Showing papers in "Orthodontics & Craniofacial Research in 2006"

Effects of low-level laser therapy on the rate of orthodontic tooth movement.

Abstract: Structured Abstract Authors – Limpanichkul W, Godfrey K, Srisuk N, Rattanayatikul C Objectives – To test the hypothesis that mechanical forces combined with low-level laser therapy stimulate the rate of orthodontic tooth movement. Study design – This study was a double blind, randomized placebo/control matched pairs clinical trial to test the efficacy of GaAlAs low-level laser therapy (LLLT) on 12 young adult patients who required retraction of maxillary canines into first premolar extraction spaces using tension coil springs with fixed edgewise appliance. LLLT was applied on the mucosa buccally, distally and palatally to the canine on the test side and using a pseudo-application on the placebo side. Dental impressions and casts were made at the commencement of the trial and at the end of the first, second and third months after starting the trial. Measurement of tooth movements was made on each stage model using a stereo microscope. Results – There was no significant difference of means of the canine distal movement between the LLLT side and the placebo side for any time periods (p-value = 0.77). Conclusion – The energy density of LLLT (GaAlAs) at the surface level in this study (25 J/cm2) was probably too low to express either stimulatory effect or inhibitory effect on the rate of orthodontic tooth movement.

Levels of RANKL and OPG in gingival crevicular fluid during orthodontic tooth movement and effect of compression force on releases from periodontal ligament cells in vitro.

Abstract: Structured Abstract Authors – Nishijima Y, Yamaguchi M, Kojima T, Aihara N, Nakajima R, Kasai K Objective – To determine the levels of the receptor activator of NFkB ligand (RANKL) and osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) during orthodontic tooth movement. A second objective was to investigate the effect of compression force on RANKL and OPG production from human periodontal ligament (hPDL) cells. Design – Ten adolescent patients were included. GCF was collected at the distal cervical margins of the experimental and control teeth 0, 1, 24, and 168 h after the retracting force was applied. Thisin vitro study was performed to examine the secretion of RANKL and OPG from hPDL cells following a compression force (0, 0.5, 1.0, 2.0, or 3.0 g/cm2 for 48 h). Enzyme-linked immunosorbent assay (ELISA) kits were used to determine RANKL and OPG levels in the GCF and the conditioned medium. Results – GCF levels of RANKL were significantly higher, and the levels of OPG significantly lower, in the experimental canines than in the control teeth at 24 h, but there were no such significant differences at 0, 1, or 168 h. In vitro study indicated that the compression force significantly increased the secretion of RANKL and decreased that of OPG in hPDL cells in a time- and force magnitude-dependent manner. The compression-stimulated secretion of RANKL increased approximately 16.7-fold and that of OPG decreased 2.9-fold, as compared with the control. Conclusions – The results obtained suggest that the changes of amount of RANKL and OPG may be involved in bone resorption as a response to compression force.

A new method for the 3D measurement of postoperative swelling following orthognathic surgery

Abstract: Objective: To describe a new method for measuring facial swelling following orthognathic surgery using a 3D laser scanning device. Design: Prospective clinical trial. Setting and Sample Population: University Dental Hospital, Wales College of Medicine, Biology Life and Health Sciences. Three subjects requiring bi-maxillary orthognathic surgery were recruited for the study. Experimental Variables: Laser-scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. 3D laser scans were recorded over six time periods (T1 – re-surgical scan, postoperatively: T2 – 1 day, T3 – 1 week, T4 – 1 month, T5 – 3 months and T6 – 6 months). Outcome Measure: Facial scans from different time periods were overlaid onto the baseline (T6) facial scan to determine the reduction and changes in swelling following orthognathic surgery. Results: The results showed that swelling could be accurately quantified following surgery. Furthermore, there was a significant reduction in the amount of swelling 1 month postoperatively. Furthermore, the facial morphology returned to approximately 90% of the baseline facial scan at 3 months. Conclusion: The 3D laser-scanning device and the method described was a reliable and accurate measure of facial swelling following surgery.

The effect of drugs on orthodontic tooth movement.

