2 INSIDE DENTISTRY—APRIL 2009 CLINICAL A review from the experts. TREATMENT optioNs Treatment Options for the Significant Dental Midline Diastema Michael R. Sesemann, DDS, FAACD

From the beginning of time people stymata are prominently displayed in the his dental midline diastema. A compre- have noticed, and perhaps passed judg- mouths of many famous and successful hensive dental examination revealed excel- Michael R. Sesemann, DDS, FAACD ment on, people with prominent spaces people from all walks of life, including lent overall oral health. The only treatment President-Elect and in their dentitions. In France, the teeth David Letterman, Elton John, Eddie Mur- recommendation, made for the purpose Accredited Fellow on either side of a space or gap are called phy, Madonna, Lauren Hutton, Michael of maintenance, was for the replacement American Academy of “dents du bonheur” or “lucky teeth.” In Strahan,Arnold Schwarzenegger,and Con- of a few older restorations that were show- Cosmetic Dentistry Nigeria, a dentition sporting gaps be- doleezza Rice, to name a few. However, ing signs of marginal deterioration. tween teeth is considered an exception- there remain a significant number of peo- When asked to smile, the patient’s lip Private Practice ally attractive physical trait. In early English ple who do wish to eliminate a diastema retraction capability was moderately dy- Omaha, Nebraska societies, the presence of a gapped-tooth if it is part of their dentition. namic, yet high enough to yield a clear presentation in a female smile was equat- Because of the varying perceptions, a view of a midline diastema measuring ed with lustful connotations. person may decide to make a dental mid- 1.79 mm at its most coronal aspect, wid- In Western society, ambivalence ex- line diastema part of who they are or they ening to 2 mm at the height of the cen- with the condyles in centric relation (CR).5,6 ists as to whether a diastema is a favor- may wish to eliminate it. If a person de- tral papilla (Figure 1). When in repose, Clinically, upon analysis of the patient’s oc- able physical trait or not. A small midline cides not to livewith their diastema and the patient’s maxillary incisorswere hid- clusion, it was determined that maximum diastema is usually not considered unat- they seek dental intervention, the task of den fromview (Figure 2). intercuspation (MI) of the patient’s den- tractive by any group of people.1 How- finding a dental solution that eliminates The maxillary incisors were diminutive tition was different than the patient’s oc- ever, as the size of the gap increases to a the space in a responsible way is placed in size with the central incisors measur- clusion when his temporomandibular more easily seen physical trait, the level squarely on the dental professional. ing approximately 8.5 mm in height to 8 joints were placed in a CR position. of comfort someone has in personally Many clinical options exist that can mm in width, giving a height-to-width This discrepancy was meticulously car- possessing a “gapped-tooth appearance” be used for a given situation. The deci- ratio of 94%. The prevailing height-to- ried over to the mounting of the patient’s may decrease to the point of creating a sions that are ultimately made in render- width ratio was significantly distanced study models in the laboratory. When feeling of self-consciousness. If the con- ing the appropriate treatment solution from a visually pleasing range of 75% the models were mounted using the CR dition develops an outward self-conscious- are ones that the patient will have to live to 80%, with 78% being the ideal.4 All bite registration from the data collection ness in relation to the way a person feels with for the rest of their lives, particu- six maxillary anterior teeth had incurr- appointment, MI and CR occlusion were about a personal physical trait they pos- larly if the treatment solution chosen is ed slight wear over the patient’s lifetime, not coincident. When the mandibular sess, it can affect the way that person acts one involving irreversible tooth prepa- with the incisors exhibiting enough wear study model was closed to occlude against in life. This, in turn, could have a negative ration. Therefore, it is extremely impor- of the incisal enamel to expose dentin the maxillary study model, early occlusal influence in certain career and social sit- tant that the dentist and patient discuss (Figure 3). contact occurred on the mesial marginal uations in which they are placed. all of the treatment options in detail to ridges of the maxillary first bicuspids, There can be wide variations