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Periodontally accelerated osteogenic orthodontics
This article was originally published by Wolters Kluwer and was migrated to Scientific Scholar after the change of Publisher.
How to cite this article: Bhandari SM. Periodontally accelerated osteogenic orthodontics. APOS Trends Orthod 2016;6:265-70.
Abstract
This case report demonstrates an orthodontic method that offers short treatment time and the ability to simultaneously reshape and increase the buccolingual thickness of the supporting alveolar bone. A 23-year-old female with Angle’s Class I moderately to severely crowded malocclusion with periodontal pocket with 31 and reduced thickness of the buccal cortical plate of lower anteriors, requested shortened orthodontic treatment time. This surgery technique included buccal full-thickness flaps, selective partial decortication of the cortical plates, concomitant bone grafting/augmentation, and primary flap closure. Following the surgery, orthodontic adjustments were made approximately every 2 weeks. From bracketing to debracketing, the case was completed in approximately 7 months and 3 weeks. Posttreatment evaluation of patient revealed good results. Preexisting thin labial bony cortical plate with lower anteriors was covered. This finding suggests credence to the incorporation of the bone augmentation procedure into the corticotomy surgery because this made it possible to complete the orthodontic treatment with a more intact periodontium. The rapid expansive tooth movements with no significant apical root resorption may be attributed to the osteoclastic or catabolic phase of the regional acceleratory phenomenon.
Keywords
Accelerated orthodontics
interdisciplinary treatment
periodontal pathologies
INTRODUCTION
Periodontal accelerated osteogenic orthodontics (PAOO) is a clinical procedure that combines selective alveolar corticotomy, particulate bone grafting, and the application of orthodontic forces.[1] This procedure is theoretically based on the bone healing pattern known as the regional acceleratory phenomenon (RAP).[2] PAOO, as claimed by distinguished authors, helps in an increase in alveolar bone width,[3] shorter treatment time,[4] increased posttreatment stability,[5] and decreased amount of apical root resorption.[6] The purpose of this article is to describe a case report that comprises the PAOO procedure.
Kole[7] believed that the surgical preparation of the alveolus would permit rapid tooth movement, suggesting that it was the continuity and thickness of the denser layer of cortical bone that offered the most resistance to tooth movement. Kole’s interpretation of the rapid tooth movement being attributable to “bony block” movement did prevail until the 2001 publication of Wilcko et al.[1] Case reports were presented, in which computed tomography scan evaluation of patients who had undergone corticotomy showed that the rapid tooth movement was not the result of bony block movement but rather a transient localized demineralization/ remineralization process in the bony alveolar housing consistent with the wound healing pattern of the RAP.[7] Wilcko et al.[1] proposed that after the demineralization of the alveolar housing over the root surfaces, a soft tissue matrix of the bone, which could be carried with the root and later remineralize, occurred after the completion of the orthodontic treatment. In an effort to enhance bony volumes, after the application of orthodontic forces, they also suggested the use of particulate bone grafting in combination with the decortications procedures. Wilcko combined the refined corticotomy-facilitated orthodontic technique with alveolar augmentation and named the orthodontic and periodontal aspects of this procedure the AOO technique, and more recently, the PAOO surgical technique, respectively.
CASE REPORT
PAOO has been shown to be efficacious in the treatment of Class I malocclusions with moderate to severe crowding, Class II malocclusions requiring expansion or extractions, and mild Class III malocclusions. Careful coordination between the surgeon and orthodontist is required for successful outcomes. It is suggested that both the surgeon and orthodontist be trained together in the use of this technique to ensure a common basis of knowledge. The surgical specialist must also evaluate the esthetic needs of the patient and incorporate these requirements into the surgical treatment plan. For example, if a patient presents with the gingival recession in an area requiring corticotomy, a subepithelial connective tissue graft can be placed in conjunction with the PAOO surgery.
