In 1984, the Monroe County Parks Department in the Highland Park section of Rochester, New York, accidentally unearthed part of an unmarked cemetery while landscaping. The cemetery was in use from approximately 1826 to 1863 and was associated with the Monroe County Almshouse. Anthropological examination of dental and skeletal pathology revealed a high incidence of dental infection, known to occasionally be a causal agent of maxillary sinus infection. Therefore, maxillary sinus infections in this sample were studied to ascertain their relationship with dental infections, sex, and age at death. The maxillary sinuses of 99 skeletons were examined for evidence of infection. The presence, location, type and extent of dental infections in the posterior teeth were also recorded. Half the sample exhibited bone remodelling in the maxillary sinus (54 individuals). Dental infections were observed in 82 individuals. Forty‐eight demonstrated signs of dental infection and maxillary sinusitis. Statistical analysis revealed that dental infection and maxillary sinus infection were not statistically related. Rather, a rhinogenic method of infection seems likely, which would appear related to the squalid air quality the 19th‐century poor were exposed to in the almshouse and city tenements. Copyright © 2016 John Wiley & Sons, Ltd.