Evaluation and comparison of periodontal and orthodontic parameters in patients managed with periodontally accelerated osteogenic orthodontics versus conventional orthodontic treatment

Abstract

Introduction: 

Periodontally Accelerated Osteogenic Orthodontics (PAOO) is a clinical procedure which is gaining popularity due to its claims to increase in alveolar bone width, shorter treatment time, increased post treatment stability, and decreased amount of apical root resorption. However, there is paucity of literature available on changes in periodontal and orthodontic parameters following (PAOO).

Aims and Objective: 

The aims of the current study were to evaluate the efficacy of orthodontic treatment with PAOO and compare the treatment duration between the PAOO based fixed orthodontic treatment and the conventional fixed orthodontics in patients with bi-maxillary dentoalveolar protrusion.

Materials and Methods: 

Group A consisted of 12 bimaxillary dentoalveolar protrusion patients who underwent PAOO during orthodontic treatment and Group B consisted of 12 Bimaxillary dentoalveolar protrusion patients who underwent conventional orthodontic treatment without PAOO. Statistical analysis was performed using the Wilcoxon test for a paired group comparison. Pre- and posttreatment measurements of each parameter were averaged (mean – SD), and all tests were performed at the 5% significance level. P values ≥0.05 were regarded as statistically significant.

Results: 

No significant changes were seen in values probing depth, clinical attachment loss, width of keratinized attached gingiva, plaque index and gingival index between the two groups. However, statistically significant difference was seen in the orthodontic treatment duration between the two groups.

Conclusion: 

It can be concluded that PAOO is a safe and reliable procedure which decreases the total orthodontic treatment duration significantly with stable periodontal results as achieved with conventional orthodontic treatment.

INTRODUCTION

Periodontally accelerated osteogenic orthodontics (PAOO), is a clinical procedure that combines selective alveolar corticotomy, particulate bone grafting and the application of orthodontic forces.[^1,2] This procedure is theoretically based on the bone healing pattern known as the regional acceleratory phenomenon (RAP).[³] It results in an increase in alveolar bone width, shorter treatment time, increased post-treatment stability and decreased amount of apical root resorption.

Corticotomy is defined as a surgical procedure whereby only the cortical bone is cut or perforated or mechanically altered and the medullary bone is not changed, whereas osteotomy is a surgical procedure through both the cortical and medullary bone. The mechanical nature refers to the brackets and wires and the biological/augmentative nature refers to the bone and gums around the teeth. The amalgamation of these philosophies has resulted in a new orthodontic treatment name the 'accelerated osteogenic orthodontics (AOO).' Surgically assisted orthodontic tooth movement (OTM) has been used since the 1800s. Corticotomy-facilitated tooth movement was first described by L. C. Bryan in 1893. However, it was first introduced in 1959 by Kole as a mean for rapid tooth movement. Kole's procedure involves the reflection of full-thickness flaps to expose buccal and lingual alveolar bone, followed by interdental cuts through the cortical bone and barely penetrating the medullary bone (corticotomy style). The subapical horizontal cuts connecting the interdental cuts were osteotomy style, penetrating the full thickness of the alveolus.[⁴] Due to the invasive nature of Kole's technique, it was never widely accepted.

Experimental studies evaluating the PAOO are scarce in the literature, and till now very few studies have demonstrated its efficacy by piezosurgical intervention. Furthermore, there are very rare published clinical trials comparing the traditional extraction-based treatment outcomes versus the PAOO-based non-extraction treatment outcomes in the correction of bimaxillary protrusion cases. Therefore, the aims of the current study were to evaluate the efficacy of orthodontic treatment with PAOO and compare the treatment duration between the PAOO-based fixed orthodontic treatment and the conventional fixed orthodontics in patients with bimaxillary dentoalveolar protrusion.

MATERIALS AND METHODS

A prospective randomised controlled trial was conducted on 24 patients with a mean age of 21.33 ± 2.12 years who were diagnosed with Class I bimaxillary protrusion requiring prophylactic extraction of first premolars in both maxillary and mandibular arches. Patients were divided into two Group A and Group B after random sampling. Group A consisted of 12 patients which were selected to be managed with fixed orthodontic treatment with PAOO and Group B consisted of the control group of Class I bimaxillary dentoalveolar patients from the department of orthodontics managed by fixed orthodontic treatment without PAOO.

