Monday, October 8, 2012

Notice

Hi guys please remember to post your info by the end of the day

Cheryl Wolfe Theory 2

The objectives of Functional Therapy (treatment):

In order for normal development of the dental arches in the correct relationship to occur, favourable equilibrium of muscle forces between the tongue, lip and cheeks are essential. Malocclusion is therefore a result of persistant deviation from normal function. The purpose of functional therapy is therefore to change the functional environment of the dentition to promote normal function. The purpose of a functional appliance is to control the forces applied to the dentition by the surrounding soft tissues as well as the muscles that control the position and movement of the mandible. A new functional behaviour pattern is therefore established in order to support a new position of equilibrium by eliminating unfavourable environmental factors in a developing malocclusion. Functional thereapy also aims to unlock a malocclusion and stimulate growth by applying favourable forces that enhance skeletal development.

Clark, W.J. 1995. Twin Block Functional Therapy: Applications in Dentofacial Orthopaedics. London: Mosby-Wolfe. p31-32

Sunday, September 30, 2012

Posts to blog

Guys please check that when you are posting information that it loads correctly. Title is your name and surname and the subject matter, Theory or Materials.

Cheryl Wolfe Theory 1

Describe/explain the position, extension and angulation of the mandibular acrylic block and its occlusal planes of a Twin Block appliance for the correction of a Class II division I malocclusion with a deep overbite.
Answer:
The position of the occlusal inclined plane is determined by the mandibular block and is important in the treatment of a deep overbite. The inclined plane should be clear of the mesial surface contact with the mandibular molar. This would allow the mandibular molar to erupt unobstructed, thereby reducing the overbite.

The inclined plane on the mandibular acrylic block is angled from the mesial surface of the 2nd premolar or deciduous molar at 70 degrees to the occlusal plane. In cases where the mandibular forward protrusions are inconsistent, the angulation may be reduced to 45 degrees in order for the block to occlude correctly.

The inclined block should extend distally to the buccal cusp of the mandibular 2nd premolar or deciduous molar, stopping short of the distal marginal ridge (this allows the leading edge of the inclined plane of the maxillary appliance to be positioned mesial to the mandibular 1st molar, thereby not obstructing eruption). 
Buccolingually the mandibular block covers the occlusal surfaces of the mandibular premolar or deciduous molars, to occlude with the inclined plane on the maxillary twin block. The flat occlusal bite block passes forward over the 1st premolar, and becomes thinner buccolingually in the mandibular canine region. The thickness of the block can be reduced in that area in order to improve speech by allowing the tongue freedom of movement in the phonetic area. In order to avoid breakage, the lingual flange in the midline should be of adequate thickness.

Clark, W.J. 2002. Appliance design and construction. Twin block functional therapy: applications in dentofacial orthopaedics. 2nd ed. London: Mosby. p80. 

Cheryl Wolfe Dental Materials

In which way is an arrangement of forces called a "couple" related to the force called "moment"?
Answer:
When a body is rotated without translation by two moments equal, parallel, opposite and noncollinear, then this arrangement of forces are called a couple.
A moment is the tendency of a force to cause rotation of a body around a fixed axis. It is one force producing a sliding vector.

Moyers, R.E. 1980. Biomechanics of tooth movements. Handbook of orthodontics. 3rd ed. London: Year Book Medical Publishers Inc. p429.

Tuesday, September 25, 2012

BTech Orthodontics 2012

Dear Students

Welcome to the Orthodontics block for 2012. This block is aimed at improving your skill in orthos as well as maintaining the skill.

Please post comments forwarded to you via this media. I will also start a discussion on each of the ortho cases you have for classwork. A picture will be posted and you suggest treatment, each student will receive marks on their comments, whether you agree or disagree with another students treatment or not. You need to justify your comments.

Good luck