8
Orthodontically Driven Osteogenesis: Tissue Engineering to Enhance Adult and Multidisciplinary Treatment
Federico Brugnami1 and Alfonso Caiazzo2
1 Private Practice Limited to Periodontics, Oral Implants and Adult Orthodontics, Rome, Italy
2 Department of Oral and Maxillofacial Surgery, Practice Limited to Oral Surgery and Implants, Centro Odontoiatrico Salernitano, Italian Society of Oral Surgery and Implants (SICOI), MGSDM Boston University, Salerno, Italy
ODO in Multidisciplinary Treatment
Throughout earlier sections, we explored surgically facilitated orthodontic treatment (SFOT) and how it can substantially decrease the overall treatment duration for orthodontic therapy. When paired with bone grafting, SFOT can broaden the basal bone, reducing the need for extractions, better safeguarding periodontal health, and a powerful tool in complex adult cases requiring an interdisciplinary approach. Nonetheless, patients may be hesitant to undergo surgery. In adult patients with mutilated dentition cases, malocclusion can be linked to various issues such as periodontal disease, missing teeth, resorbed edentulous alveolar ridge, and pathologic migration of remaining teeth. These complications can make achieving an acceptable functional and aesthetic rehabilitation of the mouth difficult. As a result, alternative oral surgical procedures like wisdom extractions, bone augmentation, and/or implant placement may already be in the works. Corticotomy may be used to minimize the patient’s surgical exposure. Although it may appear to be a cumbersome and time‐consuming approach, it has the potential to produce optimal outcomes and benefit many patients. This necessitates effective communication between numerous clinicians with expertise in different fields. When properly coordinated and executed, each specialist’s input can help facilitate the working of other team members. In previous chapters, we learned about surgically accelerated orthodontics (SAO), which can significantly reduce the total treatment time of orthodontic therapy. When combined with bone graft, SAO can expand the basal bone, resulting in less need for extractions, better protection of periodontal health, and becoming a powerful tool in complex adult cases that require an inter or multidisciplinary approach. However, patients are often hesitant to undergo surgery. In adult patients with mutilated dentition cases, malocclusion can be associated with many problems, such as periodontal disease, missing teeth, resorbed edentulous alveolar ridge, and pathologic migration of remaining teeth. These complications can make it challenging to achieve an acceptable esthetical and functional rehabilitation of the mouth. Therefore, other oral surgical procedures such as wisdom extractions, bone augmentation, and/or implant placement may already be planned. Corticotomy can be combined with these procedures to minimize the patient’s surgical exposure. Although it may seem cumbersome and time‐consuming, this approach has the potential to achieve optimal results and benefit many patients. It requires effective communication between multiple clinicians who have expertise in varying fields. When appropriately coordinated and executed, the input of each specialist can help facilitate the working of other team members.
Orthodontics for Prosthetic
In certain cases, an orthodontist can align the alveolar arches to create a path for a prosthesis or to correct a gummy smile or asymmetry before esthetic prosthetic rehabilitation. Orthodontic therapy can also be used to move teeth into predesigned positions for surgical implant placement and dental restoration in patients with dental migration. Adult malocclusion cases often require implants or periodontal treatment and bone augmentation procedures due to tooth loss and bone resorption. In these cases, endosseous implant placement by a surgical specialist can reshape and augment bone for better anchorage and precision of tooth movement by the orthodontist.
Periodontics and Orthodontics Synergy: The Two Dental Specialties that Need a Healthy Periodontium
In the previous chapters, it has been shown that viewing osteogenetic corticotomy simply as a method to speed up orthodontic movement is limiting. Clinical and histologic evidence suggests that the technique can expand basal bone (as discussed in Chapter 2), which has two positive effects. First, it creates more space to accommodate crowded teeth, reducing the need to extract healthy premolars in growing patients. Second, it creates a thicker, stronger periodontium that helps to minimize the risk of gingival recession during or after orthodontic movement. According to Williams and Murphy (2008), “the alveolar envelope” or limits of alveolar housing may be more adaptable than previously thought and may be defined by the position of the roots. For a detailed discussion on periodontal considerations during or after orthodontic treatment, please refer to Chapter 6.
The number of adults seeking orthodontic treatment is expected to rise, and many of them have a periodontium with suboptimal bone width and volume. Even with slow, traditional orthodontic movement and light forces, there is a high risk of creating root dehiscence in patients with thin periodontium. Root fenestrations or dehiscences may be present without the clinical manifestation of gingival recession. In cases where corticotomy‐facilitated orthodontic mechanics are necessary, careful treatment planning using a multidisciplinary approach is critical for success. Accelerated orthodontic movement techniques can be used to hasten dental movement, treat and prevent periodontal problems, and regenerate ridge defects, allowing for delayed implant placement. This chapter presents several different combinations of corticotomy in adult patients to facilitate the multidisciplinary treatment.
