Demystify Treatment Planning With a Correct Functional Diagnosis

Wade Kifer, DDS

Worn dentition may elicit assumptions of bruxism or other occlusal dysfunctions, which can compromise the accuracy of a diagnosis.¹ Occlusal disorders, however, are not the only cause of severe damage to dentition. In the case presented, the patient's gastroesophageal reflux disease (GERD), chronic vomiting, polypharmacy, and other non-dental factors contributed to rapid deterioration of his teeth despite the patient having an acceptable functional occlusion.² After a detailed medical history and in-depth patient interview were completed, previously diagnosed sleep apnea, GERD, and treatments related to leukemia were identified as the more likely etiologies of the dental damage. Although these medical conditions had led to the severe state of the patient's dentition, they had been largely managed by him and his physicians over the past few years. Once a preliminary diagnosis of "acceptable" occlusion was validated, the workup and execution of the case became simplified, and the patient's prognosis improved.

Clinical Case Overview

A 54-year-old man was referred to the author for dentition wear and erosion that were perceived to be from severe bruxism (Figure 1 and Figure 2). His existing dentist was unsure of where to begin treatment planning due to the perceived complexity of the case. The patient's main concern was fear of losing some or all of his teeth due to extensive enamel destruction (Figure 3). Records and in-depth medical and dental histories were obtained, and a detailed clinical examination was performed. The complete records, photographs, and digital scans were sent to a dental laboratory, and a treatment plan was developed. The patient had a strong desire to act and accepted the plan. The case was segmented for a predictable and more comfortable reconstruction.

Medical and Dental History

The patient reported allergies to multiple medications, including Imitrex, Nuprin^®, Inderal^®, Topamax^®, and penicillin. He was being treated for diabetes (hemoglobin A1c of 7.5) and hypertension with lisinopril and verapamil. The patient also reported previous diagnoses of sleep apnea and acid reflux. These two conditions had largely been managed with significant weight loss and sleep habit changes, thus his physician no longer recommended use of a continuous positive airway pressure (CPAP) machine or reflux medication. The patient's medical classification was determined to be American Society of Anesthesiologists (ASA) III.³

The patient's dental history included thinning and chipping of teeth, limited mouth opening, jaw fatigue, and an inability to eat hard foods. He reported being told by previous dentists that he grinds his teeth. He also reported having a dry mouth.

Diagnosis, Risk Assessment, and Prognosis

Periodontal: The patient's probing depths were 3 mm with three locations of bleeding on probing. Attached gingiva was adequate. Radiographic bone loss was generalized at 2 mm to 4 mm. The patient's periodontal condition was diagnosed as American Academy of Periodontology (AAP) stage II, grade C due to the slight bone loss and comorbidity of diabetes.⁴

Risk: Moderate

Prognosis: Good

Biomechanical: Severe erosion with dentin exposure was noted on the lingual surfaces of teeth Nos. 5 through 12 (Figure 4) and the facial and incisal surfaces of teeth Nos. 19 and 22 through 30 (Figure 5). Tooth No. 21 had previous root canal treatment, and teeth Nos. 19 and 20 had large restorations greater than one-third of their isthmus width. Chipping was present on teeth Nos. 6 through 11. While no decay was noted in the patient's dentition, the loss of tooth structure had created severe structural compromises in all teeth except the maxillary posterior molars. Teeth Nos. 3 and 14 had occlusal amalgam restorations that were acceptable with slight erosion on their cusp tips. Teeth Nos. 4 and 13 had slight occlusal erosion.

Risk: High

Prognosis: Poor

Functional: Examination revealed that the maximum mouth opening was 48 mm with no muscle tenderness on palpation, loading, or immobilization. The patient had no pain when eating, did not have to squeeze his jaw to fit his posterior teeth together, did not have multiple bite positions, and did not notice any grinding or clenching while awake. The patient was aware that his teeth were chipping and wearing down. He had a fear of eating certain foods, especially hard foods, as he was highly concerned that his teeth would break. Close review of the medical and dental histories led to a hypothesis that, as intimated earlier, these conditions were not related to his bite. The diagnosis was acceptable function.

Risk: Low

Prognosis: Good

Dentofacial: The patient's full Duchenne smile revealed all the upper teeth and the gum tissue at the apical portion of the teeth (Figure 6). Tissue display was moderate. His initial tooth shade was C4 on the Vitapan^® classical shade guide (VITA North America, vitanorthamerica.com). The patient's expectations were for a full, whiter, and natural-looking smile that would last.

