Clinical Case Report: Orthodontic-Restorative Treatment to Enhance Smile

Peter S. Balle, DDS, FAGD

Background

Age at Initial Presentation: 27
Initial Presentation: April 2008
Active Treatment Completed: August 2008

The patient’s chief concern was that her teeth appeared too small, and she was unhappy with her smile (Figure 1 and Figure 2). She said she has never been satisfied with her smile and wanted bigger teeth. The patient has been a dental assistant for several years, working for a few dentists. Her dental literacy was higher than the average patient. The patient desired conservative dentistry.

Medical History

The patient’s medical history was unremarkable.

Dental History

When she was an adolescent, orthodontic treatment with brackets and bands were used to close spaces of anterior teeth. Shortly after treatment concluded, the spaces reopened as teeth relapsed because she had stopped wearing her removable retainer.

In her late teens, a removable orthodontic appliance was used to close the spaces again. A permanent bonded wire retainer was placed on the lingual surfaces of teeth Nos. 7 to 10 to retain the incisor and prevent proclination and spacing (Figure 3).

The patient had direct and indirect restorations placed on her posterior teeth before and after orthodontic treatment. All restorative needs had been addressed, with no decay or defective restorations.

Extraoral: Incisors were in reverse arc to lower lip. Lip length and mobility was normal. Teeth in repose were 0.5-mm display (Figure 4).

Temporomandibular Joints (TMJ): History and signs of reciprocal click for at least 10 years.

Intraoral: Localized mild attrition to the lower anterior incisors. Few direct composite restorations on posterior teeth and one ceramo-metal crown. Gingival architecture was symmetrical, and probing depths were normal: 1 mm to 3 mm.

Symptoms: Patient indicated long periods of chewing were uncomfortable, and her jaw clicked when chewing gum. She also indicated she chewed gum for long periods.

Signs: Fremitus was noted on teeth Nos. 7 to 10.

Diagnosis

Periodontal: AAP type I

Biomechanical: No caries; restorations in good condition.

Functional: Constricted chewing envelope; history and sign of right-side TMJ click that she had noticed for years. She stated that her jaws were uncomfortable when chewing gum for long periods.

Dentofacial: Inadequate incisor tooth proportions (Figure 5).

Risk Assessment

Periodontal: Low

Biomechanical: Low

Functional: Medium risk

Esthetics: Medium

Radiographic Assessment

Bone level appeared excellent. The shape of incisors appeared to be deficient in proportion mesial-distally.

Prognosis

The prognosis for this patient was good. A series of diagnostic digital photos and four vertical bitewing radiographs were taken during the examination. A panoramic radiograph was obtained from her orthodontist before treatment (Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9 and Figure 10).

After examination and review, it was determined mesial-distal width of maxillary central and lateral incisors were deficient for the arch form. Esthetically, the overall appearance of the incisors were small, especially the undersized lateral incisors.

To eliminate the diastemas, the incisors were retroclined and the overall arch was constricted. Closing the spaces between the incisors resulted in a reverse contour of the incisal edges relative to upward arc of the lower lip (Figure 5).

Concerns

1. Would increasing overjet by predominantly proclining incisors be sufficient for elimination of fremitus and to relieve constricted chewing envelope?

2. Would moving the incisors facially still allow conservative preparation of tooth structure?

A key concern prior to initiating treatment was the fremitus on the anterior maxillary teeth. Increasing the horizontal parameter of overjet was expected to relieve the constricted envelope of function. The overjet change was more important for allowing normal function despite the increase in visual vertical display and increase of overbite relationship of anterior incisors. The vertical parameter of overbite was less a concern of function and more a concern of esthetics. Increased overbite as well as overjet was expected to result in improved esthetic and functional goals of treatment.

Treatment Goals

1. Create space between incisors.
2. Increase length, width, and ideal proportions of incisors.
3. Improve overjet relationship of anterior teeth and eliminate fremitus.
4. Restore as minimally as possible, and be conservative in tooth preparation.

