MIDDLEBURY — Middlebury-based Open Door Clinic (ODC) has received a $14,594 grant through the Northeast Dental Foundation, money that Addison County’s free clinic will use in support of a University of Vermont study of the oral health of migrant workers. Migrant farm workers are among the heaviest users of the ODC, located on the Porter Medical Center campus off South Street. Other recipients from this latest round of Northeast Delta grants were: $5,000 to South Royalton School Clinic in South Royalton for general operating expenses, and $60,000 to the Vermont Head Start/Early Head Start Tooth Tutor Program, a state-wide program, for salaries and dental supplies.