Dentistry Today Diagnosis Optimum Dental Care, Part 1 – The Diagnostic Phase
Diagnosis

Optimum Dental Care, Part 1 – The Diagnostic Phase

  • March 1, 2003
  • 15 minutes read
  • 22 years ago

Today’s general practice has the opportunity to offer a variety of services that will solve a wide range of problems. Optimum dental care requires the isolation of any factor that could contribute to the breakdown of the dentition. Additionally, it should provide the patient with the aesthetic result he may be looking for. It is in the integration of providing the want, while eliminating disease, that state-of-the-art care resides. The purpose of this 3-part article is to look at optimum dental care and to review technologies that will add predictability to all phases of treatment. This article discusses the diagnostic phase and why this is easily the most important aspect of treatment, as it determines the direction treatment will take. Part 2 will discuss the treatment phase and will show how to use provisional restorations to determine the necessary aesthetic and functional parameters for the patient. The final article will discuss case finishing, reviewing how we utilize current technologies to be sure we have realized all the aesthetic and physiologic goals of the plan.

 
Figure 1. Full smile frontal view-note the worn incisal plane. Figure 2. Full smile right lateral view.

Figure 3. Full smile left lateral view Figure 4. Retracted frontal view.

 

PATIENT DRIVEN

One of the most important advances in dental care is the realization that the patient’s wants as well as needs play a huge role in determining the direction of the treatment plan. For example, it is sometimes difficult for clinicians to realize that elective cosmetic dental procedures are completely about what the patient wants and what he or she views as aesthetic. Unless the patient has and expresses a desire to make a change, then a discussion of elective cosmetic procedures is simply inappropriate. 
One of the best ways to open up a dialogue is through the use of intraoral and extraoral digital photographs. The photographs (Figures 1 through 9) that can be used as part of the patient’s comprehensive examination are full face, smile, maxillary occlusal, mandibular occlusal, frontal retracted, right lateral retracted, and left lateral retracted. The photographs were taken with a Fuji S1 digital SLR camera. 
Printing these photographs, and combining them with a discussion of the patient’s long-term dental goals,will provide great insight regarding what he expects from the practice. The photographs are a powerful way for patients to see themselves in reality. The team will very quickly find out if an aesthetic component exists. It is also helpful to have before-and-after pictures of actual cases restored by the team to show the new patient, to get a clear idea of the look he is after. This also crystallizes in the patient’s mind that what he wants is possible, and creates motivation to accept treatment. 
AESTHETICALLY DRIVEN 
Visualizing the position of anterior teeth in the face is an excellent place to begin the evaluation process. Stepping away from the patient and viewing the flaws in the smile is a very important step. The previously mentioned photographs will provide the team with exquisite detail when viewing the aesthetic flaws. Two critical positions can be utilized to see if teeth could be lengthened from an aesthetic standpoint. The “E” position and “rest” position is a perfect starting point.1,2 
Figures 10 and 11 exhibit a patient with short maxillary teeth. In the “E” position, you have the patient say the letter “E” (Figure 10), holding the sound. The goal is to see the maxillary incisal edge equal distance between the upper and lower lip. If the edge is short of the halfway point, it is an indication that the teeth could be lengthened for a larger, fuller smile. 
Similarly, the rest position can be used to determine maxillary incisal length (Figure 11). Studies have indicated3 that at age 30, patients will show 3 mm of the maxillary central incisiors at rest, while 0.5 mm of the mandibular incisors are seen. By age 70, 0 mm of the maxillary incisors are displaced at rest, while 3 mm of the mandibular incisors are seen. To make a smile more youthful, therefore, requires making sure that an adequate amount of maxillary tooth is seen in the rest position. 
Photographing the “E” and “rest” positions is great information to utilize when waxing the case prior to restoration. It allows the dentist to wax the increased length and properly visualize the proposed changes on the diagnostic casts. Provisionals can be fabricated from the wax-up with the new length and then tested aesthetically, phonetically, and functionally in the treatment phase. This will add necessary objective data when determining the ideal aesthetic contours for the patient. The net result is a more predictable process to solving complex aesthetic problems.

 
Figure 5. Retracted left lateral view. Figure 6. Retracted right lateral view.

Figure 7. Full face Figure 8. Mandibular occlusal view- note wear onanterior teeth.

 

 

FUNCTIONALLY DRIVEN
While the topic of occlusion remains a heated subject in the dental community, some very interesting technological advances allow us to objectively evaluate the patient in a way that previously has been impossible. These improvements now allow us to measure many aspects of the gnathostomatic system, eliminating many of t
he subjective aspects of the examination process. This physiological approach to patient evaluation is an exciting addition to every dental practice. The functional aspects of the plan can be broken into different aspects of the system. They are the TM joint, muscles of mastication, and the teeth. Today, technologies exist to objectively evaluate each part of the system. Objective data is information that can be measured and compared and does not rely on subjective interpretation.

