Letters From Our Readers

To: Editor, The Angle Orthodontist

Re: Response to: Rapid 3D mandibular superimposition for growing patients. Leonardo Koerich; André Weissheimer; Luciane Macedo de Menezes; Steven J. Lindauer. Angle Orthod. 2017;87:473–479.

First, we would like to thank Drs. Xiaoying Hu and Jintao Xu for their interest in our paper. The mandibular superimposition in growing patients requires more steps than our previous method for non-growing patients.

To address the first question, once the time point 1 image is opened for the first time in the Dental Volume Reformat (DVR) module, the observer has the option to change the image orientation and select the “reslice” option to save the new orientation. Once that is done, a new DICOM sequence is created with the new orientation within the software database. This new file is the one that needs to be used for future superimposition. If the new orientation is not saved using “reslice”, it is not possible to load it with the new orientation in the Fusion module later on.

To answer the second question, we believe that selecting areas inside the mandible would not add any clinical relevance to the reliability. As long as the areas being evaluated were far away enough from each other, we could identify if there were small differences between the superimposition of observer 1 and 2. In addition, the segmentation of the lingual part of the mandible is more challenging to be standardized and to have a solid smooth surface because of thinner cortical bone in some areas, which would make the measurement step less reliable.

We hope we were able to answer the questions and please do not hesitate to contact us if you have any other questions in the future.