Corrigendum to "The effect of low intensity pulsed ultrasound on mandibular condylar growth in young adult rats" [Bone Rep. 15 (2021) 101122 (December)].

[This corrects the article DOI: 10.1016/j.bonr.2021.101122.].

Datasets describing the morphometric evaluation of the adult rat mandible following growth stimulation of the condyle using ultrasound.

Evaluating morphological changes of the mandible due to the unique role of the condyle in mandibular special growth and remodeling pattern is challenging. This data describes a comprehensive evaluation using new techniques to detect morphological changes of the young adult rat mandibles treated by low intensity pulsed ultrasound (LIPUS) comparing to matching controls. Two-dimensional (2D) analysis was performed on digital photographs of the hemi-mandibles using AutoCAD software with high accuracy. The anatomical points which were more determinative and prone to visual illusion were defined with particularity. Selective combination of measurements was done to allow for a thorough morphometric evaluation of the mandible focusing on the condyle and the main direction of condylar and mandibular growth. The procedure was simulated for three-dimensional analysis of virtual models of the hemi-mandibles via Geomagic-Qualify software. In the whole procedures, conditions were strictly standardized to ensure reliability and repeatability. Further Insights, Interpretations and discussions of the present datasets can be find in https://doi.org/10.1016/j.bonr.2021.101122[1].

Mandibular condyle tissue reaction to low intensity pulsed ultrasound in young adult rats: Micro computed tomographic and histomorphometric datasets.

Mandibular condyle (MC) in postnatal life, grows mainly by endochondral bone growth which is a multistep process and the condylar cartilage plays a vital role in its regional adaptive growth. Hence, for determining the exact effect of a treatment such as low Intensity pulsed ultrasound (LIPUS) on the MC growth in animal models, it is important to reliably and reproducibly detect changes at different tissue levels and correct regions of the condyle. To this aim, micro computed tomography (µCT), as well as Alcian Blue-Pas staining, in vivo flourochrome labeling via calcein green, and Goldner's Trichrome staining on proper decalcified and undecalcified sections was performed for the harvested samples from young adult rats. Standardized procedures were used to determine volumes or regions of interest for microstructural evaluations in the middle and posterior areas of the MC. In the condylar cartilage, the thickness of fibrous, proliferative, chondroblastic, and total fibrocartilage layers; also the cell population in proliferative and chondroblastic layers were precisely measured. On the other side, using accurate methods percentage of calcifying cartilage and newly formed bone areas/bone area, bone volume fraction and specific surface, trabecular number, thickness, and separation, degree of anisotropy, bone mineral density; furthermore, the amount of actual endochondral bone growth and the osteoid thickness were quantified in subchondral cancellous bone subjacent to condylar cartilage. Data provided herein present the robust µCT and histomorphometric evaluations of the control and LIPUS treated adult MCs at cartilage and bone level. Data also highlights the difference in tissue response to the stimuli between the middle and posterior regions of the condyle. Further interpretation of these datasets can be found in https://doi.org/10.1016/j.bonr.2021.101122[1].

The effect of low intensity pulsed ultrasound on mandibular condylar growth in young adult rats.

