Creating an Extraordinary Outcome With Ordinary Digital Planning
A systematic approach to manage esthetic, functional, and biomechanical concerns while minimizing risk
Ellen Katz, DDS
Restorative dental teams often may be unsure how to approach a complex case, as many different avenues may be available to accomplish a successful outcome. This case report demonstrates a systematic approach to data collection and diagnosis, followed by a process for risk assessment and the creation of an appropriate treatment plan. It shows that with careful execution, successful results and patient satisfaction can become more attainable and predictable.
Clinical Case Overview
A 35-year-old woman presented reporting that she was self-conscious about the appearance of her teeth and disappointed with the esthetics of previous dental work. She wanted to replace the discolored restorations, have a less "gummy" smile, and have her worn down mandibular front teeth restored. Her esthetic goal was to create a smile that she never had.
The patient's high biomechanical and dentofacial risks along with her functional risks needed to be precisely managed to achieve a successful result. Treatment goals were the creation of an esthetic smile that provided a balanced, functional occlusion. The esthetics would be improved with crown lengthening and new ceramic restorations, which would also restore carious lesions. The high gingival lip dynamic and excessive gingival display meant that any restorative treatment would be highly visible (Figure 1).
Medical and Dental History
The patient's medical history was unremarkable, garnering an American Society of Anesthesiologists (ASA) I classification. Her mandibular posterior teeth and all of her maxillary teeth had been restored 10 years prior with full-coverage, cohesively cemented restorations. She reported that before the restorative treatment her natural teeth were small with large interdental spaces and underdeveloped third molars. Although these features are characteristic of microdontia,1 a review of her medical history did not show any correlations with other genetic conditions.
Diagnosis, Risk Assessment, and Prognosis
Periodontally, the patient reported some localized bleeding when flossing. The alveolar bone levels were within 2 mm of the cementoenamel junction. All pocket depths were 4 mm or less with isolated areas of bleeding on probing. No radiographic bone loss was present. Generalized moderate biofilm was present. Isolated areas of inflammation existed around gingival margins. The periodontal diagnosis was determined to be American Academy of Periodontology (AAP) stage I, grade B.2 Her risk was assessed as low, and her prognosis was determined to be fair.
Biomechanically, questionable restorations were present on teeth Nos. 3, 5 through 7, 12 through 14, 18 through 20, 22, and 29 through 31, resulting in a fair prognosis without treatment. Teeth Nos. 4, 8 through 11, 21, and 28 had carious lesions at the margins of existing restorations and were given a hopeless prognosis without treatment. The risk was assessed as high, and the prognosis was determined to be hopeless for the teeth with carious lesions but fair for those with questionable restorations.
Functionally, the patient reported no muscle or joint discomfort but needed to shift her jaw back and squeeze to bring her molars into contact. In the past 5 years, she noticed that her mandibular anterior teeth showed an increasing amount of wear and her maxillary anterior teeth had minor chipping. The functional examination showed normal range of motion. Load and immobilization tests were negative. Teeth Nos. 22 through 27 had 1 mm or less of attrition. No fremitus or mobility was noted on any teeth. A functional diagnosis of a constricted chewing pattern (CCP) was determined and later confirmed by using a deprogramming device (Kois Deprogrammer, Kois Center).3 The risk was assessed as moderate, with a fair prognosis.
Dentofacially, the patient wanted less visible gum tissue when smiling and longer, whiter, more symmetrical teeth. The Duchenne smile revealed a hypermobile upper lip displaying all of her maxillary teeth and more than 4 mm of gingival tissue (Figure 2). The risk was assessed as high, with a poor prognosis.
Treatment Goals
The overall treatment goals were to create long-term functional success, decrease the biomechanical risk, and address the patient's esthetics concerns. To accomplish the dentofacial and functional goals, correction of the CCP was necessary.
The maxillary incisal edge position and occlusal plane were determined to be in the proper positions for ideal esthetics (Figure 3). No changes would be made to the maxillary incisal edge position or occlusal plane; however, the maxillary teeth would be lengthened with gingival and osseous surgery. Adding 1 mm of incisal length to the mandibular incisors would restore the worn-away tooth structure. By leveling the mandibular posterior occlusal plane with the incisors, the occlusal vertical dimension would be increased to correct the CCP. This would not only allow for a functional chewing pathway but also minimize tooth preparation on the mandibular anterior teeth.