of per- identify the pertinent and important DATA COLLECTION AND mimicking the clinical presentation seen ception concerning the significance of a ramifications that are associated with ANALYSIS in the operatory. midline diastema when translated through each particular choice. After the new patient examination and in- A diagnostic laboratory equilibration different cultures, socioeconomic groups, itial consultation, the patient returned for of the CR-mounted study models dem- and ethnic backgrounds.2 Indeed, unfair CASE STUDY further data collection which included onstrated that very little tooth structure and ill-perceived judgments are leveled at A 42 year-old man in excellent physical polyvinylsiloxane impressions, a maxil- would need to be eliminated through se- people who possess certain physical traits. health and no medical compromises pre- lary arch registration with the Kois Dento- lective odontoplasty to make MI and the When testing the perceptions of subjects sented to the dental office seeking informa- Facial Analyzer System (Panadent Corp, patient’s CR occlusion coincident. Be- viewing anonymous faces with certain tion and possible treatment to eliminate Colton, CA), and a bite registration taken cause of the necessity to have an optimally features, including dental midline dia- stemas, the subjects ranked the individ- uals in the images to be significantly less intelligent, beautiful, and sexually attrac- tive. Inaddition, the anonymous faces werejudgedtobelong to a lower socioe- conomic class than the same faces with an ideal occlusal presentation.3 This find- ing illustrated that a social disadvantage was wrongly implied, simply on the ap- pearanceof one’s dentition—even if it was a healthyone. Figure 1 Patient’s smile appearance exhibiting Figure 2 Patient’s oral presentation when lips Figure 3 Occlusal view of the maxillary arch The decision whether to live with one’s a dental midline diastema of 1.79 mm to 2 mm. were in repose. showing wear of the incisors through to dentin. diastema or not is a personal one. Dia- INSIDE DENTISTRY—APRIL 2009 3

posterior teeth in lateral and functional movements, it was time to fabricate a di- agnostic wax-up to see what clinical di- mensions the incisor restorations could be while using the natural maxillary cus- pids for protection. Initially, the wax-up illustrated that the size of the central in- cisors could be increased to a dimension of 10.85 mm in height without contact in functional movement (Figure 4 through Figure 6). This was important because Figure 4 through Figure 6 The diagnostic wax-up showing possible dimensions of the proposed incisor restorations and their interplay with the mandibular the width of the central incisors would be teeth when the mandible is in lateral excursive movements. increasing to compensate for the restora- tive elimination of the midline diastema. Any further increase in the width of the restorations, without an increase in their height, would not allow us to reach a de- sirable height-to-width ratio. The last factor to work out in the diag- nostic wax-up was the appropriate dimen- sions of the lateral incisors. Specifically, what dimensions would the lateral incisors have to be to complement the proposed new dimensions of the central incisors, Figure 7 The patient’s gingival levels before gin- Figure 8 Gingivoplasty procedures carried out Figure 9 Palatal silicone putty preparation and how far would they need to extend givoplasty procedures. with consideration of the future restoration size and guide tried in before tooth preparation. mesially to portray a favorable and har- intended gingival zenith location. monic dimensional change? This deter- mination was critical because it would dictate the commensurate distal exten- sion of the central incisor restorations. This in turn would decide whether or- thodontics would be necessary to spatial- ly arrange the incisors by moving the central incisors mesially for an optimal restorative solution. It would also affect the choice of material options available. The completed laboratory analysis via the diagnostic equilibration and wax-up Figure 10 Labial silicone putty preparation Figure 11 Preparations finalized after periodon- Figure 12 Margin placement on the prepared provided a great deal of information: guide allowing visualization of critical interproximal tal gingivoplasty and frenectomy. tooth relative to interproximal alveolar crest verified contact location. through “sounding” procedure. • The number of restorative units need- ed to optimally eliminate the patient’s the provisional prototypes, to make sure dental