Interdisciplinary Treatment of Aggressive Periodontitis: Three-Dimensional Cone-Beam X-Ray Computed Tomography Evaluation

Periodontitis is characterized by an inflammatory reaction that affects tooth attachment tissues and can be classified as chronic periodontitis or aggressive periodontitis (AgP) according to clinical characteristics and rate of progression. The current classification of periodontal disease describes two clinically distinct forms of periodontitis. AgP is characterized by rapid progression and severe periodontal destruction, mainly seen in younger individuals (Meng et al., 2007). Chronic periodontitis is characterized by a lower rate of progression (Schatzle et al., 2009). AgP constitutes a group of rare and rapidly progressing forms of periodontitis that are frequently characterized by an early age of clinical onset (Genco et al., 1986). AgP is defined as a destructive periodontal disease affecting more than 14 teeth in young individuals. Its etiology has been linked to the presence of Aggregatibacter actinomycetemcomitans (Fine et al., 2007; Haraszthy et al., 2000; Di Rienzo et al., 1994), host response defects (Page et al., 1984, 1985; Lavine et al., 1979), and possibly to genetic inheritance (Hart & Kornman, 1997; Kinane et al., 2000; Boleghman et al., 1992; Beaty et al., 1987; Hart et al., 1992; Melnick et al., 1976; Page et al., 1985). In contrast, chronic periodontitis is characterized by a lower rate of progression (Schatzle et al., 2009), although like AgP it can reach a severe stage, leading to tooth loss and edentualism. Many clinicians report difficulty in establishing a differential diagnosis for AgP and chronic periodontitis due to an overlapping “gray area” that often negates a clear-cut diagnosis. Such issues raise the question of whether these are actually two distinct clinical entities.


Introduction
Periodontitis is characterized by an inflammatory reaction that affects tooth attachment tissues and can be classified as chronic periodontitis or aggressive periodontitis (AgP) according to clinical characteristics and rate of progression.The current classification of periodontal disease describes two clinically distinct forms of periodontitis.AgP is characterized by rapid progression and severe periodontal destruction, mainly seen in younger individuals (Meng et al., 2007).Chronic periodontitis is characterized by a lower rate of progression (Schätzle et al., 2009).AgP constitutes a group of rare and rapidly progressing forms of periodontitis that are frequently characterized by an early age of clinical onset (Genco et al., 1986).AgP is defined as a destructive periodontal disease affecting more than 14 teeth in young individuals.Its etiology has been linked to the presence of Aggregatibacter actinomycetemcomitans (Fine et al., 2007;Haraszthy et al., 2000;Di Rienzo et al., 1994), host response defects (Page et al., 1984(Page et al., , 1985;;Lavine et al., 1979), and possibly to genetic inheritance (Hart & Kornman, 1997;Kinane et al., 2000;Boleghman et al., 1992;Beaty et al., 1987;Hart et al., 1992;Melnick et al., 1976;Page et al., 1985).In contrast, chronic periodontitis is characterized by a lower rate of progression (Schätzle et al., 2009), although like AgP it can reach a severe stage, leading to tooth loss and edentualism.Many clinicians report difficulty in establishing a differential diagnosis for AgP and chronic periodontitis due to an overlapping "gray area" that often negates a clear-cut diagnosis.Such issues raise the question of whether these are actually two distinct clinical entities.
In AgP, comprehensive mechanical/surgical and antimicrobial therapy is usually required for long-term stabilization of periodontal health (Buchmann et al., 2002).Enamel matrix proteins have been proposed to promote regeneration of the lost periodontal tissues when used during periodontal surgery (Gestrelius et al., 2000;Hammarström, 1997).Indeed, clinical studies showed that applying the commercially available enamel matrix derivative (EMD) to deep intrabony defects during periodontal flap surgery Pathogenesis and Treatment of Periodontitis 128 promotes a favorable clinical outcome in terms of clinical attachment gain and probing depth reduction (Heijl et al., 1997;Heden & Wennström, 2006).Other treatment alternatives for bone defects include grafting or extraction of the affected teeth, with possible orthodontic movement into the involved sites (McLain et al., 1983).AgP has the potential to cause tooth mobility and pathological tooth movement, and thus orthodontic treatment might become necessary.It is well established that despite bone loss, teeth can be moved orthodontically if the remaining bone and the periodontium can be brought back to a healthy state (Boyd et al., 1989).
Although the use of conventional computed tomography (CT) is well established in oral surgery (Gold et al., 2003), three-dimensional (3D) CT imaging can provide particularly useful information that may assist in diagnosis and planning of treatment strategies (Ferrario et al., 1996).Furthermore, computational simulations that include 3D image processing and biomechanical calculations show promise as useful tools for orthodontic research and assist in clinical decision-making (Maki et al., 2003).
This report describes the multidisciplinary treatment of AgP patient with progressing fullmouth bone resorption.Orthodontic treatment was performed after completion of periodontal treatment including regenerative surgery using EMD.

