Notes, summaries, assignments, exams, and exercises for Biology for University

Understanding Occlusion and Malocclusion

Occlusion: The manner in which the maxillary and mandibular teeth articulate.

Malocclusion: Normal biological variation in how jaws are articulated with the mandibular teeth. Not all malocclusions require orthopedic or orthodontic treatment; only those that have the capacity to generate changes at a psychological, social, growth, and developmental level, or affect other oral structures, require intervention.

Etiology of Malocclusion

Time is a critical etiological factor that intervenes in several ways:

• Age of Onset: The age at which an alteration appears can lead to poor positioning. If left untreated, the malocclusion may become more severe and sometimes incorrigible.
• Duration: The length of time the etiologic

Congenital Mandibular Aplasia and Agenesis

Congenital Aplasia or Mandibular Agenesis is often associated with abnormalities of the first branchial arch.

First Branchial Arch Syndromes

Pierre Robin Syndrome: Characterized by micrognathia, cleft palate, and tongue retraction (glossoptosis with pseudomacroglossia).

Treacher Collins Syndrome (Mandibulofacial Dysostosis): Features include micrognathia, deafness, hypoplasia of the average lower third of the face, coloboma in the lower eyelid, ear malformations, and cleft palate.

First and Second Branchial Arch Syndromes

Goldenhar Syndrome: Also known as hemifacial microsomia or unilateral mandibular hypoplasia. This congenital condition accompanies ear alterations and is caused by a default in the migration...