Treatment Plan
Cohesive restorations would be placed on all the maxillary teeth and the mandibular posterior teeth. Adhesive restorations would be placed on the mandibular anterior teeth. A deprogrammer would be used to establish a repeatable centric relation position to confirm the diagnosis of CCP.
The patient's esthetic concerns would be addressed by performing crown lengthening on teeth Nos. 3 through 14. The mandibular anterior teeth would be lengthened by 1 mm to gain restorative space and allow placement of restorations with minimal preparation to avoid increasing the patient's biomechanical risk. The mandibular posterior teeth would be restored with indirect cohesive restorations.
Treatment Phases
Phase 1: Diagnostic Records and Preventive Care
The patient received routine scaling and prophylaxis with oral hygiene instructions and was placed on a 6-month recare regimen. Because of her high caries risk, it was recommended that she use an anticavity rinse (Treatment Rinse, CariFree) and 1.1% neutral sodium fluoride toothpaste (PRO Gel 5000, CariFree) daily.
A Kois deprogrammer was fabricated and delivered (Figure 4).4 After the patient wore the deprogrammer for 2 weeks, upon its removal the first point of contact was on the anterior teeth, confirming the diagnosis of CCP.
When the deprogramming was complete, diagnostic records were taken, including intraoral and extraoral photographs utilizing facial reference glasses (Kois Facial Reference Glasses, Kois Center), which aid in communicating the natural head position with a known reference distance. This helps ensure that the digital orientation of the maxillary plan matches that of the face. The facial reference glasses are designed to enable critical aspects of dentofacial esthetics, like lip movement, tooth dimension, tooth display, and more, to be digitally measured (Figure 5). A full-mouth radiographic series and intraoral scans (iTero Element™ 5D, Align Technology, Inc.) with the patient in maximum intercuspation (MIP) and also with the deprogrammer in place were also taken.
Phase 2: Smile Design and Treatment Planning
The patient returned 2 weeks later. Flowable composite was placed on the maxillary teeth at the proposed gingival margins of the future restorations (Figure 6). The patient was then able to visualize the proposed tooth length. One millimeter of flowable composite was added to the incisal edges of the mandibular anterior teeth to restore tooth structure that had been worn away and evaluate the new esthetic position. The patient could see and approve the proposed changes to her smile before the case was set up in the planning software (Smile Creator, Model Creator, and Bite Splint Module, exocad).
Once the proposed changes were approved, the maxillary and mandibular arches and bite were scanned with an intraoral scanner (Medit i700, Medit) with the intraoral mock-up in place. Photographs were taken in all views (full-face smile, lips in repose, Duchenne smile, and patient saying "shush") to confirm that the proposed margin location and tooth length of the incisors were acceptable. The case was exported and set up in the exocad software.
Phase 3: Smile Design and Maxillary Provisional Placement
3D designs of the proposed gingival zeniths and tooth shapes were created in the software (Figure 7). The designs were finalized, and maxillary and mandibular models were printed. Two weeks later the patient returned for a try-in and evaluation of the smile design. Photographs were taken so that the esthetics of the proposed smile could be critiqued (Figure 8), and phonetics were also evaluated.
One week before the crown lengthening surgery, all maxillary crowns were sectioned and removed. Any decay was removed, and the teeth were built up as necessary. The maxillary teeth were provisionalized to the unaltered gingival margins in three segments (Nos. 3 through 5, 6 through 11, and 12 through 14). The provisionals were segmented to provide for easy removal and insertion and to aid in the seating, thus limiting the need to over-prepare the teeth. A scan of the prepared teeth was sent to the dental laboratory for fabrication of surgical guides.
Phase 4: Guided Surgical Esthetic Crown Lengthening
A clear resin surgical guide was designed and printed from the approved digital prototype. The guide was scalloped to allow visualization of the desired free gingival margins (FGMs). The superior border of the guide was placed 3 mm apical to the proposed FGM to indicate the required position of the bone (Figure 9).