Abstract: Structured Abstract Authors – Krishnan V, Davidovitch Z Objective – Molecules produced in various diseased tissues, or drugs and nutrients consumed regularly by patients, can reach the mechanically stressed paradental tissues through the circulation, and interact with local target cells. The combined effect of mechanical forces and one or more of these agents may be inhibitory, additive or synergistic. The objective of this review is to outline the mechanisms of action and effects of some commonly used drugs on tissue remodeling and orthodontic tooth movement. Design – All the existing published literature on the effects of various drugs that are prescribed by orthodontists, which are consumed by patients for systemic diseases and those that are known to promote and retard the tooth movement process was obtained and subjected to thorough review process. Results – All the drugs reviewed have therapeutic effects, as well as side effects, that may influence the cells targeted by orthodontic forces. Therefore, it is imperative that the orthodontist pays close attention to the drug consumption history of each and every patient, before and during the course of orthodontic treatment. When the use of drugs is revealed, their effects and side effects on tissue systems should be explored, to determine their potential influence on the outcome of mechanotherapy. Conclusion – Drug-consumption history must be an integral part of every orthodontic diagnosis and treatment plan.

Effects of aging on RANKL and OPG levels in gingival crevicular fluid during orthodontic tooth movement

Abstract: Structured Abstract Authors – Kawasaki K, Takahashi T, Yamaguchi M, Kasai K Objectives – To compare the levels of the receptor activator of NFkB ligand (RANKL) and osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) during orthodontic tooth movement in juvenile and adult patients. Design – Fifteen juveniles and 15 adults served as subjects. GCF was collected from the distal cervical margins of the experimental and control teeth at 0, 1, 24, and 168 h after application of a retracting force. Enzyme-linked immunosorbent assay kits were used to determine RANKL and OPG levels in the GCF samples. Results – The amount of tooth movement for juveniles was larger than for adults after 168 h. Further, after 24 h RANKL levels were increased and those of OPG decreased in GCF samples from the compression side during orthodontic tooth movement in both juveniles and adults. The RANKL/OPG ratio in GCF from adult patients was lower than that in the juvenile patient samples. Conclusion – Our results suggest that the age-related decrease in amount of tooth movement may be related to a decrease in RANKL/OPG ratio in GCF during the early stages of orthodontic tooth movement.

Facial templates: a new perspective in three dimensions.

Abstract: Structured Abstract Authors – Kau CH, Zhurov A, Richmond S, Cronin A, Savio C, Mallorie C Purpose – This paper describes the use of adult facial template in gender-specific facial analysis. Subjects and Methods – Eighty adults, mean age 24.5, were selected for the study. Laser-scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. These scanned images were processed and merged to form a composite three-dimensional soft tissue reproduction of the subjects using commercially available reverse modelling software. The differences in facial morphology were measured using shell deviation colour maps. The facial template was used to compare differences between males vs. females groups and two subjects with facial disproportions. Results – The difference between the male and female facial templates was 1.28 ± 1.02 mm. The areas of greatest deviation were at the nasal, zygomatic area and lower jaw line. The results of the surface deviation maps between the templates and subjects with facial disproportion showed that the results could be applied for orthodontic diagnosis. Conclusions – The construction of the adult facial templates provides an interesting perspective into measuring changes in groups of patients and also acts as a useful template for the comparison of skeletal disproportion.

Fetal alcohol syndrome and developing craniofacial and dental structures – a review

Abstract: Structured abstract Authors – Sant'Anna LB, Tosello DO Objectives – Fetal alcohol syndrome (FAS) is a collection of signs and symptoms seen in children exposed to alcohol in the prenatal period. It is characterized mainly by a distinct pattern of craniofacial malformations, physical and mental retardation. However, with the increased incidence of FAS, there is a great variation in the clinical features of FAS. Design – Narrative review. Results – This review describes data from clinical and experimental studies, and in vitro models. Experimental studies have shown that alcohol has a direct toxic effect on the ectodermal and mesodermal cells of the developing embryo, particularly in the cells destined to give rise to dentofacial structures (i.e. cranial neural crest cells). Other effects, such as, abnormal pattern of cranial and mandibular growth and altered odontogenesis are described in detail. The exact mechanism by which alcohol induces its teratogenic effects remains still unknown. The possible mechanisms are outlined here, with an emphasis on the developing face and tooth. Possible future research directions and treatment strategies are also discussed. Conclusion – Early identification of children affected by prenatal alcohol exposure leads to interventions, services, and improved outcomes. FAS can be prevented with the elimination of alcohol consumption during pregnancy. We need to provide education, target high-risk groups, and make this issue a high priority in terms of public health.