There is a need for more effective methods to enhance mandibular growth in young adults with mandibular deficiency. Previous studies suggest that low intensity pulsed ultrasound (LIPUS) can enhance mandibular growth in growing individuals. This study aimed to evaluate the potential growth changes of the mandible following 4-week LIPUS application in young adult rats. Nineteen ≈120-day-old female rats were allocated to experimental (n = 10) and control (n = 9) groups. The animals in the experimental group were treated with LIPUS to their temporomandibular joints (TMJs) bilaterally, 20 min each day for 28 consecutive days. Animals were then euthanized; gross morphological evaluation was performed on 2D photographs and 3D virtual models of hemi-mandibles, and microstructural assessment was done for the mandibular condyle (MC). Evaluation of mineralization and microarchitecture properties of subchondral cancellous bone was performed by micro-computed tomography (µCT) scanning. Qualitative and histomorphometric analysis was done on condylar cartilage and subchondral bone following Alcian Blue/PAS and Goldner's Trichrome staining. Vital flourochrome (calcein green) labeling was also utilized to determine the amount of endochondral bone growth. Gross morphological evaluations showed a slight statistically non-significant increase especially in the main condylar growth direction in the LIPUS group. Moreover, 3D evaluation depicted an enhanced periosteal bone apposition at the site of LIPUS application. Microstructural analysis revealed that LIPUS stimulates both chondrogenesis and osteogenesis and enhances endochondral bone formation in young adult rat MC. Furthermore, the effect of LIPUS on osteogenic cells of subchondral cancellous bone was notable. To conclude, LIPUS can enhance young adult rats' MC residual growth potential.

Corticotomy-assisted orthodontic treatment. A systematic review of the biological basis and clinical effectiveness.

OBJECTIVES: To systematically review the literature to assess the quality of evidence related to corticotomy-assisted orthodontic treatment (CAOT) as adjunctive treatment in orthodontics. METHODS: The study was conducted in the Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia between 2013 and 2014. Various electronic  databases were searched and abstracts were retrieved. Defined inclusion criteria were then applied to the obtained original articles for further evaluation by 2 examiners independently. The criteria of selection included human, or animal studies, which assessed some aspects of CAOT and/or the biological principles behind it. Case reports and series were excluded. The quality of the studies was evaluated by the methodological score for clinical trials developed. RESULTS: Fourteen articles were retrieved initially, but only 12 articles were finally selected for the study. The CAOT was found to accelerate tooth movement by 2-2.5 folds when compared with conventional orthodontic tooth movement. The CAOT was found safe on periodontal health and exhibits no or little risk of root resorption. A localized turnover of alveolar spongiosa and the absence of a hyalinized zone was the acceptable biological explanation of CAOT. There is no evidence to support that CAOT enhances the movement of ankylosed teeth, closing old extraction sites, post-orthodontic stability, or transverse expansion. CONCLUSIONS: Corticotomy-assisted orthodontic treatment should be considered with caution. Long term randomized clinical trials are still needed.

Cephalometric craniofacial features of growing patients with chronic renal failure.

INTRODUCTION: Chronic renal failure (CRF) in growing children can affect their physical growth status. The objective of this research was to study the craniofacial morphology of children with CRF as evaluated by cephalometric analysis. METHODS: Twenty-three growing children with CRF were included in this study. They were divided into three groups according to age ranges. The age ranges were >5-11 (group 1); >11-14 (group 2); >14-16 (group 3). Another twenty-three matching controls (in age and gender) were also included. Lateral cephalometric radiographs were taken as part of these children's orthodontic records. Lateral cephalometric radiographs were corrected for magnification distortion, digitized, and cephalometric analysis was performed. Data were analysed using ANOVA test. RESULTS: The results showed that CRF patients in all age groups have statistically significantly decreased posterior cranial base lengths. Posterior facial heights showed a significant decrease in CRF patients in groups 1 and 2. Younger CRF patients (group 1) showed statistically significant increased gonial angle and FH-Mandibular plane angle, SN-Mandibular plane angle and decreased posterior to anterior face height ratio, total anterior facial height (N-Me), Mandibular body length (Go-Me), upper anterior facial height (N-ANS), Y axis length, pterygomaxillary-A point length. CONCLUSION: Younger children (groups 1 and 2) with CRF showed a decrease in posterior facial growth (posterior facial height and posterior cranial base) when compared to matching normal controls. This decrease is not significant in older group (group 3). This finding suggests that children with CRF might catch up in growth with normal subjects and most of the earlier retarded growth features disappear with age.

Cephalometric evaluation of airways after maxillary anterior advancement by distraction osteogenesis in cleft lip and palate patients: a systematic review.