midline diastema would equal that the new restorations would be com- four (on teeth Nos. 7 through 10). patible with habitual movements such as • The wax-up illustrated how the indi- those that occur in mastication8 and vidual restorations would appear di- speech.9 The steepness of the interarch mensionally and whether an occlusal/ relationship in the area of the cuspids functional scheme could be worked (along with the type of food) determines out that would provide proper force to a large degree the path of closure dur- management for longevity of the res- ing mastication.10,11 torations. There was one important factor that • The wax-up would serve as the proto- Figure 13 Patient displays natural smile for Figure 14 Profile view of provisionals shared would work in the restorative team’s favor type design for the direct fabrication visualization of prototypes and satisfaction of smile with laboratory to convey the importance of the to incorporate the natural cuspid mor- of the provisional restorations so that design principles. exact incisal edge position for phonetics and lip phology into an optimal anterior guid- laboratory approximations could be closure. ance, thereby reducing the number of adjusted and verified in vivo. restorative units necessary for treatment. functioning occlusal scheme postopera- necessary to accommodate restorations Because of the diminutive size of the max- The only factor left to contemplate and tively, the decision was made that if any on the incisors when the mandible went illary incisors, any restorative effort could decide on would be to determine what restorative treatment solution for the di- into lateral excursive movements? This be additive, not only adding incisal length would be the best restorative material for astema was undertaken, it would have to was especially important because the res- to the incisors but also positioning the this particular case, taking into account include a clinical equilibration to achieve torations would be longer than the pa- incisal edge of the maxillary incisors fur- various elements of the patient’s person- a similar clinical outcome for the patient’s tient’s current incisors, which exhibited ther facial. This would provide a greater al life and career. postoperative occlusion. This would cre- incisal wear. Those same cuspids would distance for clearance between the max- ate a favorable synergy between esthetics need to provide complete disclusion of illary and mandibular incisal edges when MATERIAL SELECTION and function that would enhance the po- the posterior teeth without balancing con- the patient was in function. As a matter of record, this author believes tential to have increased longevity in the tacts during those same movements. that the practitioner who professes to pos- life of the restorations.7 In addition to establishing occlusal DIAGNOSTIC WAX-UP (FOR sess a certain level of esthetic expertise An important determination needed stability from centric relation, a func- ESTHETICS AND FUNCTION) should be able to competently use a va- to be made: would the patient’s natural tional analysis would need to be done in After determining that the cuspids could riety of materials for a given situation. cuspids provide the anterior guidance the diagnostic wax-up, and eventually be viable guidance for disclusion of the This particular case could be handled 4 INSIDE DENTISTRY—APRIL 2009

Provisionalization was accomplished using a bis-acryl temporization material (Luxatemp®; Zenith/DMG Brand Divi- sion, Foremost Dental LLC, Englewood, NJ) that had been formed directly in the mouth, removed, finished in the labo- ratory, characterized with resin tints for a polychromatic appearance and sealed with a composite sealer (LuxaGlaze®; Zenith/ DMG). After fabrication, the Figure 15 The leucite-reinforced porcelain Figure 16 Boley gauge showing the thickness Figure 17 Prepared teeth after acid-etching provisionals were seated by using a spot- restorations. Note the extensive over-contour of the restoration to be 0.65 mm. for bonding illustrate the enamel surface that etch procedure by etching a 2-mm area necessary to eliminate a 2-mm midline was meticulously preserved. on the tooth’s prepared facial surface and diastema. using low-viscosity resin as a temporary cement. The patient was seen in 48 hours not the prevailing tooth position (Figure to verify the appearance and function- 8). A labial frenectomy was subsequently ality of the provisionals (Figure 13 and completed, as well as papillary re-shaping. Figure 14). Images and impressions were then taken to be used as 3-dimen- PROSTHODONTIC