Case Presentation
Case 1 Mutilated Dentition #1: Orthodontics and Prosthodontics Connection, Enhancing the Periodontal Outcome
A 42‐year‐old white female presented with a Class II Division I malocclusion, deep bite, and severe crowding in the lower jaw (Figure 8.1).
She also complained of her smile and crowding of her lower teeth and wanted a replacement for her missing lower teeth (Figure 8.2).
Figure 8.1 (a–c) A 42‐year‐old white female presented with a Class II Division I malocclusion, deep bite, severe crowding in the lower jaw, severely atrophic mandibular alveolar ridge, and missing teeth #24 and 25.
Figure 8.2 Detail of the anterior sextant, showing mild crowding and gingival misalignment.
Clinical examination revealed an edentulous and severely atrophic mandibular alveolar ridge (Figure 8.3).
Moreover, missing teeth #24 and 25. The patient also had ceramic dental restorations on teeth #5 and 6 and an implant‐supported ceramic restoration on tooth #11. Radiographically, there were no signs of periodontal or periapical disease. Clinically, periodontal health was good with only mild buccal gingival recession on teeth #21, 23, and 28 (Class I Miller classification).
The objective of the orthodontic therapy was to resolve lower crowding, correct deep bite, and level gingival margin of the anterior upper sextant to facilitate the prosthodontist’s work in achieving an optimal esthetic. No attempt to correct the skeletal and dental Class II were planned.
Figure 8.3 Occlusal view of edentulous ridge before augmentation.
The comprehensive dental treatment plan included: Ridge augmentation of edentulous ridge. The fixed restoration on the implant for missing lower right premolar, crown on teeth 6, 7, and 8 for esthetic.
She was given the two following options:
- Conventional treatment whereby the orthodontic treatment would be performed, followed by the augmentation procedure and then the implant placement once the orthodontic movement is completed later as a secondary procedure.
- Innovative accelerated treatment by using SAO periodontal surgical procedure.
She was delighted to accept the latter proposal, mainly because it was possible to perform ridge augmentation, including the harvesting of autologous bone, and the corticotomy in one combined surgical procedure.
Technical Procedure
The patient was bracketed 2 weeks before surgery (Figure 7.8a). She opted for ceramic brackets (Leone, Firenze, Italy) in the upper arch and metal ones for the lower arch for aesthetic reasons. Nickel–titanium 0.016 archwire was used in the upper, and 0.012 archwire was used in the lower arch. The periodontal procedure to accelerate the orthodontic movement was planned at the lower incisor level with the ridge augmentation in the contiguous edentulous area and performed 2 weeks after bracketing. The symphysis area was also targeted as a source of autologous bone for the bone augmentation procedure. The patient was premedicated orally with 2 g of amoxicillin 1 hour before surgery. A full‐thickness mucoperiosteal flap was elevated under local anesthesia using a sulcular incision extending from the distal line angle of the second lower right molar to the distal line angle of the first lower right premolar. Care was taken to preserve the papillae in the anterior area (lower incisors level). The autologous graft was then harvested from the same area, with a manual bone‐scraping instrument and placed over the deficient ridge. This area was then further augmented with xenogeneic bone (Endobone, Biomet Palm Beach Gardens, FL, United States) and covered up with a resorbable membrane (Osseoguard, Biomet Palm Beach Gardens, FL, United States). The xenogeneic bone was also placed over the buccal plate in the anterior sextant, with particular care to ensure coverage of the areas with dehiscence of the roots. In the region of tooth #26, a resorbable membrane was used to cover the osseous defect following the principles of the conventional guided tissue regeneration (GTR) technique. In contrast, the recession over #28 was left uncovered by both graft and membrane to act as a control (Figure 7.8c, d). The flap was then coronally repositioned and sutured in an interrupted fashion to obtain primary closure. The patient was placed on chlorhexidine 0.2% rinses twice a day, oral amoxicillin for 1 week, and non‐steroidal anti‐inflammatory drug (NSAID) (naproxen) for pain b.i.d. as needed. The orthodontic wires were replaced 1 week after surgery. The patient had no significant pain or discomfort during the first postoperative week. On postoperative day 7, a 0.014 nickel–titanium archwire was placed. The patient was put on a soft diet for 10 days and instructed to continue rinsing with the antimicrobial agent. On postoperative day seventeen, the archwire was changed to 0.016, and the patient advanced to a regular diet. The lower anterior dental alignment was almost completed 3 weeks postoperatively and 6 weeks after surgery, the anterior crowding was resolved entirely (Figure 7.8b). Soft tissue architecture and the periodontium remained healthy, and the area of teeth #29 and 30 retained the horizontal augmentation. Six months after surgery, an endosseous implant was placed into the augmented area. At the reentry time, an adequately regenerated area was evident, with enough bony width and height to place an implant (Figure 8.4).