OBJECTIVE: This study was conducted to review the changes in airways after maxillary anterior advancement by distraction osteogenesis in patients with cleft lip and palate. MATERIALS AND METHODS: Several electronic databases were searched. The selection criteria were set to include clinical trials and at least 1 year of postsurgical data. The original articles were then retrieved and evaluated by two investigators to ensure that they met the selection criteria. The references were also hand searched for possible missing articles. RESULTS: Forty-three abstracts were found in the electronic searches. After the first set of selection criteria was applied to these abstracts, 14 articles were retrieved. After the final selection criteria, only four articles were finally selected. However, sample sizes of the selected articles were small, and the methodological quality of the studies was inadequate. All selected articles were consistent in that upper airway sizes increased and nasal resistance was reduced after distraction osteogenesis. CONCLUSIONS: Despite the consistency of increasing the upper airway size and reducing nasal resistance in the only four found articles, limitations of the studies merit caution in interpreting these findings. We conclude that there are insufficient prospective randomized controlled clinical trials to confirm these results.

Efficacy of light-activated sealant on enamel demineralization in orthodontic patients: an atomic force microscope evaluation.

OBJECTIVE: The purpose of this study was to investigate the efficacy of (Pro Seal) sealant in preventing enamel decalcification in-vivo and compare its effect with fluoride varnish and unfilled sealant using atomic force microscopy. MATERIALS AND METHODS: Eight orthodontic patients who were candidates for extraction of all first premolars for orthodontic treatment were recruited to this study. Thirty two premolars (upper and lower) were randomly divided into four groups (n=8) for each group, 4 maxillary and 4 mandibular); Control (no -treatment); Fluoride varnish, Unfilled sealant (Light Bond) and filled sealant (Pro-Seal). After two months the brackets were debonded and the teeth were extracted and prepared for Atomic force microscopic scanning. Each sample was scanned twice at two different scan areas 50 and 10µm at the buccal cervical third of the crown. Images were recorded with slow scan rate and resolution and the mean roughness height and total surface area were calculated for each scan area. Comparison between groups was performed using one way analysis of variance test with level of significance was set to be 0.05. RESULTS: Pro Seal treated samples show the lowest roughness height and total surface area. CONCLUSION: Pro Seal was the most effective prophylaxis technique in preventing enamel demineralization during orthodontic treatment.

In vitro osteogenic induction of human gingival fibroblasts for bone regeneration.

BACKGROUND AND OBJECTIVE: Periodontitis is an inflammatory disease causing bone loss, and is a primary cause of tooth loss. Gingival fibroblasts are readily available with minimal donor site morbidity and may be ideal for tissue engineering efforts in regenerating lost alveolar bone. Dexamethasone (Dex) is commonly employed for in vitro osteogenic induction of a variety of cells, but its effect on human gingival fibroblasts (HGF) is still controversial. Therefore, the aim of our study was to investigate the osteogenic differentiation of HGF following Dex treatment. METHODS: Cultured HGFs were exposed to osteogenic medium containing a wide range of Dex concentrations (0.01-10 µM). The osteogenic phenotype was assessed based on changes in alkaline phosphatase (ALP) activity, the mRNA expression of selected extracellular matrix proteins critical for mineralization and the extent of extracellular mineralization (Von Kossa staining and Ca-content). RESULTS: All assays showed a consistent and maximal osteogenic effect of Dex on HGF at 0.1 and 0.5 µM (weeks 3 and 4), as evidenced by significant osteopontin and osteocalcin expression and mineralization. Longer cultures (week 4) also yielded positive osteogenic effect of Dex at 0.01 µM. Moreover, ALP activity was significantly stimulated at 0.1 and 0.5 µM Dex initially after one week, but ALP was subsequently reduced under Dex. Higher Dex concentrations caused down regulation of osteogenic effects observed at the optimal (0.1-0.5 µM) concentrations. CONCLUSION: Under appropriate osteogenic conditioning, Dex treated HGFs could be a potential source of cells for cell-based therapy for periodontal bone regeneration.