sional communication with the dental PREPARATION laboratory. Silicone putty (Sil-tec Putty; Ivoclar Vi- vadent, Amherst, NY) preparation guides PROSTHODONTIC SEATING formed over the diagnostic wax-up would The restorations were fabricated and re- serve as a reference during preparation turned to the dental office for seating Figure 18 The patient’s natural smile with Figure 19 A close-up view of the restoration. (Figure 9). They would prove particu- (Figure 15). Though their composition leucite-reinforced porcelain veneer restoration larly useful in helping to guide the prep- was leucite-reinforced material (IPS Em- on teeth Nos. 7 through 10. aration depth on the distal surfaces of press®; Ivoclar Vivadent), the restora- the maxillary central incisors to accu- tions were only 0.65 mm in thickness in competently with two distinctly different ability to resist structural deformity upon rately provide the correct space for the some areas (Figure 16). Although not classes of restorative materials and tech- being stressed.13 In a number of studies, intended restoration thickness (Figure advocated to be used at that thickness niques: either direct composite or indi- when the structural integrity of the DEJ 10). Because of the changing position of by the manufacturer, the restorative team rect porcelain veneers. is conserved and an appropriate restora- the interproximal contacts between the of the author and Lee Culp, CDT, has It is an incredible advantage for the tive modality is carried out, the complete central and lateral incisors, the prepara- repeatedly used IPS Empress at that thick- esthetic-minded practitioner to possess biomimetic properties of the natural tooth tion had to be carried through the contact ness successfully throughout their work- the skills necessary to competently use can be retained in the restored tooth.14,15 between those teeth to provide the room ing relationship of 12 years. The thinness composite restorative material with direct Because either composite or porcelain for natural emergence contours. The nat- of the restoration and the additive na- resin bonding for composite veneers, es- material could work for this case, a de- ural interproximal contacts between the ture of the technique allowed for the pecially for a “no-preparation” option. scription of the pros and cons of each lateral incisors and the cuspids were pre- retention of etched enamel for bonding Composite resin could certainly work for material and its longevity was reviewed served (Figure 11). Margin placement was and conservation of the DEJ for defor- this case; however, the composite resto- with the patient. Images of previously verified after preparation through sound- mation resistance, resulting in a conser- rations would have to be placed over pre- treated cases were shown to the patient ing to the alveolar crest (Figure 12). vation of the tooth’s natural biomimetic pared teeth or orthodontic movement so he could make an informed decision. As stated previously, stringent objec- behavior (Figure 17).13-15 would need to take place before any res- The patient chose the porcelain option. tives concerning preparation design were torative work to attain the sought-after put forth for enamel and DEJ preserva- CONCLUSION dimensions for the anterior restorations. PERIODONTAL TREATMENT tion.11-14 The list of manuscripts and The dental midline diastema is present There was acute attention paid to un- To compensate for the central incisor res- research documents supporting conser- in a significant portion of the world’s derstanding the proportionate balance torations and to make the centrals ap- vative preparation are well represented population. People in western civilizations of the incisors in the work-up of this case. pear to be in a more mesial position, the in the literature.17-19 vary as to their views on whether to retain Therefore, it was known that in order for periodontal tissues needed to be altered the case to be dimensionally optimum, to make that mirage appear real (Figure either orthodontic movement of the cen- 7). After the administration of local an- tral incisors mesially or a compensatory esthesia, sounding of the gingival complex preparation of the distal contour of the surrounding the maxillary incisors was central incisors would have to be com- carried out to determine if the gingival pleted to perceptively move the central treatment would include crown length- incisors closer to the midline. Because ening of the alveolar crest or soft tissue the nature of the restorations would be changes only via gingivoplasty.16 Because additive, it was