Case 100: Talk About Anchorage!

The patient arrived at our restorative office looking for a dentist closer to his home. He had been seeing a dentist about an hour away and was tired of driving back and forth. He was currently in Invisalign treatment and had been in treatment for the past year and a half. He was frustrated by his deep bite and worried about having problems with any provisional restorations needed while he waited for his implants and implant restorations. At initial presentation, teeth nos. 4 and 10 had already been extracted and socket preservation procedures had been completed in preparation for implants. The patient wanted to address his missing teeth along with changing the appearance of his severely worn lower anterior teeth.

Initial full face.
Initial lips at rest.

Chief Concerns

“I have missing teeth, broken teeth and I’ve been in ortho/Invisalign for over a year and a half. I just really want to have my teeth fixed, but I can’t have temporary crowns falling out.”

Dental History

Extractions, retained primary teeth, worn dentition, crowns, fillings, and bone grafting in preparation for implants. After two series of Invisalign with strong, deep bite mechanics and 13 months of treatment, the patient was switched to lower conventional braces in a further attempt to help open the bite and intrude the mandibular anteriors. This was largely unsuccessful as well.

Social History

The patient is a high-profile person who entertains and lectures to clients. He had a high demand for an esthetic solution where he would not be in temporaries that would break or cause problems while he traveled. He also did not want to make any changes/improvements to his existing anterior crowns as he liked the color and appearance.

Medical History

No significant medical history.

Initial view in maximum intercuspation.
Initial occlusal planes.
Initial maxillary occlusal view.
Initial mandibular occlusal view.

Diagnostic Findings

Extraoral/Facial

  • Normal facial symmetry.
  • The dental midline is in line with the facial midline.
  • The mandibular midline is approximately 3mm to the right of the maxillary midline.
  • Lip movement and gingival display are normal.

TMJ/Mandibular Range of Motion/Muscles of Mastication and Facial Expression

  • Temporomandibular joints are normal.
  • Normal range of motion.
  • No history of pain, clicking or popping.
  • No muscle pain or tenderness on palpation.

Intraoral Findings

Dental

  • Missing teeth nos. 1, 4, 10, 13, 16, 17, 18, 31, and 32.
  • Retained primary tooth no. J.
  • Teeth nos. 2, J, 14, 20, and 30 have composite restorations.
  • Tooth no. 15 has an amalgam restoration.
  • Teeth nos. 3 and 19 have zirconia crowns.
  • Teeth nos. 7, 8, and 9 have porcelain fused to metal crowns.
  • Teeth nos. 3 and 25 have had endodontic treatment.
  • Excessive wear on teeth nos. 23, 24, 25, and 26.
  • Decay in tooth no. J.

Periodontal

  • Fair plaque control/oral hygiene.
  • No mobility noted on any anterior or posterior teeth.
  • All probing depths are 3mm or less.
  • No furcation involvements noted.

Occlusal Notes

  • Centric relation coincident with maximum intercuspation position.
  • 100% anterior overbite present.
  • Class II molar relationship bilaterally with Class I canine relationship on the patient’s left, and Class II canine relationship on the patient’s right.
  • No posterior excursive interferences were noted, but patient is restricted in the anterior due to his deep overbite.
  • Bruxism and daytime clenching are noted—patient also mentions he feels he grinds his teeth during the nighttime as well as the daytime.
  • Angle Skeletal Classification: Class II dental and skeletal malocclusion.

Initial Pano and FMX

Initial panorex before no. 10 extraction.
Initial FMX 2019
  • Normal root morphology.
  • Adequate/healthy bone levels.
  • Widened PDL tooth no. 5.
  • No radiopacities noted.
  • No periapical pathology.
  • Pneumatized sinus limiting bone availability for tooth no. 4 implant placement.

Diagnosis and Prognosis

  • AAP Type I—Overall healthy periodontal tissues with localized inflammation around the mandibular anterior teeth.
  • Complete vertical anterior overbite with steep anterior guidance.
  • Prognosis for all teeth is good with the exception of tooth no. 25, which has a fair prognosis due to excessive wear and previous endodontic treatment.

