I want to attach a paper of 3 case reports which discusses different scenarios which all finished with Class III molars.
I think that the paper is beneficial in terms of expanding our horizon when it comes to different treatment options, especially and as we all know that the introduction of extraction treatment by Tweed made Angle’s sagittal molar relationship less critical in orthodontics.
The paper will follow.
( PDF ) STRATEGIES TO FINISH ORTHODONTIC TREATMENT WITH A CLASS III MOLAR RELATIONSHIP:THREE PATIENT REPORTS
First :Seek the cause of class III discrepancy , whether it is skeletal or dental ? Using clinical examination and diagnostic records ; A deficiency in maxilla ,a prognathism in the mandible or both can be addressed.Checking functional shift or Psudo Class III by guiding mandible to Centric relation.
This study assessed the effect of water and saliva contamination on the shear bond strength and bond failure site of 3 different orthodontic primers (Transbond XT, Transbond Moisture Insensitive Primer, and Transbond Plus Self Etching Primer; 3M Unitek, Monrovia, Calif) used with a light-cured composite resin (Transbond XT). Bovine permanent mandibular incisors (315) were randomly divided into 21 groups (15 in each group). Each primer–adhesive combination was tested under 7 different enamel surface conditions: (1) dry, (2) water application before priming, (3) water application after priming, (4) water application before and after priming,
For dental orthodontic applications, NiTi wires are used under bending conditions in the oral environment for a long period. The purpose of this study was to investigate the effect of bending stress on the corrosion of NiTi wires using potentiodynamic and potentiostatic tests in artificial saliva. The results indicated that bending stress induces a higher corrosion rate of NiTi wires in passive regions. Continue reading Effect of Load Deflection on Corrosion Behavior of NiTi Wire→
Asymetric manibular appearnce can be caused by unilateral overgrowth of one condyle.The overgrowth can be due to Rheumatic Artheritis , Trauma or inflammation of the condyle (s).
Mandibular condylar hyperplasia ( CH ) is a condition that causes excessive growth of the condylar head and neck , as well as the mandible , creating functional and cosmetic deformities of the face and jaw .
Signs of unilateral Condylar hyperplasia (most common):
According to them, even after the use of bonded RPE, some vertical adverse effects are inevitable. They explained that the vertical change is not caused by buccal tipping of maxillary molars only (which can be controlled by using bonded RPE) but also caused by the whole maxilla being displaced downward. So it was suggested that in cases where vertical dimension is critically sensitive, the use of vertical pull chin cup (or I would also add high pull HG) might be an option.
Today we discussed expansion and mentioned that in most of the cases mandibular arch “follows” the expansion of the maxillary arch and so we rarely use expansion appliances in the mandible.
I just wanted to share the explanation to help the junior residents and refresh the info for the rest of us.
According to Hass, this happens due to several factors:
1- The forces of occlusion were altered by expansion so that the normal lingual vector on the mandibular teeth was lost and the lateral movement of maxilla widened the area of attachment of buccal musculature which caused change in balance between buccal surface and the tongue (a decrease in pressure from the cheeks as result of upper arch expansion will allow the tongue to exert more pressure thus uprighting and expanding lower arch).
2- Thickness of the appliance (3 quarters of an inch) might have caused the tongue to be in a lower position thus exerting even more lingual pressure on mandibular teeth.
Cephalometric superimposition is a way to aid in monitioring the progress of skeletal and dental changes that occur over time.It is helpful in craniofacial growth studies as well as in evaluation of treatment outcomes.