Regional Acceleratory Phenomenon Research Articles

Preortodonciai kortikocízió és szimultán csont augmentáció a bukkális alveoláris dehiszcencia prevenciójában : Esetismertetés

Buccal orthodontic tooth movement (OTM) of the anterior teeth out of the osseous envelope of the alveolar process incase of front teeth crowding may be associated with a higher tendency for developing gingival recessions. The aim ofthis case report is to present the effectiveness of a minimally invasive preorthodontic corticotomy combined with a buccalbone augmentation according to the rules of periodontally accelerated osteogenic orthodontics (PAOO). The maingoal of our therapy is to increase or maintain the buccal bone thickness, which could prevent the development of gingivalrecessions. Corticotomy possibly have an additional benefit throughout regional acceleratory phenomenon, reducingthe duration of OTM in the early treatment phases. A generally and periodontally healthy individual at the age of17 presenting crowding and thin bone morphotype in the mandibular y front area, who requiresting OTM with incisorproclination, was treated. Surgery was performed under local anesthesia. Three vertical incisions were performed onthe midline and on both sides between lateral incisors and canines, with preservation of the papilla integrity. Incisionswere connected by tunneling knifes in 2 layers, subperiosteally in the whole length and supraperiosteally apically fromthe mucogingival junction. Corticocisions were utilized by ultrasonic instrument penetrating through the cortical bone.“Sticky bone” plates, a combinations of platelet rich fibrin (PRF) and xenograft, were used subperiosteally for bone, andPRF membranes supraperiosteally for soft tissue augmentation. Initiation of OTM started 1 week postoperatively, andactivation of the multibond appliance was performed activated in 2 weeks. The extent of tooth movement measuredon the central incisor was compared followed-up on cephalometric radiographs made taken at the different treatmenttime appointments, while buccal bone thickness on the 6 front teeth was evaluated in CBCT before and after OTM. Thealignment phase ended up at the 20th week due to an initial arch wire sequence using light forces. The buccal bony wallthicknesses showed similar values compared to the initial ones, and there was no radiologically proven substantial verticalbone loss. The presented comprehensive treatment approach promised a good option in the prevention of the periodontalside effects during orthodontic treatment.

Increase in bone metabolic markers and circulating osteoblast-lineage cells after orthognathic surgery

Increased mineralisation rate and bone formation after surgery or fracture is the regional acceleratory phenomenon (RAP), and its systemic impact is the systemic acceleratory phenomenon (SAP). The proportion of circulating osteoblast lineage cells, including osteocalcin-positive (OCN+) cells, in the peripheral blood is markedly higher during pubertal growth and in patients with bone fractures. This study aimed to elucidate the dynamic changes in bone metabolic activity after orthognathic surgery by longitudinal prospective observation. Peripheral venous blood samples were collected from patients who had undergone orthognathic surgery, and serum bone metabolic markers and the proportion of OCN+ cells were measured. Orthognathic surgery induces systemic dynamic changes in bone metabolic activity by targeting steps in the bone healing process and related proteins, such as surgical stress/inflammation (C-reactive protein), bone resorption (type I collagen C-telopeptide), and bone formation (alkaline phosphatase and bone-specific alkaline phosphatase). During the early post-operative period, the population of OCN+ cells significantly increased. Confocal microscopy revealed that OCN proteins were localised in the cytoplasm in Triton X-100-treated OCN+ cells. Furthermore, OCN, ALP, and COL1A1 gene expression was detected in OCN+ cells, suggesting the contribution of the local maturation of bone marrow-derived OCN+ cells at the site of bone healing.

Remote Corticotomy Accelerates Orthodontic Tooth Movement in a Rat Model.