Summary of Concerns

  • Can we restore the patient adequately without further orthodontic intervention?
  • Can we restore the patient adequately with an uneven maxillary occlusal plane?
  • Can we restore the patient adequately while honoring his request to leave the current maxillary anterior crowns and maxillary posterior teeth as they are?
  • What other options do we have to intrude the mandibular anterior teeth?
  • How can we convince the patient to proceed with further orthodontic treatment after having been in Invisalign for one and a half years already?

Proposed Treatment Plan

Phase I: Diagnostic Work Up

  • Obtain initial Itero scans of maxillary and mandibular arches, bilateral bite records, facebow record, photos, clinical and periodontal charting, and all necessary x-rays.
  • Schedule an interdisciplinary treatment planning consult with the periodontist and orthodontist.

Phase II: Periodontal/Hygiene Therapy

  • Establish ideal gingival health and plaque control habits.

Phase III: Treatment Presentation/Consultation

  • Schedule a consult with patient in the restorative office to help him understand the different objectives and possibilities to address his chief concerns.
  • Discuss the advantages of attempting a different strategy for intruding the mandibular anterior teeth despite minimal success with Invisalign.
  • Present the option of a TAD plate with SFOT (surgically facilitated orthodontic treatment) to help intrude the mandibular anteriors.
  • Help the patient understand that after we intrude the mandibular anterior teeth we will be able to restore the missing spaces and the appropriate teeth to give him a protected and more idealized occlusion.

Phase IV: Periodontal/Orthodontic Therapy

  • Place the hook in the area of the chin and initiate surgically facilitated orthodontics to intrude the mandibular anterior teeth.
  • Continue to make final maxillary arch improvements with Invisalign clear aligners.

Phase V: Implant Placement

  • Place implants in teeth nos. 4, 10, and 21 positions.

Phase VI: Definitive Restorative Treatment

  • Place maxillary resin restorations on teeth nos. 5, 11, J, and 14.
  • Place crowns on the implants in teeth nos. 4, 10, and 21 positions.
  • Place a new zirconia crown on tooth no. 19 and a zirconia onlay on tooth no. 30.
  • Restore teeth nos. 22, 23, 24, 25, 26, and 27 with monolithic ¾ e-Max crowns.
  • All restorations will be designed to idealize the occlusion as best as possible including improving the anterior guidance.

Phase VII: Maintenance Therapy

  • Instruct patient on best oral hygiene maintenance procedures.
  • Fabricate maxillary and mandibular Essix retainers to help retain the teeth in their post orthodontic and post restorative positions as well as to provide protection against the patient’s bruxing and clenching habits.

Active Clinical Treatment

Review of Treatment Goals

The patient arrived at the restorative dentist’s office already having been in Invisalign orthodontic treatment for one and a half years trying unsuccessfully to intrude the mandibular anterior teeth. After interdisciplinary treatment considerations were discussed, the patient was referred to the periodontist’s and orthodontist’s offices to evaluate the potential for surgically facilitated orthodontic therapy. Prior to beginning further treatment, the patient was happy with the crowns on his maxillary anterior teeth and did not want us to involve those teeth in the restorative plan. He also had financial implications preventing him from pursuing a complete ideal full-mouth rehabilitation. Adhering to those considerations, we were able to diagnostically visualize a compromised restorative outcome through our wax-up.

Phase I: Diagnostic

Itero scans, facebow transfer, clinical and periodontal charting, and intraoral and panoramic radiographs along with pre-op photos were obtained.

