**1. Introduction**

In this chapter, the radiographs of important developmental dental defects (DDD) will be displayed and important radiologically related questions will follow together with the answers. This is to assist the reader in understanding not only the radiology of the DDD and also the clinical significance, but also the various possible differential diagnoses. It is my intention to clinically (clinical significance) and radiographically demonstrate to the readers that correlation matters between the later and the former since some clinically obvious DDD can in fact not have any specific or pathognomonic radiological presentation. The case of multiple bilateral parapremolars that was recently managed by me is replete of this statement, "*the more you look at the X-ray, the less you see of the clinically significant presentation of the developmental dental defects*."

In this chapter, the questions posed which follows the presented radiograph will be in black and brown and the answers are in red. This is to aid the sound understanding of the radiology of the developmental dental defects at a glance. Each radiograph is as such within a plate.

This chapter will end with the developmental dental defect called regional odontodysplasia. The regional odontodysplasia is very rare and I have decided to correlate the radiology with the clinical findings and histological findings by encouraging the readers to read the classical article of Jahanimoghadam et al. [1] on the subject and for them to utilize such knowledge obtained to present a power point lecture for presentation on regional odontoplasia with the expectation that they will be opportune, 1 day to make such presentation to an audience of dental practitioners and academics.
