Virtual reality training compared with apprenticeship training in laparoscopic surgery: a meta-analysis.

INTRODUCTION: Since its inception, laparoscopic surgery has evolved and new techniques have been developed due to technological advances. This requires a different and more complex skill set in comparison with open surgery. Reduced working hours, less training time and patient safety factors demand that such skills need to be achieved outside the operating theatre environment. Several studies have been published and have determined the effectiveness of virtual reality training. We aimed to compare virtual reality training with the traditional apprenticeship method of training and determine whether it can supplement or replace the traditional apprenticeship model. We also aimed to perform a meta-analysis of the literature and develop conclusions with respect to the benefits achieved by adding virtual reality training on a regular basis to surgical training programmes. METHODS: A literature search was carried out on PubMed, MEDLINE, EMBASE and Google Scholar academic search engines using the MESH terms 'randomised controlled trials', 'virtual reality', 'laparoscopy', 'surgical education' and 'surgical training'. All randomised controlled trials published to January 2018 comparing virtual reality training to apprenticeship training were included. Data were collected on improved dexterity, operative performance and operating times. Each outcome was calculated with 95% confidence intervals and with intention-to-treat analysis; 24 randomised controlled trials were analysed. FINDINGS: Meta-analytical data were extracted for time, path length, instrument handling, tissue handling, error scores and objective structure assessment of technical skills scoring. There was significant improvement in individual trainee skill in all meta-analyses (p < 0.0002). CONCLUSION: This meta-analysis shows that virtual reality not only improves efficiency in the trainee's surgical practice but also improves quality with reduced error rates and improved tissue handling.

Evaluation of effectiveness of photobiostimulation in alleviating side effects after dental implant surgery. A randomized clinical trial

BACKGROUND: To assess if photobiostimulation (PBS) alleviates pain intensity/duration and swelling after implant surgery. MATERIAL AND METHODS: Sixty subjects (27 male and 33 female, with a mean age of 47,13 8.05 years) were included and randomly assigned to experimental group (implant surgery and photobiostimulation), placebo group (implant surgery and simulated photobiostimulation) and control group (implant surgery only). INCLUSION CRITERIA: subjects older than 20 years, with a healthy oral mucosa and requiring implant surgery. EXCLUSION CRITERIA: pregnancy, history of implant failure, light sensitivity, metabolic deseases, consumption of antibiotics or corticosteroids in the last two weeks, smokers and alcohol drinkers. Patients reported the pain experienced by using a numeric rating scale (NRS) at 2 hours, 6 hours, 12 hours, 24 hours and from day 2 to 7. Swelling score was assessed by linear measurements and type and number of analgesic drugs within each time-point were recorded on a spreadsheet. Data of pain and amount of swelling were compared among the three groups by using the Kruskal-Wallis H Test and post-hoc comparisons tests. RESULTS: Pain in the experimental group was less compared to controls and placebo group, at each time intervals (p < 0.001) as well as the maximum pain score (experimental group: median = 2, interquartile range 2-3; control group: median = 8, interquartile range 3,75-9; placebo group: median = 8, interquartile range 6,25-9). Swelling was almost insignificant in the experimental group (maximum value = 1, interquartile range 0-2,75, at 24 hours) compared with control (maximum value = 6, interquartile range 5-8,75, at 24 hours) and placebo (maximum value = 6, interquartile range 5-8, at 24 hours). Subjects in the experimental group assumed less analgesics compared to both controls and placebo groups. CONCLUSIONS: Photobiostimulation is an effective method to reduce pain intensity/duration and swelling after implant surgery

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Evaluation of effectiveness of photobiostimulation in alleviating side effects after dental implant surgery. A randomized clinical trial.

