Tissue response during Piezocision-assisted tooth movement: a histological study in rats.

OBJECTIVES: Piezocision is a novel, minimally invasive technique combining micro-incisions and decortications made by a piezotome in order to enhance the rate of orthodontic tooth movement. The combined technique allows simultaneous hard and/or soft tissue grafting via selective tunnelling to correct gingival recessions or bone deficiencies. The present study was designed to evaluate the effects of Piezocision on bone with or without tooth movement on a rat model. MATERIALS AND METHODS: Ninety-four Sprague-Dawley rats were divided into four groups: no treatment (n = 3), TM (tooth movement alone; n = 21), PS (Piezocision alone; n = 35), and PS + TM (Piezocision and tooth movement; n = 35). In each group, seven time points were studied: 1, 3, 7, 14, 28, 42, and 56 days. After sacrifice, the maxillae were removed, defleshed, stained with haematoxylin and eosin for morphometric analyses and tartrate-resistant acid phosphatase for osteoclastic activity. RESULTS: Three days after the surgery, the bone content decreased significantly in the PS and PS + TM groups compared to baseline (P < 0.01) and the TM group (P < 0.05). This trend continued until Day 28 and was particularly evident in the PS + TM group. At Day 56, alveolar bone returned to its baseline levels in all groups. Osteoclastic activity followed similar change pattern found in the amount of bone, suggesting a strong role for the coupling of the resorptive and formative turnover of the bone. Osteoclastic activity increased as soon as Day 1 in the PS (29.0±3.0, P < 0.05) and PS + TM groups (39.0±6.0, P < 0.01) compared to baseline (22.0±4.0). The highest level of osteoclastic activity in TM group was observed at 3 days (64.3±8.0, P < 0.01) with a steady decrease thereafter. The Piezocision-induced osteoclastic activity showed a steady increase up to 7 days in both PS (39.0±7.0, P < 0.01) and PS + TM (51.8±7.0, P < 0.01) groups and decreased thereafter until Day 56. CONCLUSIONS: Within the limitations of our study (number of animals, duration in time, and limited data on the anabolic activity), our preliminary results suggest that Piezocision-facilitated orthodontic tooth movement increases the rate of movement of the teeth undergoing orthodontic treatment through the coupled remodelling of the alveolar bone. This process is initiated by the osteoclastic activity following surgery and extended via the synergistic relationship between Piezocision and tooth movement.

[Accelerated orthodontic treatment with piezocision: a mini-invasive alternative to conventional corticotomies]. / Traitements orthodontiques accélérés par piézocision : une alternative mini-invasive aux corticotomies alvéolaires.

An increasing number of adult patients are seeking orthodontic treatment and a short treatment time has become a recurring request. To meet their expectations, a number of surgical techniques have been developed to accelerate orthodontic tooth movement. However, these have been found to be quite invasive. We are introducing here a new, minimally invasive flapless procedure, combining micro incisions, piezoelectric incisions and selective tunneling that allows for hard- or soft-tissue grafting. Combined with a proper treatment planning and a good understanding of the biological events involved, this novel technique can locally manipulate alveolar bone metabolism in order to obtain rapid and stable orthodontic results. Piezocision allows for rapid correction of severe malocclusions without the drawbacks of traumatic conventional corticotomy procedures.

Rapid treatment of Class II malocclusion with piezocision: two case reports.

An increasing number of adult patients are seeking orthodontic treatment to enhance their smile or their masticatory function. In this fast-paced and self-conscious society, time and esthetics have become increasingly important. One of the biggest challenges an adult orthodontic patient faces is the time spent wearing brackets. Over the years, several surgical techniques have been developed to address this issue and reduce overall treatment time. Although very effective, these techniques have proven to be quite invasive. A new, minimally invasive procedure (piezocision) is presented that combines microincisions and localized piezoelectric surgery to achieve similar results rapidly and with minimal trauma.

Piezocision: a minimally invasive, periodontally accelerated orthodontic tooth movement procedure.

An increasing number of adult patients have been seeking orthodontic treatment, and a short treatment time has been a recurring request. To meet their expectations, a number of surgical techniques have been developed to accelerate orthodontic tooth movement. However, these have been found to be quite invasive, leading to low acceptance in patients and the dental community. The authors are introducing a new, minimally invasive procedure, combining microincisions with selective tunneling that allows for hard- or soft-tissue grafting and piezoelectric incisions. This novel approach is leading to short orthodontic treatment time, minimal discomfort, and great patient acceptance, as well as enhanced, or stronger, periodontium. Because of the added grafting (bone and/or soft tissue), the periodontium is much thicker buccally.

Modeling of trabecular bone and lamina dura following selective alveolar decortication in rats.

BACKGROUND: Modifying the balance between resorption and apposition through selectively injuring the cortical plate of the alveolus has been an approach to speed tooth movement and is referred to as periodontally accelerated osteogenic orthodontics. The aim of this study was to investigate the alveolar response to corticotomy as a function of time and proximity to the surgical injury in a rat model. METHODS: Maxillary buccal and lingual cortical plates were injured in 36 healthy adult rats adjacent to the upper left first molars. Twenty-four animals were euthanized at 3, 7, or 11 weeks. In one group, the maxillae were removed and stripped of soft tissues, and histomorphometric analysis was performed to study alveolar spongiosa and periodontal ligament (PDL) modeling dynamics. Catabolic activity was analyzed with tartrate-resistant acid phosphatase-positive osteoclasts and preosteoclasts. Anabolic actions were measured using a fluorescent vital bone stain series followed by sacrifice at 30 and 51 days. To further analyze the new bone formation, a separate group of animals were fed with calcein fluorescent stain and processed for non-decalcified fluorescent stain histology. RESULTS: At 3 weeks, the surgery group had significantly (P <0.05) less calcified spongiosa bone surface, greater periodontal ligament surface, higher osteoclast number, and greater lamina dura apposition width. The catabolic activity (osteoclast count) and anabolic activity (apposition rate) were three-fold greater, calcified spongiosa decreased by two-fold, and PDL surface increased by two-fold. Surgical injury to the alveolus that induced a significant increase in tissue turnover by week 3 dissipated to a steady state by postoperative week 11. The impact of the injury was localized to the area immediately adjacent to the decortication injury. CONCLUSION: Selective alveolar decortication induced increased turnover of alveolar spongiosa, and the activity was localized; dramatic escalation of demineralization-remineralization dynamics is the likely biologic mechanism underlying rapid tooth movement following selective alveolar decortication.

[Alveolar osteotomy and rapid orthodontic treatments]. / Corticotomie alvéolaire et traitements orthodontiques rapides.

When combined with orthodontics, selective periodontal decortication has been shown to be clinically effective in eliminating severe malocclusions three to four times more rapidly than conventional orthodontic treatment. Our technique combines surgical scarring of the cortical bone on both labial and lingual sides of the teeth to be moved, with an augmentation graft to increase alveolar volume. Alveolar spongiosa undergoes rapid transformation as the body attempts to heal the wounds to the cortices resulting in marked tissue turnover. The patient is seen every two weeks and most cases are completed within six months of orthodontic treatment. Moreover, this technique significantly expands the scope of treatment in resolving many skeletal problems such as openbites and severe maxillary constrictions, conditions typically relegated to orthognathic surgery. Clinical outcomes research has shown that the immediate post treatment results settle better during retention and that the long term results become more stable. These facts are likely due to the high tissue turnover induced by decortication as well as the thicker cortical bone resulting from the augmentation grafting.