The placement of orthodontic brackets and activation of the archwires are typically done the week before the surgical aspect of PAOO is performed. However, bracketing can occur up to 1–2 weeks after surgery. If complex mucogingival procedures are combined with the PAOO surgery, the lack of fixed orthodontic appliances may enable easier flap manipulation and suturing. In all cases, initiation of orthodontic force should not be delayed more than 2 weeks after surgery. A longer delay will fail to take full advantage of the limited period that the RAP is occurring.
The orthodontist has a limited amount of time to accomplish accelerated tooth movement. This period is usually 4–6 months after which finishing movements occur with normal speed. Given this limited “window” of rapid movement, the orthodontist will need to advance archwire sizes rapidly, initially engaging the largest archwire possible.
Diagnosis and etiology
A 23-year-old postpubertal female patient wanted to improve esthetics of her smile. She presented with Angle’s Class I malocclusion on a Class I skeletal base, hypodivergence, crowding with upper and lower anteriors, periodontal pocket with 31 and reduced thickness of buccal cortical plate of lower anteriors, with straight profile, and decreased lower facial height and missing 27 and erupting 28 [Figures 1 and 2]. The possible etiology of crowding can be traced to arch length tooth size discrepancy. The patient’s gingival health was reasonably good except with lower anteriors and her oral hygiene was satisfactory. Sulcus depths were in the normal range in most areas, with no bleeding on probing. Her temporomandibular joints were asymptomatic. Her goal was to have better smile esthetics.
- Pretreatment photographs
- Pretreatment Lat Ceph and orthopantomogram
Treatment objectives
Correction of periodontal problem with lower anteriors
Correction of anterior deep bite and lower anterior crowding without compromising the thin labial cortical plate
Correction of rotated teeth.
Treatment alternatives
Several orthodontic treatment alternatives could have been employed to achieve these aforementioned goals or objectives:
Alignment of upper and lower anteriors to their proper position in the arch and closure of space in lower arch with the extraction of lower single incisor for correction of curve of Spee and Bolton’s discrepancy. Contemplating the distance to be moved for derotating the lower incisors to their normal position in the arch, there was further risk of iatrogenic dehiscence and fenestration with lower anteriors. The patient wanted to save her natural teeth and opposed any extraction of teeth. Hence, this treatment plan was neglected
Because of the scarcity of attached fibrotic gingiva, the prominence of the roots, and the fact that these teeth would be expanded facially, free gingival grafting with freeze dries bone graft of lower anterior teeth was deemed advisable. It was hoped that the increased zone of attached fibrotic gingiva would lessen the likelihood of significant additional gingival recession. It was, however, explained to the patient that because of the reduction in the height of the crestal bone that had resulted from the earlier periodontal disease in some areas she might experience some additional gingival shrinkage. All teeth registered vital to ice. All of the erupted teeth were designated for expansive movement (decrowding). The orthodontic treatment plan included maxillary and mandibular braces and pure orthodontic expansion of the arches to assist in correcting the crowding. When presented with the option of completing the orthodontic treatment in about 1 ⁄ 4–1 ⁄ 3 of the time needed for conventional orthodontic treatment and reduced risk of further periodontal problems, she readily accepted the new treatment method. She had no objection to the inclusion of a periodontal plastic surgical procedure with resorbable grafting materials. The patient was informed of the possible sequelae to her decisions.
Treatment progress
A thorough scaling before orthodontic banding was done, with maintenance appointments for tooth cleaning every 4 months during active orthodontics. Orthodontic brackets McLaughlin, Bennett, Terevisi 0.22” ×0.028” slot (3M Clarity SL*) were placed on all teeth in both arches [Figure 3].
- Initial bonding photographs
Surgical technique
The objectives of the flap design were to: (1) Provide access to the alveolar bone wherein corticotomies are to be performed, (2) provide for coverage of the particulate graft, (3) maintain the height and volume of the interdental tissues, and (4) enhance the esthetic appearance of the gingival form where necessary.