BACKGROUND: To assess if photobiostimulation (PBS) alleviates pain intensity/duration and swelling after implant surgery. MATERIAL AND METHODS: Sixty subjects (27 male and 33 female, with a mean age of 47,13 8.05 years) were included and randomly assigned to experimental group (implant surgery and photobiostimulation), placebo group (implant surgery and simulated photobiostimulation) and control group (implant surgery only). INCLUSION CRITERIA: subjects older than 20 years, with a healthy oral mucosa and requiring implant surgery. EXCLUSION CRITERIA: pregnancy, history of implant failure, light sensitivity, metabolic deseases, consumption of antibiotics or corticosteroids in the last two weeks, smokers and alcohol drinkers. Patients reported the pain experienced by using a numeric rating scale (NRS) at 2 hours, 6 hours, 12 hours, 24 hours and from day 2 to 7. Swelling score was assessed by linear measurements and type and number of analgesic drugs within each time-point were recorded on a spreadsheet. Data of pain and amount of swelling were compared among the three groups by using the Kruskal-Wallis H Test and post-hoc comparisons tests. RESULTS: Pain in the experimental group was less compared to controls and placebo group, at each time intervals (p < 0.001) as well as the maximum pain score (experimental group: median = 2, interquartile range 2-3; control group: median = 8, interquartile range 3,75-9; placebo group: median = 8, interquartile range 6,25-9). Swelling was almost insignificant in the experimental group (maximum value = 1, interquartile range 0-2,75, at 24 hours) compared with control (maximum value = 6, interquartile range 5-8,75, at 24 hours) and placebo (maximum value = 6, interquartile range 5-8, at 24 hours). Subjects in the experimental group assumed less analgesics compared to both controls and placebo groups. CONCLUSIONS: Photobiostimulation is an effective method to reduce pain intensity/duration and swelling after implant surgery.

Guidelines for achieving the best implants survival rates in the rehabilitation of the atrophic posterior maxilla.

The first option in the rehabilitation of the posterior atrophic maxilla is the sinus lift. The aim of this study is to highlight the characteristics that a sinus lift should have to maximize the subsequent implant survival rate. 33 systematic reviews regarding sinus lift procedures, implants success and survival rates were identified through scientific archives and analysed. The obtained results indicated that a heterogeneity of sinus lift procedures are described in the literature. The sinus lift should be performed through the apposition of particulate xenograft materials, in at least 4mm residual bone. Implants should have a rough surface and the patient should be non-smoker.

An overview of socket preservation.

Socket preservation is a surgical procedure whose aim is to limit the physiological resorption of the alveolar ridge that occurs after a dental extraction, in order to have sufficient bone to perform an implant placement. 16 articles regarding socket preservation procedures were identified through scientific archives and analysed. The biological rationale, the graft materials and the predictive factors are identified to help the clinicians in their practice. Socket preservation is an effective treatment to prevent bone resorption if performed after an atraumatic extraction with the use of biomaterials and membranes. It is also important not to forget local and systemic predictive factors.

No Compliance Correction of Class II Malocclusion in Growing Patients Whit HERBST Appliance: A Case Report.

BACKGROUND: Class II malocclusion is the most common sagittal skeletal discrepancy, with a prevalent skeletal pattern of mandibular retrusion. The correction of mandibular retrusion with functional removable appliance needs a good patient's compliance; for this reason, some clinicians prefer to use no compliance apparatus. OBJECTIVE: Objective of the present therapy note is to demonstrate that the use of no compliance apparatus can provide a good correction of skeletal class II malocclusion. METHODS: In the present study, authors report a therapy note referred to a 10 years old patient, woman, affected by Class II, with mandibular retrusion and deep bite, treated in 2013 at the Dep. of Orthodontics of Messina University. An orthodontic treatment has been planned with the aim of stimulating mandibular growth; an Herbst appliance with a cantilever design, bonded on first maxillary and mandibular molars, has been used. After eleven months of functional therapy a bilateral molar class I have been obtained. RESULTS: In the therapy note proposed, authors obtained a resolution of mandibular retrusion, a correction of overjet, overbite and dental crowding in both arches, and a bilateral molar and canine class I has been achieved. CONCLUSION: Herbst appliance seems to be efficient in the correction of II Class Malocclusion, independently from patient's cooperation; moreover , early correction of Class II malocclusion with functional appliances produces several clinical advantages.

