Digital macro-photogrammetry in orthodontic tooth movement: case report

Digital macro-photogrammetry (DMP) method was used to assess the 3-dimensional (3D) movement of the canine during retraction with a Hybrid Retractor (HR) spring (Forestadent, Pforzheim, Germany) following extraction of first premolars. Computer images of the canine were generated from multiple synchronous digital photos of a patient taken during clinical follow-ups. Time intervals were recorded from the begining of the treatment before the insertion of the spring (T0), to the last follow-up session of canine retraction (T8). All movements of the canine were calculated from the generated three dimensional co-ordinates (X,Y, & Z). The results indicated that the canine was distalized about 6,78 mm over a period of 258 days. The maximum velocity of the canine movement was found to be approximately 1 mm/month. In conclusion, it was found that DMP can be applied in clinical orthodontics to monitor orthodontic tooth movement. This technique is cost-effective and measurements can be made on site as the use of computers and digital photographs have been incorporated in the majority of orthodontic practices.