| Abstract|| |
Objective: Even with beautifully done restorations, an unattractive gingival zenith position, can negatively affect the smile of a person. In this short communication we describe the treatment of a rotated maxillary right central incisor using a digital photographic approach instead of the conventional approach.
Background: The conjecture literature on prosthodontic considerations and gingival zenith position in cases of rotated maxillary central incisors is sparse. The gingival zenith level (GZL) in an apical-coronal direction of lateral incisors, relative to the gingival tangential zenith line joining the adjacent central incisor and canine, is approximately 1 mm under healthy conditions.
Materials and Methods: For our patient, the treatment plan was decided by CAD-CAM technique as Zirconia, jacket crown. Clinical procedures included enameloplasty on the left central and right lateral maxillary incisors. Reduction of the rotated and crooked incisor was performed in the normal manner; periodontal plastic surgery was also done.
Results: The patient expressed satisfaction with the intermediary (preliminary) two-dimensional photographs that were provided by the CAD-CAM system. The technique distinguished among the different treatment modalities for aesthetics and to relieve the emotional problems which were faced by female patient. The gingival zenith level of the rotated incisor was also improved.
Conclusion: Digital imaging provides an immediate treatment option for the patients. Software also provides an interim aid, for the clinician as well as technician, in the form of two-dimensional photographs. CAD-CAM is entirely a helping instrument against the conservative prosthetic options and gingival zenith position for a rotated central incisor. It helps in patient education and in motivation.
Keywords: Computer-aided designing and computer-aided machining, digital imaging, fix dental prosthesis, gingival zenith position, immediate option, interim option
|How to cite this article:|
Singhal M, Singhal R. A CAD-CAM prosthodontic option and gingival zenith position for a rotated maxillary right central incisor: An evaluation. Indian J Dent Res 2012;23:112-5
The gingival zenith (GZ) is defined as the most apical point of the marginal gingival scallop; however, its quantitative orientation in the apico-coronal (AC) and mesio-distal (MD) directions has not been reported. , The GZ has always been an important component of a beautiful smile [Figure 1] and [Figure 2]. Generally, crooked and discolored teeth result in a distorted GZ position. Nordland and Tarnow's description , of a normal interdental papilla is one that fills the embrasure space up to the apical extent of the interdental contact area. Deviation from the normal interdental papilla will result in an aesthetically undesirable gingival 'black triangle,' and gingival asymmetry can lead to visual stress and imbalance [Figure 3]. The disfigurement associated with rotated (crooked) anterior teeth causes physical, emotional, and social problems. Adjunctive therapies, including periodontal plastic surgery, have also been recommended to optimize gingival contours during restorative treatment in the presence of severe gingival deformity.  Authors describe a CAD-CAM  technique, through the use of digital photography  which was based on clinical report. Photographic records aid in identifying aesthetics and disharmony and in planning aesthetics correction. Photographs also help the dentist and the patient in establishing mutually compatible expectations.  Author consulted the textbook of Fradeani M on aesthetic rehabilitation in fixed prosthodontic and aesthetic analysis to prosthetic treatment. In this case report we describe the patient's presentation and the technique used for correction of a rotated maxillary right central incisor tooth.
|How to cite this URL:|
Singhal M, Singhal R. A CAD-CAM prosthodontic option and gingival zenith position for a rotated maxillary right central incisor: An evaluation. Indian J Dent Res [serial online] 2012 [cited 2020 May 25];23:112-5. Available from: http://www.ijdr.in/text.asp?2012/23/1/112/99053
|Figure 1: The ideal gingival zenith is knife-edged gingival margins, tightly adapted to the teeth and interdental grooves, and with cone-shaped interdental papilla|
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|Figure 2: The gingival zenith level (GZL) for both right and left lateral incisors relative to the adjacent gingival zenith position of the central incisor and canine teeth are coronal by approximately 1 mm|
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| Materials and Methods|| |
A 40-year-old female patient presented to the Department of Prosthodontics, Kothiwal Dental College, Moradabad, about 3 years back with the main complaint of a malaligned right maxillary central incisor. She was working as a vice-principal. On extraoral examination the face profile was convex. Intraoral examination revealed excellent oral health. There were no cavities or periodontal disease. Angle class 1 normal occlusion was observed. She had normal vertical and horizontal overlap. Anterior view (Front view) showed a right malaligned (crooked) central incisor and an unaesthetic GZ position [Figure 3]. On examination, she had no evidence of any medical illness. IOPA x-rays disclosed a rotated right central incisor. Negligible bone loss was present. The pulpal condition was normal.
An inter-disciplinary approach was considered for her treatment like combining orthodontic treatment, extraction of the crooked incisor, FPD, RPD, implant, jacket crown, or laminate. The diagnosis and treatment plan were guided by computer-aided designing and computer-aided machining (CAD-CAM).