Diagnosis and etiology
An 18-year-old female patient was referred by a general practitioner to the Department of Periodontology at Showa University Dental Hospital for treatment of AgP (Fig. 1A).A review of her medical history did not reveal any systemic disease.Familial aggregation of AgP was denied.An initial examination revealed probing depths of 7 to 10 mm at teeth numbers 16, 15, 14, 13, 11, 21, 23, 24, 25, 26, 36, 35, 42, 43, 44, and 46, with bleeding on probing (Table 1A).Suppuration was registered at teeth numbers 15, 14, and 21.Full-mouth periapical radiographs revealed an overall pattern of severe horizontal bone loss with localized cratering (Fig. 1B).

Table 1. (A-C
). Probing depths (PD) and bleeding on probing (BOP) in the patient before, during, and after periodontal treatment.Prior to commencing orthodontic treatment, the patient underwent periodontal treatment.Periodontal treatment involved oral hygiene instructions, scaling, root planing, temporary fixation using 4-META/MMA-TBB resin, occlusal adjustment, and periodontal surgery.After periodontal treatment the patient was introduced to the Department of Orthodontics at Showa University School of Dentistry for tooth alignment.She presented with a Class II malocclusion.Cone-beam CT (CBCT) imaging confirmed aggressive horizontal and vertical alveolar bone resorption throughout the whole area.Facial photographs before orthodontic treatment are presented in Fig. 2A.The maxillary central incisors were crowded (Fig. 2B).The patient's chief concerns for orthodontic treatment were the longevity of her front teeth and the possibility of enhancing aesthetics.

Treatment objectives
The clinical objectives of treatment were as follows: (1) to achieve adequate daily plaque control and clinically healthy gingiva, (2) to avoid occlusal trauma, and (3) to correct the planarization of the alveolar bone level.Furthermore, orthodontic treatment was also planned with the patient's expectations regarding with the longevity of her teeth and enhanced aesthetics.

