ORTHODONTICS

Ugly Duckling Stage

(Broadbent phenomenon)

• It is a transient/self-correcting malocclusion seen in the maxillary incisor region between 8-9 yrs of age.
• Erupting permanent canines displace the roots of lateral incisors mesially, resulting in transmission of force on to the roots of central incisors which also get displaced mesially.
• A resultant distal divergence of crowns of two central incisors causes midline spacing. This situation has been described by Broadbent as the UGLY DUCKLING STAGE as      children tend to look ugly during this phase of development.

Inter-transitional Period

• Under the influence of tongue, the mandibular lateral incisors assume their proper position in the arch & its initial lingual location is eliminated.
• Small discrepancies are corrected by pressure exerted by tongue & lips.
• No fixed intercusp relation is pre sent, this helps in mesial drift of mandibular teeth.

Second Transitional Period

It is characterized by the replacement of the primary molars & canines by the premolars & permanent canines respectively.

The combined mesiodistal width of the permanent canines & premolars is usually less than that of the primary canines & molars. This surplus space is called LEEWAY SPACE.

It is – 1.8 mm in Maxilla (0.9 mm each side)

– 3.4 mm in Mandible (1.7 mm each side)