The TM Joint

Joint vibration analysis (JVA) is based on simple principles of motion and friction. If surfaces are smooth, little friction exists and vibrations are minimal (Figure 12). If surfaces are rough through pathologic breakdown, friction will increase and specific vibrations will be observed. Different disorders produce different vibration patterns or “signatures.” 4-6 Using computer enhanced JVA, the restorative dentist can quickly identify a healthy joint from others with a variety of pathologic problems. 
It takes approximately 2 minutes to conduct a JVA on a patient. It can be delegated to a staff person, and both joints can be recorded simultaneously. This allows the doctor to read the vibrations at a convenient time. Figure 13 exhibits the bilateral JVA of the example patient. 
Like JVA, TMJ Doppler auscultation is another good way to hear joint noise. When applied carefully, the Doppler yields highly reliable information about the status of the condyle-disc assembly, and it provides further clues as to the existence of other pathology such as perforations, joint space adhesions, and inflammation in the retrodiscal tissues.7-10 
Unlike JVA, the clinician must hear and interpret the sounds one joint at a time. This is a more subjective analysis, and a bit more labor intensive for the doctor, during the records-gathering process Load testing remains a valuable tool to quickly access the health of the joint and general position of the articular disc.11-14 The T joint is a load-bearing joint. Therefore, in a healthy individual, it should be able to accept firm pressure. Using bilateral manipulation described by Dawson11, one can firmly seat the condyle into the eminence and ultimately the glenoid fossa (Figure 14). If the disc is anteriorly displaced, then the highly innervated retrodiscal tissue will be pinched between the condlye and eminence. This will immediately induce a painful response. If, however, the disc is in the proper position, the patient can accept firm loading without any sign of tension or tenderness in either joint. 
Imaging in the form of panoramic radiographs offers an excellent screening device to evaluate gross bony changes on the medial pole of the condyle or other problems such as fractures and tumors.15 For detailed information with patients who have signs or symptoms of craniomandibular disorders, additional imaging may be required. 
Tomograms are views of a preselected plane of joint anatomy, from a 0.5- to 10-mm thickness, produced by synchronous movement of the x-ray source and the film during exposure. With this technique, several “slices” or images can be made through the joint. The patient experiences nothing more than a series of x-rays. If tomographic examinations are done skillfully and interpreted well, the major advantage over plain films is that clear images of all portions of the bony articulating surfaces are provided (medial pole, mid-condylar area, and lateral pole), so that abnormalities that are not shown in conventional films are revealed.16 
Over the last few years, Magnetic resonance imaging (MRI) has become a dominant modality in medical diagnosis of TMJ pathology. The critical features of the MRI are detailed images of bone and soft tissues that are produced by computer-aided analysis of signals from within the body (Figure 15). This is produced without using x-rays and without injection contrast, thereby eliminating the concern of exposure to ionizing radiation. In addition, the process is painless. The major benefits of this image are the ability to see soft tissue and its detailed relationship to the condlyle. Conditions such as intra-articular restricted mouth opening, disc displacements, and degeneration can be diagnosed with 80% accuracy.17-19 
MUSCLE EVALUATION 
While muscle palpation is still the standard method of evaluating the muscles of mastication,20 it remains a very subjective analysis. The use of surface electromyography is an excellent way to objectively analyze these muscles before, during, and after treatment. 
According to the published scientific literature, patients with TMDs have statistically (P < 0.05) higher activity at rest than normal controls (Figures 16 and 17).21 This higher activity may be due to occlusal interferences or some other structural deficiency. Additionally, muscles can be evaluated during all aspects of occlusal function (Figures 18 and 19). It has been have shown that a properly adjusted occlusion (correct anterior guidance) allows the elevator muscles (masseter and temporalis) to “shut down” during any excursive movement. Figure 19 exhibits increased elevator muscle activity during various mandibular movements.22-24 Using EMG to be sure that the restorative team has reduced muscle activity during the treatment phase adds tremendous confidence that the prescribed plan of decreasing damaging forces to the system has been successful.

 
Figure 9. Maxillary occlusal view-note extreme wear. Figure 10. “E” position: Ideally the maxillary incisal edge should be half the distance between the upper and lower lip. Evidence that these teeth are short from an aesthetic perspective.

Figure 11. “Rest” position: From an aesthetic standpoint, 1 to 3 mm of tooth structure should be seen at rest. This patient’s teeth could be lengthened.

