9- included, impacted and retained teeth

What is an included tooth?

Remains inside bone having reached normal period of eruption

What is an impacted tooth?

Lack of eruption by a physical barrier- either another tooth, bone or soft tissues- or abnormal position of tooth

What is a retained tooth?

No physical obstacle, malposition or abnormal development to explain the interrupted eruption 

What are the 2 subtypes of retained teeth?

Primary- tooth located in thickness of bone

Secondary- tooth emerges but eruption stops- fails to reach occlusal plane

What is an ectopic tooth?

Tooth developed outside its normal position

Ectopic inclusion- included in an abnormal position near its normal site

Heterotrophic inclusion- included in an abnormal position far from its normal site

What are the frequency of inclusions?

Lower 3rd molar 

Upper canine

Upper 3rd molar

Lower 2nd premolar

Lower canine 

What are 9 hereditary prenatal general retention factors?

Facial asymmetries

Micro and macrognathia

Oligodontics and hypodontics

Alteration in shape

Paladar and cleft lip

Diastemas by frenulum

Deep overbite

Crowding and rotating teeth

Upper maxillary retrognathism and mandibular prognathism

What is a congenital prenatal general retention factor?

By maternal pathology in pregnancy 

What are 2 postnatal general retention factors and give an example?

Endocrine disturbances- hypothyroidism

Metabolic alterations- rickets

What are 4 rare conditions of general retention factors and their presentations?

Gardner syndrome

Gliford progeria or premature old age

Crouzon syndrome

Fibrous dysplasias

How do embryological factors cause retention?

Abnormal position of germ

Delayed germ eruption

Common in upper canine or lower third molar

What are 4 DENTAL mechanical obstacles causing included teeth?

Inclined teeth due to premature loss of temp tooth

Retained temp tooth

Supernumeraries

Tumours- odontomas, osteomas- block germ

What 5 SOFT TISSUE mechanical obstacles cause included teeth?

Dental cysts

Congenital gingival fibromatosis

Post traumatic mucous scars

Infectious pathology

Chronic non infectious inflammation

How does lack of space cause included teeth?

Blocked by adjacent structures- 2nd M, bone cortical, mand ascending branch

Dento-maxillary disharmony- large teeth vs small base

No space maintainer

Retrognathia of upper alveolar bone

Excess dental material

Upper lip frenulum with low insertion and diastema

What therapeutic possibilities before a dentarian inclusion?

Abstention

Place tooth in arch

Extract

Why should you abstain from treating included teeth?

Patient has general contraindications

Manipulating tooth causes complications

No associated pathology- regular check up

Why do you treat included teeth by placing tooth in arch and what 3 techniques?

For aesthetics and functional

Conductive alveolotomy- remove bone to guide eruption

Dental transplant- reposition tooth into socket

Orthodontic-surgical methods

Why should you extract an included tooth?

Pathology, can’t place in arch

3rd molar associated with cysts, tumours or destruction of adj bone/tooth

Prophylatic extraction

Operation sequence in exodontia of included teeth (6)

1. Incision and full thickness flap detachment

2. Ostectomy- remove enough alveolar bone to move tooth/perform odontosection

3. Luxation

4. Odontosection- decreases bone resection, less pain/swelling post op

5. Extract

6. Repair area- edge regularisation, replace flap and suture

What instruments are used in each stage of operation sequence in exodontia of included teeth?

1. Scalpel- blade 15, periosteal elevator, separator/retractor

2. Handpiece- irrigate, round tungsten or lindemann carbide

3. Elevators

4. Fissure bur, handpiece

5. Elevator and forceps

6. Regularise with rongeur forceps and bone files, curette granulation tissue