Exclusion of coding region mutations in MSX1, PAX9 and AXIN2 in eight patients with severe oligodontia phenotype.

Abstract: Structured Abstract Authors – Gerits A, Nieminen P, De Muynck S, Carels C Purpose – This paper describes the screening of eight patients with severe oligodontia for PAX9 and AXIN2 mutations. Subjects and Methods – Anamnestic data and a panoramic radiograph were collected to study the phenotype of eight patients with oligodontia and their first-degree relatives. A blood sample was taken for a mutational screening for PAX9 and AXIN2 mutations. Results – No mutations were discovered, but a unique nucleotide change in a conserved 5′ flanking region of PAX9 was revealed. Earlier screening of the same patients for MSX1 mutations also had a negative outcome. Conclusions – Considering the discrepancy between the high incidence rate of agenesis and the relatively small number of reported causative mutations in PAX9, MSX1 and AXIN2 genes, the genetic contribution to oligodontia probably is much more heterogeneous than expected so far. Therefore negative results, like the present exclusion data, should be published more often in order to get a better appreciation of the relative contribution of these specific mutations causing oligodontia. In this context the exact number of tested probands also should be mentioned at all cases. Recent evidence of PAX9–MSX1 protein interactions in odontogenesis as well as other genes and developmental factors should receive more attention.

Maxillary incisor torque with conventional and self-ligating brackets: a prospective clinical trial.

Abstract: Structured Abstract Authors – Pandis N, Strigou S, Eliades T Objectives – To test the hypothesis that the engagement mode of wire to bracket affects the buccolingual inclination of maxillary incisors in extraction and non-extraction treatment with self-ligating and conventional brackets Design – A randomized clinical trial employing a random distribution of variables among the studied populations Setting and Sample Population – Private practice of one author A total of 105 patients followed prospectively, were divided into two groups based on the inclusion of extraction in the treatment planning These groups were further divided in two subgroups each, one receiving a self-ligating bracket and the other treated with a conventional Edgewise appliance of the same slot size and prescription Experimental Variable – Difference in the buccolingual inclination of maxillary incisors before and after treatment with the two appliances across the two treatment groups (extraction and non-extraction) Outcome Measure – Angular measurements of the Sella-Nasion and Nasion-A point to maxillary incisor axis Results – No difference was found in the mean difference of the two angles measured for the two bracket groups studied Conclusion – Self-ligating brackets seem to be equally efficient in delivering torque to maxillary incisors relative to conventional brackets in extraction and non-extraction cases

Parental craniofacial morphology in cleft lip with or without cleft palate as determined by cephalometry: a meta-analysis.

Abstract: Structured Abstract Authors – Weinberg SM, Maher BS, Marazita ML Objective – To integrate findings from previous cephalometric studies comparing the craniofacial complex of unaffected parents with cleft lip with or without cleft palate (CL/P) children to controls with no history of the disease. Design – Meta-analysis of case-control cephalometric data. Inclusion criteria – Studies were selected if the unaffected parents of children with CL/P were included and were not combined with parents of children with isolated CP; quantitative data were obtained through cephalometry; the cephalometric variables used were not unique to a study; a case-control design was used; and the means and standard deviations for all variables were reported or could be calculated for both the experimental and the control group. Outcome measure – Using raw data obtained from nine studies, mean weighted effect sizes with 95% confidence intervals were calculated for 28 cephalometric variables (mothers and fathers combined) or 18 variables (mothers and fathers separately). Heterogeneity statistics for the effect sizes were also calculated. Results – In general, unaffected parents of children with CL/P possessed significantly wider interorbital, nasal cavity and upper facial dimensions, narrower cranial vaults, longer cranial bases, longer and more protrusive mandibles, shorter upper faces and longer lower faces compared with controls. Increased width of the nasal cavity was the most robust finding. Significant effect size heterogeneity was observed in roughly half of the variables examined. Conclusion – Unaffected parents of children with CL/P are characterized by a suite of consistent, yet subtle, craniofacial differences, which could indicate an underlying genetic liability.

Influence of steroid drugs on orthodontically induced root resorption.