Phase II: Treatment Presentation

Multiple consultations and planning meetings were held with the restorative dentist, periodontist, orthodontist and patient to establish the final restorative plan and make sure the patient was comfortable with our approach. Having mounted models available alongside digital imaging made our treatment discussions and timeline easily understood. A thorough discussion was had regarding the compromise we were making due to the patient’s requested limitations regarding the maxillary anterior teeth. It was explained that we could achieve the best results restoratively by intruding the mandibular anterior teeth via surgical intervention. With successful intervention we would then be able to restore the appearance and function of the mandibular anterior teeth. The patient was able to see the importance of replacing the crown on tooth no. 19 and placing an onlay to tooth no. 30 to provide better posterior stops/contacts. The wax-up and pre-op photos were instrumental in helping the patient realize the importance of each planned step, and he agreed to our treatment plan.

Phase III: Hygiene Therapy

This was straightforward as the patient only had localized inflammation with localized plaque-induced gingivitis. A hygiene visit was completed with a detailed review of home care instructions and techniques in order to help the patient prepare for long-term success of his final restorations.

Phase IV: Implant Placements

A BioHorizons Tapered PLUS 4.6 x 9mm implant was placed in position no. 4 and a BioHorizons Tapered PLUS 3.8 x 12mm implant was placed in position no. 10.

Phase V: Surgically Facilitated Orthodontics

The orthodontic goal was to intrude the mandibular anterior teeth to provide more prosthetic space for the future restorations on teeth nos. 22, 23, 24, 25, 26, and 27. After brackets were placed on the mandibular arch, surgical access was created with vertical releasing incisions distal to teeth nos. 22 and 27, and intrasulcular incisions from tooth no. 22 to tooth no. 27. Selective corticotomies took place utilizing piezosurgery. The surgical mini-plate was manually shaped to accommodate installation on the symphysis, and then stabilized with screws. Onlay grafting was followed with cortical cancellous mineralized particulate allograft infused with A-PRF (advanced platelet-rich fibrin). In order to further enhance soft tissue phenotype, an allogenic dermal matrix was placed and stabilized with periosteal sling resorbable sutures. Advancement of the flap and closure was completed after the mucosa was perforated to accommodate access to the mini-plate’s hook.

At the completion of orthodontics, re-entry for retrieval of the surgical mini-plate took place utilizing a mucosal incision. This prevented disturbance of the gingival margins of the mandibular anterior teeth.

Intra-foramena osseous exposure.
Selective corticotomies.
Hook fixated.
Cortical cancellous mineralized particulate allograft.
Allogenic dermal matrix.
Flap closed with dressing covering hook.
Orthodontic mechanics prior to debanding.
Post ortho maximum intercuspation.

Phase VI: Definitive Maxillary and Mandibular Restorative Treatment

Composite restorations were placed on teeth nos. 5, 11, J, and 14 to create better maxillary occlusal stops and a better maxillary occlusal plane. Teeth nos. 19 and 30 were prepared for zirconia restorations and teeth nos. 22, 23, 24, 25, 26, and 27 were prepared for monolithic ¾ e-Max crowns. The restorations on teeth nos. 19 and 30 were done in part to create better mandibular occlusal stops. Four weeks later the mandibular restorations were delivered and impressions were made of the implants in the no. 4 and 10 positions to create their final restorations. Four weeks later the no. 4 implant was restored with a lab cemented zirconia crown over an Atlantis custom abutment to make a one-piece screw retained abutment/crown. The no. 10 implant was restored with an Atlantis custom abutment and an intraorally cemented monolithic zirconia crown. The no. 10 fixture angulation prevented a screw retained restoration.

Phase VII: Implant Placement

Once mandibular orthodontics had torqued the roots of teeth nos. 21 and 22 apart enough to create adequate space for an implant, a BioHorizons PLUS implant 3.8 x 9mm was placed.

Phase VIII: Definitive Implant Restoration

After 3 months of healing, the no. 21 implant was restored with a lab-cemented zirconia crown over an Atlantis custom abutment to make a one-piece, screw-retained abutment/crown.

Phase IX: Maintenance

Regular 6-month hygiene appointments were established. Final maxillary and mandibular retainers were fabricated to help with orthodontic retention and provide bruxism protection.