Effect of dental care on the oral health of Sjögren’s syndrome patients.

Sjögren’s syndrome (SS) is a chronic, systemic autoimmune disease affecting the exocrine glands, particularly the salivary and lacrimal glands. Xerostomia is a major feature of this syndrome and greatly affects patient quality of life. The most typical clinical signs associated with hyposalivation are dysgeusia and dysosmia, dental caries, candidiasis, periodontal disease, gland inflammation, mucositis and oral ulcers. The aims are to investigate on Plaque Index (PI) and Gingival Index (GI) before and after dental care of SS patients. Fifty-two consecutive patients (mean age 48.9±2 years) were analysed. At T0, (baseline) T1 (3 months after T0) and T2 (6 months after T0), a Plaque Index and a Gingival Index were calculated. The statistical analysis was performed using one-way ANOVA test. If distribution was not normal, Friedman test was chosen instead of ANOVA. Dunn’s multiple comparison procedure was performed as post-hoc (IBM SPSS Statistics 21 software). A statistically significant decrease was observed both in PI and in GI between T0 and T1, T1 and T2, T0 and T2 (P less than 0.05).

Standard and low-dose cone beam computer tomography protocol for orthognatodontic diagnosis: a comparative evaluation.

Considering the diagnostic capability offered by cone-beam computed tomography (CBCT), nowadays orthodontists often use this exam for treatment planning, especially in cases of impacted teeth, maxillary ipoplasia, orthognathic surgery etc. The aim of this study was to compare the radiation doses related to a conventional CBCT setting and that of a low dose protocol, usable in orthodontic practice. The absorbed organ doses were measured using an anthropomorphic phantom loaded with thermo-luminescent dosimeters related to sensitive organs (brain, bone marrow, salivary glands, thyroid, esophagus, oral mucosa, extrathoracic airways, lymph nodes). The device used was a MyRay Hyperion X9-11x5. The standard setting of the apparatus was 90 Kv, 36 mAs, CTDI/Vol 4.09 mGy, instead the low dose one was 90 Kv, 27 mAs, CTDI/Vol 2.89 mGy. Equivalent and effective doses have been calculated; the measurement of the effective doses was based on the ICRP recommendations. For the assessment of image quality, five readers, independent and experienced orthodontists, were asked to state if the images were sufficient enough to perform an orthodontic diagnosis. The lowest organ dose (5.01 microSv) was received by the esophagus during low dose CBCT acquisition. The highest mean organ dose instead (1227.67 microSv) was received by the salivary glands during conventional setting CBCT acquisition. Image quality has been considered sufficient for orthodontic diagnostic needs for both CBCT protocols. CBCT low dose setting should be preferred over the standard one in orthodontic practice, because it provides a significant lower radiation dose to the patients ensuring a good image quality. However, further studies are necessary to evaluate the opportunity of CBCT exams in orthodontic treatment planning.

Is static friction affected by aging and amount of elastomeric ligatures in orthodontic sliding mechanics? An in-vitro investigation.

In straight-wire mechanics, friction can significantly influence the forces expressed by wires. The aim of this study is to assess whether the aging and the sum of elastomeric ligatures affect the static friction during orthodontic space closure. A 0.017x 0.025-in SS was drawn throughout a 3-bracket experimental model and engaged with elastomeric ligatures. Before performing the test, the ligatures were soaked in artificial saliva for 48 hours (Group 1), 2 weeks (Group 2) and 4 weeks (Group 3); brand-new ligatures were also tested as control group (Group 4). The resistance to sliding (RS) was recorded at 3 different numerical configurations of ligatures using a customized testing machine and tests were repeated for ten times. Data of RS were statistically analysed by using two way analysis of variance (ANOVA) and Tukey's multiple comparison tests. RS was found to increase systematically when more elastomeric ligatures were included in the wire engaging system. At two weeks of immersion in artificial saliva elastomeric ligatures showed the lowest values of RS while they became significantly more frictional after immersion for 4 weeks. The results of this study showed that in multi-bracket orthodontic therapy, the RS increases with the number of elastomeric ligatures involved for arch-wire engagement. Differently from the frictional behavior of elastomeric modules, the aging of these ligatures does not influence their incremental effect of frictional forces.