Introduction With an increasing demand for orthodontic treatment for adult patients, orthodontic professionals are constantly seeking novel strategies and technologies that can accelerate tooth movement in order to shorten the treatment period. For instance, in recent years, the influences of different surgical techniques on orthodontic tooth movement in the ipsilateral side of surgery were intensively investigated. Here, we attempt to examine if corticotomy could also affect the rate of tooth movement in the contralateral side of the surgery by using a rodent model. Materials and Methods 72 eight-week-old Sprague-Dawley rats were randomly divided into three groups as follows: the Control group (orthodontic treatment devices delivered only, no tooth movement), the orthodontic tooth movement (OTM) group (orthodontic treatment devices delivered and orthodontic treatment performed), and the Corticotomy + OTM group (remote corticotomy performed, orthodontic treatment devices delivered, followed by orthodontic treatment). The surgical procedure was conducted on the right side of the maxilla at the time of appliance placement and a force of 60 g was applied between the maxillary left first molar and maxillary incisors using nickel-titanium springs to stimulate OTM. The OTM distance and speed were tracked at 3, 7, 14, and 28 days post-surgery, followed by histological and immunohistochemical assessments. Results In comparison with orthodontic treatment only, the contralateral corticotomy significantly accelerated OTM. Furthermore, animals undergoing corticotomy + OTM presented with a greater number of osteoclasts on the compression side, stronger staining of the osteogenic marker on the tension side, and higher expression of an inflammatory marker than the OTM group animals. Conclusion Our current study demonstrates that remote corticotomy effectively accelerates alveolar bone remodeling and OTM. The study enriches our understanding of the regional acceleratory phenomenon (RAP) and offers an alternative strategy for accelerating OTM to shorten the orthodontic treatment period.

Study of bone remodeling in corticotomy-assisted orthodontic tooth movement in rats.

The goal of this study was to determine the structure change of the alveolar bone and the expression of a group of bone remodeling-related factors. Sixty healthy male Wistar rats were randomly divided into three groups. Selective alveolar decortication (SAD), tooth movement (TM), and "combined therapy" (SAD+TM) was performed in group I, II, and III, respectively. On days 0, 7, 14, 21, and 42, a Micro-CT scan was performed on the maxillary alveolar bone and tooth. In addition, on days 0, 7, 14, 21, 28, and 42, some of the rats were killed by cervical dislocation and tissues were harvested. Analysis of scan data revealed a significant decrease in bone density of the alveolar bone at 14 days post-surgery, and increased at 42 days post-surgery to a level higher than that before the surgery. Microarray and bioinformatics analysis were performed to explore gene expression profile in three groups (SAD, TM, and SAD+TM),and a large number of differentially expressed genes were identified. In addition, real-time polymerase chain reaction was performed to determine the expression of bone remodeling-related factors. The expression of osteoblast-related cytokines, including osteopontin, bone sialoprotein, and osteocalcin,and osteoclast regulators macrophage-colony stimulating factor (M-CSF) and RANKL (activator of nuclear factor KB receptor ligand) were increased in group III, suggesting that there was increased bone synthesis and activation of bone absorption. Moreover, group III had a unique alveolar bone remodeling pattern: RANKL and osteoprotegerin-promoted alveolar remodeling. In conclusion, during the early stage of orthodontic tooth movement, corticotomy can accelerate the movement of teeth, modulate the state of bone metabolism, and activate osteogenesis and osteoclast, which support the theory of regional acceleratory phenomenon.

Residents' journal review

Residents' journal review

Orthognathic surgery deteriorates the osseointegration of dental implants: a propensity-matched multicenter cohort study

Background: There have been many studies that the regional acceleratory phenomenon (RAP) affects dental implant osseointegration.

Impaired osseointegration of dental implants associated with orthognathic surgery: Possible regional acceleratory phenomenon.

Regional acceleratory phenomenon (RAP) is demonstrated to decrease regional bone mineral density and accelerate bone turnover. Hypothesizing that RAP can negatively affect the osseointegration of biomaterials, this study aimed to investigate the possible influence of the RAP on dental implant osseointegration. Orthognathic surgery, one of the major surgeries on oral and maxillofacial region was set as intervention for RAP. Considering that RAP exerts its physiologic effects until 4 months after noxious stimuli, patients were classified according to the time interval between orthognathic surgery and dental implant installation; group I was designated to patients who had implant installation within 4 months from orthognathic surgery. Group II were those with installation after 4-12 months and group III was longer than 12 months. Radiographic and clinical evaluations of dental implants including peri-implant marginal bone changes (MBR), implant stability, cumulative survival rates were analyzed. A total of 54 patients with 106 implants (mean follow-up of 72.6 months) were included in the study. MBR was significantly higher in group I (2.62 ± 0.91 mm) and II (2.25 ± 0.95 mm) compared to that of group III (0.94 ± 0.90 mm) at last follow up (P < 0.05) and this group difference over time was also significant (P < 0.001). Compared to group III, groups I and II exhibited lower ISQ values and higher biological complications including peri-implantitis and peri-implant gingivitis (P < 0.05). Group I showed significantly low-cumulative survival rate (89.2%; implant-level) compared to groups II and III. In this study, impaired osseointegration of dental implants was demonstrated associated with orthognathic surgery. Micro-environmental changes of hard tissue induced by major surgery on the jaw showed deteriorating effects on integrity of biomaterial osseointegration. Special considerations should be addressed for ideal treatment results and prognosis.

