Asymmetry

Question 1

Definition

Answer 1

Imbalance/ disharmony of the size and relationship of the 2 sides of the craniofacial complex about a dividing plane

Question 2

Categories for eitiology

Answer 2

• Development
• Pathological
• Functional
• Trauma

Question 3

Developmental etiologies

Answer 3

• Hemifacial atrophy
• Hemifacial microsomia
• Hemi-mandibular enlongation
• Hemi-mandibular hyperplasia
• Hemifacial hypertropy
• Unilateral CLP

Question 4

Pathological eitiologies

Answer 4

• Tumors and cysts
• Infection
• Condylar resorption: Idiopathic, post OGS, Juvenile rheumatoid arthritis

Question 5

Traumatic pathologies

Answer 5

• condylar fracture

- nerve damage

Question 6

Functional eitology

Answer 6

Functional shift

Question 7

Difference between hemi-mandibular enlongation vs hyperplasia

Answer 7

Elongation:

• Horizontal displacement of Mn and chin
• Cant
• Lateral OB
• Rotated facial appearance

Hyperplasia:

• 3d enlargement of the horizontal and vertical plane
• abruptly stops at ML
• long ramus and body of Mn
• no cant

Question 8

Types of assessment

Answer 8

1) Clinical
2) History taking
3) Radiographic

Question 9

What qns to ask at history taking

Answer 9

• CC
• FHx
• Trauma
• DHx
• Habits
• Pattern of onset and worsening

Question 10

What is part of clinical exam

Answer 10

Skeletal: Mx cant, chin deviation, AP

Dental: occlusal interference, OB, ML, x-bite

ST: - deviation of nasal septum, nose tip, philtrum

Functional: CRMI slide, TMJ, lip posture, speech

Question 11

What to look out for in radiographs

Answer 11

OPG: shape, size, length of ramus/ condyles, any gross pathology

PA ceph: Grummons analysis (comparative, not normative)

Question 12

What is the Grummons analysis

Answer 12

MSR: vertical line from crista galli - ANS

- divide face into triangles and polygons

Question 13

What to look out for in PA ceph

Answer 13

1) Mx occlusal plane
2) Chin
3) Mn morphological diff
4) MxMn comparison of asymmetry

Question 14

What bone scans can you do

Answer 14

Radionuclide bone scan

• detects area with increase/decrease bone metabolism
• distribution of radioactive isotopes
• “hotspots”
• uniform dist. in healthy bone

Question 15

What to look out for on dental cast

Answer 15

• localised dental asymm.
• DAC
• U/L arch shapes
• occlusal interference in CR-MI slide

Question 16

Considerations to decision making

Answer 16

• Pt CC
• Esthetic acceptability of deviation
• Amt of DAC req.

Question 17

Limit of asymmetry acceptability + evidence

Answer 17

Veeranki et al., 2018
ML: <2.2
ML Cant: <10
Occlusal cant: <4
Asymm chin: <5.6mm