 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Spring 2001 Presentation Summary:
State-of-the-Art in Orthognathic Surgery and TMD
Presented by Dr. Larry Wolford
on October 2, 2000, at the PCSO Annual Session, Reno, NV
Summarized by Dr. Owen Nichols,
Central Region Editor
Dr. Wolford conducted a wide spectrum tour of surgical issues and joint pathologies that affect orthodontic patients. His topics included routine orthognathic procedures and diagnostic and surgical issues surrounding the temporomandibular joint.
He stated that surgeries for dento-facial deformities and TMJ pathology can be combined into one operation if the surgeon has adequate experience and judgment.
Bone screws and rigid fixation have replaced inter-maxillary wire fixation for orthognathic surgeries. As a result, the surgeon has better control over condyle-fossa relationships. The speaker performed his last intraoral fixation in 1983.
The orthodontist can help ensure the ultimate success of orthognathic surgery by avoiding certain pitfalls. For example, long-term orthodontic treatment with Class II mechanics and splints intended to project the mandible tend to distort centric occlusion, which can complicate surgical repositioning. These forces also increase the possibility of disk displacement and alterations in the bilaminar zone—both of which can contribute to post surgical relapse.
Rigid fixation in maxillary surgeries has all but eliminated fibrous union complications. Most maxillary procedures (80%–90%) are segmentalized. This allows the surgeon to control the Curve of Wilson giving a more stable expansion. The surgeon usually prefers to section between cuspids and laterals, which permits greater control over incisor angulation as well as inter-incisal relationship.
At the time of down-fracture, the surgeon can usually resolve airway obstructions, such as deviated septa and enlarged concha.
Synthetic bone is now considered to be nearly the equal of autogenous material. Dr. Wolford currently favors a coral, bone-like substitute that is osteo-conductive. He claims that within four months, bone will grow through the synthetic lattice.
Today’s oral surgeon evaluates the angulation of the occlusal plane and contemplates its alteration to increase facial height in short face, deep overbite patients, or to decrease facial height in long face retrognathic patients. The latter group can anticipate benefits in cases of sleep apnea and lip incompetence. (See: Wolford, LM, Chemello PD, Hilliard F. Occlusal plane alteration in Orthognathic Surgery - Part I: Effects on function and esthetics. Am J Orthod Dentofacial Orthop. 1994,106:304–316.)
Dr. Wolford continued to emphasize the theme that successful orthognathic surgeries depend on a sound temporomandibular joint and that this joint must be considered to be the foundation of a successful orthognathic surgery.
He cautioned that too often we misdiagnose disk displacements or fail to give them the serious consideration they merit. Internal derangement unleashes "a cascade of events that end in osteo-arthritis" more frequently than we realize. For the 25% of patients with displaced disks who present no symptoms, diagnosis presents a major challenge.
Patients with disk displacement who receive orthognathic surgery risk a higher incidence of complications. Loading tissues that have previously achieved an equilibrium can reactivate the disease process, which results in unacceptable post-surgical relapse.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Copyright © 1999 - 2006 Pacific Coast Society of Orthodontists. All Rights Reserved.
Please review our legal notices and privacy policy.
Created by WebResults.