A bone core biopsy as a part of the implant placement, as described by Brugnami et al. (1996), was performed (Figure 8.5).
The specimen was fixed in formalin and decalcified in Mielodec Bio‐Optica for 90 minutes. After being embedded in paraffin and cut to a 3‐micron thickness, the sections were stained with hematoxylin and eosin and examined using light microscopy. The ImageJ software was used to calculate the percentage of mineralized tissue at a 4X. The histology showed residual particles of the graft, which were completely surrounded by a newly regenerated mixture of woven and lamellar bone. Histomorphometry resulted in 62% of the area occupied by bone. Despite the movement outside the original bony envelope that eventually takes place in decrowding treatment for the nature itself of the straight‐wire technique, in the anterior area, a regeneration of the bony dehiscence overlying tooth #26 was evident, while the control (tooth #28) remained unchanged (Figure 7.8e), confirming the importance of the combination of the corticotomy with a regenerative procedure (bone graft alone or with GBR/GTR). The buccal plate on tooth #27 also appeared augmented in thickness. In the area of tooth #27, where the bone graft was not originally covered with the membrane, a tissue fragment was harvested with a blade (Figure 7.8f) and processed as previously described. The result showed prominently bone marrow portion with some rare fibrous connective tissue and mature bone for 35% (Figure 7.8g). Although we should refrain from getting to definitive conclusions by analyzing one histologic, we can make some preliminary hypotheses:
Figure 8.4 At the reentry time, an adequately regenerated area was evident, with enough bony width and height to place an implant.
Figure 8.5 The histology showed residual particles of the graft which were completely surrounded by newly regenerated mixture of woven and lamellar bone. Histomorphometry resulted in 62% of the area occupied by bone.
- Particulate graft alone may be enough to regenerate some bone (on the inner side, facing the tooth), while some of the original graft become encapsulated in fibrous connective tissue (on the outer side, facing the soft tissues).
- Approximately, 2/3 of the graft facing the tooth may turn into new bone.
- Some of the graft facing the flap may be encapsulated by fibrous connective tissue. This part will not contribute to the regeneration of periodontal attachments and may act as a (modified) connective tissue graft. In other words, it does not regenerate the periodontal attachment but may thicken the soft tissue, changing the periodontal biotype. The slow resorption particles of the graft may act as a filler and contribute to the long‐term stability of the soft tissues (Figure 8.6).
- The difference in mature bone percentage between the implant area and the buccal plate of 27 (62% versus 35%) may be explained by the difference in harvesting (trephine for a depth of 6/7 mm versus blade for a superficial only layer), but also by the presence/absence of the membrane. It is an interesting topic that may require further investigation and clarification. The original PAOO® technique, in fact, does not include the use of a membrane, and the reentry at 10 years shown by the Wilcko brothers has proven their way of grafting to be very effective (Wilcko et al., 2001).
The main difference between the PAOO® and our single flap corticotomy (SFC) is the quantity of bone graft used; 0.5–1 cc per tooth and 0.5 cc for quadrant, respectively. To overcome the difference in quantity, we suggest using a membrane.
- In SFC, the use of membrane may be required in cases where the surgery attempts to solve skeletal transverse or sagittal discrepancy (i.e., palatal expansion and/or minor Class II Class III). It may be less crucial in protecting the periodontium in decrowding cases.
Figure 8.6 According to histologic sample harvested in the area, the inner portion of the graft may turn into newly regenerated bone, with some portion of bone marrow, while the outer layer most likely becomes encapsulated by fibrous connective tissue. This is not necessarily a negative result, since it may be speculated that the slow resorption particles of the graft may act as a filler and contribute to a long‐term stability of the soft tissues.
Six months after implant placement, a provisional crow was delivered. The case was debracketed when decrowding, deep bite correction, and proper alignment of the cervical margin of the anterior sextant were achieved (Figures 8.7 and 8.8).
Figure 8.7 End of orthodontic treatment, before definitive prosthetic treatment: note resolution of deep bite and crowding and alignment of cervical margins of upper anterior sextant.
Figure 8.8 (a, b) Pre‐ and postoperative detail of over‐bite correction, before definitive crown delivery on teeth 7, 8, and 9: note difference in thickness of periodontal tissues of the lower anterior sextant.
Figure 8.9 Delivery of final restorations. Note excellent final esthetic as result of combination of optimal prosthetic work and gingival health and harmony.
