Abstract
Abstract: Proper alignment of the maxillary dental midline is essential in prosthetic rehabilitation and orthodontic treatment. This study investigated the alignment of the maxillary dental midline with three facial landmarks, the facial midline, philtrum, and nasal tip, in an Iranian population. Photographs of 608 randomly selected individuals were taken, each captured in a frontal view while smiling. A Nikon D5300 digital camera with a 105-mm lens was used, positioned 1.2 meters from the subjects. A metallic scale marked with millimeters was placed along the face in each photo to serve as a reference for resizing during later computer analysis. The distances between the maxillary dental midline and each facial landmark (facial midline, philtrum, and nasal tip) were measured using Adobe Photoshop software, and the data were analyzed with SPSS software. The alignment results showed that the philtrum coincided with the maxillary dental midline 3.3% of the time, the facial midline aligned 1.6%, and the nasal tip had the least alignment with the dental midline. Significant differences were found in the alignment of the maxillary dental midline with the facial midline, philtrum, and nasal tip, with the highest alignment seen at the philtrum, followed by the facial midline and the nasal tip showing the least alignment.