Treatment results
Prior to commencing orthodontic treatment, the patient underwent periodontal treatment by a periodontist for 20 months.The primary goal in the treatment of this patient was to control her periodontal infection.Periodontal treatment was started by oral hygiene instruction and subsequent scaling and root planing under local anesthesia.Manual and ultrasonic instruments were used for scaling and root planing.Then, temporary fixation using 4-META/MMA-TBB resin (teeth numbers 16, 15, 14, 13, 23, 24, 25, 26, 33, 34, 35, 36, and 37) and occlusal adjustment were performed with the goals of reducing occlusal interferences in lateral excursions and improving canine guidance.Following the reevaluation after this initial treatment phase, periodontal surgery was performed.The bone defects at the maxillary right second premolar were subjected Interdisciplinary Treatment of Aggressive Periodontitis: Three-Dimensional Cone-Beam X-Ray Computed Tomography Evaluation 131 to regenerative periodontal surgery.Intrabony defects and root surfaces were degranulated and cleaned with curettes, rinsed with saline, and dried with cotton swabs.The exposed root surfaces were demineralized using EDTA for 2 minutes.After thorough rinsing with saline, EMD (Emdogain; Institut Straumann, Basel, Switzerland) was applied to the root surfaces.The autogenous bone was then blended with EMD, and the osseous defect was grafted.The autogenous bone was harvested using a trephine bar from the extraction fossa around the right third molar in the mandible and crushed using a bone mill (Fig. 3A, B).Radiographs obtained 3 years after surgery showed marked filling of the defects and sharp contours of the hard tissue that had developed (Fig. 4A, B).Fig. 3. Buccal view of the surgical wound after a full-thickness flap was reflected, granulation tissue was removed, and the root surfaces and bone defect were conditioned with EDTA.After thorough rinsing with saline, EMD was applied (A).The autogenous bone was harvested using a trephine bar from the extraction fossa around the right third molar in the mandible and crushed using a bone mill (B).The right first molar in the mandible had class I furcation involvement at the lingual sites.The furcation involvement was treated by a flap operation with furcation plasty (odontoplasty and osteoplasty) (Fig. 5).Clinical examination showed improved probing depths after periodontal treatment (Table 1B).All teeth were sequentially bonded or banded with 0.018-× 0.025-in standard edgewise brackets.For the upper teeth, a 0.012-in round stainless steel archwire was initially placed, followed by a 0.014-in round stainless steel archwire.By 6 months, the incisors were leveled by the use of a 0.016-in round stainless steel archwire.The alignment proceeded until a 0.016-× 0.016-in rectangular archwire was placed.For the lower teeth, the initial archwires consisted of the following: 0.012-in round stainless steel, 0.013-and 0.014-in nickel titanium, followed by 0.016-× 0.016-in nickel titanium archwires by the 9 th month of treatment.The alignment proceeded until a 0.016-× 0.016-in rectangular archwire was placed.The patient was instructed to carefully clean around the orthodontic appliances and was monitored for gingival and tooth mobility changes at every orthodontic visit.The patient compliance was good throughout the orthodontic treatment period with regular periodontal maintenance appointments.Scaling, localized root planing, polishing, and follow-up examinations of plaque control were performed at each maintenance visit.After 12 months of orthodontic treatment, a removable Hawley retainer for the maxilla and mandible was recommended for nighttime use over the course of a year.
Post-treatment facial photographs are shown in Fig. 6A.Intraoral views (Fig. 6B) showed an acceptable occlusion in which a normal overbite and overjet were achieved.However, the intraoral view also showed that the midlines of the incisors were not coincident.We avoided aggressive tooth movement concerning to the damage of tooth root and periodontal tissue.This resulted in dis-coincident of midline.Cephalometric superimpositions (Fig. 7, Table 2) showed that the incisors were retracted 2 to 3 mm with a slight reduction in protrusion.After full orthodontic treatment, the left central incisor and canine in the maxilla were treated with a connective tissue graft (Fig. 8).The data indicate mean and standard deviation (SD).
Table 2. Cephalometric analysis of patient pre-and post-treatment.The satisfactory clinical results including the reduction in mean pocket depth from 3.9 ± 2.3 mm to 2.1 ± 0.6 mm and flattening of the alveolar bone level were achieved.Clinical examination showed appreciable gains in clinical attachment levels and improved probing depths from 1 to 4 mm at all sites after periodontal and orthodontic treatment (Table 1C).Radiographic analysis showed improvement in bone height at all sites.Overall, full mouth radiographs showed significant changes in the crater-like bone defects on teeth numbers 21, 23, 35, and 46 (Fig. 9A), and intraoral views showed aesthetic improvement by prosthetic treatment of the central incisor on the upper right side.Tooth mobility was also significantly www.intechopen.com Interdisciplinary Treatment of Aggressive Periodontitis: Three-Dimensional Cone-Beam X-Ray Computed Tomography Evaluation 135 reduced compared with pretreatment values.A complete blood count including differential blood counts also improved compared with pretreatment levels.
3D CT allows for precise assessment of bone defects caused by periodontal disease (Naito et al., 1998).In this study, CBCT (CB MercuRay; Hitachi Medical Technology, Tokyo, Japan) was performed prior to orthodontic treatment (Fig. 10, Fig. 12A) and during retention phases (Fig. 11, Fig. 12B).It was confirmed that all teeth were positioned appropriately in alveolar bone.

