Favourable and Unfavourable Mandibular Fracture

Favourable and Unfavourable Fracture

Classification of fractures:

When viewed from side:

1. Horizontally Favourable
2. Horizontally Unfavourable

When viewed from oclusal surface:

1. Vertically Favourable
2. Vertically Unfavourable

When viewed from side

1.Horizontally Favourable.

Line starts at alveolar margin and extends forwards or anteriorly and downwards till lowest border of mandible.

The horizontal direction of fracture line favours the unopposed action of masseter n medial pterygoid muscle in an upward direction.

The depressor n elevator act in different direction.

2.Horizontally unfavourable.

Fracture line starts at alveolar margin and extends backwards and posteriorly till lowest border of mandible.

Fracture line starts at alveolar margin and extends forwards or anteriorly and downwards till lowest border of mandible.

The horizontal direction of fracture line favours the unopposed action of masseter n medial pterygoid muscle in an upward directions.

The depressor n elevator act in different direction.

When viewed from oclusal surface:

1. Vertically favourable fracture.

It opposes the unopposed action of medial pterygoid.

Fracture line starts at the buccal or outer border of the mandible n extends obliquely towards lingual margin of mandible, it will resist displacement of fragment.

The elevator and depressor act against each other and help in keeping the bones on either side of fracture line in position.

2. Vertically unfavourable fracture.

Fracture line starts at the lingual or inner border of mandible extending obliquely backwards towards buccal margin of mandible.

It favours the unopposed action of the medial pterygoid muscle.

The elevator n depressor muscle act in the same direction do not help in keeping the bones in position in fracture line.