Introduction: Cleidocranial dysplasia is a genetic disease affecting bone growth. Observations: 3 patients, aged 12, 14, and 15 followed an orthodontic and surgical treatment to solve an eruption issue of the permanent teeth. Temporary teeth were extracted and impacted teeth were progressively exposed by multiple surgeries under local anesthesia. Anchorages were placed on the teeth and a traction started, on incisors and molars first, then on premolars, and finally on canines. The treatments lasted for 6 to 8 years. Comments: These patients presented minor form of cleidocranial dysplasia which only affected the teeth. The difficulty of these cases lied in the lateness of their diagnosis and treatment. Adaptations had to be made to simplify treatment plans (shortened dental arch, premolar extractions, etc.).

Introduction: In the field of oral and maxillo-facial surgery, the avulsion of third mandibular molar is a very common procedure. However, and although the injury on the alveolar inferior nerve is very rare, the neurological risk must not be underestimated. Indeed, it may lower the patient’s quality of life in a significant way. The coronectomy is a technique that allows us to avoid this risk. It consists in remaining in place the third mandibular molar’s roots. Educational objectives: After a clinical introduction to this surgical technique, the main characteristics of this type of procedure will be presented with the help of an exhaustive literature review. Thus, we will refer to the following subjects: the obvious decrease of neurological risks, the potential pre and post-operating complications, the potential necessity of an endodontic treatment for the residual roots, the becoming of these same roots, and finally the bony and mucosal cicatrization of the operated area. Conclusion: Every oral surgeon should have in mind this technique of coronectomy and master it. Indeed, when the case justifies it, the benefits are numerous for the patient.