Treatment plan

In the treatment planning, the goals were to increase visual display, improve proportion of incisors, and correct the reverse smile appearance of the incisal edge. Key diagnostic determinants were used to plan a more desirable display of incisors. Factors, such as lip length, lip reveal or dynamic movement, and display of teeth at smile and repose, were all used to determine desirable incisal edge. Also, the patient’s desires for appearance were calculated in the treatment planning. Other factors, such as age and facial type, were also considered. In a dolichocephalic type, a clinician can further increase the length of teeth to match the face. Shorter teeth may be more appropriate for brachiocephalic faces because they are broader. The key factor in determining incisal edge length is repose. In this case, the patient had a repose display of 0.5 mm (Figure 4). It is more desirable for a young female to display more incisal edge at repose, which is a more youthful attribute. The patient’s incisors were undersized in both length and width. Expansion of the dental arch and proclination of the incisors are desirable to achieve the necessary interproximal room to allow for increased proportion of the incisors. Proclination and arch expansion increase the overjet, which creates the necessary space to alleviate the constricted envelope of function and eliminate the fremitus on the maxillary incisors.

After measuring width and length of incisors, it was determined that length of incisors would improve size and increase display by increasing length by 2 mm. Increasing space between all incisors by 1 mm was planned to allow greater width and improve proportions to compensate the added length. Feldspathic porcelain is a coreless ceramic restoration, and feldspathic porcelain veneers allow for minimal thickness as low as 0.3 mm and have the highest amount of translucency. Because no major value change was planned and minimal teeth preparation was desired, feldspathic veneers were determined to be the best choice. The patient also chose teeth-whitening prior to restorations. Because the lateral incisors are disproportionately smaller than the central incisors, the space volume that would be created mesial and distal of the lateral incisors would be used to increase the dimension more so of the lateral incisors than the central incisors. The space created between the central incisors would be divided equally to increase the width of the central incisors.

Phase I: Orthodontic Phase

From study casts, a polyvinyl putty index was made of the incisal edges. The cast was cut vertically between the incisors, using a dental laboratory hacksaw. When the vertical cuts were made down apically approximately 3 mm to 4 mm past the cervical portion of teeth, a horizontal cut was done, separating the teeth from the cast. More stone was removed between the teeth and the cast to allow wax to flow into the space. The teeth were then placed back on the incisal jig, which was made from the original unaltered cast of the incisors. Pink base plate wax was added to reattach the incisors that were cut away from the model.

The incisors were attached by wax to create a wax-altered cast to manipulate position of model teeth and plan the patient’s orthodontic tooth movement. To accomplish spacing and proclination of the incisors, the wax-altered cast was warmed and the incisors were prolined and spaced in small increments (Figure 11, Figure 12 and Figure 13). A duplicate cast was then made from each incremental change to the wax-altered cast. After each incremental change in position of the incisors, a duplicate cast was created. A vacuum-form thermoplastic aligner was made on each of the duplicate casts. These appliances were trimmed and then given to the patient to wear continually, except when eating, to procline her incisors into the desired restorative position. The amount of movement was accomplished with four aligners. She was instructed to wear each aligner for 2 weeks and to remove them for meals. The patient chose to use carbomide peroxide gel for whitening while undergoing orthodontic treatment in the thermoplastic aligner trays (Figure 14). When the desired amount of space was attained, the patient was instructed to wear the last aligner for 6 weeks to retain the desired positioning in preparation for restorative treatment (Figure 15).

Phase II: Restorative Phase

New casts were made of the teeth and sent to a local laboratory for a diagnostic wax-up. The laboratory was instructed not to make any reduction to the cast but only add volume to increase proportions to the incisors. The Kois Dento-Facial Analyzer System (Panadent^®, Grand Terrace, CA) was used to communicate to the facility the steepness and tilts of the occlusal plane. This information was now transferred to the articulator in all three planes of space related to an average axis-incisal distance of 100 mm. A jaw relation record was made with Jet Bite (Coltène/Whaledent^®, Cuyahoga Falls, OH) in maximal intercuspation.

