] The harpist —who may be either male or female— is usually described as the most noteworthy of the figures, given that it is, along with the 11th century Breac Maodhóg, one of the earliest depictions of a Celtic harp.

[23] The instrument is triangular with a carved fore-pillar (the column joining the neck and soundbox), and held in place between the knees and left shoulder.

According to the surgeon and antiquarian[24] William Wilde, Prendergast collected a number of early medieval relics, including the tooth and Cross of Cong.