Reverse scan technique: A verification method for the implant position in intraoral scans.

This article describes a fully digital method of verifying and increasing the accuracy of the position of implants in extensive prosthetic restorations. This cost-effective, timesaving, and versatile procedure uses a laboratory scanner, a scannable implant analog, and a printed interim implant-supported prosthesis to refine the virtual definitive cast.

Amelogenesis imperfecta: Next-generation sequencing sheds light on Witkop's classification.

Amelogenesis imperfecta (AI) is a heterogeneous group of genetic rare diseases disrupting enamel development (Smith et al., Front Physiol, 2017a, 8, 333). The clinical enamel phenotypes can be described as hypoplastic, hypomineralized or hypomature and serve as a basis, together with the mode of inheritance, to Witkop's classification (Witkop, J Oral Pathol, 1988, 17, 547-553). AI can be described in isolation or associated with others symptoms in syndromes. Its occurrence was estimated to range from 1/700 to 1/14,000. More than 70 genes have currently been identified as causative. Objectives: We analyzed using next-generation sequencing (NGS) a heterogeneous cohort of AI patients in order to determine the molecular etiology of AI and to improve diagnosis and disease management. Methods: Individuals presenting with so called "isolated" or syndromic AI were enrolled and examined at the Reference Centre for Rare Oral and Dental Diseases (O-Rares) using D4/phenodent protocol (www.phenodent.org). Families gave written informed consents for both phenotyping and molecular analysis and diagnosis using a dedicated NGS panel named GenoDENT. This panel explores currently simultaneously 567 genes. The study is registered under NCT01746121 and NCT02397824 (https://clinicaltrials.gov/). Results: GenoDENT obtained a 60% diagnostic rate. We reported genetics results for 221 persons divided between 115 AI index cases and their 106 associated relatives from a total of 111 families. From this index cohort, 73% were diagnosed with non-syndromic amelogenesis imperfecta and 27% with syndromic amelogenesis imperfecta. Each individual was classified according to the AI phenotype. Type I hypoplastic AI represented 61 individuals (53%), Type II hypomature AI affected 31 individuals (27%), Type III hypomineralized AI was diagnosed in 18 individuals (16%) and Type IV hypoplastic-hypomature AI with taurodontism concerned 5 individuals (4%). We validated the genetic diagnosis, with class 4 (likely pathogenic) or class 5 (pathogenic) variants, for 81% of the cohort, and identified candidate variants (variant of uncertain significance or VUS) for 19% of index cases. Among the 151 sequenced variants, 47 are newly reported and classified as class 4 or 5. The most frequently discovered genotypes were associated with MMP20 and FAM83H for isolated AI. FAM20A and LTBP3 genes were the most frequent genes identified for syndromic AI. Patients negative to the panel were resolved with exome sequencing elucidating for example the gene involved ie ACP4 or digenic inheritance. Conclusion: NGS GenoDENT panel is a validated and cost-efficient technique offering new perspectives to understand underlying molecular mechanisms of AI. Discovering variants in genes involved in syndromic AI (CNNM4, WDR72, FAM20A … ) transformed patient overall care. Unravelling the genetic basis of AI sheds light on Witkop's AI classification.

Maxillary Sinus Volume and Its Effect on Treated Impacted Canines.

The goal of study was to explore the role of 3D CBCT (cone beam computer tomography) in detecting impacted canines and their movement to evaluate the influence of orthodontic therapy parameters on treatment options, and to monitor quality of healing process based on shape and size of sinus maxillae volume. It is known that the volume of maxillary sinus plays an important role in patients with impacted teeth. The prospective study consisted of 26 individuals. For each individual, pre-treatment and post-treatment CBCT data were acquired. Changes of size, and position of impacted canine in 3D CBCT image before and after therapy were prepared using 3D reconstruction. Volumetric measurements of the maxillary sinuses were performed before and after orthodontic therapy of impacted canines, using InVivo6 software. The main effects MANOVA performed on linear measurements showed metric differences between pre-op and post-op images. A paired t-test showed no statistically significant differences between pre-op and post-op values of the sinus volume. Changes of size and position of impacted canine in 3D image before and after therapy were precise and reproducible, using 3D reconstruction in three planes - horizontal, midsagittal, and coronal. The linear measurements showed metric differences between pre-op and post-op images.

Photobiomodulation Therapy After Mesiodens Surgery: Evaluation of Immunological Markers and Three-Dimensional X-Ray Analysis-Placebo-Controlled Study.