Facial asymmetry correction: From conventional orthognathic treatment to surgery-first approach.

The surgery-first approach (SFA), which proceeds without presurgical orthodontic treatment, is assumed to shorten the treatment course because the direction of post-surgical orthodontic tooth movement conforms to the normal muscular forces. Moreover, the regional acceleratory phenomenon (RAP), evoked by surgery, helps in tooth alignment and compensation in a faster way. Although SFA has definite advantages, especially in class III individuals, there is a lack of data about its indications in patients with facial asymmetry. In this article, we reviewed recently published articles on the treatment of asymmetric patients using the SFA. Different aspects, including the three-dimensional assessment of stability in different planes, approaches for fabrication of a surgical splint, predictability of the results, skills needed for bimaxillary surgery, indications as the treatment of choice for condylar hyperplasia, and combination with distraction osteogenesis in candidates with severe asymmetries were found to be the main topics discussed for patients presenting with facial asymmetry

Corticotomy for orthodontic tooth movement

Corticotomy was introduced as a surgical procedure to shorten orthodontic treatment time. Corticotomy removes the cortical bone that strongly resists orthodontic force in the jaw and keeps the marrow bone to maintain blood circulation and continuity of bone tissues to reduce risk of necrosis and facilitate tooth movement. In the 21st century, the concept of regional acceleratory phenomenon was introduced and the development of the skeletal anchorage system using screw and plate enabled application of orthopedic force beyond conventional orthodontic force, so corticotomy has been applied to more cases. Also, various modified methods of minimally invasive techniques have been introduced to reduce the patient's discomfort due to surgical intervention and complications after surgery. We will review the history of corticotomy, its mechanism of action, and various modified procedures and indications.

Orthognathic surgery Deteriorates the osseointegration of dental implants: A propensity-matched multicentre cohort study.

This study aimed to investigate the possible influence of the regional acceleratory phenomenon (RAP) on dental implant osseointegration. Orthognathic surgery was set as an intervention for RAP, and a multicentre cohort study of two groups was undertaken. Group O included patients with single implant placement at least 4months after orthognathic surgery and functional loading for more than 1year, while controls (Group C) were without any major surgery. Clinical and radiographic assessments of implants, including changes in marginal bone levels, were analysed at baseline, 6- and 12-month follow-up. Bivariate analysis of two groups with propensity score matching was performed. After propensity score matching, all 10 confounding variables had acceptable standardised difference scores (<20%), indicating that the matching procedure had efficiently balanced the two groups. Following the propensity score adjustment, the marginal bone loss was significantly higher in Group O than the control at 6months (1.66±1.05mm vs 0.59±0.64mm, P<0.001) and 12months (2.30±1.27mm vs 0.82±0.78mm, P<0.001). Compared to Group C, subjects in Group O had a higher incidence of peri-implant mucositis and implantitis (11.8% vs 1.5%, P=0.033). Impaired osseointegration of dental implants was associated with orthognathic surgery. Special considerations for peri-implant soft and hard tissue stability should be addressed to obtain ideal treatment results and prognosis for patients who have had prior orthognathic surgery.

Regional Acceleratory Phenomenon after Orthodontic Force Exertion in Ovariectomized Rats

The application of orthodontic forces may be one of the factors that produce a regional acceleratory phenomenon (RAP) in mandibular and maxillary bones. The effect of exerted forces on bone tissue ahead of their point of application has not been extensively studied. Moreover, limited information exists regarding this phenomenon on osteoporotic bone. The study aim was to examine the role of orthodontic forces on the expression of RAP in normal and osteoporotic mature rats. Thirty-six eight-month-old skeletally mature female Wistar rats, half of which had been previously ovariectomized (OVX) at the age of 6 months, were subjected to orthodontic movement of the upper right first molar. An orthodontic force of 60 gr* was generated through a closed coil spring for 14 days. The maxillae were then removed and the area ahead of the first molar was examined histologically. On the side of orthodontic force application, distortion of bone structure and woven bone formation were observed in non-OVX rats, whereas in the OVX rats, extensive remodeling was apparent. In conclusion, the application of orthodontic forces on both normal and osteoporotic mature rats in the present study created a RAP ahead of the loaded teeth demonstrated histologically, indicating increased bone resorption and formation in the OVX rats.

Methods of accelerating orthodontic tooth movement: A review of contemporary literature.

