2017 AAO Annual Session - Temporary Anchors and Surgical Orthodontics / Rotations of the Maxilla and the Occlusal Plane: The Key to Successful Orthopedics / Revisiting Malocclusions with Mini-implants

Temporary Anchors and Surgical Orthodontics

Conventional orthodontic preparation of the dentition prior to surgery is often limited by the extent of required pre-surgical orthodontics. Temporary anchors may be used to assist in expanding the range of decompensation of the dentition prior to surgery or compensation of the dentition when surgery is performed prior to complete decompensation of the dentition. This lecture will discuss the rationale for selection of the appropriate pre and/or or post-surgically assisted application of temporary anchors.

Learning Objectives:

• Identify limitations associated with routine orthodontic preparation for combined surgery and orthodontics.
• Evaluate the indications for pre-surgical application of temporary anchor devices.
• Determine the indications for post-surgical application of temporary anchor devices.

Rotations of the Maxilla and the Occlusal Plane: The Key to Successful Orthopedics

Rotations of the occlusal plane not only affect the vertical dimension of the growing face but also the anteroposterior relation between upper and lower jaw. Conventional tooth born class III orthopedics often result in upper molar extrusion and posterior rotation of the mandible, with increase of the length and convexity of the face, which sometimes is wrongly interpreted as a restraint of mandibular growth. Furthermore, a counter clockwise rotation of the palatal plane, by the line of force passing below the center of resistance of the zygomatico-maxillary complex, may also result in a downward movement of the upper molars. These maxillary rotations can be altered by changing the angulation of the orthopedic force and it’s perpendicular distance to the center of resistance, or by adding an extra moment of force. Finally the moment-to-force ratio of the resulting orthopedic force system applied to the upper jaw will determine the direction of the maxillary rotation, and the subsequent rotations of the occlusal plane and the mandible.

Learning Objectives:

• Identify rotations of the occlusal plane and palatal plane by different class III orthopedics.
• Evaluate biomechanics of maxillary rotations.
• Analyze the effect of canting of the occlusal plane on mandibular rotations.

Revisiting Malocclusions with Mini-implants

Mini-implants are one of the latest successful technologies introduced and widely used in orthodontic treatment, as a reinforcement of anchorage. Same concepts adopted to treat different types of malocclusions in the past are still used, but with the raise of mini-implants era, the mechanical considerations of these traditional strategies need to be revisited. Nevertheless, ignorance of the entire mechanical effects that result from usage of mini-implants might cause undesirable outcomes which can complicate the orthodontic treatment. In this lecture, we will show how mini-implants can facilitate our orthodontic treatment, highlighting at the same time the failure of these techniques in some circumstances.

Learning Objectives:

• Compare the treatment of malocclusions between the traditional orthodontic methods versus systems that include mechanics based on mini-implants.
• Manage the side effects that can result from uncontrolled mechanics of usage of miniscrews.
• Identify the different factors that may contribute to the failure of mini-implants.