Discussion

The present case report is concentrated on the treatment plan for a patient with pathologic deep bite, progressive wear, and anterior deep bite. The pathological deep bite has signs and symptoms (including traumatic palatal soft tissues, unstable occlusion, tooth wear, and aesthetic issues) that their treatment process may demand decisions like orthodontic treatment or reshaping or compromised restorations(14). One of the challenges in the treatment of deep bite patients is the limited available space for placement of the required restorations. These conditions become increasingly complicated when the occlusal wear occurs in a deep bite occlusion.
The compensatory dentoalveolar growth, which occurs continuously and following wear issues, fills the space required for the reconstruction of the worn teeth. Under these circumstances, the following treatment options can be used to provide the space needed for retention, stability, and aesthetics:
1. Orthodontic intrusion and proclination of the supra-erupted teeth
2. Teeth reduction in the same or opposite arch, occlusal plane correction, and occlusal reconstruction with and without surgical crown lengthening.
3. Temporally increasing the VDO in posterior teeth (using Dahl appliance, direct or indirect restorations with full or partial coverage, and orthodontic extrusion of posterior teeth)
4. Elective endodontic procedure to provide adequate space and grip from inside of the dental structure using the post-retained restorations or Richmond crown(15, 16).
Each of these treatment options has its particular indications and considerations. On the other hand, the wear of buccal surfaces of the anterior teeth in the lower jaw (which also occurred in the present case) is another problem that demands reconstructing anterior guidance.
VDO can be increased using the fixed prosthesis or removable appliance. Concerning the method applied to increase the VDO, those studies that used the fixed prosthesis reported fewer complications compared to those that used the removability feature. The Dahl technique utilizes a local appliance or restoration in the supra-occlusion position on the anterior teeth, allowing the posterior teeth to extrude and anterior teeth intrude to achieve full arch contacts over a time period. However, the success of this appliance is fully dependent on the patient’s cooperation. Several complications have been reported, including TMJ dysfunction, possible tenderness during treatment, sensitivity, unpredictable tooth movement, and tilt or drift of other teeth(17). Another method for increasing the VDO includes orthodontic extrusion, usually the posterior extrusion of teeth combined with anterior-posterior repositioning of anterior teeth with limited intrusion. Nevertheless, the intrusion is much more complicated in adults, and orthodontic treatment requires a time duration of 6-12 months, which is significant for equalizing the mesiodistal spacing that occurs during the teeth forward movement(18). A better therapeutic option to gain space in this patient is fixed dahl technique, which is basically a anterior bite block in order to create space in anterior section allowing us to properly restore patients anterior guidance and esthetics while posterior teeth untouched and in contact.
Space gained by this technique in 40% anterior intrusion and 60% extrusion of posterior teeth in 10 week time period. By literature during a year original VDO is regained by muscles. It is by far the most conservative while effective treatment plants for this case.
Conservative ceramic coverage is the most durable aesthetic option among the mentioned restorative methods. However, design selection, proper preparation, skillful ceramist and choosing the ceramic material play a significant role in the long-term success of this treatment. Numerous factors, including the amount of remaining tooth structure, restoration material type, finish line design, restoration thickness, and cement types, can affect the mechanical behavior of occlusal veneers. There are various ceramic materials that can potentially be used in low thickness for high-stress situations. High-glass ceramics have lower compressive strength, whereas the low-glass types such as lithium disilicate (LDS), zirconia-reinforced lithium silicate (ZLS), and hybrid ceramics offer appropriate aesthetics and much higher strength. Bonding of glass ceramics is one of their significant properties for partial coverage restoration applications(19).
While composite resin, LDS, ZLS, and hybrid ceramics can be employed for posterior occlusal coverage, disagreement exists in the literature regarding the superiority of composite resin or ceramic restoration(20). In the present case, composite occlusal veneers were utilized to increase the VDO, which seems to be a conservative treatment. Given the higher aesthetic characteristics of ceramic laminates, disilicate lithium laminates were eventually constructed for the anterior teeth of both jaws. However, both approaches had a reliable performance for both functional and aesthetic purposes. Long-term clinical trials are needed to find the best material, thickness, and treatment plan.