Anabolic effects of low-intensity pulsed ultrasound on human gingival fibroblasts.

OBJECTIVE: Low-intensity pulsed ultrasound (LIPUS) demonstrated anabolic effects on cementoblasts, odontoblasts, and periodontal ligament cells. However, LIPUS effect on human gingival fibroblasts (HGF) remains to be investigated. Therefore, we evaluated the in vitro effects of LIPUS on HGF proliferation and differentiation to test its feasibility for periodontal therapy. DESIGN: LIPUS treatment (1.5MHz, 30mW/cm(2)) was applied to HGF in the experimental groups after 24-h of culture (5 or 10min/day for 28 days) and omitted in the control. Changes in HGF activities were evaluated in response to LIPUS treatment in dose-dependent (5 and 10min) and time-dependent (weeks 1-4) manner. The effects of LIPUS on HGF cell viability (MTT), proliferation (total DNA content and growth pattern), alkaline phosphatase (ALP) activity, and gene expression by reverse-transcriptase polymerase chain reaction (RT-PCR) were determined. RESULTS: Cell viability remained unchanged after LIPUS treatment during the 4 weeks of treatment as compared to the untreated control group which ensured a safe biological response. Both LIPUS treatments (5-10min/day) did not yield any significant changes in the proliferation, and expression of proliferating cell nuclear antigen (PCNA) and collagen-I (COL-I). Conversely, LIPUS treatment enhanced osteogenic differentiation potential of HGF as determined by significant up-regulation of specific ALP activity and osteopontin (OPN) expression, with optimum effect following 3 weeks of 5min/day LIPUS treatment. CONCLUSION: LIPUS treatment at 30mW/cm(2) selectively enhanced HGF differentiation but not proliferation. The ability of LIPUS to enhance HGF differentiation is promising for its application in cell-based periodontal therapy.

Frictional resistance in self-ligating orthodontic brackets and conventionally ligated brackets. A systematic review.

OBJECTIVE: To compare the amount of expressed frictional resistance between orthodontic self-ligating brackets and conventionally ligated brackets in vitro as reported in the literature. METHODS: Several electronic databases (Medline, PubMed, Embase, Cochrane Library, and Web of Science) were searched without limits. In vitro studies that addressed friction of self-ligating brackets compared with conventionally ligated brackets were selected and reviewed. In addition, a search was performed by going through the reference lists of the selected articles to identify any paper that could have been missed by the electronic searches. RESULTS: A total of 70 papers from the electronic database searches and 3 papers from the secondary search were initially obtained. After applying the selection criteria, only 19 papers were included in this review. A wide range of methods were applied. CONCLUSIONS: Compared with conventional brackets, self-ligating brackets produce lower friction when coupled with small round archwires in the absence of tipping and/or torque in an ideally aligned arch. Sufficient evidence was not found to claim that with large rectangular wires, in the presence of tipping and/or torque and in arches with considerable malocclusion, self-ligating brackets produce lower friction compared with conventional brackets.

Effect of bilateral mandibular osteodistration on the condylar cartilage: an experimental study on rabbits.

