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.