Objective: Photobiomodulation therapy (PBMT) applies therapeutic lasers or light-emitting diodes radiation to the surface of the body. From the medical point of view, PBMT systems have been employed for reducing pain, inflammation, and edema, promoting healing of wounds, deeper tissues and nerves, preventing tissue damage, etc. Background data: PBMT or biostimulation has a wide range of applications in maxillofacial surgery. It is known that the therapy effect using three-dimensional (3D) image was not really clear during the healing process. Materials and methods: The treatment group comprised 38 patients, 18 of them were treated with laser radiation (diode laser 808 nm) and 20 patients presented the control group. The surgery plan was monitored using cone beam computed tomography, in particular the number, shape, and size of mesiodens were registered. The effectivity of laser therapy was assessed based on immunological tests-secretory immunoglobulin A (sIgA) and lysozyme levels measured in nonstimulated saliva before and after treatment. Results: For sIgA (both in millimeters and milligrams per liter), the measurements displayed differences between pre- and postsurgery values, the postsurgery values being significantly lower than the presurgery values. In addition, interaction with the laser treatment plan was found, meaning that the laser treatment affected the sIgA levels. The decrease in sIgA levels in the control group was statistically significant. However, there was no significant change in sIgA levels in the laser group. The lysozyme trends appeared to be identical to the sIgA levels, that is, rising in the laser group and decreasing in the control group. The initial values for each group, however, go in the opposite direction. Conclusions: The study has shown that the 3D techniques and technologies in combination with therapeutic laser systems could support not only a treatment plan, but they also directly influence the process of healing and reduce inflammation. The study was carried out under clinical project No. 00064203 (FN MOTOL).

Comparison of 2D OPG image versus orthopantomogram from 3D CBCT from the forensic point of view.

Forensic dental identification has employed traditionally 2D digital radiological imaging techniques. More recently, 3D cone beam computer tomography (CBCT) data, widely applied in clinical dentistry, have been gradually used. The purpose of this study was to compare the precision and quality of 2D digital orthopantomogram (OPG) and 2D OPG images generated from cone beam computed tomography (CBCT). The study sample consisted of 50 patients with archived conventional 2D OPG and 3D CBCT images. Patients signed an informed consent form to take part in our study. Measurements of the mandible, teeth and dental restorations were taken by two observers on calibrated 2D OPG and 3D CBCT-to-OPG images using measurement functionalities of DOPLHIN software. Acquired dimensions were compared side by side and images of fillings were superimposed. For better visual comparison and more efficient image registration, the methods of spline interpolation were used. The pairs of absolute measurements obtained from conventional OPG and CBCT-to-OPG-converted images were highly correlated (p < 0.05). However, larger, and horizontally measured distances were revealed to be more affected than shorter vertically taken measurements. In relative terms, CBCT-generated width/length indices of the canines and the first molars ranged from 84% to 99.8% of those acquired from traditional OPGs. In addition, corresponding points on the teeth and fillings were compared side by side and in superimposition. The average coincidence of images was 6.1%. The results revealed that for selected metric variables 2D OPGs and 3D CBCT-generated OPGs were complementary and could be used for forensic comparisons.

Chronological Age as Factor Influencing the Dental Implant Osseointegration in the Jaw Bone.

The objectives of this study were to evaluate osseointegration of dental implant in the jaw bone in the young and elderly population and comparing the results to assess indicators and risk factors as age for the success or failure of dental implants. A retrospective study of 107 implants (Impladent, LASAK, Czech Republic) was prepared. The patients at implants surgery were divided in three groups. The patients were followed-up for a 7-year period. We evaluated osseointegration from long term point of view as a change of marginal bone levels close to dental implant. Marginal bone levels were recorded and analysed with regard to different patient- and implant-related factors. An influence of chronological age on change of marginal bone levels during 6-year retrospective study vas evaluated. The study examined 47 patient charts and 107 implants from the Second Faculty of Medicine, Charles University and University Hospital Motol. We proved that young healthy patients with long bridges or Branemarks have the same progression of marginal bone levels changes. The chronological age hasn't therefore direct influence on the osseointegration from long term point of view. But we found that the length of dental suprastrucure-prosthetic construction negatively influences marginal bone changes, though these results weren't statistically significant. More extensive dental implant suprastrucure undergoes smaller osseointegration. On the other hand the length of dental suprastrucure (prosthetic construction) negatively influences dental osseointegration in both groups of patient.

Low-Level Laser Therapy After Wisdom Teeth Surgery: Evaluation of Immunologic Markers (Secretory Immunoglobulin A and Lysozyme Levels) and Thermographic Examination: Placebo Controlled Study.