Abstract: Structured Abstract Authors – Verna C, Hartig LE, Kalia S, Melsen B Objectives – To investigate the effect of acute and chronic corticosteroid treatment on orthodontically induced root resorption. Design – ‘Split mouth’ design performing orthodontic tooth movement in 64, 6-month-old male rats divided into three groups: acute (n = 22), chronic (n = 23) and control group (n = 19). Acute and chronic group received corticosteroid treatment (8 mg/kg/day) for 3 and 7 weeks, respectively, while no pharmacological treatment was performed in the control group. Performed at the Department of Orthodontics, School of Dentistry, University of Aarhus, Aarhus, Denmark. Experimental variable – The upper left first molar was moved mesially for 21 days in all three groups with 25 g of force. Undecalcified histological sections were cut at the coronal and apical level. Outcome measure – The number of intersections hitting resorption lacunae (ES), defined as a scalloped surface with or without cementoclasts, over the total number of intersections hitting the root surface (RS) were recorded and expressed as percentage. Results – The acute group showed significantly more root resorption at the mesio-coronal level compared with the control and the chronic group. Conclusion – This could be ascribed to the lack of balance between blastic activities (inhibited by the drug) and the clastic activities (enhanced or unchanged by drug administration) occurring in the initial phase of drug administration. As a consequence, a careful monitoring of patients undergoing acute corticosteroid treatment is suggested.

Alkaline phosphatase activity in gingival crevicular fluid during canine retraction.

Abstract: Structured Abstract Authors – Batra P, Kharbanda OP, Duggal R, Singh N, Parkash H Objectives – The aim of the study was to investigate alkaline phosphatase activity in the gingival crevicular fluid (GCF) during orthodontic tooth movement in humans. Setting and Sample Population – Postgraduate orthodontic clinic. Ten female patients requiring all first premolar extractions were selected and treated with standard edgewise mechanotherapy. Experimental Variable – Canine retraction was done using 100 g sentalloy springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control. Outcome Measure – Gingival crevicular fluid was collected from mesial and distal of canines before initiation of canine retraction (baseline), immediately after initiation of retraction, and on 1st, 7th, 14th and 21st day and the alkaline phosphatase activity was estimated. Results – The results show significant (p < 0.05) changes in alkaline phosphatase activity on the 7th, 14th and 21st day on both mesial and distal aspects of the compared experimental and control sides. The peak in enzyme activity occurred on the 14th day of initiation of retraction followed by a significant fall in activity especially on the mesial aspect. Conclusions – The study showed that alkaline phosphatase activity could be successfully estimated in the GCF using calorimetric estimation assay kits. The enzyme activity showed variation according to the amount of tooth movement.

Cellular response to force application at craniofacial sutures.

Abstract: Objectives To provide a comprehensive review of the literature describing research done on the responses of suture cells to force application in vitro and in vivo. Design and results This review outlines the types of forces that can be applied, methods of applying the forces, the sutures used in experiments, and the changes in morphology, molecular biology (gene and protein expression), and cell biology (proliferation, differentiation, apoptosis) in response to these forces. Conclusion The molecular response of sutures to force needs to be further investigated as these molecules can be used to enhance the way in which craniofacial sutures respond to mechanical force during orthopedic-orthodontic treatment.

Growth factor effects on passaged TMJ disk cells in monolayer and pellet cultures.

Abstract: Structured Abstract Authors – Allen KD, Athanasiou KA Objectives – Previously, we demonstrated rapid changes in temporomandibular joint (TMJ) disk gene expression during monolayer expansion. This study's objective was to investigate the ability of pellet culture and growth factors to rescue TMJ disk gene expression changes. Design – Temporomandibular joint disk cells were isolated from mature porcine tissue and passaged up to five times. At each passage, 300 000 cells were placed in a monolayer or pellet culture environment before being exposed to transforming growth factor-beta 3 (TGF-β3) (5 ng/ml), TGF-β1 (5 ng/ml), and insulin-like growth factor I (IGF-I) (10 ng/ml). Outcome Measure – After 24 h, gene expression was analyzed via reverse transcriptase-polymerase chain reaction (RT-PCR). Results – Pelleting was detrimental to TMJ disk gene expression, marked by gene expression decreases in collagen type I (5.5-fold), aggrecan (1.4-fold), decorin (0.73-fold), and biglycan (0.73-fold) relative to monolayer cultures. IGF-I, TGF-β1, and TGF-β3 demonstrated limited ability to rescue TMJ disk gene expression in the pellet culture. In monolayer, TGF-β3 and TGF-β1 increased decorin and biglycan gene expression relative to passaged controls. Collagen type I expression, the TMJ disk's primary matrix constituent, was highest in TGF-β3 cultures; however, differences were not statistically significant. Conclusion – These results indicate that pellet cultures are a poor choice for TMJ disk tissue engineering, and the effects of TGF-β1, TGF-β3, and IGF-I on TMJ disk gene expression are minimal relative to passaging and pelleting effects.