Extraoral examination showed patients had lip incompetency with proclination of both maxillary and mandibular dentition [Figure 1]. Patients displayed no signs of temporomandibular dysfunction. Intraoral examination revealed Angle's Class I bimaxillary dentoalveolar protrusion requiring prophylactic extraction of all four premolars. Various periodontal variables such as pocket probing depth (PD), gingival index (GI) (Loe and Silness 1963), plaque index (PI) (Silness and Loe 1967) and clinical attachment levels were carried out to check for the gingival and periodontal health status and the subjects were diagnosed as having healthy periodontium. Full-mouth pre- and post- intra oral peri apical radiographs and orthopantomograph (OPG) were taken for the radiographic diagnosis. There were no bony defects present as was evident on the OPG. Extraoral photographs showed protrusive upper and lower lips with acute nasolabial angle. The objectives behind the treatment were to retract the maxillary anterior teeth and to correct the overjet and overbite by preserving the periodontal structures integrity. The study was conducted with the informed consent of the subject and ethical clearance from the ethical clearance committee of the institution.

Figure 1: Pre-treatment photographs of a representative case

After recording complete baseline periodontal variables as mentioned earlier and oral prophylaxis, all the patients were treated using. 022' MBT PEA. After orthodontic alignment and levelling, corticotomy procedure was planned. Under adequate local anaesthesia (1:80,000 adrenalines) a full-thickness mucoperiosteal flap was reflected with extensions made from the maxillary canine of one side to the other side reflecting beyond the root apices. After reflecting the flap, corticotomy cuts were given in the alveolar bone with piezocorticotomy tips. The vertical cuts were made to extend from 2 mm apical to the crestal bone and were extended apically 1–2 mm beyond the apex of the roots in the interradicular space midway between the root prominences [Figure 2]. These vertical cuts were joined by the horizontal cuts apically. After complete decortication of the alveolar bone, solitary perforations were made in the alveolar bone over the radicular surface with the help of round burs. Demineralised freeze-dried bone allograft was placed over the entire decorticated area. The flaps were repositioned and closed with interrupted silk sutures and a pack was placed. The patient was prescribed antibiotics and NSAIDS for 5 days. Patients were recalled after 24 h for a check-up and they were again recalled after 7 days for suture removal. The subject reported minimal swelling and discomfort after the corticotomy procedure. The retraction was started on a rectangular 0.019 × 0.025 stainless steel archwire with 250–300 g force applied after 2 weeks of the corticotomy procedure. The en masse retraction was done using sliding mechanics with the help of a closed coil spring. The active treatment was continued till the extraction spaces were closed and an ideal overjet was achieved [Figure 3]. All the periodontal variables were recorded after 3 months of the surgical procedure and after the closure of extraction spaces.

Figure 2: PAOO in the maxillary and mandibular arch, PAOO: Periodontally accelerated osteogenic orthodontics

Figure 3: Post-treatment photographs of a representative case

Data analysis

Statistical analysis was performed using the Wilcoxon test for a paired group comparison. The treated area was the unit of analysis. Pre- and post-treatment measurements of each parameter were averaged (mean–standard deviation), and all tests were performed at the 5% significance level. P ≥ 0.05 was regarded as statistically significant.

RESULTS

The demographic profile of patients was as follows. Out of 12 subjects, four were males and eight females in the age group of 15–25 years with a mean age of 21.33 ± 2.12 years. There was no smoker in the group. No clinical or statistical significance was seen in these when compared amongst each other.

Pre-treatment clinical measurements PD, clinical attachment loss (CAL), the width of keratinised gingiva (KG), plaque index and gingival index are reported in Table 1. There was no significant difference in the pre-treatment values between the two groups.

Table 1: Periodontal parameters comparison

The mean apicocoronal dimension of the keratinised tissue was 3.20 ± 0.38 mm (range, 3.0–7.0 mm) pre-operatively and 4.28 ± 0.87 mm (range, 5.0–8.0 mm) post-operatively. The mean apicocoronal dimension of the attached gingiva was 3.0 ± 0.3 mm (range, 3.0–5.0 mm) pre-operatively and 4.14 mm (range, 3.0–7.0 mm) post-operatively.

No statistically significant difference in the change in PD was detected pre- and post-treatment (P = 0.85) [Table 2]. Marginal recession measurements decreased from 0.82 mm pre-operatively to 0.75 mm post-operatively, and this difference was statistically significant (P = 0.004).

Table 2: Comparison of change in probing depth

No statistically significant difference was seen pre-treatment and post-treatment change of CAL and width of keratinised attached gingiva (KG) [Tables 3 and 4], respectively.

Table 3: Comparison of change in width of Clinical attachment loss (CAL)

Table 4: Comparison of change in width of keratinized attached gingiva (KG)

On assessing subjective parameters on a Visual Analogue Scale of 1–10 for each patient, the following findings were reported. Pain perception on the 1^st-day post-operatively was 3.4 ± 1.1 (range 1–6), which reduced considerably to 0.1 ± 0.3 (range, 0–1). Discomfort in chewing was 1.7 ± 0.9 (range, 0–3) which reduced to a minimal of 0.1 ± 0.2 (range, 0–1). Post-operative swelling as perceived by the patients on the 1^st post-operative day was 1.1 ± 0.8 (range, 0–4) which reduced to 0.1 ± 0.2 (range, 0–1) on the 7^th post-operative day. Aesthetic scores as assessed by the patients improved drastically from 1.2 ± 0.9 to 6.2 ± 1.8 [Table 5].

