This video is a detailed dental lecture on instrumental analysis and treatment techniques for craniomandibular dysfunction (CMD). The presentation demonstrates a range of procedures, starting with a simple, chairside method for determining a therapeutic jaw position using a facebow for hinge axis location and an intraoral needle point (Gothic arch) tracing. It covers the subsequent steps of mounting dental casts on a semi-adjustable articulator, verifying the accuracy of the mounting, and adjusting a final occlusal splint. The lecture then progresses to more precise, laboratory-fabricated registration devices and advanced methods for capturing condylar movement, including protrusive records and electronic jaw motion analysis (axiography). The practical application of these principles is illustrated through two clinical case studies: one involving a patient with hypermobility and subluxation, and another with an anterior open bite resulting from a pituitary adenoma. The overall goal is to equip dental professionals with the knowledge to accurately diagnose and manage CMD through instrumental analysis and splint therapy.
Instrumental Analysis and Splint Therapy for Craniomandibular Dysfunction
0:26 Chairside Registration for Splint Therapy: The lecture begins by demonstrating a simple chairside procedure to establish a therapeutic jaw position for a splint. This involves creating custom intraoral needle point registration devices using impression material.
1:59 Facebow Transfer for Accurate Mounting: A facebow (SAM facebow shown) is used to record the spatial relationship of the patient's upper jaw to their hinge axis (jaw joints). This record is crucial for accurately transferring this relationship to a dental articulator, ensuring the models simulate the patient's actual anatomy.
6:08 Gothic Arch Tracing to Find Centric Relation: The process of intraoral needle point tracing is shown, where the patient's jaw movements create a "Gothic arch." The apex of this arch represents the centric relation, and a therapeutic position for the splint is typically chosen slightly anterior to this point.
13:32 Verification of Articulator Mounting: A critical verification step is recommended. A new interocclusal record is created on the mounted casts in the articulator and then taken back to the patient's mouth to check for a perfect, balanced fit. This confirms the accuracy of the entire mounting procedure.
18:40 Proper Splint Adjustment: After a splint is fabricated, it must be meticulously checked in the patient's mouth for both static occlusion (stable, even contacts) and dynamic occlusion (smooth anterior guidance with no posterior interferences during movement). The presenter stresses that any deflective contacts on a new splint likely indicate a technical error in the lab.
22:01 Advanced Laboratory-Fabricated Devices: For higher precision, laboratory-made resin tracing devices are recommended over simpler chairside ones. These devices are more rigid, do not interfere with occlusion, and allow for a minimal increase in vertical dimension, which reduces the potential for errors.
25:40 Recording Protrusive Movement: To program the articulator to mimic the patient's jaw movements accurately, a protrusive interocclusal record is taken. This allows the practitioner to set the condylar guidance angle on the articulator, which is essential for fabricating functional occlusal surfaces.
31:42 Electronic Jaw Motion Analysis: The lecture introduces electronic axiography systems as a more sophisticated and accurate method for analyzing jaw movement. These devices can simultaneously record movements on both sides, providing detailed data for programming the articulator and diagnosing complex dysfunctions.
40:22 Case Study 1: Hypermobility and Subluxation: A case is presented of a 40-year-old female patient with joint hypermobility and a history of subluxations. Treatment with a stabilization splint and physiotherapy successfully managed her condition, eliminating pain and preventing further subluxations.
45:02 Case Study 2: Anterior Open Bite: A second case details a patient with an anterior open bite caused by abnormal mandibular growth from a pituitary adenoma. A splint was fabricated with a significant anterior component to re-establish anterior guidance, which is critical for proper jaw function and is often the primary source of problems in such cases.