Airway and peripheral urokinase plasminogen activator receptor is elevated in asthma, and identifies a severe, nonatopic subset of patients.

RATIONALE: Genetic polymorphisms in the asthma susceptibility gene, urokinase plasminogen activator receptor (uPAR/PLAUR) have been associated with lung function decline and uPAR blood levels in asthma subjects. Preliminary studies have identified uPAR elevation in asthma; however, a definitive study regarding which clinical features of asthma uPAR may be driving is currently lacking. OBJECTIVES: We aimed to comprehensively determine the uPAR expression profile in asthma and control subjects utilizing bronchial biopsies and serum, and to relate uPAR expression to asthma clinical features. METHODS: uPAR levels were determined in control (n = 9) and asthmatic (n = 27) bronchial biopsies using immunohistochemistry, with a semi-quantitative score defining intensity in multiple cell types. Soluble-cleaved (sc) uPAR levels were determined in serum through ELISA in UK (cases n = 129; controls n = 39) and Dutch (cases n = 514; controls n = 96) cohorts. MEASUREMENTS AND MAIN RESULTS: In bronchial tissue, uPAR was elevated in inflammatory cells in the lamina propria (P = 0.0019), bronchial epithelial (P = 0.0002) and airway smooth muscle cells (P = 0.0352) of patients with asthma, with uPAR levels correlated between the cell types. No correlation with disease severity or asthma clinical features was identified. scuPAR serum levels were elevated in patients with asthma (1.5-fold; P = 0.0008), and we identified an association between high uPAR serum levels and severe, nonatopic disease. CONCLUSIONS: This study provides novel data that elevated airway and blood uPAR is a feature of asthma and that blood uPAR is particularly related to severe, nonatopic asthma. The findings warrant further investigation and may provide a therapeutic opportunity for this refractory population.

Effects of rapid vs slow maxillary expansion on nasal cavity dimensions in growing subjects: a methodological and reproducibility study.

AIM: To evaluate the methodological feasibility of a RCT comparing skeletal changes of nasal cavity size obtained with RME and SME, assessed via CBCT. MATERIALS AND METHODS: Twenty Caucasian children with a mean age of 10.4 years were recruited and allocated to receive RME (10 subjects, mean age 10.4 years) or SME (10 subjects, mean age 10.5 years). INCLUSION CRITERIA: constricted maxillary arch, upper and lower first molars erupted, unilateral or bilateral posterior crossbite. EXCLUSION CRITERIA: age above 15 years, history of previous orthodontic treatment, periodontal disease, systemic disease affecting craniofacial growth, or craniofacial congenital syndrome. CBCT examinations were performed before treatment (T0) and 7 months after expander removal (T1). Changes of nasal width (NW), palatal width (PW) and total nasal volume (TNV) were assessed; palatal and nasal expansion was also calculated as a percentage of the increase of intermolar width IMW (PW% and NW%). RESULTS: The correlation between the first and the second readings ranged from 0.991 to 0.995 for linear measurements and was of 0.915 for volumetric measurements. The method error, as described by the value of ?, was in general less than 0.3 mm for linear measurements and 0.372 cm³ for volumetric measurements. All linear transverse skeletal and dental measurements and the nasal volume increased with both RME and SME protocols. CONCLUSION: The reported methodology can be reasonably used to investigate the transverse dimension of nasal cavity. The PW% and NW% parameters more accurately described the efficacy of the two expansion protocols as compared to their corresponding absolute measurement (PW and NW).

Unilateral condylar hyperplasia: diagnosis, clinical aspects and operative treatment. A case report.