The periodontist used the guide to mark the new gingival margins with a laser (Figure 10). Gingivectomies were performed on teeth Nos. 3 through 14. A papilla-sparing full-thickness flap was employed to visualize and recontour the osseous levels to obtain a 3 mm, normal crest relationship with the desired FGM (Figure 11).5 Immediately following surgery, a second set of provisionals conforming to the new gingival levels was seated using a temporary polycarboxylate cement (UltraTemp™, Ultradent). Figure 12 shows the new relined provisionals 2 days after surgery.
Phase 5: Restoration of the Mandibular Arch
Two weeks after the maxillary surgery, the patient returned to begin the restoration of the mandibular arch. The posterior crowns on teeth Nos. 19 through 21 and 28 through 30 were removed and decay was excavated. The preparations were refined for full-coverage lithium-disilicate restorations. Teeth Nos. 22 through 27 required minimal preparation for lithium-disilicate veneers. A final impression was taken with a polyether impression material, and an injectable bite registration (Futar®, Kettenbach Dental) was made. Intraoral scans (Medit i700) were also taken. The provisionals were fabricated and cemented, and the occlusion was checked and adjusted.
One week later, the patient returned for evaluation of occlusion, esthetics, function, and oral hygiene. The provisional restorations required no esthetic or functional changes. An intraoral scan, photographs, and videos were taken and sent to the laboratory. Home care instructions were reviewed, and the importance of maintaining healthy gingival tissue was emphasized.
The patient returned 4 weeks later for cementation of the definitive mandibular restorations. At this appointment, new maxillary provisional restorations were fabricated. After wearing the provisionals for 2.5 months, the patient desired a broader smile and wider buccal corridors. The maxillary prototype was refined to accommodate this change and a new matrix was made. New maxillary provisionals were fabricated in this matrix.
The occlusion was evaluated in MIP for even bilateral and equal simultaneous posterior contacts. In addition, the chewing envelope was checked with 200-µm articulating paper with the patient in an upright position. All blue streaks were removed on the incisors and inclines of cusps to eliminate chewing interferences.6
Phase 6: Maxillary Definitive Restorations
Four months after the crown lengthening surgery, the patient returned for the maxillary definitive restorations. The provisionals were removed and preparations were refined. Final impressions and scans were done as described above for the mandibular arch. Four weeks later, the patient returned for seating of the final restorations. The occlusion was evaluated to verify bilateral, equal simultaneous posterior contacts as described above.
Phase 7: Preventive Maintenance
A recare interval of every 4 months was recommended. The patient was told that if she maintained excellent oral hygiene and gingival health, the interval could increase to every 6 months. A daily at-home regimen of anticavity tooth gel (CTx4 Gel 1100, CariFree) was recommended.
Discussion
Proper risk assessment was critical in managing this case. While orthodontic treatment could have been utilized to correct the patient's CCP, the biomechanically necessary restorative treatment accomplished this goal. The patient's functional risk and esthetics were improved, while periodontal and biomechanical risks were not increased. Digital treatment planning improved communication with the entire team and also enhanced outcome predictability (Figure 13 and Figure 14). This case demonstrates how proper diagnosis and systematic treatment planning in a complex case can create predictable, successful results utilizing digital technology tools. The clinician and patient were able to visualize the outcome and more easily make modifications through the use of digital planning. Surgical guides could be easily made to enhance communication with the periodontist. Digital planning helped create a successful outcome in a predictable and stress-free manner.
Acknowledgements
The author thanks John Kois, DMD, MSD, for his mentorship and restorative systems; Edgard El Chaar, DDS, MS, for his periodontal skills and collaboration on this case; Ken LeVos, DDS, and Jean Martin, DDS, MPH, for their editing and guidance on this article; and Justin McElroy and Jimmy So for the digital design and beautiful indirect ceramic restorations.
About the Author
Ellen Katz, DDS
Clinical Director, Full Mouth Rehabilitation CE course, Adjunct Clinical Assistant Professor, New York University College of Dentistry, New York, New York; Adjunct Faculty, Department of Prosthodontics, Nova Southeastern University College of Dental Medicine, Fort Lauderdale, Florida; Mentor, Kois Center, Seattle, Washington; Private Practice, New York, New York
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