Table 5: VAS group test comparison

Table 6 depicts the comparison of orthodontic parameters. A significant difference was seen between the total treatment time required to close the extraction spaces between the two groups. Treatment time to close the extraction spaces in Group A was significantly lower than that of Group B which indicates that the PAOO helps in reducing the orthodontic treatment time which is an important factor from the patients' perspective.

Table 6: Orthodontic parameters

DISCUSSION

PAOO can play an important role in the comprehensive treatment of patient's functional and aesthetic needs, as this procedure has shown optimal results regarding increased alveolar bone thickness, decreased treatment time, reduced patient discomfort of long-term use of brackets and also increased the long-term stability of the orthodontic treatment with healthy periodontium. The results of the present study are in accordance with the results of the study done by Wilcko et al. in which the corticotomy procedure has reduced the treatment time and the teeth moved 3–4 times faster than the conventional orthodontics. According to Wilcko et al., it is the placement of the bone graft which is an additional step that is believed to be responsible for the increased post-treatment stability and increased alveolar bone width as well as the maintainable periodontium.

The current findings corroborate the clinical observations of Wilcko et al.[^2,5] and Hajji[⁶] who reported similar significant reductions in treatment times and found that the AOO technique provides efficient and stable OTM.[³] In the case study of Nowzari et al.,[⁷] ideal aesthetic and functional results were achieved in 8 months (one-third of the average treatment time). Our study result agreed with these observations.

According to Aljhani and Zawawi,[⁸] the comprehensive orthodontic treatment of the adult patient who presented with severe lower crowding was completed in 8 months; the treatment duration was significantly less than that of a conventional orthodontic treatment.

Unlike usual corticotomy, PAOO cuts into the bone and decorticates it, thereby removing some of the bone's external surface. The bone then goes through a phase of osteopenia, where its mineral content is temporarily reduced. Now, the tissues of the alveolar bone release rich deposits of calcium, and soon, the new bone begins to mineralise in about 20–55 days. As the bone is still in a transient state with the bone being softer and less resistant to forces, braces can move the teeth very quickly. Studies have shown that the results of PAOO are as stable and long-lasting as conventional orthodontic braces.[^{9,10,11,12,13,14}] Corticotomy facilitated orthodontics have been employed in various forms over the past to speed up orthodontic treatment. Kole[¹¹] was the first to introduce this as a means for rapid tooth movement. The cortical plates of bone were believed to cause the main resistance to tooth movement and by disrupting its continuity, orthodontics could be completed in much less time than normally expected. Kole's procedure included the reflection of full-thickness flaps to expose buccal and lingual alveolar bone, followed by interdental cuts through the cortical bone, barely penetrating the medullary bone. PAOO has expanded the realm of traditional OTM protocols. The spirit of interdisciplinary collaboration in orthodontics incorporates periodontal tissue engineering and regenerative surgery to expedite OTM with reduced side effects such as root resorption, tooth devitalisation, relapse, inadequate basal bone and bacterial time load factors such as caries and infection.[¹⁵] This technique is mutually beneficial situation with an increasing number of adults considering orthodontic treatment. This process was consistent with the wound-healing pattern of the RAP, developed by Frost[^16,17] and described in the periodontal literature by Yaffe et al.[¹⁸] RAP is a local hard- and soft-tissue response to a surgical wound where tissue forms faster than the normal regional regeneration process. The surgery results in a substantial increase in alveolar demineralisation resulting in transient osteopenia which enables rapid tooth movement because teeth are supported by and moved through trabecular bone. When OTM is complete, an environment is created that favours alveolar remineralisation.

Reduction of orthodontic treatment time is considered an important goal in the management of malocclusions in adult patients. Corticotomy facilitated orthodontic treatment has been found useful in reducing treatment time and allowing for conventional orthodontic measures in treating adult patients with severe malocclusion.[¹⁹]

CONCLUSION

PAOO is a safe, reliable and stable clinical procedure which decreases the total orthodontic treatment duration considerably when compared with conventional orthodontic treatment in the management of orthodontic patients with bimaxillary dentoalveolar protrusion. There is no decrease in stability of periodontal parameters in patients managed with PAOO. However, the results of this study are not complete in itself, as the study is limited by the number of patients evaluated. Similar long-term studies with a larger sample size are recommended.

Declaration of patient consent

The authors declare that they have obtained consent from patients. Patients have given their consent for their images and other clinical information to be reported in the journal. Patients understand that their names 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.