BACKGROUND: Condylar hyperplasia of the mandible is an uncommon idiopathic disorder of the jaw characterised by increased volume of the condyle, unilaterally or bilaterally, leading to facial asymmetry, mandibular deviation, malocclusion and articular dysfunction. CASE REPORT: The authors present one case of unilateral condylar hyperplasia of a 16-year-old patient affected by severe facial asymmetry. Conventional X-rays examinations, multislice spiral CT and bone SPECT were used for the final diagnosis of primary condyle hyperplasia. The patient was treated with a combined orthodontic and surgical approach. CONCLUSION: Treatment of condylar hyperplasia with a combined orthodontic and surgical approach including condylectomy yield good aesthetic and functional outcomes.

Genetic risk factors for the development of allergic disease identified by genome-wide association.

An increasing proportion of the worldwide population is affected by allergic diseases such as allergic rhinitis (AR), atopic dermatitis (AD) and allergic asthma and improved treatment options are needed particularly for severe, refractory disease. Allergic diseases are complex and development involves both environmental and genetic factors. Although the existence of a genetic component for allergy was first described almost 100 years ago, progress in gene identification has been hindered by lack of high throughput technologies to investigate genetic variation in large numbers of subjects. The development of Genome-Wide Association Studies (GWAS), a hypothesis-free method of interrogating large numbers of common variants spanning the entire genome in disease and non-disease subjects has revolutionised our understanding of the genetics of allergic disease. Susceptibility genes for asthma, AR and AD have now been identified with confidence, suggesting there are common and distinct genetic loci associated with these diseases, providing novel insights into potential disease pathways and mechanisms. Genes involved in both adaptive and innate immune mechanisms have been identified, notably including multiple genes involved in epithelial function/secretion, suggesting that the airway epithelium may be particularly important in asthma. Interestingly, concordance/discordance between the genetic factors driving allergic traits such as IgE levels and disease states such as asthma have further supported the accumulating evidence for heterogeneity in these diseases. While GWAS have been useful and continue to identify novel genes for allergic diseases through increased sample sizes and phenotype refinement, future approaches will integrate analyses of rare variants, epigenetic mechanisms and eQTL approaches, leading to greater insight into the genetic basis of these diseases. Gene identification will improve our understanding of disease mechanisms and generate potential therapeutic opportunities.

Temporomandibular joint involvement in a cohort of patients with Juvenile Idiopatic Arthritis and evaluation of the effect induced by functional orthodontic appliance: clinical and radiographic investigation.

AIM: The aim of the study was to assess possible correlations between the clinical parameters of temporomandibular joint (TMJ) arthritis and pathologic MRI findings of the TMJ in patients affected by juvenile idiopathic arthritis (JIA), and the effect of a functional orthodontic therapy on the evolution of TMJ disorders. MATERIALS AND METHODS: A prospective clinical and nuclear magnetic resonance (NMR) investigation was conducted on a sample of 53 patients (41 female, 12 male) with JIA, treated for 24 months with an Andresen appliance. The involvement of TMJ was defined by clinical and radiological signs. NMR assessments were performed in closed and maximum opening mouth position before (T0) and at the end of functional orthodontic therapy (T1). RESULTS: Fifteen patients showed physical and radiologic TMJ abnormalities. Changes were not uniformly distributed among the different JIA subtypes. Patients with poliarticular JIA (≥5 peripheral joints affected) showed more destructive bony changes. No correlation existed between clinical symptoms and NMR alterations. Approximately one half of the patients experienced significant improvement of the TMJ and muscular pain using the Andresen appliance. CONCLUSION: The prevalence of TMJ involvement in patients suffering of JIA, and the improvement of TMJ and muscular pain associated with the use of functional appliance found in the present study, suggest an alert for TMJ dysfunction in patients with JIA and demonstrate the utility of functional orthodontic therapy in preventing the morbidities associated with TMJ arthritis in JIA.