A case of amelogenesis imperfecta, cleft lip and palate and polycystic kidney disease

Abstract: Structured Abstract Authors – Suda N, Kitahara Y, Ohyama K Objective – Amelogenesis imperfecta (AI) is a heterogeneous group of genetic disorders characterized by developmental abnormalities of tooth enamel. The AI is also seen as part of multi-organ abnormalities, e.g. with cone-rod dystrophy, hypothalamo-hypophyseal insufficiency and renal failure. The present patient with AI and nephrocalcinosis exhibited a phenotype different from previous cases with renal failure. To highlight the characteristics of this rare case, extensive analysis that included histological, biochemical and genetic examinations was performed. Patient – The present Japanese male patient exhibited dentition with AI and bilateral cleft lip and palate. Ground sections of his extracted tooth showed that it was hypomaturation-type AI, unlike previous cases with nephrocalcinosis were hypoplastic-type. He showed nephrocalcinosis and hematuria at 15 years of age but these symptoms appeared to be secondary to polycystic kidney disease. He showed skeletal Class II pattern with a retrognathic profile and retroclined incisors of both arches. A dolicofacial appearance was seen with an enlarged gonial angle. Biochemical makers including serum alkaline phosphatase, parathyroid hormone, calcitonin, calcium, and phosphate, were all in the normal range. Sequence analysis of the genes encoding amelogenin and enamelin, which are known to be responsible for hypoplastic-type AI, did not reveal any mutations. Since mouse null mutant of homeobox transcription factor, Msx2, exhibits a phenotype resembling AI, the human homolog of this gene, MSX2, was sequenced. There was a missense mutation of T447C that resulted in the conversion of methionine to threonine at 129.

Synchrotron radiation-based microtomography of alveolar support tissues.

Abstract: Structured Abstract Authors – Dalstra M, Cattaneo PM, Beckmann F Objectives – To study the alveolar support structures using synchrotron radiation (SR)-based microtomography with particular focus on the alveolar surface. Design – High-resolution microtomography of jaw segments of various species and subsequent three-dimensional (3D) reconstruction. Setting and Sample Population – Microtomography was performed at the DORIS-ring of the synchrotron facility of HASYLAB/DESY in Hamburg, Germany. The samples consisted of human, simian and porcine jaw segments. Results – With SR being monochromatic, no beam-hardening artifacts could occur and the grey values in the scans were therefore directly related to the local tissue densities. Apart from the mineralized tissues, the beam energy was low enough to allow for the visualization of soft tissues like the fibers of the periodontal ligament (PDL) and blood vessels. 3D reconstructions of the alveolar bone showed that it can be rough and sharply edged. Furthermore, an intricate network of marrow cavities and blood vessels penetrates its surface. Differences in the local grey value distribution in the alveolar bone pointed to remodeling activity in the close vicinity of the PDL. Conclusion – The assumption that the alveolar bone surface is smooth and continuous is not correct. This means that even small orthodontic loads can already give rise to high local stresses and strains in the bone and thus initiate remodeling processes.