 
Figure 12. Joint vibration analysis: Smooth surfaces elicit a flat wav
e pattern; rough or diseased surfaces will display a variety of “signature” vibrations.

 

Dental Evaluation(Wear, Mobility, Migration) 

A thorough inspection of the teeth for signs of wear, migration, and mobility is necessary to access the dental component of occlusal breakdown. Patterns of parafunction should also be evaluated to see if they are associated with the damaged structures. treatment?

 

Diagnostic Photos
Like the aesthetic evaluation, photography is an essential part of the occlusal examination. It allows the restorative dentist to closely evaluate the surfaces of the teeth and shows the patient potential problems such as wear.

Mounted Diagnostic Casts

Mounted diagnostic models (mounted with a face-bow and centric bite registration, Figure 20), allow the doctor to closely evaluate all aspects of the occlusion. This allows corrections to be made to the models to see what has to be done to fulfill the requirements of an ideal occlusal scheme.
Figure 13. The green sine wave is the pattern the patient follows during opening and closing. The purple wave patterns display the vibrations in both joints simultaneously. With a little practice, it is easy to recognize a variety of common TM joint problems Figure 14. The TMJ showing the ideal relationship of the condyle-disc assembly.
Figure 15. A magnetic resonance image (MRI). The arrows indicate the position of an anteriorly displaced disc. Figure 16. Patient readied for electromyographic recording of the anterior temporalis, masseter, digastric and sternocleidomastoid muscles, bilaterally.

 

 


Antimicrobially Driven
Traditional dental examinations have been focused on evaluating the deleterious effects of bacterial breakdown of the dentition. Whether this breakdown is in the form of caries or periodontal disease, a full dental examination should include a full periodontal probing and a tooth-by-tooth examination for caries. Additionally, a full-mouth series of radiographs will allow the restoring dentist to uncover any area that is breaking down or not cleansable by the patient. Traditional periodontal therapy and general dental procedures can be outlined to restore the mouth to a disease-free state.

 
Figure 17. EMG recording of muscles at rest illustrates the difference between peaceful and hyperactive neuromusculature. Figure 18. Right lateral working movement. The worn anterior teeth have caused numerous posterior interferences on the working and balancing side.

Figure 19. EMG recording of the right lateral movement from Figure 18. The patient was instructed to clench at the 2-second mark, holding until second 4, then sliding into a right working movement. Note the sustained hyper-contraction of the right temporalis and masseter, and to a lesser degree, the left temporalis. Figure 20. Mounted diagnostic casts. Mounted on a Sam III articulator with a facebow and a centric relation record. Three-dimensional visualization for optimum care will be worked out in wax. This 3-D picture will drive the plan.

RESTORATION DRIVEN

The last thing to treatment plan is the specific restoration of each individual tooth. Once the aesthetic, functional, and microbiological aspects have been properly visualized, it is then appropriate to develop a tooth-by-tooth plan for the individual restorations. Using the clinical findings, radiographs, and models, additional procedures such as crown lengthening, buildups, and post and cores need to be considered so that each tooth will be optimally restored. While some excellent articles have been written outlining the specific materials for different clinical situations, it is my goal to choose a restoration that will conserve the most amount of tooth structure and give the patient the best long-term results from an aesthetic as well as a functional standpoint.25

