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Using Functional Analysis to Determine If Esthetically Driven Treatment Requires Comprehensive Care for Long-Term Success
This article reviews the case of a male patient with esthetic concerns about a large diastema between teeth Nos. 8 and 9. Through functional analysis, the clinician determined that the patient had a mild temporomandibular disorder, as well as a constriction in his anterior envelope of function. These issues will affect the prognosis of treatment if only orthodontics is used to close the diastema. The clinician determined that implementing a systematic treatment planning approach was critical in achieving a successful outcome, which was accomplished with a combination of orthodontics, occlusal deprogramming, and complex prosthodontics restorations.
A 32-year-old man presented with the desire to improve the esthetics of his front teeth (Figure 1). His primary concerns were a substantial diastema between teeth Nos. 8 and 9 (Figure 2), as well as the overall darkened color of his teeth. He noted that the diastema had been increasing in size. His medical history was unremarkable and he was deemed ASA 1. His dental history form revealed a familial history of periodontal disease, and the patient noted that he experienced episodic bleeding from flossing. The patient reported receiving regular preventive and restorative dental care during the past 10 years. Clicking in the temporomandibular joint (TMJ) was initially noted by the patient a few years prior, but he reported no history of pain.
Diagnosis, Risk Assessment, and Prognosis
Periodontal: The periodontal examination revealed four sites with probing depths of 4 mm, with all other sites measuring 3 mm or less. Only light, localized bleeding on probing was seen. No mobility or furcation involvements were noted. Radiographic analysis revealed slight (< 2 mm) bone loss on all posterior teeth. A periodontal diagnosis of AAP type II (mild periodontitis) was made.
Biomechanical: The patient had active carious lesions in teeth Nos. 4 and 13. Structural compromises were noted in tooth No. 29 due to a large defective restoration and recent root canal treatment. Although this tooth did not currently have a periapical lesion, the failing restoration put the tooth at significant risk for catastrophic fracture. Several direct restorations in the pit and fissure areas of the posterior molars were noted as acceptable. Tooth No. 19 had been missing for approximately 8 years, having been lost after endodontic treatment failed.
Prognosis: Fair overall, except for tooth No. 29, which was poor, and teeth Nos. 4 and 13, which were hopeless
Functional: The patient’s teeth showed wear on the facial inclines of the lower teeth and the lingual inclines of the upper teeth (Figure 3 and Figure 4). The posterior teeth had minimal wear. The masseter and temporalis muscles were comfortable on palpation. Both temporomandibular joints accepted loading without discomfort, and the range of motion was normal. Clicking in the left TMJ was observed when the patient opened and closed his mouth, which may be an indication of a temporomandibular dysfunction (TMD). The maxillary anterior teeth had a diastema between teeth Nos. 8 and 9 that was increasing in size, and fremitus was noted on the upper anterior teeth when the patient tapped his teeth together. A preliminary functional diagnosis of a constricted chewing pattern was made, and this diagnosis was later confirmed using the Kois deprogrammer.1
Prognosis: Usually a constriction would result in a fair prognosis, but due to the presence of a click, the clinician opted to assess the prognosis as poor.
Dentofacial: In repose, both the maxillary and mandibular incisors revealed 1 mm to 2 mm of the incisal edges (Figure 5). The patient often presented a somewhat guarded smile that only displayed his maxillary teeth to the gingival zeniths. However, when in his full smile he displayed the entirety of the maxillary teeth, including substantial gingiva above the zeniths of his anterior teeth on the right. This observation was consistent with a diagnosis of high lip dynamics and tooth display. The interarch position of the teeth in the maxilla needed alteration due to the large diastema between teeth Nos. 8 and 9. Incisal edges in the lower arch were noted to be irregular. The overall color of the teeth was assessed as A3, and the patient specifically expressed a desire for lighter teeth.
The patient’s chief concern of a widening diastema could not be appropriately addressed without treating the constriction in the chewing envelope.2 To allow better proportionality in the final restorations, the intra-arch position of the maxillary anterior teeth also needed to be altered to spread out the space that needed to be closed. The patient agreed to orthodontic treatment followed by fixed restorations. The final treatment goals were to:
• lower the biomechanical risk by treating all active carious lesions
• use centric relation (CR) joint position to treat the constriction in the functional chewing envelope and the TMD as needed
• lower the functional risk to the anterior teeth by providing adequate space for the envelope of function
• eliminate the anterior diastema using a proportional and esthetically pleasing design
• improve function of the posterior teeth by replacing the missing No. 19
The patient accepted the treatment plan of orthodontic repositioning of his maxillary anterior teeth, followed by occlusal deprogramming and restoration of his esthetics and occlusion in CR. The patient also accepted the plan to restore the edentulous space with an implant and crown.