Technological progress and the introduction of modern therapeutic methods are constantly changing contemporary orthodontics. More and more orthodontic patients are working adults, who expect satisfactory therapeutic effects as soon as possible, increasing the importance of methods accelerating tooth movement. The aim of this study was to review the current literature regarding methods of accelerating tooth movement and reducing the duration of the active phase of therapy. The literature was collected from the PubMed and EBSCO databases using "accelerated orthodontic tooth movement" as the search key words. The methods described were categorized as conservative and surgical. The pharmacological agents used in conservative treatment, such as growth hormone, parathyroid hormone, thyroxine, and vitamin D, are especially worth mentioning. They stimulate osteoclasts to increase resorption through a variety of mechanisms. Effective methods also include physical stimuli, e.g., vibrations or photobiomodulation. Most studies describing the effects of pharmacological agents were based on animal subjects and they may therefore lack clinical relevancy. Corticotomy and its modifications based on the regional acceleratory phenomenon (RAP) might prove to be a useful augmentation of orthodontic treatment, especially in adults, including patients with periodontal disease.

Other interesting effects of alveolar corticotomies in orthodontics apart from the acceleration of tooth movement

The acceleration of orthodontic tooth movement due to alveolar corticotomies has been well documented in the literature. It is defined by a phenomenon of transient osteopenia named “the regional acceleratory phenomenon” by Frost. This biological mechanism has been described in studies on both humans and animals. However, other interesting effects in orthodontics are associated with alveolar corticotomies: higher amplitude of tooth movements, a decrease of the root resorptions and an increase of stability after orthodontic treatment.

Residents' journal review

Residents' journal review

Magnetic Bead-based Salivary Peptidome Profiling for Accelerated Osteogenic Orthodontic Treatments.

To identify a panel of differentially expressed candidate biomarkers for patients undergoing accelerated osteogenic orthodontics (AOO). This study included 36 saliva samples taken from six Class III surgical patients at six time points: the date before the corticotomy procedure (T1) and at 1 week, 2 weeks, 1 month, 2 months and 6 months after the procedure (T2, T3, T4, T5 and T6, respectively). After the maxillary dental arch was aligned and levelled, AOO procedures were performed in the maxillary alveolar bone. Saliva samples were used to create peptide mass fingerprints using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) combined with magnetic beads. When the six groups were compared, 182 peaks were significantly different (P < 0.01), and the biomarker profiles changed over time. After corticotomy, the mass peaks predicted to be the Apolipoprotein A-I precursor (APOA1) increased sharply in T2 then decreased. The peptides predicted to be complement component 3 decreased in T2, then gradually increased and declined in T6. The peptides predicted to be the vitamin D-binding protein precursor increased in T2, then fell to the preoperative level. The mass peaks of the peptides predicted to be Isoform 1 of the fibrinogen alpha chain precursor (FGA) first decreased, then increased with time. The salivary protein profiles changed with accelerated tooth movement induced by AOO. This method provides a tool for investigating corticotomy-induced accelerated tooth movement in humans, and explored the critical factors responsible for the regional acceleratory phenomenon.

Effect of micro-osteoperforations on the rate of canine retraction: a split-mouth randomized controlled clinical trial

INTRODUCTION: The prolonged orthodontic treatment time is considered a major concern both for patients and clinicians.Corticotomy has been proposed as a method for acceleration of orthodontic tooth movement and was found successful. However, its popularity decreased because of its invasiveness. Micro-osteoperforations have been proposed for acceleration with minimal invasiveness. OBJECTIVE: The purpose of the study was to clinically evaluate the effect of micro-osteoperforations on the rate of orthodontic tooth movement as evaluated by its effect on the rate of canine retraction. MATERIALS AND METHODS: The study was a split-mouth randomized controlled clinical trial, with a sample size of 10 adult patients (mean age 17.5±2.5 years) requiring the therapeutic extraction of maxillary first premolars’ followed by canine retraction. Micro-osteoperforations were randomly assigned to one side of the maxillary arch at the canine-premolar region, and the contra-lateral side served as control. Anchorage reinforcement was performed usingmini-screws, and canine retraction was performed using nickel-titanium closed coil springs, delivering a force of 150 grams on each side. The rate of canine retraction was measured throughout the study period from dental models obtained at the follow-up visits every 3 weeks. RESULTS: The average daily rate of canine retraction was significantly higher on the experimental side compared to that on the control side by approximately 2 times during the first 9 weeks of the study. CONCLUSION: Micro-osteoperforations have been found clinically successful in accelerating orthodontic tooth movement and shortening the treatment duration. However, acceleration of tooth movement has been found significant during the first 9 weeks, which represent the period of regional acceleratory phenomenon.

