Accelerated Osteogenic Orthodontics™ for retreatment of a patient with diminished root length and absence of the maxillary central incisor.

An 18-year-old female patient visited a university orthodontics department with a chief complaint of an unesthetic appearance of her teeth, including a protruded upper central incisor and unsatisfactory results from previous orthodontic treatment. Pretreatment records showed a Class II skeletal and dental relation with proclined upper and lower incisors, replacement of an absent upper left central incisor with the left upper cuspid, presence of the upper left deciduous cuspid, mild crowding, and 4 mm of overbite and overjet. The panoramic radiograph showed shortened roots of multiple teeth. Accelerated Osteogenic Orthodontics™ (AOO™) was recommended as an approach to reduce the treatment time and the risk of further root shortening. Despite being more expensive and requiring a surgical procedure, this treatment option was very attractive to the patient. The overall treatment time was 14 months. Facial balance was improved, and good occlusal relationships were achieved from the functional and esthetic perspectives. In conclusion, surgically facilitated orthodontics (specifically, AOO™) is an efficient and safe therapeutic tool for treating or retreating orthodontic patients with diminished root length.

Introduction

Objectives in orthodontics have evolved from the correction of dental malocclusion to the achievement of functional occlusion, facial balance, stability, and periodontal integrity, which are obtained through different treatment philosophies, mechanics, and modalities. In some cases, patients are not treated according to these objectives, leading to poor results as a result of incorrect treatment decisions or inefficient mechanotherapy. When these patients seek orthodontic retreatment, the new orthodontist faces some dilemmas because the previous treatment may have involved extractions, led to undesirable tooth movements, or caused root shortening (as one of the worst possible complications). The orthodontist must apply the best treatment for the patient’s specific condition to obtain the contemporary objectives of orthodontic treatment.

Diagnosis and etiology

An 18-year-old female patient visited a university orthodontics department with the chief complaint of a protruded upper central incisor and dissatisfaction with the overall final results from a previous orthodontic treatment at adolescence. The patient was not very enthusiastic for conventional retreatment, and the duration of treatment was a concern (Fig. 1). The patient had no significant medical history. Her pretreatment records revealed a Class II skeletal relation and proclined upper and lower incisors (Table 1). Dental findings included an Angle Class II malocclusion, replacement of an absent upper left central incisor with the left upper cuspid, presence of the upper left deciduous cuspid, mild crowding, and 4 mm of overbite and overjet (Fig. 2). The panoramic radiograph showed shortened roots of teeth 11, 22, 24, 25, 34, 33, 32, 31, 41, 42, and 44 (Fig. 3).

Figure 1

Pretreatment facial and intraoral photograph.

Table 1

Cephalometric measurements.

Measurement	Norm	Pretreatment	Posttreament
SNA	82°	81°	81°
SNB	80°	76°	76°
ANB	2°	5°	5°
Go Gn-SN	32°	35°	35°
Facial axis	90°	89°	89°
1-1	130°	109°	136°
1-SN	102°	118°	99°
IMPA	90°	100°	90°
Profile
Upper lip-E line(mm)	1 to −4 mm	−2.5	−3 mm
Lower lip-E line (mm)	0 to 2 mm	0.2	−2 mm

Figure 2

Pretreatment dental casts.

Figure 3

Pretreatment cephalometric and panoramic radiograph.

Treatment

Treatment objectives

Treatment objectives for this patient were as follows: (1) to obtain, as much as possible, a Class I dental relationship, (2) to reduce dental protrusion arising from the absence of the upper left central incisor and replacement with the transposed cuspid, (3) to eliminate dental crowding, (4) to achieve better facial balance, and (5) to maintain the root length of the teeth.

Treatment options

Accelerated Osteogenic Orthodontics™ (AOO™) was recommended to the patient to avoid another conventional orthodontic treatment, reduce the treatment time, and preserve the root length. AOO™ involves selective alveolar decortication, augmentation bone grafting, and the application of orthodontic forces. Its characteristics set the technique apart from other corticotomy techniques. Despite being more expensive and requiring a surgical procedure, AOO™ was a very attractive option for the patient and was selected as the treatment approach.

Two treatment options were offered to the patient, both involving AOO™. The first option involved extraction of the mandibular first bicuspids, upper right first bicuspid, and upper left deciduous canine. The upper left cuspid would be kept in place of the absent maxillary upper incisor, with remodeling or prosthetic rehabilitation to an upper incisor anatomy at the end of orthodontic treatment. The upper left first bicuspid would be left in place and remodeled to function as an upper left cuspid. The second treatment option would be to distalize the upper dentition to achieve an Angle Class I relationship. The deciduous cuspid would be extracted and adequate space created for a prosthetic implant to be rehabilitated as a cuspid. The patient chose the first treatment option because it allowed improved facial balance through bicuspid extractions and uprighting of the lower incisors, and offered the best occlusal relationship possible without the use of dental implants.

Treatment process

One week before surgery, an MBT appliance (3 M Unitek, Monrovia, CA) measuring 0.022” × 0.028” was bonded to the teeth without engagement of archwires (Fig. 4). The orthodontist drew a surgical map, which the periodontist used to identify where the corticotomies would be required. Extractions of the upper right first bicuspid, upper left deciduous cuspid, and lower first bicuspids were made at the time of surgery. Full-thickness flaps were made facially and lingually. Selective alveolar corticotomies were performed with a Piezotome (Satelec Acteon Group, France) and the BS1Slim tip (F87525), drawing the radicular anatomy of each tooth. Bone grafting employed a mixture of 0.5 g of bovine bone (NuOss™, ACE Surgical Supply Co., Inc., Brockton, MA) and 150 mg of clindamycin chlorhydrate in saline (10 cc). Vicryl 4–0 (Ethicon Endo-Surgery, Inc., Cincinnati, OH) was used as the suture material in both arches (Fig. 5). After surgery, Niti 0.014” archwires were engaged.

