There are 13 words that end with 'tonia'.
| atonia | boltonia | dystonia | 
| myotonia | amyotonia | catatonia | 
| claytonia | clintonia | houstonia | 
| hypotonia | vagotonia | hypertonia | 
| rhizoctonia | ||
Note: These 13 words that end with 'tonia' are found from the USA & Canada version of the tournament Scrabble word list.