Phase 1: Deprogramming and Caries Treatment
A Kois deprogrammer was used to reposition the mandible into centric relation (Figure 6). After wearing the device for 3 weeks, the patient reported that the clicking in his left TMJ went away. Upon removing the deprogrammer, the first point of contact when the patient closed was on the front teeth. This finding indicated that the mandible moved forward into a CR position, which confirmed the initial diagnosis of a constricted chewing pattern (Figure 7).3 All active caries lesions were treated at this time with Enamel Plus HFO™ (Micerium S.p.A., www.micerium.com) direct composite restorations.
Phase 2: Orthodontic Treatment and Implant Placement
Orthodontic treatment was used only on the maxillary arch, for the purpose of spreading the space of the diastema between all of the front teeth (Figure 8). To avoid further constriction of the functional envelope, the teeth were not retroclined. Treatment time in active orthodontics was 6 months. Two months prior to the completion of the orthodontics, the implant for tooth No. 19 was placed.
Phase 3: Whitening and Contouring
A combination of in-office and at-home whitening was completed. The color of the teeth improved from A3 to 1M1 (Figure 9). The incisal edges of teeth Nos. 25 through 27 were contoured to better align with the lower incisal plane.
Phase 4: Prosthodontic Treatment
Post-orthodontics, a new Kois deprogrammer was fabricated, and the patient again wore it for 3 weeks. After confirmation of deprogramming, upper and lower impressions and a bite record were taken to mount the case in CR for the diagnostic wax-up. Diagnostic casts were mounted on a Panadent articulator using the Kois Dento-Facial Analyzer™ and a Kois adjustable platform™ (Kois Center, www.koiscenter.com).
The parameters for the wax-up were developed using the Kois 10-Step Management tool. After the upper cast was mounted, the mounting platform was adjusted vertically to reflect the desired final tooth length4 and maxillary occlusal plane.5 Teeth Nos. 3 through 13 were then waxed to the new vertical dimension. A matrix of the wax-up was used to create a template of the final result in the patient’s mouth using bisacryl temporary material (Luxatemp®, DMG America, www.dmg-america.com). This provided an opportunity for the patient to visualize the endpoint of the treatment and also generated a guide for tooth preparation.6 Once the esthetics of the template were approved by both the patient and dentist, the template served as a guide for tooth reduction. Depth cuts were made through the acrylic, thereby minimizing unnecessary removal of tooth structure while still ensuring adequate reduction in all dimensions. Teeth Nos. 3 through 13 and 29 were prepared for IPS e.max® restorations (Ivoclar Vivadent, www.ivoclarvivadent.com). The preparations of the maxillary teeth were designed to minimize the biomechanical risk to the teeth, provide adequate retention and resistance form, and allow sufficient space to satisfy the parameters of the restorative material.
The provisionals were fabricated directly using the matrix produced from the diagnostic wax-up. The provisional for the implant was placed at the same time. After final adjustment of the provisional restorations, new bite records were taken following a cross-mounting protocol for the laboratory. The patient experienced no problems while wearing the provisional restorations.7
Facial veneers with occlusal overlays were constructed for teeth Nos. 3 through 5, 12, and 13 and were cemented with RelyX™ ARC adhesive resin cement (3M ESPE, www.3MESPE.com). The veneers for teeth Nos. 6 through 11 were cemented with RelyX™ Veneer cement (3M ESPE). The crowns placed on tooth No. 29 and the implant on No. 19 were cemented with RelyX™ U200 (3M ESPE) using standard protocols. The occlusion was then balanced, verifying that there were even, bilateral, simultaneous posterior contacts. The envelope of function was also reassessed, ensuring there was no excess friction on the maxillary anterior teeth during function (Figure 10). Upon completion of the definitive restorations and final equilibration (Figure 11 and Figure 12) the patient was advised to follow a 6-month re-care regimen due to his periodontal health and caries risk assessment.
The patient’s primary dental concern initially appeared to be treatable with simple orthodontics. However, once a full diagnostic evaluation was performed, the complexities of the case were identified and managed using functional analysis and interdisciplinary treatment planning. The Kois deprogrammer was used for predictable management of the occlusion. Omitting the treatment of the functional disorders would have led to an increase in risk to the anterior teeth. The patient would likely have experienced relapse of the diastema, as well as increased damage to his anterior teeth or breakage of the restorations.
The patient was extremely pleased with the final esthetic and functional result (Figures 13 and 14). As of this writing, the click in his TMJ has not returned and his occlusion is stable. By treating the underlying occlusal disorders, the long-term prognosis of the case is greatly improved.
The author would like to recognize Margarita Kushnir, DDS, St. Petersburg, Russia, for providing the orthodontic treatment, and Dmitry Bednarsky, CDT, St. Petersburg, Russia, for his laboratory expertise. He also wishes to acknowledge the careful editing and writing assistance of Matthew J. West, DMD, AEGD.
About the Author
Ilya Sklyarov, DDS
Private Practice, St. Petersburg, Russia
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