CATEGORY AUSTRALASIAN DENTIST 75 CLINICAL patient reported TMD symptoms and an attempt at occlusal equilibration resulted in a negligible improvement to 20% (Table 1). The only way to create a stable protective occlusal scheme was to perform an occlusal reconstruction at an increased vertical dimension. The treatment plan involved gold crowns with molar guidance on all second molars at an increased vertical dimension, initially amalgam crowns followed by ceramic crowns on the first molars to create full contacts in hinge occlusion. Finally, ceramic crowns on the 11 and 21 teeth with protrusive ramps (Darveniza 2001) for mid to final protrusive path. The remaining incisors and premolars were unrestored and in open bite. To bio-design molar guidance involved making direct temporary acrylic resin (white Duralay, Reliance Manufacturing) crowns aided by a molar metal template crown shell (Iso-Form crowns, 3M). After filling the shell with resin and seating it orally on the prepared tooth it was removed and cured in hot water and the metal template sectioned off. Further additions of resin and selective grinding were performed until all design elements were achieved for molar guidance. Alginate impressions of the temporary crowns was followed by fabrication of plaster models allowing duplication of the design elements for crown construction. At the 17 years follow up the patient six reported a 100% improvement of their TMD including restoration of normal mouth opening and was still wearing the splint nocturnally. Patients one and 161 Both dolichofacial patients with premolar and anterior open bites had the following TMD symptoms including TMJ pain, chronic restricted mouth opening, clicking TMJs and painful masseter and temporalis muscles (Table 1). These patients underwent ‘full occlusal therapy’ with molar guidance crowns as indicated at the existing vertical dimension and claimed a 100% resolution of their TMD at follow up of nine years. This included restoration of normal mouth opening and cessation of all clicking (Table1). Patient one was wearing the splint at the nine year followup whereas patient 161 was not. Results Molar guidance was performed on three out of 200 patients namely, numbers one, six and 161. All reported 100% improvement of their TMD (Table 1). These above patients’ improvement, following formal fully protective occlusal splint therapy with full counselling, was only 30%, 10% and 60 % respectively. These patients continued onto occlusal equilibration with only a slight improvement to 60%, 20% and 70% respectively. They were all rewarded with an 100% improvement on completion of molar guidance and the follow-up was 9, 17 and 9 years, respectively. Patients one and six were wearing their splints at their respective follow up (Table 1). Discussion A TMD patient who grinds their teeth without restrictive lateral ridges creates a horizonto-lateral or disto-lateral destructive vector which results in damage to the teeth, fatigue to the muscles of mastication and stretching of TMJ ligaments often resulting in disc displacement (De Coster et al. 2005, Shore 1970). The three patients with various degrees of disc displacement were bio-designed molar guidance (after other occlusal therapies and full counselling) and claimed a 100% improvement in signs and symptoms (Table 1). This result was achieved, in part, by bio-designing lateral restriction with a crown on a molar which stabilized the re-centring discs following splint therapy and occlusal equilibration. This bio-designed guidance restricts the patient’s ability to continue stretching the TMJ ligaments by preventing the mandible moving into a destructive vector. With the absence of overly stretched ligaments and destructive (Alpern and Wharton 1997) mandibular vectors, future disc displacement can be minimized, and the TMD symptoms resolved. This type of patient was advised that the restoration of such a tooth was to create a protective left or right movement; but this would modify but not stop bruxism and nocturnal use of a fully protective occlusal splint was mandatory. The author has found no studies on molar guidance for occlusal reconstruction other than the use of first molar guidance instead of canine guidance for occlusal splints using EMG and the course of symptomatology for evaluation (Graham 1986, Graham 1988, Rugh 1989). The results indicated decreased muscle activity and symptoms in both lateral guidance groups and with no significant difference Early molar rise path Final protrusive path on 11 unilaterally Mid molar rise path Final molar rise path Final protrusive path on 11 and 21 bilaterally Final molar rise path Fig. 5 An antero-lateral view of direct bio-designed acrylic resin temporary crowns on 27 and 37 during molar rise, for patient six in 1991. The view on the left shows left lateral mandibular movement in early path with molar guidance, generating a vertico-lateral protective vector. The right view shows final path ending at edge-toedge lateral occlusion. Fig. 7 The left view during treatment, shows a unilateral contact of 11 and 42 at edge to edge protrusive developing a non-sagittal unprotected protrusive path. The gold crowns on 17 and 27 had protrusive ramps built-in to the mesial fossa to create early to mid-protrusive path against a lower buccal cusp. The right view shows crowns placed later on the 11 and 21 teeth which had protrusive ramps placed on the palatal surface for mid to final path along with longer incisal edges. Fig. 6 An antero-lateral view of the completed gold crowns on 27 and 37 in left lateral occlusion. The left view shows molar rise at mid-lateral path guided by the mesio-buccal cusp of 37 on the palatal side of the mesio-buccal cusp of 27. The right view shows the final molar rise path at edge to edge ending on the landing pad of the mesio-buccal cusp of the 27 tooth, with disclusion of the canines by about 2mm. This represents a protective left lateral occlusion with the required vertico-lateral mandibular vector.
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