.Treacher Collins Syndrome (Mandibulofacial Dysostosis)

Treacher Collins Syndrome (Mandibulofacial Dysostosis)

Introduction to Syndrome

     It is a rare syndrome that is characterized by defects of structures derived from the first and

        second branchial arches.

Etiology 

     It is an inherited disorder.

Clinical Features 

    facial bones 

     Hypoplasia or underdevelopment of the facial bones, especially  zygomatic bones

        (depressed cheeks), maxilla and mandible.

    Eye 

     Antimongoloid eyes (downward sloping of palpebral fissures).

     A coloboma or notch occurs on the outer third of the lower eyelid.

     Absence of eye lashes medial to the coloboma.

    Ear 

     A tongue-shaped extension of hair in front of ears (toward the cheeks).

     Deformed external ears.

     Oral findings include: 

     Macrostomia (due to lateral facial cleft) .

     Cleft palate.

     High arched palate.

     Malocclusion.

     The parotid glands may be hypoplastic or may be totally absent.

    Macrostomia 

Definition 

     An excessively large mouth.

Pathogenesis 

     Premature arrest of fusion between maxillary and mandibular processes bilaterally.

It is considered as: an incomplete form of lateral facial cleft. 

    Microstomia 

Definition 

     An abnormally small mouth.

Pathogenesis 

     Excessive fusion between maxillary and mandibular processes.