Authors' response

Authors' response

Surgery-First Orthodontic Approach for the patients

The traditional orthognathic surgery treatment consists of three steps: preoperative orthodontic treatment, orthognathic surgery, and postoperative orthodontic treatment, and the average treatment period is usually two years. Also, patients with Class III malocclusion should spend more time getting their facial features worse during the decompensation process. However, most of the patients who want orthognathic surgery visit the chief complaints of appearance improvement, and resolve this address as soon as possible. The concept of &amp;deg;AESurgery - First 'does not cause a facial imbalance caused by decompensation for the pre - operative correction period, and the patient can obtain an improved facial profile immediately after the operation. In addition, the correction period is shortened by Regional Acceleratory Phenomenon (RAP) after surgery. However, it is not applicable to all patients. Patients with severe crowding, severe curve of spee or reverse curve of spee, severe transverse discrepancy of the maxilla and mandibular arch, and severe incisal angles are less likely to apply the technique. Although it is not yet possible to apply this technique to all patients, it has many advantages over the conventional method. Especially, the patients' preference is increasing due to the rapid appearance improvement and the shortening of the total treatment period.

Surgery first approach in orthognathic surgery: an overview and outcomes in various clinical situations

Orthognathic surgery (OGS) has evolved a great deal over the past five decades and particularly in the past 10 years, this concept and technique of surgery-first-orthognathic-approach (SFOA) or surgery-first approach (SFA) toward the correction of dentofacial anomalies is taking precedence over the conventional approach. Weighing the pros and cons of the SFA over the conventional approach, given a choice, patients now seek a quick transformation with the least possible treatment time. The prolonged treatment phase of 7–47 months before and after OGS and a temporary worsening of facial appearance is a huge disadvantage of the conventional approach over SFA. SFOA offers minimal or no presurgical orthodontics and the shortest possible postsurgical orthodontic phase taking advantage of the regional acceleratory phenomenon with completion of treatment in approximately 6–12 months. Currently, the concept of surgery-first, followed by a short orthodontic phase can be applied in the correction of various dentofacial deformities in select situations. This paper is intended to provide an overview and outcome of SFA, utilised in 15 diverse cases, discussing the indications, general and specific guidelines, different protocol variations and potential problems. All patients benefited from immediate improvement of the facial profile after surgery, a much shorter total treatment phase and highly appreciable results. I believe SFA is a good and effective treatment alternative in select cases of any dentofacial deformity.

Innovative Periodontal Surgery by Monocortical Corticotomy in Management of Bimaxillary Protrusion Cases: A Clinical Study

ABSTRACT Periodontal accelerated osteogenic orthodontics (PAOO) is a procedure applying the clinical science of alveolar corticotomy, particulate bone grafting, and the application of orthodontic forces, for accentuated tooth movement. This is theoretically based on the bone healing pattern known as the regional acceleratory phenomenon (RAP). A series of 12 cases, including 8 females and 4 males, were included in the study. The cases were referred from the Department of Orthodontia to the Department of Periodontology, ADC (R&amp;R), having bimaxillary protrusion with an increased overjet. After initial orthodontic alignment, buccal corticotomy procedure was planned. A full-thickness mucoperiosteal flap was reflected from maxillary canine to canine beyond the root apices. Vertical corticotomy cuts were given in the alveolar bone with piezo blades 2 mm apical to the crestal bone in the inter-radicular space midway between the root prominences and were joined by the horizontal cuts apically. Demineralized freeze-dried bone allograft (DFDBA) was placed in the surgical area. The flaps were sutured and pack was placed. Orthodontic retraction was started 2 weeks after the corticotomy procedure. Using this procedure, the treatment objectives were met in just half to one-third of the reported conventional treatment time and the large overjet was reduced to normal. Pre- and posttreatment clinical parameters were recorded, statistically analyzed, and corroborated with similar orthodontic treatment procedures without the use of the corticotomy technique. The present periodontal (PDL) intervention results in quick and stable results for the correction of bimaxillary protrusion cases. It enhances the esthetics and posttreatment orthodontic stability. How to cite this article Panwar M, Dubey D, Kosala M. Innovative Periodontal Surgery by Monocortical Corticotomy in Management of Bimaxillary Protrusion Cases: A Clinical Study. Int J Experiment Dent Sci 2017;6(2):55-60.