馬偕宣教旅途中，也同時四處拔牙和行醫，奠定民眾信任的基礎。雖然他並非專業醫生，但他擁有初級西方醫療知識，基本照顧疼痛概念比較好，尤其協助許多人解決痢疾和牙痛問題。馬偕拔牙的技術頗受歡迎，他自己提到：「對於數以萬計的漢人和原住民而言，牙痛是長期痛苦的折磨。他們拔牙的方法又相當粗魯而殘酷」。馬偕後來幾乎成為拔牙專家，許多被他拔牙的人充滿感謝。他的拔牙成績驚人，1888年馬偕的記錄提到，從1872年到1888年他已經拔了18,235顆牙。但是，馬偕的兒子則說他父親大概拔了超過40,000顆牙。

Although Mackay was not a physician, he acquired basic medical knowledge to relieve people’s health problems, such as the dreaded malaria fever and the common toothache. Mackay was well-recognized for his dental work among the Chinese people and aborigine communities in Taiwan. He maintained that “Toothache… is the abiding torment of tens of thousands of both Chinese and aborigines. The methods by which the natives extract teeth are both crude and cruel.” Thus, Mackay relatively became an expert in extracting teeth. In his 1888 report, Mackay recorded that he had extracted 18,235 teeth since 1872. According to his son, Mackay had extracted over 40,000 during his lifetime (G. W. Mackay p. 47).

馬偕博士為人拔牙（MacKay 1896）