Source: Prothetic work by Dr. Graziano Brugnami, Private Practice, Rome‐Italy and technical work by odt. Mauro Merletti, Rome Italy.
Final functional and esthetic adjustments were accomplished with the delivery of the final prosthetic (Figure 8.9).
Case 2 The Summer Break Case: An Alternative to Veneers to Correct Esthetics in the Anterior Area
The patient, a healthy 21‐year‐old woman who was dissatisfied with her smile, presented with a slight crowding of the anterior superior teeth and overlapping central incisors (Figure 8.10).
This college student on summer break wanted to resolve this relatively mild esthetic problem before returning to college in the fall. The medical/dental history and intraoral examination found no medical contraindication to treatment. The periodontium was healthy, with no recession or bone resorption, as confirmed by interproximal radiography.
Figure 8.10 Patient presented a very mild crowding and central incisors overlapping in the upper anterior sextant.
Various treatment modalities were proposed to the patient, including porcelain veneers and conventional orthodontic movement. Also, in an effort to accelerate the treatment, a lingual approach was proposed, combined with the minimally invasive Piezocision (R) technique, which, as noted in Chapter 5, consists of small corticotomies done through vertical incisions of the soft tissues without the reflection of a flap. Considering the relatively short time, the patient opted for the latter solution.
Case Management
The two‐dimensional (2D) lingual brackets were applied from premolar to premolar with indirect technique. A slight interproximal reduction of the upper front teeth was performed, and a lingual 0.014 nickel–titanium (Ni–Ti) arch was placed (Figure 8.11).
In the same session, the Piezocision technique, as described by Dibart et al. was performed. After achieving anesthesia through local infiltration, vertical full‐thickness incisions were made midroot level, interproximal between each tooth from the upper right first premolar to the upper left first premolar (Figure 8.12).
The localized bone decortications were done through the vertical gingival opening with a piezoelectric knife to a depth of 3 mm (Figure 8.13).
Figure 8.11 After a light interproximal reduction (IPR or stripping) a lingual 0.014 Ni–Ti arch was applied.
Figure 8.12 Following the technique described by Dibart, called PiezoincisionTM, vertical full‐thickness incisions of the mucosa were performed in the inter‐proximal area from canine to canine.
Figure 8.13 A 2–3 mm deep corticotomies were performed trough the incisions of the mucosa.
Grafting of the area was not performed because a preoperative cone‐beam computed tomography (CBCT) examination showed no presence of bony fenestrations, dehiscences, or thin buccal walls and because of the very limited amount of movement requested. Incisions were closed with single, interrupted resorbable sutures, and the patient was discharged. Patient instructions included a postoperative pain medication (naproxen sodium 550 mg b.i.d.) as needed and rinsing with chlorhexidine gluconate 0.2% from the day following the intervention for 1 week. Antibiotic coverage was not prescribed (Caiazzo et al., 2011).
Clinical Outcomes
At the 7‐day follow‐up visit, the patient reported a regular course with no pain, discomfort, or swelling (Figure 8.14).
Figure 8.14 One‐week follow‐up: the vertical cuts in the mucosa are completely healed.
Figure 8.15 At the 18‐day follow‐up, the crowding was almost completely resolved.
At the 18‐day follow‐up, the crowding was almost completely resolved (Figure 8.15).
The orthodontic appliance was maintained for stabilization. The patient left for a vacation and returned for the 30‐day follow‐up.
The crowding was completely resolved, the patient was debracketed, and a thermoformed contention was delivered (Figures 8.16 and 8.17).
When the patient was seen at 6 months post treatment, she was delighted with the esthetic result (Figure 8.18).
Case 3 Mutilated dentition #2: Adjunctive Corticotomy‐enhanced Segmental Orthodontics to Intrude Over‐erupted Molars and Allow Teeth Replacement in the Opposite Arch
One‐shot Surgical Procedure Combining Corticotomy with Anchorage Plate Positioning, Wisdom Extraction, and Periodontal Surgeries
The patient was a 39‐year‐old female with missing the lower right molars. Her general dentist referred her because the upper right molars and the second premolar extruded, preventing a possible restoration of implants. At the first oral and radiographic examination, she also presented with 4–5 mm probing on the upper molars, adequate bone volume for implant placement in the lower, and the presence of a wisdom tooth.
Figures 8.16 and 8.17 After 12 more days of stabilization, for a total of 30 days, the crowding resulted completely resolved and the patient debracketed.
Figure 8.18 Six months follow‐up, showing stability of results and nice soft tissues healing.
Two different comprehensive treatment options were proposed:
Stay updated, free dental videos. Join our Telegram channel
VIDEdental - Online dental courses