Risk: Moderate

Prognosis: Fair

Treatment Goals and Plan

The treatment goals were to create an esthetically pleasing, natural-appearing smile, prevent further tooth erosion and chipping, and relieve discomfort when the patient was eating hard foods.

The treatment plan was broken down into six steps: (1) identify a repeatable reference position of the mandible to allow increasing of the vertical dimension in the wax-up design; (2) increase the vertical dimension of occlusion (VDO) using full-coverage zirconia restorations on the mandibular posterior teeth; (3) restore the maxillary teeth with exposed dentin using full-coverage zirconia; (4) restore the maxillary posterior teeth with composite where indicated; (5) place full-coverage zirconia restorations on the mandibular incisors; (6) provide postoperative follow-up for 2 years to monitor any issues that might arise, with the patient then returning to his referring dentist for long-term recare.

Treatment Phases

Diagnosis and Occlusal Records

Complete diagnostic records were taken, including radiographs, photographs, and digital scans. The diagnosis of acceptable function allowed for the use of a printed Lucia jig (Kois Center, koiscenter.com) rather than an occlusal deprogrammer (Figure 7). Centric relation was easily found and recorded using a wax bite registration (Figure 8).⁵ Photographs with the patient wearing facial reference glasses (Kois Facial Reference Glasses, Kois Center) were used to aid in digitally mounting and analyzing the case and developing a treatment plan.⁶ The incisal edge of the maxillary cuspid was positioned at the edge of the upper lip in repose.⁷ Appropriate positions of the maxillary and mandibular central incisors and posterior occlusal planes were determined using Kois Center principles.^8,9

Records were sent to the laboratory for a diagnostic wax-up, and a comprehensive plan was presented to the patient. He expressed concerns about becoming fatigued during longer appointments, therefore the case was segmented to alleviate this concern. The patient accepted the plan.

Restorative Phase 1

The mandibular molars and canines were prepared for full-contour zirconia restorations. Zirconia was chosen as a precaution in case the patient's reflux or other erosion comorbidities were to return.¹⁰ Temporary restorations (Luxatemp, shade B1, DMG America, dmg-america.com) were fabricated at the new VDO. A silicone matrix was used to transfer the wax-up to the mouth, and the restorations were trimmed chairside. A vertical anterior jig was used to record the bite at the new VDO using an elastomeric bite registration material (Futar^®, Kettenbach Dental, kettenbach-dental.us). Bite records, photographs, and scans of the preparations and temporaries were sent to the dental lab. The restorations were created at this new vertical dimension and delivered 3 weeks later.

At the delivery appointment, the teeth were cleaned using an air-abrasion system (PrepStart^™, Zest Dental Solutions, zestdent.com) with 27-µm aluminum oxide. The restorations were also micro air-abraded, followed by placement of a zirconia primer (Monobond^® Plus, Ivoclar, ivoclar.com) on the intaglio surfaces of the crowns. The restorations were cemented with dual-cure resin cement (RelyX^™ Unicem 2, 3M Oral Care, 3m.com) (Figure 9).

Restorative Phase 2

Minimally invasive composites were placed on teeth Nos. 3, 4, 13, and 14 to correct minor biomechanical issues and cover exposed dentin. This conservative approach was used because vertical changes on the maxillary posterior teeth were not indicated based on the initial treatment plan. The maxillary posterior teeth were determined to be in the proper positions to meet the patient's esthetic goals.

Full-coverage zirconia restorations were placed on the maxillary anterior teeth and premolars. The increased vertical dimension built into the mandibular arch had created an anterior open bite that allowed significantly less tooth structure removal during the preparation of these teeth. Temporary restorations were fabricated based on the original wax-up using provisional material (Luxatemp). A silicone matrix was used to transfer the wax-up to the mouth, and the restorations were trimmed and polished chairside. Maxillary full-coverage restorations were delivered using the previously described protocol.

Restorative Phase 3

The mandibular incisors were the last four teeth to be completed and were also covered with full-coverage zirconia restorations and delivered using the same protocols as the other restorations. The patient was thrilled with his new smile (Figure 10 through Figure 12).