The purpose of the decortication was to initiate the RAP response and not to create movable bone segments. By the use of no. 2 round bur in a high-speed handpiece, decortications were made in the alveolar bone. The corticotomies were placed on the labial aspect of the alveolar bone in the lower anterior region. Typically, a vertical groove was placed in the inter-radicular space, midway between the root prominences in the alveolar bone. This groove extended from a point 2–3 mm below the crest of the bone to a point 2 mm beyond the apices of the roots. These vertical corticotomies were then connected with a circular-shaped corticotomy. Solitary perforations were placed in the alveolar bone over the radicular surface [Figure 4].
- Corticotomy cuts photographs
Grafting was done in most areas that have undergone corticotomies. The volume of the graft material used was dictated by the direction and amount of tooth movement, the pretreatment thickness of the alveolar bone, and the need for labial support by the alveolar bone. The graft material used was decalcified freeze-dried bone allograft. A typical volume used was 0.25–0.5 mL of graft material per tooth. The decorticated bone acts to retain the graft material [Figure 5].
- Graft placement photographs
Primary closure of the gingival flaps without excessive tension and graft containment were the therapeutic endpoints of suturing. These were typically achieved with nonresorbable interrupted sutures. The sutures that approximate the tissues at the midline were placed first to ensure the proper alignment of the papillae. The remaining interproximal sutures were placed next followed by the closure of any vertical incisions. No packing was required. The sutures were left in place for 1 week [Figure 6].
- Flap suturing photographs
The short-term steroids were given orally, which enhanced patient comfort and clinical healing. Antibiotics and pain medications were administered. However, long-term postoperative administration of nonsteroidal anti-inflammatory agents is discouraged because they may theoretically interfere with the regional acceleratory process. The application of icepacks to the affected areas also was suggested to decrease the severity of any possible postoperative swelling or edema. The most commonly reported postsurgical complications are edema and ecchymosis, both of which are self-limiting. The patient returned for postsurgical evaluation and gentle prophylaxis every week for the 1st month and then monthly thereafter.
Treatment results
This interdisciplinary approach to managing this patient’s occlusal, gingival, and esthetic discrepancies allowed the team to achieve all of the periodontal and orthodontic objectives that were established before treatment within 7 months and 3 weeks [Figure 7]. Her facial profile did not change. Her maxillary and mandibular anterior dental esthetics has been improved. The patient has canine-protected occlusion bilaterally with no balancing interferences.
- Posttreatment photographs
DISCUSSION
PAOO is an extension of previously described techniques that surgically alter the alveolar bone to decrease time. It differs from prior techniques by the additional step of alveolar bone grafting. It is this additional step that is believed to be responsible for the increased posttreatment alveolar bone width. An evaluation of this method in nonextraction orthodontics for decrowding with normal orthodontic forces demonstrates dramatic decreases in treatment times and an increased thickness of alveolar bone at the cephalometric landmark B point [Figure 8].[4] Likewise, the additional alveolar bone width may be responsible for enhanced long-term orthodontic stability.
- Posttreatment Lat Ceph and orthopantomogram
Trauma to cortical bone has been shown to be a potentiating factor in producing a localized osteoporosis.[8-10] Surgery invokes an RAP, wherein both hard and soft tissue reorganization is potentiated, leading to a transient catabolic condition. For bone, this transient osteoporosis means increased mobilization of calcium, decreased bone density, and increased bone turnover, all of which would facilitate more rapid tooth movement. Osteoporosis provides a favorable environment for increasing the rate of tooth movement without increasing the risk of root resorption in rats.[11] Moreover, it has been demonstrated that the residual soft tissue matrix has the ability to induce remineralization after the cessation of tooth movement.[12]
A distinct disadvantage of this procedure is the additional cost and morbidity and shrinkage of periodontal tissues associated with surgery. Conversely, the true increase in treatment cost may be offset by the decreased treatment time or, in some cases, the need for orthognathic surgical procedures.
The incidence of root resorption by use of PAOO is decreased when compared with conventional treatment. The frequency of other possible complications, such as ankylosis and devitalization, is unknown, but such complications have not been reported.
CONCLUSION
A key component to this increased efficiency and these clinically significant decreased treatment times is the successful coordination of the orthodontic and surgical specialists. Without this coordination of the treatment plan and therapy, chances for a successful treatment outcome are decreased.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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