Primary enamel permeability: a SEM evaluation in vivo.

AIM: The aim of this study was to evaluate in vivo the occurrence of outward fluid flow on primary tooth sound enamel surface. MATERIALS AND METHODS: Sixty primary upper canines from preadolescent patients (mean age 8.0±1.9) and 24 retained primary upper canines from adult subjects (mean age 35.0±1.8) were analysed. The enamel surface was gently polished and air dried for 10 s. An impression was immediately obtained by vinyl polyxiloxane. Replicas were then obtained by polyether impression material, gold coated and inspected under SEM. The hydrophobic vinyl polyxiloxane material enabled to obtain in situ a morphological image of the presence of droplets, most likely resulting from outward fluids flow through outer enamel. For each sample three different representative areas of 5µ² in the cervical, medium and incisal third were examined and droplets presence values was recorded. All data were analysed by by Fisher's exact test. RESULTS: Primary enamel showed a substantial permeability expressed as droplets discharge on its surface. Droplets distribution covered, without any specific localisation, the entire enamel surface in all the samples. No signs of post-eruptive maturation with changes in droplets distribution were observed in samples from adult subjects. No statistically significant differences (P = 0.955) were noted in the percentage distribution of enamel area covered with droplets among the two group studied. CONCLUSION: SEM evaluation of droplets distribution on enamel surface indicated a substantial enamel permeability in primary teeth, accordingly with histological features, without changes during aging. A relationship between enamel permeability, caries susceptibility and bonding procedures effectiveness could be hypothesised.

Transverse changes determined by rapid and slow maxillary expansion--a low-dose CT-based randomized controlled trial.

OBJECTIVES: To compare transverse skeletal changes produced by rapid (RME) and slow (SME) maxillary expansion using low-dose computed tomography. The null hypothesis was that SME and RME are equally effective in producing skeletal maxillary expansion in patients with posterior crossbite. SETTING AND SAMPLE POPULATION: This study was carried out at the Department of Oral Sciences, University of Naples Federico II, Italy. Twelve patients (seven males, five females, mean age ± SD: 10.3 ± 2.5 years) were allocated to the SME group and 14 patients (six males, eight females, mean age ± SD: 9.7 ± 1.5 years) to the RME group. MATERIALS AND METHODS: All patients received a two-band palatal expander and were randomly allocated to either RME or SME. Low-dose computed tomography was used to identify skeletal and dental landmarks and to measure transverse maxillary changes with treatment. RESULTS: A significant increase in skeletal transverse diameters was found in both SME and RME groups (anterior expansion = 2.2 ± 1.4 mm, posterior expansion = 2.2 ± 0.9 mm, pterygoid expansion = 0.9 ± 0.8 mm). No significant differences were found between groups at anterior (SME = 1.9 ± 1.3 mm; RME = 2.5 ± 1.5 mm) or posterior (SME = 1.9 ± 1.0 mm; RME = 2.4 ± 0.9 mm) locations, while a statistically significant difference was measured at the pterygoid processes (SME = 0.6 ± 0.6 mm; RME = 1.2 ± 0.9 mm, p = 0.04), which was not clinically relevant. CONCLUSION: Rapid maxillary expansion is not more effective than SME in expanding the maxilla in patients with posterior crossbite.

A proportional correlation index for space analysis in mixed dentition derived from an Italian population sample.

AIM: The aim of this study was to establish a specific proportional correlation method for space analysis in mixed dentition applicable to the Italian population. MATERIALS AND METHODS: A retrospective analysis was performed on 300 plaster models taken from Italian subjects, 156 females and 144 males, aged between 12 and 25 years, visited at the Department of Orthodontic and Paediatric Dentistry of the University of Messina. RESULTS: The variance analysis (ANOVA) showed a high correlation between the dimension of the mesio-distal diameters of the four mandibular incisor and those of the upper canine and premolars. The correlation coefficient showed the existence of a directly proportional, positive intra- dependence between the two groups. DISCUSSION: The correlation tables used in the present study appear to be much more accurate if applied to groups of patients with similar ethnic backgrounds, thus explaining the differences between the various prediction indexes found in previous publications. CONCLUSION: This study highlights the need to develop specific values to fit the features of the different ethnic groups.