Discussion
Rescala et al. ( 2010) reported similar microbiological and immunological parameters for subjects with chronic periodontitis and AgP who showed comparable periodontal disease severity.Herein we report dental management of an otherwise healthy patient diagnosed with generalized AgP and rapidly progressing bone loss throughout the mouth.Generalized AgP features loss of supporting tissues in addition to changes in tooth mobility and pathological tooth movement that are associated with sustained periodontal tissue destruction.In such cases, a comprehensive and effective treatment plan often includes periodontal therapy to relieve inflammation and orthodontic treatment to correct malocclusion.Comprehensive periodontal therapy is also often necessary in severe chronic periodontitis.The present patient showed a successful periodontal response with no progressive bone loss during or after treatment.
The strategy of treatment planning for periodontitis patients with aggressive or chronic periodontitis is well established.For patients with aggressive or chronic periodontitis, phases of treatment -systemic, initial, re-evaluation, surgical, maintenance, and restorativeare generally accepted.The amount of active planning required at each step may be greater for the patient with aggressive periodontal disease.To retain teeth cannot help but complicate the treatment-planning process.Therefore, the patient with aggressive periodontitis to have experienced attachment loss would be expected at a younger age, at a www.intechopen.com Interdisciplinary Treatment of Aggressive Periodontitis: Three-Dimensional Cone-Beam X-Ray Computed Tomography Evaluation 139 faster rate and to a greater extent than the patient with chronic periodontitis (Deas et al., 2010).
Some authors reported that tooth intrusion might deepen the defect and improve blood circulation (Vandevska-Radunovic et al., 1994;Ericsson et al., 1977), suggesting that this provides a better environment for guided tissue regeneration procedures (Rabie et al., 1996).
In the presence of osteoinductive factors, mesenchymal cells differentiate into cells capable of regenerating the periodontal structures.This procedure is an alternative to rebuilding the bone and the original periodontal architecture.It therefore seems reasonable to manage a patient with compromised periodontal dentition using an interdisciplinary approach consisting of both orthodontic and periodontal treatment strategies.
In this study, the initial periodontal treatment was followed by periodontal regeneration therapy using EMD for the maxillary right second premolar.The bone defect involved one to two wall defects and the radiographic bone gain was 4-5 mm in the 3 year follow-up evaluationafter surgery.In prospective controlled clinical trials using EMD therapy, clinical attachment gains of 2.2-3.4 mm have been observed in addition to bone growth (Pontoriero et al., 1999;Sculean et al., 2001;Heijl et al., 1997).Thus, the clinical findings presented herein are equal to or better than those in previous reports, and there are a number of clinical scenarios associated with this therapy: (1) EMD only, if the defect is well contained, i.e., twoand three-walled intrabony defects and craters; (2) a combination of EMD and graft material, as in cases of moderate to deep, non-contained intraosseous defects; and (3) a combination of EMD, graft material, and barrier membrane, as in supracrestal cases with shallow intraosseous defects.In each case, a coronally advanced flap procedure must be performed (Froum et al., 2001).Because the patient in this report presented with a noncontained intraosseous bone defect of the maxillary right second premolar, we performed combination therapy of EMD and autogenous grafting, which resulted in a satisfactory and uneventful treatment outcome.
Meticulous initial therapy and good oral hygiene are considered prerequisites for successful regenerative periodontal surgery (Cortellini et al., 1994).In studies reporting the best regenerative outcomes, patients with chronic periodontitis were carefully selected regarding oral hygiene performance, the proportion of bleeding sites remaining after initial periodontal therapy, as well as smoking habits (Cortellini & Tonetti, 2005;Wachtel et al., 2003).In agreement with these reports, the present patient with AgP qualified for periodontal regeneration therapy using EMD as a nonsmoker with low plaque levels and minimal bleeding scores.
Early comparisons of imaging techniques have shown that CT yields more detailed information than conventional radiography for visualizing bone (Sarikaya et al., 2002;Ericson & Kurol, 1988).Consequently, CT is now frequently used to qualitatively and quantitatively assess potential implant sites (Fuhrmann et al., 1995), instead of conventional dental radiographs, which do not allow for the evaluation of dehiscence at the implant site.Cone Beam CT (CBCT) and other such 3D technologies compare well with traditional methods, with the additional advantage that periodontal defects can be observed in all directions (Misch et al., 2006).It is clinically important to determine the direction of orthodontic movement and the groups of teeth with higher risks of dehiscence and fenestration.In the present case, all teeth were appropriately maintained in alveolar bone, and the recovery of such bone in molar regions was also investigated using CBCT.
An important factor underlying the successful periodontal outcome and lack of progressive bone loss during and after treatment in the present case was the patient's strict adherence to regular periodontal maintenance at 3-monthly intervals.A recent longitudinal study indicated that patients with reduced, but healthy periodontal tissues (after successful periodontal treatment) undertook a full course of orthodontic treatment with fixed appliances without the occurrence of additional bone loss, provided that plaque removal was effective and a 3-monthly periodontal maintenance schedule was followed (Boyd et al., 1989).Periodontal disease progression was successfully arrested in 95% of the initially compromised lesions, while 2-5% of patients experienced discrete or recurrent episodes of loss of periodontal support (Buchmann et al., 2002).It is therefore clear that periodontal follow-up is crucial for successful treatment.In many patients with a periodontally involved dentition, pathological tooth migration can create serious functional and aesthetic problems.The coordination of proper orthodontic and periodontal therapies has proven to be effective in such situations, with long-term stability of the results obtained.A key point for achieving therapeutic success is therefore the patient's periodontal health status prior to and during the orthodontic treatment.Because periodontal health is essential for any form of dental treatment, good oral hygiene at home and professional maintenance care are important during and after active orthodontic treatment.