It was initially determined that four veneers of the incisors would be sufficient to achieve desired results. The patient wanted to include the canines as well for veneers so the diagnostic wax-up returned with Nos. 6 to 11 modified. Even though the mesial distal width of the canines was adequate, it was thought that placing thin veneers on the canines would change the shape from a less pointed triangular to a more oval and softer appearance.

A temporary silicone putty matrix (Sil Tech, Miamisburg, OH; Ivoclar Vivadent, Inc., Amherst, NY) was made of the diagnostic wax-up cast. Provisional veneers (Integrity^™, DENTSPLY Caulk, Milford, DE) were placed over the patient’s incisors for her to evaluate esthetics.

When the provisional restorations were modified and approved by the patient, the provisional veneers were removed and the teeth prepared ultra-conservatively prior to final impression. The preparation consisted of flattening the cusp tip of the canines and incisors. An Aquasil light viscosity (DENTSPLY Caulk) impression was made of the maxillary arch. The Sil Tech putty impression of the wax-up model was used for placement of temporary veneers.

Impressions were made of the provisional restorations and photos (Figure 16) taken to communicate to laboratory the desired contours and length of the definitive veneers. The polyvinyl impression of the temporary veneers produces a “go-by” impression for the laboratory to follow the contours and shape of approved provisional veneers.

No facial enamel was removed in the preparation of the incisors and canines. The veneers were prepared with Interface (Apex Dental Materials, Inc., Lake Zurich, IL) and Simplicity bonding resin (Apex Dental Materials, Inc.).

The teeth were prepared with 35% phosphoric etch (Ultradent Products, Inc., South Jordan, UT), Interface, and Simplicity bottle No. 2 bonding, 3M RelyX^™ translucent light-cured veneer bonding resin (3M ESPE, St. Paul, MN). The laboratory services were donated by Donnell Brox of Performance Dental Lab, Las Vegas, Nevada, who is a family friend of the patient.

Although restorations are not exactly symmetrical, they met the patient’s expectations. The authors were able to bond to enamel and minimize irreversible tooth structure changes.

In regard to symmetry, the patient said the incisors are “sisters” not “twins” (Figure 17 and Figure 18).

Phase III: Maintenance Phase

A vacuum-form thermoplastic 0.8 mm was made of the maxillary arch for nightwear to retain maxillary teeth.

Commentary

The final results met the patient’s expectations. The treatment met the patient’s goal for larger teeth and a more pleasing smile with very conservative dentistry. She smiles more and has more confidence in her appearance.

Most of the risk in this case was in areas of function and esthetics. Her occlusion was compromised. The retainer bonded to hold the incisors in a retroclined position directly contributed to the constricted envelope and resulted in fremitus and more attrition to the incisors. Posttreatment radiographs can be noted in Figure 19.

By understanding all the factors in esthetics of tooth length, lip dynamics, lip length, repose, patient age, facial types, and esthetic tooth proportions, a desirable smile can be achieved.

Clearly, this is a case that required an interdisciplinary approach to achieve an ideal outcome. When orthodontics alone was performed to correct the problem of spacing because of a lack of adequate incisor proportions, torquing, retroclining, and bonding a metal wire retainer were required. The treatment achieved closure of diastemas but resulted in unesthetic and functionally compromised incisors position. The long-term effects could be detrimental. With the evidence of TMJ clicking, greater incisor wear compared with the rest of the dentition may have been a direct result of the compromised limited disciplinary treatment. Had the spaces never been closed, the functional risk may have been lower.

For planning, all risk factors must be considered. Functional risk can sometimes directly conflict with esthetics. Increasing length can impact the chewing envelope. Phonetics must not be overlooked when changing esthetics.

Acknowledgments

Ceramics by Donnell Brox, Performance Dental Lab, Las Vegas, Nevada.

About the Author

Peter S. Balle, DDS, FAGD
Private Practice
Las Vegas, Nevada