A CONCEPTUAL APPROACH

This article has reviewed a process as well as current technologies that will help the dental team identify a wide range of problems. Once the aesthetic and functional aspects of the case are identified, the restoring dentist can conceptually visualize a 3-dimensional plan of tooth position and contour. This 3-dimensional plan is designed to place the teeth in a position of optimum aesthetics and optimum function. These goals should be waxed onto the mounted diagnostic casts, shared with the patient, and then utilized as a guide in the treatment phase. This information can then be incorporated with the periodontal and clinical data that were gathered to plan the necessary procedures to restore the mouth to a maintainably healthy state. 
Spending a little extra time up front to clearly understand the patie’s wants, combined with the disease processes that need to be corrected, will add tremendous predictability in solving patients’ aesthetic, functional, and general dental problems. 
References 
1. Lerner JM, Rosenthal L, Kim JJ. The diagnostic wax-up: a blueprint for predictable success. Contemp Esthet Restor Pract. May 2002:46-56. 
2. Refenenacht CR. Fundamentals of Esthetics. Chicago, Ill: Quintessence Publishing Co; 1990:186. 
3. Vig RG, Brundo GC. The kinetics of anterior tooth display.
J Prosthet Dent. 1978;39:502-504. 
4. Eriksson L, Westesson PL, Sjjobert H. Observer performance in describing temporomandibular joint sounds. J Craniomandib Pract. 1987;5:32-35. 
5. Dworkin SF, Lereshche L, Derouer T. Subject reliability of clinical measurement and temporomandibular disorders. Clin J Pain. 1988;4:89-99. 
6. Christensen LV, Donegan SJ, McKay DC. Temporomandibular joint vibration analysis in a sample of non-patients. J Craniomandib Pract. 1992;10:35-41. 
7. Ishigaki S, Bessette R, Maruyama T. A clinical study of TMJ vibrations in TMJ dysfunction patients. J Craniomandib Pract. 1993;11:7-13. 
8. Stegenga B, DeBont L, Boering G, et al. Tissue responses to degenerative changes in the TMJ: a review. J Oral Maxillofac Surg. 1991:49:1079-1088. 
9. Hans M, Lieberman J, Goldberg J, et al. A comparison of clinical examination, history and mri for identifying orthodontic patients with temporomandibular disorders. AMJ Orthod Dentofac Orthop. 1992;101:54-59. 
10. Watt DM. Temporomandibular joint sounds. J Dent. 1980;8:119-127. 
11. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. 2nd ed. St Louis, Mo: Mosby; 1989:39-47. 
12. Okeson J. Fundamentals of Occlusion and Temporormandibular Disorders. St Louis, Mo: C.V. Mosby; 1985. 
13. Mongini F. Influence of function on temmporomandibular joint remodeling and degeneratiave disease. Dent Clin North Am. 1983;27:479-494. 
14. Williamson E, Navarro E, Zwemer J. A comparison of the EMF activity between anterior reposition splint therapy and a centric relation splint. J Craniomand Pract. 1993;11:178-183. 
15. Chilvarquer I. A new technique for imaging the TMJ with a panoramic x-ray machine. Oral Surg Oral Med Oral Pathol. 1988;65:626. 
16. LGM de Bont. Computed tomography in differential diagnosis of TMJ disorders. Int J Oral Maxillofacial Surg. 1993;22:200-209. 
17. Santler G. MR diagnosis and intraoperative findings. J Cranio-maxillafacial Surg. 1993;21:284-288. 
18. Katzberg RW. Magnetic resonance imaging of the TMJ Meniscus. Oral Surg Oral Med Oral Patho. 1985; 59:332-335. 
19. Schellhas KP. The diagnosis of TMJ disease: two-compartment arthrography and MR. Am J Radio. 1988;151:341-350. 
20. Braun B, Schiffman E. The validity and predictive value of four assessment instruments for evaluation of the cervical and stomatognathic system. J Craniomandib Disord Facial Oral Pain. 1991;5:239-244. 
21. Burdette BH, Gale EN. The effects of treatment on masticatory muscle activity and mandibular posture in myofascial pain-dysfunction patients. J Dent Res. 1988;67:1126-1130. 
22. Williamson EH, Lundquiest DO. Anterior guidance. Its effect on EMG activity of the temporal and masseter muscle. J Prosthet Dent. 1983;49:816. 
23. Manns A, Rocabado M, Cadenasso P, et al. The immediate effect of the variation of anterioposterior laterotrusive contact on elevator EMG activity. J Craniomandib Pract. 1993;11:184-191. 
24. Riise C, Sheckholestan A. The influence of experimental Interfering occlusal contact on postural activity of the anterior temporal and masseter muscles in young adults. J Oral Rehabil. 1982;9:419-425. 
25. Chiche GJ, Pinault A. Esthetics of Anterior Fixed Prosthodontics. Chicago, Ill: Quintessence Publishing Co; 1994:121-123.

 

 

Dr. Cranham has an aesthetic oriented restorative practice in Chesapeake, Va. An honors graduate of the Medical College of Virginia in 1988, Dr. Cranham maintains a strong relationship with his alma mata, where he is an associate clinical professor, teaching in the graduate prosthodontics and AEGD programs. He was also appointed to serve for 2 years on the school’s board of advisors. He is an internationally recognized speaker on the Esthetic Principles of Smile Design, Contemporary Occlusal Concepts, Laboratory Communication, and Happiness and Fulfillment in Dentistry. After 2 years as a faculty member for Ross Nash Seminars (The Esthetic Epitome), Dr. Cranham has founded Cranham Dental Seminars, which provide a combination of lecture, mobile hands-on programs, and intensive 2- to 3-day hands-on experiences (The Predictable Restorative Excellence Series) at his office in Chesapeake. Additionally, he provides occlusion lectures for Dr. Larry Rosenthal’s Aesthetic Advantage in New York City, NY, and West Palm Beach, Fla. A published author, Dr. Cranham has a strong commitment to developing sound educational programs that exceed the needs of today’s dental professional. He can be reached at smildoc@aol.com or visit cranhamdentalseminars.com.