Craniofacial cephalometric morphology in children with CATCH 22 syndrome

Abstract: Structured abstract Authors – Heliovaara A, Hurmerinta K Objectives – To evaluate cephalometrically the craniofacial, pharyngeal and cervical morphology in children with CATCH 22, and to compare and quantify the findings with age- and sex-matched controls. Design – A retrospective case–control study. Setting and Sample Population – Forty-one children (20 girls) with CATCH 22 were compared with age- and sex-matched controls from lateral cephalograms taken at the mean age of 8.5 years (range 5.8–12.9). The deletion of 22q11 was verified by fluorescence in situ hybridization techniques. Thirteen of the children with CATCH 22 had palatal clefts. Outcome measure – Linear and angular measurements were obtained from lateral cephalograms. A Student's t-test and a paired Student's t-test were used in the statistical analysis. Standard deviation scores (SDS) were calculated to quantify the variation. Results – Children with CATCH 22 had obtuse cranial base angles and long anterior cranial bases. Their faces were long with increased facial convexity. The maxillae were long but both jaws were retrognathic and the lower jaws posteriorly diverged. The pharynges were wide in the nasopharyngeal area and narrow in the hypopharyngeal area. The development of the hyoid bones was delayed, and hyoid bone and atlas lengths were reduced. The morphology of the children with CATCH 22 with and without a palatal cleft was similar. Despite several statistically significant differences between the children with CATCH 22 and the controls, the SDS did not exceed ±2 for any of the measurements. Conclusion – Children with CATCH 22 have several minor distinctive morphological features in the craniofacial, pharyngeal, and cervical areas.

Steiner cephalometric analysis: predicted and actual treatment outcome compared

Abstract: Structured Abstract Authors – Abdullah RTH, Kuijpers MAR, Berge SJ, Katsaros C Objective – To examine the accuracy and precision of the Steiner prediction cephalometric analysis. Setting and Subjects – The sample consisted of 275 randomly selected patients, treated between 1970 and 1995 at a university department. Methods – Lateral cephalograms before (T1) and after orthodontic treatment (T2) were analyzed using the Steiner analysis. A prediction of the final outcome at T2 for the variables ANB°, U1 to NA mm, L1 to NB mm, and Pg to NB mm was performed at T1. The difference between the actual outcome at T2 and the Steiner predicted value (SPV), which was done at T1, was calculated. Accuracy (mean difference between T2 and SPV) and precision (standard deviation of the mean prediction discrepancies) of the prediction were studied. Paired t-test was used to detect under- or overestimation of the predicted values. Results – The mean decrease in angle ANB was 1.4 ± 2.7° and for U1 to NA 2.0 ± 2.6 mm, while L1 to NB increased 0.8 ± 2.0 mm and Pg to NB 0.7 ± 1.1 mm. The predicted values for the changes in ANB angle, the distance of upper incisor U1 to NA as well as the distance Pg to NB were significantly overestimated when compared with the actual outcome, while the change in the distance of lower incisor L1 to NB was underestimated. Conclusion – The prediction of cephalometric treatment outcome as used in the Steiner analysis is not accurate enough to base orthodontic treatment decisions upon.

Morphological differences in the temporomandibular joints in asymmetrical prognathism patients.

Abstract: Structured Abstract Authors – Kawakami M, Yamamoto K, Inoue M, Kawakami T, Fujimoto M, Kirita T Objective – To investigate the morphology of the temporomandibular joints (TMJ) in skeletal asymmetry with prognathism. Design – Three-group observational clinical study. Setting and Sample Population – University setting. Thirty-five patients undergoing orthognathic surgery without signs and symptoms of TMJ disorder were assigned to three groups (right deviation, n = 11; left deviation, n = 14; and non-deviation; n = 10) based on anteroposterior cephalometric analysis. Outcome Measure – Positional and morphological differences of the TMJs were evaluated using a total of 70 bilateral sagittal TMJ magnetic resonance images. Results – In both the right and left deviation groups, the TMJ on the deviated side showed a significantly steeper eminence than that on the non-deviated side (p < 0.05). The anterior joint space was narrower on the deviated side than on the non-deviated side whereas the posterior joint space did not differ markedly, indicating an anterior position of the condyle in the glenoid fossa of the TMJ on the deviated side. Disk displacement comparisons revealed no significant differences between left and right sides in the symmetry or asymmetry group. Conclusion – Asymmetrical prognathism patients exhibit significant morphological differences between the right and left TMJs concerning the slope of the articular eminence, which correspond to facial asymmetry.

Application of magnetic resonance imaging movie to assess articulatory movement.

Abstract: Structured Abstract Authors – Inoue MS, Ono T, Honda E, Kurabayashi T, Ohyama K Objective – To introduce the technique of magnetic resonance imaging (MRI) movie and to propose its feasibility for investigating articulatory movement. Subjects – Five healthy adult females participated in the study. Methods – Dynamic changes in oropharyngeal structures were assessed with MRI movie during the articulation of a bilabial consonant. Results – Movements of the velum and tongue at a time resolution of 30 ms were complex at the tip of the tongue and the anterior part of the velum. These movements that were seen with a time resolution of 30 ms could not be interpolated or in any way derived from the results obtained with a time resolution of 120 ms. Conclusion – The results suggest that MRI movie may be useful in the evaluation of articulation. It is important to reduce the time resolution to 30 ms to obtain images of articulators.

