December 1, 2006
by Bruce Kleeberger, BSc, DDS
Often patients present in our offices with aesthetic and functional problems which require addressing issues such as excessive overbite and insufficient posterior crown height. This case presentation will demonstrate treatment planning for a multiple disciplinary approach to the restoration of a dentition with reduced restorative dimension posteriorly, excessive overjet and severe overbite. Provisional laboratory processed restorations were used to increase vertical dimension to facilitate orthodontic therapy and then replaced during the definitive restorative phase.
Most dental practices have patients of record who have extensive failing dental restorations but for many reasons do not accept recommendations for comprehensive restorative therapy. Many of these patients at some point in time develop an interest in preserving their remaining dentition for their lifetime. The restoration of dentitions which are characterized by multiple failing restorations together with teeth which have drifted into un-restorable bite relationships may be impossible to manage without a multiple disciplinary approach.1
In this case study the patient presented with a known history of parafunction, masticatory system symptoms including pain and fractured teeth compromised by a significant malocclusion. Restoration required management of symptoms created by the parafunctional activity, orthodontic treatment to decompensate the malocclusion, and finally comprehensive restoration of the fractured and worn teeth. The pre-orthodontic restoration of the mandibular teeth served to protect the failing molars and open the bite to facilitate the orthodontic treatment. Post-orthodontic retention and stability of the bite opening accomplished provisionally is not predictably stable2 and must be monitored before the definitive restoration.
HISTORY AND DIAGNOSIS
The patient, J.W., age 53, attended the dental clinic with chief complaint of symptoms in the muscles of mastication and temporomandibular joints bilaterally. In addition there were fractured posterior teeth associated with old amalgam restorations and dissatisfaction with the aesthetics of the anterior teeth and dark posterior restorations
Comprehensive pre-treatment records (Figs. 1-6) were obtained and history taken. Cephalometric analysis revealed a mild Angle Class II skeletal, Class II, division 1 subdivision left dental malocclusion with dental compensations including increased overjet, overbite and splaying of maxillary incisors but with flat mandibular Curve of Spee. There was significant tenderness of the muscles of mastication on palpation. There was also excessive wear and an awareness of parafunctional habits (clenching) but there was no joint pathology apparent with palpation or Doppler auscultation. Several molar teeth had fractured cusps. The posterior teeth crown height was significantly reduced. Periodontal health was acceptable except for the upper right bicuspid, which was associated with an 8mm interproximal defect.
In consultation with J.W., and with the aid of an orthodontic set-up (Figs. 7-9) the following treatment plan was determined:
– Provisional management of the muscle symptoms with anterior deprogramming appliance (NTI).
– Removal of hopeless upper right bicuspid tooth.
– Temporary restoration of the mandibular posterior teeth to preserve them for the period of orthodontic treatment and to open the bite and disclude the anterior teeth to permit maxillary anterior retraction during orthodontic pre-prosthetic alignment (and thereby reduce the amount of time required to complete the orthodontic alignment).
– Orthodontic alignment predominantly including space closure and maxillary retraction with maximum maxillary anchorage (transpalatal arch with headgear tubes).
– Definitive restoration of the anterior and bicuspid teeth at the vertical dimension achieved by provisional posterior restoration.
– Definitive restoration of the molar teeth.
– Long term management of the parafunctional habit with bruxism appliance.
An anterior deprogramming device (NTI Tension Suppression System, www.nti-tss.com) was customized to provide relief from muscle symptoms. Other deprogrammers3 can also be used for this purpose, but the NTI is particularly easily adjusted and this was a benefit during orthodontic treatment in this case. Within weeks of sleep time wear, the symptoms had abated. Working models were prepared, mounted and verified for centric relation mounting accuracy on the SAM 3 semi-adjustable articulator (Great Lakes Orthodontics). A wax-up of the mandibular molar and bicuspid teeth and a stent for intra-oral provisional fabrication were made in the laboratory.
The patient attended for preparation of the mandibular posterior teeth and records for laboratory fabrication of long term temporary restorations (as these restorations would be functional for up to 24 months, ceramic bonded restoration were prepared for the bicuspid teeth and gold crowns were fabricated for the molar teeth). The restorations were inserted at an appointment 2 weeks subsequent to the preparation appointment.
The upper right second bicuspid was extracted and the maxillary straight-wire orthodontic appliance bonded. A trans-palatal arch ensured adequate maxillary posterior anchorage to aid in the anterior retraction. The mandibular straight wire appliance was bonded 10 months after the initiation of orthodontic treatment. The orthodontic alignment was completed in 24 months (Figs. 10-12). The NTI deprogrammer was easily adjusted to be worn as needed during the orthodontic phase.
After completion of orthodontic treatment, (Figs. 13-17) a provisional night guard was supplied with minimal posterior thickness and anterior disclusion to be worn for 6 months. Its purpose was to permit settling of the dentition, to be an orthodontic retainer and serve as an interim bruxism appliance. This time period is also important to monitor stability of the bite opening achieved with the mandibular provisional restoration provided at the beginning of orthodontic therapy. This is the most critical opportunity to evaluate the stability of the increased vertical dimension in the early months of the restorative bite opening procedures.
Finally, once the patient had tested the new provisional vertical dimension sufficiently (for six months), and was free of muscle or joint symptoms, the records for the wax-up for the definitive restoration were prepared. In conjunction with an intra-oral mock-up, photographs and mounting on the semi-adjustable articulator, the restorative wax-up for the anterior and bicuspid teeth was created in the laboratory. The teeth were then prepared according to the Biomimetic approach described by Magne4,5 restored over a two-week period with diagnostic, patient approved provisionals in place (Figs. 18-19).
Following restoration of the anterior teeth, an assessment of the muscle and joint health revealed absence of symptoms or dysfunction, the molar teeth were restored with laboratory fabricated restorations (Figs. 20-26).
Remaining asymptomatic, J.W. was then provided with a equilibrated maxillary, full coverage, anterior discluding splint for wear when sleeping to guard against excessive wear and to serve as an orthodontic retainer.
Careful treatment planning involves thorough assessment of the entire stomatomatic system and consultation with the patient to ensure all needs and wants are met. It is particularly important that complex interdisciplinary treatment plans begin with the final outcome in mind.
The use of orthodontic treatment to assist in the restoration of a compromised dentition can be the optimal treatment which minimizes tooth preparation and tooth loss while providing an excellent aesthetic and functional result.
Dr. Kleeberger is a general practitioner in full time practic
e in Langley, British Columbia. He graduated from the University of Alberta in 1978 and is an alumnus of the Millenium Institute in Calgary and of PAC~Live programs at UOP in San Francisco. He mentors study clubs and presents courses in Aesthetic Restorative dentistry, materials and treatment planning. firstname.lastname@example.org
The author mentors the Fraser Valley Dental Fundamentals Study Club which is in part supported by Dentsply Canada
Oral Health welcomes this original article.
1.Ascheim, K., Dale, B., Esthetic Dentistry 2nd Ed.. Mosby: 2001.
2.Dawson, P.E. Functional Occlusion From TMJ to Smile Design St. Louis, MO: Mosby Esvier: 2007.
3.Spear, F. Occlusion in Clinical Practice. Seattle Institute for Advanced Dental Education, Seattle, WA, 2003.
4.Magne, P., Belser, U. Bonded Porcelain Restorations, A Biomimetic Approach. Quintessence Pub: 2002.
5.Magne, P, Belser, U, Novel porcelain laminate preparation approach driven by a diagnostic mock-up. JERD 16:01 Jan 04 page 7-19.