A patient presentation: Planning and executing a difficult case in a full digital workflow

Does increasing vertical dimension of occlusion in centric relation affect muscular activity? An electromyographic study

OBJECTIVE

In many esthetic treatments, clinicians may consider the option to modify the maxillo mandibular position. A raise of the vertical dimension of occlusion (VDO) may help restore esthetics, increase the space for dental materials, and reduce the invasiveness of dental procedures. Traditionally, VDO increases are done by using the centric relation (CR) position. Despite a long history of use, the neuromuscular effects of different maxillo mandibular relations are not fully studied. The aim of this study was to investigate the effect of alterations of maxillo-mandibular relation from maximal intercuspal position (MIP) to a raised VDO CR position on jaw-elevator muscle activity.

MATERIALS AND METHODS

Fifteen healthy individuals were asked to carry out maximal voluntary clenching (MVC) in MIP and in CR on individual splints. Electromyographic (EMG) activity of the masseter and anterior temporalis muscles was assessed in μV as the root mean square of the amplitude. Specific indexes and ratios were also computed. Data analyzed in MIP and CR were compared by paired student's t-tests.

RESULTS

MVC levels were not negatively affected by a VDO increase in CR position. On the contrary masseter muscles showed a statistically significant increase (p < 0.005). No significant effect on the anterior temporalis was observed.

CONCLUSION

These results suggest that no immediate negative effect on maximum voluntary clenching was induced by a VDO increase in CR position. A slight increase observed in EMG clenching levels could be explained by the increase in VDO when clenching on the splint.

CLINICAL IMPLICATIONS

The results of this study support the use of CR position as a pragmatic reference position due to the absence of relevant or negative changes in neuromuscular function.

Full-mouth rehabilitation in a completely digital workflow using partially adhesive monolithic zirconia restorations

OBJECTIVE

This clinical case describes a completely digital workflow using current digital technologies for a full-mouth adhesive rehabilitation with ultra-translucent multilayer zirconia restorations.

CLINICAL CONSIDERATIONS

A healthy 60-year-old man with abfractions on all upper and lower molars and severe tooth wear underwent a full-mouth rehabilitation with laminate veneers and partial adhesive restorations. A proper zirconia bonding protocol was realized to provide a durable bond between the ultra-translucent zirconia and the resin cement. Furthermore, the implementation of a digital workflow enables the clinician to have an effective communication during treatment planning and simplify the clinical and laboratory procedures, providing the patient with long-term esthetic treatment and functional results.

CONCLUSION

The implementation of a completely digital workflow and the use of ultra-translucent multilayer zirconia for indirect adhesive restorations can be an alternative with simplified and predictable procedures for patients with dental wear and teeth discolorations.

CLINICAL SIGNIFICANCE

The digital workflow described is intended to facilitate the planning and execution of a full-mouth adhesive rehabilitation and demonstrates to clinicians a reliable zirconia bonding concept for minimally invasive anterior and posterior restorations.

Aesthetic and functional rehabilitation of collapsed occlusal vertical dimension using an advanced digital workflow

This report presents a clinical case that follows a comprehensive digital workflow to increase occlusal vertical dimension of a patient presenting with occlusal wear. A 56-year-old patient with aesthetic and functional problems presented to the authors' clinic. An intraoral scanner was used to obtain digital models of the patient's existing maxillary and mandibular arches. Advanced sculpting software and digital tooth libraries were used to design the patient's ideal smile. A three-dimensional (3D) printer was used to fabricate temporary restorations and resin casts. Full-mouth restoration was successfully completed with zirconia crowns using an advanced digital workflow.

Interdisciplinary 3D digital treatment simulation before complex esthetic rehabilitation of orthodontic, orthognathic and prosthetic treatment: workflow establishment and primary evaluation

Background

An interdisciplinary treatment simulation and smile design before a complex esthetic rehabilitation is important for clinicians’ decision-making and patient motivation. Meanwhile, intervention and interaction are necessary for dental specialists in these complex rehabilitations. However, it is difficult to visualize an interdisciplinary treatment plan by using the conventional method, especially when orthognathic surgery is involved, thus hindering communication between dental specialists. This research aims to establish a 3D digital workflow of interdisciplinary treatment simulation to solve this problem.

Methods

An interdisciplinary 3D digital workflow of simulated treatment plan for complex esthetic rehabilitation was established. Eleven patients were enrolled and illustrated with their treatment plans using 3D treatment simulation, as well as 2D digital smile design (DSD) plus wax-up. Visual analogue scales (VAS) were used to rate the intuitiveness, understanding, and satisfaction or help between the two methods by patients and dental specialists.

Results

According to the ratings from the patients, 3D treatment simulation showed obvious advantages in the aspects of intuitiveness (9.7 ± 0.5 vs 6.4 ± 1.4) and treatment understanding (9.1 ± 0.8 vs 6.6 ± 1.5), and the satisfaction rates were also higher (9.0 ± 0.6 vs 7.1 ± 1.8). Dental specialists regarded the 3D digital plans as more intuitive (8.9 ± 0.8 vs 5.9 ± 1.0) and useful to understand the plans from the other specialists (8.9 ± 0.7 vs 6.1 ± 1.0) and helpful to their own treatment plans (8.7 ± 0.9 vs 5.9 ± 1.4).

Conclusions

The interdisciplinary 3D digital treatment simulation helps both patients and dental specialists to improve treatment understanding, and facilitates dental specialists for decision-making before complex esthetic rehabilitation.

Trial registration

This study was registered in the National Clinical Trials Registry under the identification number MR-11-20-002862. This is an observational study in which we did not assign the intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02070-z.