Hypodontia, supernumaries, impacted canines Flashcards
What is hypodonita
a congenital absence of one or more primary or secondary teeth
How is hypodontia classified?
Mild = 1-2 teeth missing
Moderate 3 -5 teeth missing
Severe - 6 or more teeth missing also known as oligondontia
What factors are associated with hypodonita?
Genetic - family pattern/history of missing teeth
Local - cleft lip or palate
Syndromes - down’s syndrome, hemifacial microsomia
Dental factors associated with hypodontia?
Microdontia - peg laterals Impacted canines Abnormal tooth positions Transposition Alveolar atrophy Retained deciduous teeth
What are the treatment options for hypodontia related to missing 5’s?
Close spaces
Open spaces for prosthetics
What are the treatment options for hypodonita related to missing 2’s?
Close spaces - modify canines to look like lateral incisor (invert canine bracket, place canine bracket on 4’s, place lateral brackets on canines)
Build up the canines
Open space for prosthesis
What are the treatment options for missing lower central incisors?
Close space - especially in a class III Open space for prosthesis
What are the clinical features of supernumaries
Failure of eruption Diastema Crowding Displaced or rotated teeth Root resorption of adjacent teeth
Medical syndromes associated with supernumaries?
CLP
Cleidocranial dysplasia
What factors can cause an impacted canine?
Displacement of the crypt Long path of eruption Short-rooted or absent upper laterals Crowding Retained deciduous canines Genetics Retention of primary canine
Clinical signs of an impacted canine
Canine is unable to be palpated in the buccal sulks
Retained deciduous canines are not mobile
Palatal bulge
Severe crowding and inadequate space within the arch
Increased mobility of incisors
What is horizontal parallax?
Uses 2 PA’s or 2 PA’s and upper standard occlusal - tube head moves around the arch in horizontal plane and moves left and right
What is vertical parallax?
Uses an OPG and an upper standard occlusal
vertical parallax moves tube head in the vertical plane
What are the two exposures that can be performed on impacted canines?
Open - canine is uncovered, packing is placed to prevent exposure from closing, an attachment is added by the orthodontist/therapist
Closed - Canine is uncovered and a gold chain is placed, the gum is stitched back over the tooth, the tooth is pulled through the soft tissue via gold chain
What are the other options for impacted canines?
Surgical removal - if in unfavourable position, severe crowding and unmotivated patient
Auto transplantation - surgical removal and implantation of tooth into normal position with the maxillary alveolus - not commonly done due to risk of ankylosis.