determined that the ex- the gingival complex was in a low-crest tent of the preparation would not remove relationship around the incisors, it was significant tooth structure that would determined that a simple gingivoplasty compromise the biologic properties of would be all that was needed to place the the tooth when compared to its non-pre- free gingival margin in harmony with pared state. the intended restorations and in a very Essentially, the preparation would leave stable normal crest relationship, as de- enamel over 90% of the bondable sur- scribed by Kois. face, therefore leaving an optimum tooth The gingivoplasty was completed using surface for bonding the restoration.12 a soft tissue diode laser at the preparation In addition, the structural component appointment. Particular attention was of the dentino-enamel junction (DEJ) given to making the gingival zenith in Figure 20 A confident patient, at ease with his decision to eliminate the midline dental diastema. would be saved, conserving the tooth’s harmony with the future restorations, INSIDE DENTISTRY—APRIL 2009 5 a diastema or whether to eliminate it recovery of the crown. Int J Prosthodont. through cosmetic dentistry when they 1999;12:111-121. personally possess one. When a patient 15.Magne P,Douglas WH. Cumulative effect of presents to a dentist wishing to eliminate successive restorative procedures on ante- a diastema, the situation requires a sys- rior crown flexure: Intact vs veneered inci- tematic evaluation that can determine all sors. Quintessence Int. 2000;31:5-18. of the esthetic, functional, and biologic 16. Kois JC. Altering gingival levels: The res- implications that apply to the particular torative connection Part I: Biologic vari- case. The dentist and patient need to ables. J Esthet Dent. 1994;6(1):3-9. work together to analyze all of the op- 17. Magne P, Douglas WH. Rationalization of tions and identify a proper course of esthetic restorative dentistry based on bio- treatment for the individual and their mimetics. J Esthet Dent. 1999;1:5-15. circumstances. When a proper course of 18. Castelnuovo J, Tjan AHL, Phillips K, et al. action is taken, an optimal result with Fracture load and mode of failure of ceram- favorable esthetic, functional, and bio- ic veneers with different preparations. J logic consequences can be provided (Fig- Prosthet Dent. 2000;83:171-180. ure 18 through Figure 20). 19. Stappert CFJ, Ozden U, Strub JR. Longevity and failure load of ceramic veneers with REFERENCES different preparation designs after expo- 1. Kokich VO, Kokich VG, Kiyak HA. Percep- sure to masticatory stimuli. J Prosthet tions of dental professionals and laypersons Dent. 2005;94:132-139. to altered dental esthetic: asymmetric and symmetric situations. Am J Orthod Dent- ofacial Orthop. 2006;130(2): 141-151. 2. Reichmuth M, Greene KA, Orsini MF, et al. Occlusal perceptions of children seeking orthodontic treatment: impact of ethnicity and socioeconomic status. Am J Orthod Dentofacial Orthop. 2005;128(5):575-582. 3. Kerosuo H, Hausen H, Laine T, Shaw WC. The influence of incisal malocclusion on the social attractiveness of young adults in Finland. Euro J Orthod. 1995;17(6):505-512. 4. Chiche G, Pinault A. Esthetics of Anterior Fixed Prosthodontics. Chicago, IL: Quintes- sence Publishing Co, 1994. 5. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. 2nd ed. St. Louis, MO: CV Mosby Co, 28-55. 6. Dawson PE. Optimum TMJ condyle position in clinical practice. Int J Perio Rest Dent. 1985;3:11-31. 7. Miller L. Symbiosis of esthetics and occlu- sion: Thoughts and opinions of a master of esthetic dentistry. J Esthet Dent. 1999; 11(3):155-165. 8. Pameijer JHN, Glickman I, Roeber FW. Intraoral occlusal telemetry III. Tooth con- tacts in chewing, swallowing and bruxism. J Periodont. 1969;40:253-258. 9. Howell CT. Incisal relationships during speech. J Prosthet Dent. 1986;56:93-98. 10. Nishagawa K, Nakano M, Bando E. Study of jaw movement and masticatory activity dur- ing unilateral chewing with and without bal- ancing side molar contacts. J Oral Rehab. 1997;24:691-696. 11. Hiiemae K, Heath MR, Heath G, et al. Natural bites, food consistency and feeding behavior in man. Arch Oral Biol. 1996;41: 175-189. 12. Anusavice KJ. Structure of matter and prin- ciples of adhesion. Phillip’s Science of Dental Materials. 10th ed, Philadelphia, PA; WB Saunders; 1996. 13. Magne P, Belser U. Bonded Porcelain Restorations in the Anterior Dentition: A Biomimetic Approach. Carol Stream, IL: Quin- tessence Publishing Co, Inc; 2003;23-54. 14. Magne P, Douglas WH. Porcelain veneers: dentin bonding optimization and biomimetic