Conclusion
Prior to the commencement of orthodontic treatment, periodontal inflammation should be appropriately addressed by eliminating calculus and overhanging restorations, scaling, root planing, and instructing patients on proper oral hygiene.Deep pockets must be eliminated before orthodontic treatment to avoid apical displacement of plaque to avoid establishing progressive periodontal lesions.
Unlike other imaging methods, CBCT allows detailed imaging of periodontal defects to be gathered from a number of directions.The application of this technology is highly relevant for oral health professionals because it potentially provides the necessary information on tooth movement to the treating orthodontist and allows the periodontist to make treatment plans for periodontal disease.

Acknowledgment
We would like to acknowledge the clinically relevant technical advice given by Professor Hajime Miyashita.

Fig. 4 .
Fig. 4. Radiographs obtained 3 years after surgery showing a marked filling of the defects and sharp contours of hard tissues gained through therapy.

Fig. 5 .
Fig. 5.The mandibular right first molar had class I furcation lesion at the lingual site.The furcation lesion was treated with furcation plasty.

Fig. 7 .
Fig. 7. Superimposed cephalometric tracings, pretreatment (solid line) and post-treatment (dotted line).(A) Superimposed on the SN plane registered at S. (B) Superimposed on the palatal plane registered at ANS. (C) Superimposed on the mandibular plane registered at Me.

Fig. 10 .BFig. 12 .
Fig. 10.Cone-beam X-ray computed tomography (CBCT) images of the upper arch in preorthodontic treatment (A) and CBCT images of the lower arch in pre-orthodontic treatment (B).