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Lamberto Villani, John C. Kois

Digital Smile Design Meets the Dento-Facial Analyzer : Optimizing Esthetic WhilePreserving Tooth Structure (Two)

Abstract: This case of an adult male patient with missing maxillary lateral incisors who was unhappy with his smile focuses on implementation of the digital smile design (DSD) concept. Combined with the use of a dento-facial analyzer, DSD, which employs a series of extraoral photographs, allowed the clinician to preoperatively plan different approaches to the treatment and visualize the outcome of each one, as well as to effectively communicate critical tooth position references to the laboratory technician and the patient The additive approach used in this case minimized tooth preparation while creating an esthetic smile.
Phase 2: Transfer of Digital Wax-Up to Master Cast

A dento-facial analyzer (Kois Dento-Facial Analyzer SystemTM, Panadent, (www.panadent .com) was used to record and then communicate the essential functional and esthetic parameters for mounting the maxillary cast (Figure 9). The combination of the DSD and the dentofacial analyzer system enabled the clinician to effectively communicate the proposed midline and maxillary occlusal plane一critical tooth position reference9,10一to the laboratory technician. When placed on the articulator, the platform ensured the symmetry of the incisal edges, as well as the horizontal and vertical tooth positions (Figure 10). The platform can be lowered or raised as needed to allow for more or less incisal length. In this case, the platform did not need to be adjusted because tooth No. 11, the longest tooth in the arch, was the correct length and tooth No. 9 needed to be lengthened by 1 mm.
The use of an index tray provided an easy reference for the wax-up fabrication (Figure 11 and Figure 12). The reference platform on the articulator was used to determine the width, length, and facial position of the maxillary central incisor. A 9.5-mm index tray was used, which allowed the technician to wax all of the front teeth using the proportion guide on the tray. A custom incisal guide table can be used to establish the labial contour as determined previously by the DSD.

9. 用于记牙合平面朝向的牙颔面分析放置

10. 紧贴平合安装的上颔模型

图11. 选定9.5-mm切牙宽印模托

12. 技木人比例引高效地制作

Phase 3: lntraoral Evaluation

Temporization material (Protemp™, 3M ESPE, was injected into the silicone index and applied intraorally without any tooth preparation. The esthetics, phonetics, func-tional outcome, lip support, and facial harmony were evaluated at this time. 13-16 The fnal treatment plan was initiated after the patient's approval of the intraoral mock-up (Figure 13).

图13. 就绪的试验微笑 

Phase 4: Surgical Treatment

A stent was fabricated from the wax-up and placed intraorally to provide guidance for both the  periodontal surgery and tooth preparation. Clinical crown lengthening was performed on teeth Nos. 8 and 9. Bone sounding17,18 was done, and Er:Cr:YSGG laser therapy19 (WaterlaseTM, Biolase, was used to recontour the gingiva (Figure 14).

   图14. 通过激光治疗完成的牙周手术

Phase 5: Definitie Restorations

Two months after the periodontal surgery, the patient returned for the final restorations. The silicone index of the diagnostic wax-up was now used as a guide to minimize the amount of tooth reduction. Based on the silicone index, the central incisors were planned to have 1 mm of facial volume added and a 0.3-mm chamfer. 

For the lateral incisors, tooth preparation followed the preoperative preparation guide and required more tooth removal on the mesial surfaces to provide adequate width for the veneers on the central incisors. The incisal edge was reduced by 1 mm and the proximal surfaces were reduced by 0.5 mm. The margins were smoothed with soft discs (SONICfex®, KaVo Dental, Using a two-cord retraction technique, a polyvinyl siloxane impression was taken (ImprintTM, 3M ESPE) and acrylic temporaries (Protemp) were fabricated. 

An alveolar model with gingival cast and interchangeable dies was fabricated. Feldspathic ceramic (Creation, Jensen Dental, Feldspathic ceramic (Creation, Jensen Dental, was layered. In order to create the illusion of smaller central and lateral incisors, the ceramist moved the distal line angle of the lateral incisors mesially. 

The veneers were cemented with a light-cured nanofilled composite resin (shade CT, FlitekTM Supreme Ultra, 3M ESPE). The composite was preheated in a composite warmer prior to cementation.

图15. 上頜前牙的木后特写视图

图16. 成功的新微笑全视图


This case illustrates a method to systematically diagnose, plan, and stage treatment for a smile makeover. The use of the DSD allowed the clinician to preoperatively plan various approaches to the treatment and visualize the outcome of each approach. The use of the Kois Dento-Facial Analyzer simplifed the wax-up and improved accuracy. The new veneers harmonize with the face and lower lip, and the spaces were perfectly closed (Figure 15 and Figure 16). 

The additive approach minimized tooth preparation and also made the teeth more prominent in the patient's smile. The tissue is expected to mature with interdental papillary rebound. The patient was satisfied with not only the excellent esthetics but also the minimal tooth structure removal.

The author would like to thank Lamberto Villani of Oral Design, Dubai, UAE, for the excellent ceramic work in this case.
Dr. Ryan Tse is a private practitioner in Hong Kong and he was the graduate of the University of Hong Kong. He received a Bachelor of Dental Surgery from the university of Hong Kong and he obtained a master degree in Clinical Dentistry (Prosthodontics) from University of London and Master ofScience in Implant Dentistry from University of Hong Kong. He completed one-year Clinician Program in Implant Dentistry and Esthetic Dentistry at UCLA in 2006 and 2010 respectively. He is also a graduate of Kois Centre and finished the whole comprehensive curriculum involving aesthetic, occlusion and restorative dentistry. He is one of the instructors in University of Southern California Esthetic Dentistry and Implant training program in China and Hong Kong. He is Vice President of Chinese Academy of Esthetic Dentistry (CAED) and be the chairman of Accreditation board of CAED. He is also the Founder and President of Hong Kong Society of Esthetic Dentistry and Vice President of Hong Kong Society of Implant Dentistry. Currently, he maintains a private practice in Hong Kong and focusing in Implant and Esthetic Dentistry.
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Digital Smile Design Meets the Dento-Facial Analyzer : Optimizing Esthetic WhilePreserving Tooth Structure (Two)
Lamberto Villani, John C. Kois