Ortho-hypodontia

Question 1

What is severe hypodontia?

Answer 1

congenital absence of 6 or more teeth

Question 2

What is anodontia?

Answer 2

Congenital absence of all teeth

Question 3

How prevalent is hypodontia?

Answer 3

2%in population.

Question 4

What teeth are most commonly affected with hypodontia and why?

Answer 4

8s/ L5s/ U2S/U5s/ Lower incisors.

Most commonly upper 2s due to ectopic canines

Question 5

What can be the cause of hypodontia?

Answer 5

• Familial
• Sporadic
• Mutations
• Syndromic (Cleft lip and palate/Anhydrotic ectodermal dysplasia)

Question 6

Discuss the presentation of hypodontia?

Answer 6

Delayed or asymmetric eruption
Retained/ infra-occluded deciduous teeth.
Absent deciduous tooth.
Abnormal tooth form (e.g. conical)

Question 7

What problems are associated with hypodontia?

Answer 7

• Delayed formation and eruption.
• Microdontia
• Malformation of other teeth
• Short root anomaly.
• Impaction.
• Crowding
• Malposition of other teeth.
• Transposition of maxillary canine & first premolar.
• Taurodontism
• Enamel hypoplasia
• Altered craniofacial growth.

Question 8

List the treatment options for hypodontia?

Answer 8

• Accept
• Restore
• Orthodontic treatment
• Orthodontic treatment and restore.

Question 9

How can we treat hypodontia with restorations alone?

Answer 9

• Restorations to increase size of front teeth (to reduce size of diastema)
• Restore to make canines look like laterals

Question 10

How can we treat hypodontia with combined orthdontic and restorative treatment?

Answer 10

Space closure & restore
Open the space and redistribute it to make space for new restorations.

Question 11

Compare the different options for open space + restoration treatment

As part of orthodontic and restorative treatment for hypodontia

Answer 11

• Resin bonded bridge
• Implants
• Conventional bridge
• Denture.

Question 12

Compare the open space treatment of hypodontia using a RBB to an implant.

Answer 12

Resin bonded bridge:
* Can be completed at any age
* Failure risk- relapse could cause the bridge to rotate out of line.
Implant
* Must be 18/19 at least
* Need enough bone
* Need at least 7mm of space.
* Need the adjacent roots to be at least 7mm apart.
* more expensive.
* Difficult to predict aesthetic results.

Question 13

Discuss the treatment of hypodontia by simple space closure.

Answer 13

Use orthodontics to close any gaps then use restorations to mask any aesthetic problems. (e.g. making canines look like inciors)

Question 14

Discuss the treatment of hypodontia through space closure plus.

Answer 14

This closes the gaps but also makes the teeth look as natural as possible through the alteration of the gingival margins.
(by intruding/extruding the teeth)

Question 15

What is the natural pattern of the gingival margin?

Answer 15

Central Incisor UP
Lateral incisor DOWN.
Canine UP.