Diagnostic casts were first made. These casts were mounted on a semi-adjustable articulator with centric relation and facebow record transfer. A photograph was taken using a digital camera (Cyber-Shot™ DSC-w30, Sony, Japan; 6 megapixel; sensitivity ISO-1000) [Figure 3]. The photograph, along with dental stone cast, was evaluated for GZ and a prosthesis. The format and image of the tooth in question was adjusted for the space using computer software (Photoshop™ 7.00 Adobe Systems Inc. San Jose CA).  This was performed by regaining 2mm from left central incisor and 1 mm from right lateral incisor. An printout of the adjusted final image was obtained on an inkjet printer (HP 1315) [Figure 4].  These two-dimensional photographs were shown to the patient for her opinion regarding the GZ level and future jacket crown [Figure 5].
Enameloplasty on the left maxillary central incisor and right maxillary lateral incisors was accomplished according to above mentioned dimensions. Reduction of the rotated incisor was also performed. The crooked central incisor was reduced in the normal manner. A completely reverted  form of reduced crown was created. Periodontal plastic surgery was done under aseptic conditions to reconstruct the GZ position and the interdental papilla. Soft tissue management was carried from double gingival cord procedure. The final impression was recorded with additional silicone rubber base impression material in a custom-made special tray. Provisional restoration of self-cure acrylic, polymethyl methacrylate, was fabricated and cemented with zinc oxide eugenol cement for 3 weeks. Full-veneer crown (FVC) of zirconia  via CAD-CAM was fabricated. Finally, it was cemented [Figure 6].
| Results|| |
Digital imaging has the advantage of acceptable and deserving natural aesthetics treatment modality through 2-D photographs. These photographs acted like a mediator as immediate treatment option for the patient and an interim aids for clinician and technician as well. This method also changed the treatment option from implant surgery to FDP as an all-ceramic crown. When reviewed recently, our patient was asymptomatic and very satisfied with the results of her treatment.
| Discussion|| |
There is no consequence literature available for references regarding the present case. We consider that the rotated central incisor in our patient may have been the result of a childhood injury to the premaxillary region. The injury may have displaced and misaligned the developing teeth bud. Adjacent developing teeth buds can also misalign the affected tooth. The midline was slightly shifted, but the canine position was normal. To adjust for the shorter space occupied by the maxillary arch there was crowding of the mandibular anterior teeth.
Quality has many expressions but indeed targeting perfection is its own reward. The rotated central incisor occupied little space and this produced a distorted GZ position. It affected the future treatment plan options. The main problem was distorted space, which made orthodontic treatment impossible [Figure 3]. Implant treatment was not a realistic option. Enameloplasty was done to regain space for GZ and prosthesis. This technique can help to restore the aesthetics of the smile and thus the patient's self-esteem, education and motivation. However, special digital photography equipment and computer software system is required. A zirconia all-ceramic jacket crown, is the best of the available options for anterior prosthesis.  The final restoration was cemented after 3 weeks to restore the GZ health.
| Conclusion|| |
This technique could be extremely useful for the diagnosis and treatment of discolored, mutilated, and malaligned anterior teeth. The technique described here can be valuable for both the patient and the clinician to reduce the psychological questions. Other applications of the CAD-CAM technique may be in the correction of wide diastema and distorted edentulous spaces as over to an alternative diagnostic teeth set up. It will present a better image to the patient. Thus, this CAD-CAM technique may be suggested as an alternative option in dental clinics. It absolutely helps in a future treatment plan to decide the GZ position and a prosthesis.
| References|| |
|1.||Mattos CM, Santana RB. A quantitative evaluation of the spatial displacement of the gingival zenith in the maxillary anterior dentition. J Periodontal 2008;79:1880-5. |
|2.||Chu SJ, Tan JH, Stappert CF, Tarnow DP. Gingival genith positions and levels of the maxillary anterior dentition. J Esthet Restor Dent 2009;21:113-21. |
|3.||Fradeani M. Esthetic rehabilitation in fixed prosthodontic, esthetic analysis to prosthetic treatment. Chicago: Quintessence; 2004. |
|4.||Glossary of prosthodontics terms. J Prosthet Dent 2005;94:10-92. |
|5.||Artopoulou II, Montgomery PC, Wesley PJ, Lemon JC. Digital imaging in fabrication of ocular prostheses. J Prosthet Dent 2006;95:327-30. |
|6.||Stephen RF, Martin LF, Junhei F. Contemporary fixed prosthodontics. 4 th Ed. St. Lois: Missouri; 2008. p. 750-800. |
Department of Prosthodontics, Kothiwal Dental College and Research Centre, Moradabad, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]