Endometrial seedlings. A survival instinct? Immunomodulation and its role in the pathophysiology of endometriosis.

Endometriosis occurs when ectopic cells from the endometrium implant within the peritoneum. It is considered as a disease of multifactorial aetiology and affects 7-10% of women of reproductive age worldwide. In endometriosis, the immune system is thought to be dysfunctional and various studies have shown cytokine imbalance. Commonly upregulated cytokines include Tumour necrosis factor-alpha, interferon gamma and interleukin-10. Through analysis of the molecular makeup of the peritoneal fluid, a change is shown to occur, conferring resistance from macrophages and lymphocytes to endometrial cells. This is possibly due to a reduced Inter-cellular adhesion molecule-1 synthesis. Survival of ectopic endometrial cells also arises through the expression of human leukocyte antigens. Apart from the survival of ectopic/eutopic cells in endometriosis, there is marked cellular proliferation, which has also been attributed to a change in the expression of proteins such as Bcl-2-Associated X protein, B-cell lymphoma-2 protein, transforming growth factor-beta and the enzyme aromatase. Danazol and aromatase inhibitors modulate the immune system, thus allowing partial restoration of cytokine levels. Pharmacogenomics may be the way forward in developing novel treatment modalities for endometriosis.

Genetic basis of non syndromic hypodontia: a DNA investigation performed on three couples of monozygotic twins about PAX9 mutation.

INTRODUCTION: Hypodontia, agenesis of one or of more teeth, is a common developmental dental anomaly. To date, over 200 candidate genes have been demonstrated to be active in tooth development. The genes Pax9 plays an important role in the initial stage of odontogenesis. Mutations of Pax9 are associated with autosomal dominant forms of oligodontia, the agenesis of more than six teeth and occasionally of premolars (MIM 604625) in humans. The aim of the present study was to screen the candidate gene causing the non syndromic hypodontia, with agenesis of upper third molars and upper lateral incisors, in three couples of twins. MATERIALS AND METHODS: Peripheral blood samples taken for routine laboratory investigations were used for genotyping. Total genomic DNA was extracted from the buffy coat of 1 ml of EDTA blood samples using phenol-chloroform and the salting out procedure. RESULTS: The insC mutation (nt793, exon4) was observed in the sequencing results by the use of the primers hPAX9ex4F and hPAX9ex4R. InsC raises a frameshift mutation that introduces a nonsense codon so the mRNA activity results impaired. CONCLUSION: In this work, it is described how the same mutation is responsible for a form of dental agenesis--less severe in the number of missing teeth--leading to hypodontia instead of oligodontia. Therefore, it is possible that mutations of the same gene cause different phenotypes; so we can presume that some modifier genes moderate the effect of the first mutation.

Myotonic dystrophy and craniofacial morphology: clinical and instrumental study.

AIM: The aim of this study is to assess if, and to what extent, myotonic dystrophy can affect the craniofacial growth pattern. MATERIALS AND METHODS: The research was conducted on a sample of 27 patients with Steinert's myotonic dystrophy (study group). Each subject underwent a clinical examination with impression-taking and intra- and extraoral photographs. A latero-lateral projection teleradiography in the mirror position was also taken and a cephalometric examination was performed. The assessed values were compared with those obtained from a group of healthy subjects (control group). RESULTS: Statistical analysis of the data obtained from the myotonic patients who developed the disease during the growth phase revealed alterations in the transversal plane and, to an even greater extent, the vertical one, with a high frequency of anterior open bite. Discussion and conclusions Regarding the pathogenesis of these types of skeletal dysplasias, the authors hypothesise a posterior rotation growth pattern, resulting from gravitational force prevailing over the deficit of the elevator muscles.