Cephalometric evaluation of condylar and mandibular growth modification: a review.

Abstract: Structured Abstract Authors – Shen G, Darendeliler MA Objective – Based on a wealth of orthodontic archives, this work aims to review the cephalometric analysis systems that can identify the changes in condylar and mandibular position as well as growth direction in response to bite jumping therapy. Design – Numerous cephalometric approaches were screened to testify their feasibility and reliability in accurately depicting the growth modification of the condyle and the mandible. The critical assessment of the working mechanisms of these cephalometric methods was elaborated to help build up the rationale and justification for their clinical use. Results – 1) The changes in condylar and mandibular size, position and growth direction can be identified by using lateral cephalograms with closed-mouth or open-mouth posture. 2) With superimposition methods where the anatomical structures for superimposition registration must be stable and reproducible, the growth modification of the condyle and the mandible between two time-points is qualitatively demonstrated in a diagram if reference lines are not constructed. The growth modification can be quantitatively identified if the reference lines are created. 3) With non-superimposition methods, the size and position of the condyle and the mandible are separately identified for each time-pint by relating them to the stable reference structures. The growth modification between two time-pints is evaluated by comparing the two separate measurements. Conclusion – The application of a standardized and well designed cephalometric evaluation system may reduce the bias that attribute to the arbitrariness of the clinical effects of bite jumping functional appliances.

Microdontia after chemotherapy in a child treated for neuroblastoma

Abstract: OBJECTIVE: Chemotherapy used on paediatric oncology patients often causes disturbances in dental development. Aim of this case report is to present the late effects of chemotherapy on dental development in a patient treated for neuroblastoma at early age. DESIGN: Case report. RESULTS: This paper presents a female patient treated at early age with surgery and chemotherapy for a neuroblastoma (stage IVS) in the right thorax and massive liver metastases. The examination of the patient at age 11.7 years showed microdontia of six teeth. In three of them size and form of the crown were affected, while in the other three the size was reduced but the form was not affected. CONCLUSIONS: Chemotherapy on children treated for neuroblastoma can adversely influence tooth development. This has to be taken into consideration by the dentist when monitoring the development of the dentition and occlusion.

Molecular fingerprinting of BMP2- and BMP4-treated embryonic maxillary mesenchymal cells.

Abstract: Structured Abstract Authors – Mukhopadhyay P, Singh S, Greene RM, Pisano MM Objective – To determine the differences in gene expression between control-, bone morphogenetic protein (BMP)2- and BMP4-treated murine embryonic maxillary mesenchymal (MEMM) cells. Design – Transcript profiles of BMP2-, BMP4- and vehicle-treated MEMM cells were compared utilizing the murine high-density GeneChip arrays from Affymetrix. The raw chip data (probe intensities) were pre-processed using robust multichip averaging with GC-content background correction and further normalized with GeneSpring v7.2 software. Cluster analysis of the microarray data was performed with the GeneSpring software. Changes in the gene expression were verified by TaqMan quantitative real-time PCR. Results – Expression of ∼50% of the 45 101 genes and expressed sequence tags examined in this study were detected in BMP2-, BMP4- and vehicle-treated MEMM cells and that of several hundred genes was significantly altered (up or downregulated) in these cells in response to BMP2 and BMP4. Expression profiles of each of the 26 mRNAs tested by TaqMan quantitative real-time PCR were found to be consistent with the microarray data. Genes whose expression was modulated following BMP2 or BMP4 treatment, could be broadly classified based on the functions of the encoded proteins such as the growth factors and signaling molecules, transcription factors, and proteins involved in epithelial–mesenchymal interactions, extracellular matrix synthesis, cell adhesion, proliferation, differentiation, and apoptosis. Conclusion – Utilization of the Affymetrix GeneChip microarray technology has enabled us to delineate a detailed transcriptional map of BMP2 and BMP4 responsiveness in embryonic maxillary mesenchymal cells and offers revealing insights into crucial molecular regulatory mechanisms employed by these two growth factors in orchestrating embryonic orofacial cellular responses.

