National Board Dental Hygiene Examination (NBDHE) Dental Hygienist Practice Test

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the National Board Dental Hygiene Examination. Study with multiple-choice questions, hints, and explanations. Ace your dental hygienist exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.


What processes fail to fuse during fetal development resulting in a bilateral cleft lip?

  1. Palatine and lateral nasal processes

  2. Maxillary and medial nasal processes

  3. Maxillary and palatine processes

  4. Medial nasal and lateral nasal processes

The correct answer is: Maxillary and medial nasal processes

A bilateral cleft lip occurs due to the failure of fusion between the maxillary processes and the medial nasal processes during fetal development. Normally, during embryogenesis, these structures come together to form a continuous upper lip. If this fusion does not occur correctly, it results in a gap that characterizes a cleft lip. The maxillary processes contribute to the formation of the sides of the upper lip, while the medial nasal processes are responsible for forming the center part. If these areas do not unite, a cleft can form, potentially on both sides of the lip, hence "bilateral." This is a critical aspect of embryonic facial development, and understanding it helps in recognizing the implications for surgical correction and management in affected individuals.