Definitive view in maximum intercuspation.
Definitive smile.
Definitive maxillary occlusal view.
Definitive mandibular occlusal view.

Definitive Vertical Bitewings

Commentary

Definitive full face.

The patient had been seeing an out-of-town dentist due to a family connection and had begun his orthodontic treatment one and a half years ago. When he arrived at our restorative dental office, all Invisalign aligner techniques had failed to intrude the mandibular anterior teeth. It was discussed with the patient that surgically facilitated orthodontics might be the only option remaining to attempt to attain the orthodontic treatment goals.

Surgically facilitated orthodontic therapy (SFOT) is an interdisciplinary approach to comprehensive oral healthcare involving malocclusion management that augments the soft and hard tissue architecture by expanding the available envelope of orthodontic movement and reducing the chance for unfavorable iatrogenic sequalae, such as gingival recession or compromised orthodontic decompensation. Selective corticotomies induce transient osteopenia and a regional acceleratory phenomenon. Surgical access during SFOT allows the opportunity to incorporate temporary anchorage devices (TADs) that can offer absolute skeletal anchorage and allow for significant orthodontic movement.

Mini-plates are very effective for tooth movement with high success rates. They can be used in any area of the dento-alveolar complex or basal bone, although they require extensive surgical access. The forces that can be applied are larger compared to the micro-implants. Mini-plates may be considered the TADs of choice when extensive orthodontic treatment is required. Unlike some mini-implants, they can be immediately activated since they do not rely on osseointegration. They are usually made out of a titanium alloy and are stabilized by 2–2.5mm screws. They are designed to be attached to orthodontic elastomeric or coil springs. Common designs are L-shaped, T-shaped, straight, or Y-shaped. The T-shaped are commonly used for intrusion of anterior teeth such as in this case. The anchor plate acts as an onplant while the screws act as the implants. Since they are not placed between roots of teeth, they do not interfere with their movement.

Restoratively, we were looking to gain adequate space with intrusion to help properly restore the mandibular anterior segment. We had multiple issues due to missing teeth and space allocation on the lower arch where we had to compromise by only placing one implant in the tooth no. 21 position, while leaving a small space distal to tooth no. 27. This space is masked restoratively with the design of the crown on tooth no. 27. The patient was okay with a small space in that location. The patient needed additional posterior occlusal stops that were managed with a new crown on tooth no. 19 and an onlay on tooth no. 30. In the maxillary arch, we were tasked with managing a retained primary tooth with decay and with missing teeth nos. 4 and 10. For financial reasons, we made the decision to use composite resin to balance the maxillary posterior occlusal plane and implants to replace the missing teeth.

We were additionally limited by the patient’s desire to leave the existing crowns on teeth nos. 7, 8, and 9 alone. He liked their positions and esthetics. The patient also wanted us to leave his maxillary posterior teeth alone as much as possible so we used only composite restorations to improve the maxillary occlusal plane. We were satisfied with his maxillary incisal edge position in relation to his lip and face and therefore made the decision to adhere to his requests. In the end, we were extremely lucky to have a happy and understanding patient as we overcame significant challenges to help him achieve his esthetic desires.

Lloyd F. Moss III, DDS, is a restorative dentist in Fredericksburg, VA. He practices with his father, Dr Lloyd F. Moss Jr. Dr Moss III is a fellow of the International Congress of Oral Implantologists and contributing member of the Commonwealth Study Club.

Thanos Dounis, DDS, MS, is a diplomate of the American Board of Periodontology and an internationally trained prosthodontist. Dr Dounis and his wife, Dr Lillie Pitman, maintain a private practice limited to periodontics and implant dentistry in Fredericksburg, VA. Together they are directors of the Commonwealth Study Club.

Graham Gardner, DDS, MS, is an ABO board certified orthodontist practicing in Richmond, VA. Dr Gardner is an adjunct faculty member at the Virginia Commonwealth University department of orthodontics and a member of the Invisalign faculty.