OBJECTIVE: The goal of this investigation is to analyze the effect of therapeutic low-level laser therapy (LLLT) to have a possibility to check pain and inflammation connected with surgical removal of impacted lower third molars in general anesthesia or even phobia [not accompanied by pain or fear of dental treatment, using immunologic markers-secretory immunoglobulin A (sIgA) and lysozyme]. The healing process was also monitored by infrared thermography. BACKGROUND DATA: LLLT can accelerate the proliferation phase of healing and decrease the inflammatory reaction, but the effect is not really clear. MATERIALS AND METHODS: The treatment group comprised 213 impacted third molars (144 laser group and 74 placebo group). Laser radiation (diode laser 830 nm) was applied. The effectivity of laser therapy was evaluated based on immunological tests, that is, before and after treatment with sIgA and lysozyme in nonstimulated saliva. Thermographic examination was performed by infrared camera. RESULTS: After laser irradiation, the sIgA decreases from 546.91 mg/L (SD 354.58) to 304.91 mg/L (SD 191.96), and in the control group from 602.25 mg/L (SD 343.62) to 425.62 mg/L (SD 220.51); the differences were significant, the lysozyme value being lower. After laser therapy, the laser and placebo sides in the area of the third molars were differed in 0.2°C. CONCLUSIONS: The 830 nm wavelength penetrates to deep-seated tissues. A positive association was found between concentration of salivary sIgA and lysozyme in the saliva after LLLT application. The deep-seated wounds after wisdom teeth extraction had no effect on temperature rise in the face.

3D Multislice and Cone-beam Computed Tomography Systems for Dental Identification.

3D Multislice and Cone-beam computed tomography (CBCT) in forensic odontology has been shown to be useful not only in terms of one or a few of dead bodies but also in multiple fatality incidents. 3D Multislice and Cone-beam computed tomography and digital radiography were demonstrated in a forensic examination form. 3D images of the skull and teeth were analysed and validated for long ante mortem/post mortem intervals. The image acquisition was instantaneous; the images were able to be optically enlarged, measured, superimposed and compared prima vista or using special software and exported as a file. Digital radiology and computer tomography has been shown to be important both in common criminalistics practices and in multiple fatality incidents. Our study demonstrated that CBCT imaging offers less image artifacts, low image reconstruction times, mobility of the unit and considerably lower equipment cost.

Odontogenic keratocysts in the Basal Cell Nevus (Gorlin-Goltz) Syndrome associated with paresthesia of the lower jaw: Case report, retrospective analysis of a representative Czech cohort and recommendations for the early diagnosis.

OBJECTIVES: Identification of early presenting signs of the Basal Cell Nevus (BCNS; synonyme Gorlin-Goltz) syndrome, which is associated with a principal triad of multiple basal cell nevi, jaw odontogenic keratocysts, and skeletal anomalies, in stomatological and neurological practices. Proposal of multidisciplinary diagnostic algorithm comprising other medical specialists, including pathology, imaging, laboratory and molecular analyses based on the study outcomes. DESIGN: Case report of a male patient reporting paresthesia of their lower jaw, with right facial asymmetry (maxilla and mandible) and radiological detection of large osteolytic lesions in both jaws, including a retrospective analysis of a representative Czech cohort with BCNS from within the last decade. SETTING: Clinical, imaging and laboratory analyses were carried out at a national tertiary centre. RESULTS: A multidisciplinary clinical approach followed by surgical management lead to the identification of odontogenic cysts, which were substantiated by histological examination. DNA sequencing of the PTCH1 gene detected a c.2929dupT resulting in p. Tyr977Leufs*16 pathogenic variant. This finding confirmed the clinical and laboraoty diagnosis of BCNS. Parental DNA analysis showed that this causal genetic defect arose de novo. Surgical management and orthodontic therapy were successful. CONCLUSIONS: Analysis of the reported case and retrospective data analysis provided evidence that paresthesia of the lower jaw should be considered as one of the early presenting signs of this rare disorder in stomatological and neurological practice. Obtained results allowed us to formulate recommendations for diagnostic practice in stomatology and neurology.

The Use of the Er:YAG Laser for Bracket Debonding and Its Effect on Enamel Damage.

