CDE0211

10 I I MICD _ occlusal force management the clinical belief that the appearance of paper markings can indicate forceful contacts is flawed. Three large marks are present on tooth #16 and small scratchy marks on the mesial of tooth #17. Note the lightly exposed dentine on tooth #17, wherethescratchyredmarksarelocated.Visualin- spectionofthedarkmarksontooth#16isbelieved to indicate that high force contacts are present there. The clinician has been indoctrinated to believe that this is the case. Figure 11b shows the counter-arch paper marks with large black marks on tooth #46 and lighter marks on tooth #47. The T-Scan data shows that the small contacts present on the mesial aspect of tooth #17 are ac- tually a region of extreme occlusal force and the neighbouring three large dark marks on tooth #3 areactuallythreeregionsofverylowocclusalforce (Fig. 12). Notice that tooth #17 makes up 48 % of the patient’s right arch, half of the total occlusal forces. This explains why there is visible exposed dentine. Years of unseen occlusal overload on this tooth (and the opposing tooth #47) have worn the enamel, whereas tooth #16 with its very big, dark marks has intact enamel. Compared with the results of the T-Scan III, it becomes clear that the characteristics of paper markings do not in any way describe the occlusal forces. Computer-guided occlusal analysis illus- trates the true nature of the occlusal contact force patterns. This offers clinical insight about the degree of occlusal force demonstrated by articu- lating paper markings. Lastly, had the advocated “beliefs” about the character- istics of paper markings been usedasaguidefortheclinician who,inthiscase,wasattempt- ing to make decisions regard- ing occlusal adjustment to control force, the clinician would have clearly chosen the wrong teeth to adjust, despite seeking to diminish the oc- clusal overload. This example illustrates that clinicians’ eyes and the articulating paper markings do not illustrate occlusal forces reliably. Com- puter-guided occlusal analy- sis clarifies which articulating paper markings should be treated so that the operator makes appropriate treatment decisions as to which tooth contacts truly require force lessening. Therefore, T-Scan III technology represents the essence of MI dentistry with respect to dental occlusion. A clinician treats only what needs to be treated and should not perform random occlusal adjustments judged with the naked eye according to paper markings. This method of judging force is so prone to error that it will always have more in- vasiveresultsthanwhenproperlyperformedcom- puter-guided occlusal adjustment is employed. _Computer-guided occlusal analysis for a case of six anterior veneers Improvedforceandtimingofalltoothcontacts, both static and functional, can be precisely ad- justed when corrections to the paper labelling are guided by computer analysis. The following case illustrates the utilisation of computer-guided oc- clusal analysis to refine the protrusive movement on six anterior veneers. A 21-year-old female patient presented for re- placement of six anterior veneers owing to visible material fractures (Fig. 13). The old veneers were removed, the teeth were slightly re-prepared, and six new Empress II veneers (Ivoclar Vivadent) were placed (Fig. 14). Aftertheveneershadbeencuredandtheexcess bonding material trimmed, gross occlusal adjust- ments were performed to return the patient to the pre-treatment vertical dimension of occlu- sion. Although the lingual veneer margins were Fig. 15a_Paper markings of protrusive movement pre-treatment. Fig. 15b_T-Scan data of early protrusion. Fig. 15c_High force on distal incisal region #11. Fig. 16_Mid-treatment paper markings of protrusive movement. cosmeticdentistry 2_2011 Fig. 15c Fig. 16 Fig. 15a Fig. 15b