Discussion

An accurate occlusal diagnosis was key in designing the workflow and choosing the materials for this case. The common assumption that bruxism or occlusal dysfunction is responsible for most cases of severe dental wear can unnecessarily complicate the planning and management of large cases when the actual etiology may lie elsewhere. The patient's dental and medical histories contributed to the clinician recognizing that the patient had an acceptable and functional occlusion. While the possibility of some occlusal dysfunction or parafunctional habits in the past could not be ruled out, the patient answering "no" to all questions about functional problems or concerns at the initial examination supported a diagnosis of acceptable function.

The case became more straightforward, and therefore enjoyable for the clinician, when a dysfunctional bite and/or bruxism and the challenges that accompany these conditions were ruled out and, thus, would not require management. Because this was an acceptable function case, a simple Lucia jig was used as opposed to an occlusal deprogrammer. This approach saved time and expedited the case while still providing a valid reference position for the design of the restorations.

The prognosis improved significantly because the patient had managed his GERD and sleep apnea. His commitment to weight loss and better overall health should help limit further damage to his dentition. The restorative results were aimed at being long-lasting and providing a substantial improvement in form, function, and esthetics for the patient. He returned 3 months after the final cementation for a prophylaxis and postoperative evaluation. A recommendation was made to the patient that he remain on a hygiene recall for two visits to ensure stability and address any complications should they arise. However, he declined this suggestion due to significant travel distance and instead chose to return to his previous dentist for his regular hygiene visits while agreeing to contact the author's office if he experienced any problems.

In a follow-up interview 1 year after case completion, the patient reported no problems and remained very happy with his restorative outcome. Based on that interview he continues to be low risk for periodontal and functional concerns. His biomechanical risk remains high due to the structural compromises, but his prognosis has improved. The patient's esthetic risk remains moderate because of his tissue display.

Conclusion

This case demonstrates a predictable full-mouth rehabilitation of severely worn and eroded dentition. Extensive dental damage from reflux combined with other comorbidities can make it challenging for clinicians to know where to begin a treatment plan. The principles of obtaining a proper occlusal diagnosis by utilizing a thorough clinical examination as well as taking a detailed medical and dental history simplified what had seemed to be a highly challenging case. Increasing the vertical dimension in a repeatable position minimized tooth preparation. With the patient largely managing his comorbidities prior to the restorative treatment and the clinician utilizing long-lasting restorative materials, long-term stability and success are expected.

Acknowledgment

The author thanks John C. Kois, DMD, MSD, for providing advanced training, Swiss Dental for the beautiful lab work in this case, and his staff for all their hard work.

About the Author

Wade Kifer, DDS
Clinical Instructor and Course Facilitator, Kois Center, Seattle, Washington; Private Practice, Fayetteville, Arkansas

References

1. Johansson A, Kiliaridis S, Haraldson T, et al. Covariation of some factors associated with occlusal tooth wear in a selected high-wear sample. Scand J Dent Res. 1993;101(6):398-406.

2. Ranjitkar S, Kaidonis JA, Smales RJ. Gastroesophageal reflux disease and tooth erosion. Int J Dent. 2012:2012:479850.

3. Daabiss M. American Society of Anaesthesiologists physical status classification. Indian J Anaesth. 2011;55(2):111-115.

4. Tonetti MS, Greenwell H, Kornman KS. Staging and grading of periodontitis: framework and proposal of a new classification and case definition. J Periodontol. 2018;89 suppl 1:S159-S172.

5. De Paiva HJ, Bonfante G, Lins do Valle A, Bonachela WC. Centric registration relation in dentate patients using bilateral manipulation-comparative analysis of three techniques. Rev Odontol Univ Sao Paulo. 1989;3(4):439-447.

6. Swanson K, Hermanides L. Biomechanics and function: altering paradigms to treat a patient's esthetic disability conservatively. Compend Contin Educ Dent. 2020;41(5):284-289.

7. Misch CE. Guidelines for maxillary incisal edge position - a pilot study: the key is the canine. J Prosthodont. 2008;17(2):130-134.

8. Kois JC. New challenges in treatment planning - Part 1. Shifting the paradigm toward risk assessment and perceived value. J Cosmet Dent. 2010;26(4):62-69.

9. Kois JC. New challenges in treatment planning - Part 2. Incorporating the fundamentals of patient risk assessment. J Cosmet Dent. 2011;27
(1):110-121.

10. Theocharidou A, Kontonasaki E, Koukousaki I, et al. Effect of in vitro aging and acidic storage on color, translucency, and contrast ratio of monolithic zirconia and lithium disilicate ceramics. J Prosthet Dent. 2022;127(3):479-488.