Figure 4

Bonded brackets one week before surgery, no archwires were engaged.

Figure 5

Surgical procedure: Full thickness flaps reflection, selective alveolar corticotomies, teeth extractions and bone grafting mixture.

Appointments were scheduled for every 2 weeks from the start to the finish of treatment (Fig. 6). The leveling and alignment phase was completed with Niti archwires (0.014”, 0.016”, 0.016” × 0.022”, and 0.019” × 0.025”). After 4 months of treatment, the retraction phase was started with 0.019” × 0.025” stainless-steel archwires with lacebacks and class II elastics. Upper extraction sites were closed at 5.5 months and lower sites at 7 months. A panoramic radiograph was taken to check root alignment and bracket repositioning. Niti 0.016” × 0.022” upper and lower archwires were engaged. The following archwires were used in posterior appointments: Niti 0.017” × 0.025”, 0.019” × 0.025”, and stainless-steel 0.019” × 0.025” for finishing and detailing.

Figure 6

After surgical procedure, Niti 0.014” archwires engaged.

At the end of treatment, the brackets were debonded. The upper left cuspid was remodeled and restored with a composite material as an upper left central incisor. The retention protocol was use of upper and lower circumferential retainers 24 h a day.

Treatment results

The overall treatment time was 14 months, and there were no complications during or after the surgical procedure (Fig. 7). Facial balance was improved. Final occlusal relationships from the functional and esthetic perspectives were good. The upper left cuspid was left in place of the absent upper left central incisor, and the left first bicuspid was left in place as a cuspid. The treatment objectives were achieved (Fig. 8). Root length was maintained, and further root resorption was not observed (Fig. 9).

Figure 7

Posttreatment facial and intraoral photograph.

Figure 8

Posttreatment dental casts.

Figure 9

Posttreatment cephalometric and panoramic radiograph.

Discussion

The accelerated tooth movement technique has evolved quickly in the rapidly changing world of orthodontics. Today, accelerated movement can be achieved through various approaches, including surgical techniques and nonsurgical modalities (Long et al., 2013), such as microvibration (Nishimura et al., 2008), light stimulation (Kau et al., 2013), pharmacological approaches (Kanzaki et al., 2006), and others. Surgically facilitated orthodontic treatment is very popular, and different authors have established particular sequences of procedures or steps to name, rename, or patent a particular technique, for example: Wilckodontics (Wilcko et al., 2000, Wilcko et al., 2003, Wilcko et al., 2008, Wilcko et al., 2009; Murphy et al., 2009), Piezosurgery (Vercellotti and Podesta, 2007), Piezocision (Dibart et al., 2009), and Speedy Orthodontics (Chung et al., 2009a, Chung et al., 2009b), among others. Surgically facilitated orthodontic treatment requires a corticotomy, in which a shallow perforation or cut is made on the alveolar bone (Hoogeveen et al., 2014). All surgical approaches share the same biologic mechanism, namely, the “regional acceleratory phenomenon” concept developed by Frost (1983) and described in the periodontal literature by Yaffe et al. (1994). This phenomenon affects the bone healing pattern and turnover, leading to a temporary phase of accelerated tooth movement.

As accelerated orthodontics has both advantages and disadvantages, an important question is whether there is a difference in the incidence of root resorption between patients treated by this technique with or without surgery. Surgically facilitated orthodontic treatment has been recommended for patients with diminished root length, because there is less resistance between the root surfaces and the osteopenic bone. Selective alveolar decortication results in a transient osteopenia and increased tissue turnover (Wilcko et al., 2008), which permit the orthodontist to move teeth in the desired direction and to obtain the treatment objectives with less risk of shortening the length of the dental roots. In a recent systematic review, Hoogeveen et al. (2014) did not find significant root shortening when patients were treated with surgically facilitated orthodontics compared to the pretreatment root length or control groups. Some studies, including Shoreiba et al., 2012a, Shoreiba et al., 2012b and Byloff-Clar, 1967a, Byloff-Clar, 1967b, Byloff-Clar, 1967c, have observed less root resorption in the corticotomy group. Machado et al. (2002) reported that corticotomy-facilitated nonextraction orthodontic therapy resulted in half as much resorption at debanding and long-term retention compared to conventional nonextraction orthodontics.

Overall, there is insufficient evidence to support the conclusion that surgically facilitated orthodontics lessens the risk of the root resorption associated with orthodontic treatment. However, the biological concept and available evidence suggest that this is the case. The shorter treatment time and reduced risk of continued shortening of already diminished roots made AOO™ a great option for the patient in the current study.

Conclusions

Surgically facilitated orthodontics (specifically, for the reported case, AOO™) is an efficient and safe therapeutic tool for treating or retreating orthodontic patients with diminished root length. Proper diagnostic and treatment planning between the orthodontist and periodontist can lead to excellent results without further root resorption. Additional correctly designed and conducted research is needed to confirm these statements.

Ethical approval and conflict of interest

The authors declare that the patient was treated with all ethical approval, the informed consent was explained to the patient who signed. The authors declare no conflict of interest and/or financial interest or support.