UNLABELLED: Although various aspects of bone formation during distraction osteogenesis have been studied extensively, there are only limited experimental data concerning the influence of hyper-physiologic mandibular distraction rate on structural alterations in the temporomandibular joint (TMJ) condylar cartilage. The purpose of this study was to evaluate the effect of bilateral distraction osteogenesis of the mandibular body, at a hyper-physiologic rate and length, on the integrity of the condylar cartilage in rabbits. MATERIALS AND METHODS: Eighteen healthy adult male rabbits weighing 2 to 3 kg were assigned to 1 of 2 groups: the control group (n = 2 rabbits, 4 joints) or the study group (n = 16 rabbits, 32 joints) four rabbits (8 joints) in each subgroup according to the post-distraction period (1,2,3 or 4 weeks). In the control group, rabbits received sham surgery (Osteotomy without distraction) and then left to live for 4 weeks under the same condition of the study group then euthanized using intravenous overdose of pentobarbital sodium. In the study group, an extra oral custom-made distracter was employed to achieve bilateral mandibular hyper physiologic distraction (1.5 mm twice daily for 5 days) distraction. All animals were evaluated clinically and histomorphometrically and results analyzed by MINITABE 13.1 statistical package using ANOVA test. RESULTS: Animals underwent distraction showed obvious changes in condylar surface contour related to length of the follow up period, compared to the control; these changes seemed to be partly reversible. The most pronounced observation was the irregularities and resorption in the anterior part of the condylar cartilage and the subcondylar bone. Moreover, at the first two weeks, the area of resorption was invaded by large number of osteoclasts and chronic inflammatory cells which declined later in the 3rd and 4th weeks and replaced with osteoblastic activities. CONCLUSION: These experimental data showed that distraction rate of 3 mm per day may lead to degenerative or even early arthritic changes in the TMJ condylar cartilage in the 1st and 2nd post-distraction weeks. However, all condyles showed adaptive and remodeling sings in the following 3rd and 4th weeks.

Effect of ultrasound on rabbit mandibular incisor formation and eruption after mandibular osteodistraction.

Therapeutic ultrasound is known to enhance bone-fracture healing. The purpose of this article was to study the effect of therapeutic ultrasound on mandibular incisor development and eruption in 15 skeletally mature male New Zealand white rabbits undergoing mandibular osteodistraction. The surgical cuts were made anterior to the molars and consequently transected the mandibular incisors. The animals were divided into 3 groups of 5 rabbits each. Group I received ultrasound on both sides of the mandible every other day. Group II received ultrasound on the left side of the mandible every day. Group III did not receive ultrasound. Ultrasound was given for 20 minutes per application. Mandibular incisor eruption was measured directly on the rabbits and on lateral head radiographs. The animals were killed 4 weeks after surgery, and dissected mandibular specimens that contained the incisor segments were evaluated histologically. The lengths of the tooth segments increased in the ultrasound-treated animals, compared with the controls (group III). However, the rabbits in group II had greater increases in length of the mandibular incisor segments than those in group I. Histologic examination showed that the newly formed tissues at the distraction site and at the cut ends of the incisor segments consisted of osteodentin-like tissue and cementum. Thus, therapeutic ultrasound combined with distraction enhanced mandibular incisor growth and eruption.

The effect of pulsed ultrasound on mandibular distraction.

This study evaluated the effect of pulsed ultrasound on tissue repair and bone growth during mandibular osteodistraction. Twenty-one rabbits were divided into three groups of 7. The distraction started 72 h after surgically severing both sides of the mandible and proceeded at a rate of 1.5 mm/12 h for 5 days. Group I received pulsed ultrasound (nominally 200 micros pulse of 1.5 MHz at a 1.1 kHz pulse repetition frequency, 30 mW/cm2) for 20 min on both sides of the mandible every other day (alternating sides). Group 2 received the same pulsed ultrasound treatment on one side of the mandible every day for 20 min. Group 3 did not receive any ultrasound treatment. Bone formation at the distraction site was assessed by photodensitometry on head radiographs, a vibratory coherence test across the distraction site, a postmortem three-point bending mechanical stiffness test, and a postmortem histological examination. Statistical analyses performed using analysis of variance revealed that pulsed ultrasound enhanced bone formation at the distraction site with a high level of significance when assessed by the increase in new bone photodensity (p = 0.001), vibratory coherence (p = 0.001), mechanical stiffness (p = 0.003), and qualitative histological studies, especially when the pulsed ultrasound treatment was directly applied daily.