National Dental Examining Board of Canada (NDEB) Practice Exam

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Master your National Dental Examining Board of Canada (NDEB) exams with our comprehensive practice guide. Achieve excellence in your dental certification with expertly crafted questions and detailed explanations.

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The most common cause of Class I malocclusion is

  1. Thumb sucking

  2. Tongue thrusting

  3. Genetics

  4. Inequity between tooth size and supporting bone

The correct answer is: Inequity between tooth size and supporting bone

Class I malocclusion is a type of misalignment of the teeth where the upper and lower teeth do not fit together properly. It is the most common type of malocclusion and it is typically caused by inequity between the size of the teeth and the dimensions of the supporting bone. This means that there is a mismatch between the size of the teeth and the space available for them to fit in the jaw, resulting in a misalignment. While thumb sucking and tongue thrusting can contribute to a Class I malocclusion, they are not the most common cause. Genetics can also play a role in the development of malocclusion, but it is not the most common cause of Class I malocclusion.