Osteoglophonic dysplasia: dental and orthodontic implications.

Abstract: Structured Abstract Authors – Roberts TS, Stephen L, Beighton P Aims and Objectives – Documentation of dental and orthodontic implications of osteoglophonic dysplasia (OGD). Settings and Participants – Case report describing oral and dental manifestations of a female with OGD, aged 39 years, who was first documented three decades ago. Results – This rare genetic disorder manifests with gross stunting of stature, associated with severe craniofacial malformation and multiple unerupted teeth. Radiographically, multiple lucent lesions were present in the tubular bones and mandible as well as several impacted teeth. Conclusion – We concluded that prosthetic dental replacement in this patient would be difficult because of the distorted jaw relationship and large alveolar ridges. Equally, craniofacial reconstruction might be compromised by obstruction of the nasal airways, difficulty in intubation and postoperative respiratory problems.

Correlation of Hsp110 expression with caspase-3 and -9 during apoptosis induced by in vivo embryonic exposition to retinoic acid or irradiation in early mouse craniofacial development.

Abstract: Structured Abstract Authors – Gashegu J, Vanmuylder N, Philippson C, Choa-Duterre M, Rooze M, Louryan S Objective – To analyze the expression and role of three proteins (HSP110, caspase-3 and caspase-9) during craniofacial development. Design – Seven pregnant C57Bl/6J mice received, by force-feeding at gestation day 9 (E9), 80 mg/kg of all-trans retinoic acid mixed to sesame oil. Seven pregnant NMRI mice received two grays irradiation at the same gestation day. Control mice of both strains (seven mice for each strain) were not submitted to any treatment. Embryos were obtained at various stages after exposition (3, 6, 12 and 24 h), fixed, dehydrated and embedded. Coronal sections (5 μm) were made. Slide staining occurred alternatively using anti-Hsp110, anti-caspase-3 and anti-caspase-9 immunohistochemistry. Results – Expression of HSP110, caspase-3 and caspase-9 was found in cells of well-known locations of programmed cell death. After retinoic acid exposure, expressions were increased especially in neural crest cells of mandibular and hyoid arches. Quantification of positive cells shows that caspase-9 and Hsp110 were expressed before caspase-3. After irradiation, the expression of the three proteins quickly increased with a maximum 3 h after irradiation. For all three models of apoptosis (physiological, retinoic-induced and irradiation-induced) HSP110 positive cells were more numerous than caspase-3 positive cells. Caspase-3 positive cells were more numerous than caspase-9 positive cells especially in mesectodermal irradiation-induced apoptotic cells. Conclusion – The findings show a potential function of HSP110 in apoptosis during embryo development. Caspase-3-expressing cells are more numerous than cells expressing caspase-9, especially irradiation-induced apoptotic neural crest cells. This suggests that other caspases, still to be identified, may activate caspase-3 in this model.

CD 95 mediated apoptosis in embryogenesis: implication in tooth development

Abstract: Structured abstract Authors – Matalova E, Setkova J, Blackburn J, Misek I, Sharpe PT Introduction – Understanding of apoptotic mechanisms involved in tissue shaping is of particular interest because of possible targeted modulation of the development of organ structures such as teeth. Research of CD 95 mediated apoptosis has been focused particularly on cell death in the immune system and related disorders. However, CD 95 mediated apoptosis is also involved in embryogenesis of many organs as the kidney, the lung, the intestine and tissue networks such as the nervous system. Design – Narrative review. Results – This review briefly summarizes the current knowledge of CD 95 mediated apoptosis in embryogenesis with possible implication in tooth development. CD 95 receptor and CD 95 ligand are found at early stages of tooth development. The data suggest some positive correlations with dental apoptosis distribution, particularly in the primary enamel knot where apoptosis occurs during elimination of this structure. CD 95 deficient (lpr) adult mouse tooth phenotype, however, did not show any alterations in final tooth pattern and morphology. Conclusion – To date studies of apoptotic machinery during tooth development show spatial localization of many of the components together with precise and localized timing of cell death. There is still much to be learned about the regulation and importance of apoptosis in tooth development. Nevertheless, the involvement of apoptotic regulatory mechanisms interplaying with other molecules participates to the cellular cross-talk in developing tissues, which opens possible targeted modulations as suggested, e.g. for future molecular dentistry.