OBJECTIVE: The aim of the study was to evaluate the influence of Er:YAG laser irradiation on the debonding of metal and ceramic brackets and enamel damage ex vivo. BACKGROUND DATA: The principle of safe bracket debonding is to degrade the adhesive resin strength connecting the tooth and bracket. Removal of adhesive resin from tooth surfaces without iatrogenic damage (enamel loss) is generally the main problem of the otherwise very successful method of aesthetic straightening of teeth. METHODS: Forty ceramic and metal brackets (Clarity™ Advanced and Victory Series™; 3M Unitek, Monrovia, CA) were standardly bonded to buccal polished enamel surfaces of 30 caries-free human third molars. Two types of adhesive resins (Transbond™ XT Light Cure Adhesive; 3M Unitek, and Variolink II Professional Set; Ivoclar Vivadent AG) were used. Before debonding, the brackets in the laser group were irradiated with the Er:YAG laser (FJFI CVUT) 280 mJ, 250 µs long, repetition rate 6 Hz, spot focus 1 mm, and 140 sec. The control group was debonded without the laser irradiation. During the bracket irradiation, temperature changes inside the tooth were monitored using a thermal image infrared camera. The enamel surface was investigated by SEM. RESULTS: It has been observed that bracket removal was easier after the Er:YAG laser irradiation, and temperature rise was limited (from 2.0°C to 3.2°C) also for metal brackets. As against the nonirradiated samples, SEM investigation has confirmed no damage to enamel. CONCLUSIONS: Irradiation with Er:YAG laser radiation before debonding of ceramic brackets significantly decreases the bonding failure and amount of remaining adhesive.

Medical Informatics and Information Technology Supporting Oral Medicine.

Electronic healthcare documentation is the key element of electronic healthcare (eHealth). Electronic oral health record (EOHR) supporting oral medicine is discussed. To provide dentists with a methodology and instrument to create oral health documentation in more efficient way, support information exchange and integration in dental domain and to ease dental decision-making and forensic dentistry identification tasks.The proposed methodology is used to model lifelong EOHR based on a small specific ontology where the use of other classification systems and nomenclatures, e.g. SNODENT, is possible. EOHRwith Lifelong DentCross user interface was developed and it has been supporting dental care at the University Hospital in Prague-Motol. The user interface is working in four languages and controlled by voice or keyboard. Lifelong DentCross user interface is reflecting the way of the work in dentistry and the EOHR can provide both structured and free text information to oral medicine.

Comparison of quality of facial scars after single low-level laser therapy and combined low-level with high-level (PDL 595 nm) laser therapy.

The main goal of our study was to compare the quality of resulting facials scar 12 weeks after single and combined laser therapy. Forty-one children from age 1.5 to 5 years with facial scars after injury participated in the study. Thirty-one underwent laser therapy, 14 were treated using single low-level laser therapy (670 nm, fluence 3-5 J/cm(-2) ), and 17 underwent combined high-level laser therapy with non-ablative pulsed dye laser (PDL; 595 nm, spot size 7 mm, delay 0.45 ms or 1.5 ms, fluence 9-11 J/cm(-2) , cryogen spray/delay 20/30 ms) and low-level laser therapy. The control group consisted of 10 untreated children. Before treatment and at week 4, 8, and, 12 the scars were evaluated using the POSAS questionnaire. A statistically significant improvement in scars (between ratings before treatment and 4 weeks after therapy, before treatment and 8 weeks after therapy and before treatment and 12 weeks after therapy) was observed in all parameters in both treatment groups (p < 0.0001). For the HLLT+LLLT group the most significant enhancement in the quality of scars was found for all items and at all evaluations, except pigmentation and pliability. There was no improvement observed in quality of facial scars in the control group.

Using Dental Age to Estimate Chronological Age in Czech Children Aged 3-18 Years.

The Demirjian methods to determine dental age are based on analysis of orthopantograms. The dental age estimation is based on establishing the tooth development stages. The purpose of this study was to assess the accuracy of estimation of dental age by Demirjian in the use of all of his four methods. 505 Czech healthy boys and girls aged 3 to 18 years were examined radiographically at the Department of Stomatology, Second Faculty of Medicine, Charles University in Prague. It was mentioned the factors of underlying diseases influence the accuracy of the dental age estimation. For statistical evaluation, descriptive statistics was used to compare deviations of the mean values of chronological and dental age in each age group. The resulting difference between dental age and chronological age is not significant in both genders only when using both Demirjian 7-teeth methods of 1973 and 1976. Therefore these may be most appropriately used for forensic age estimation. There are shown standard deviation differences in different countries. Demirjian's original 7-teeth method from 1973 and Demirjian's revised 4-teeth method from 1976 appear to be the best methods for calculating the dental age of healthy Czech children of both genders.

Complex morphological and molecular genetic examination of amelogenesis imperfecta: a case presentation of two Czech siblings with a non-syndrome form of the disease.

Amelogenesis imperfecta (AI) is an overarching term for a group of rare inherited disorders of hard tooth tissues. It is characterized by various defects in proper enamel formation. AI is a severe disorder that affects both the aesthetics and function of the dentition, with affected teeth increasingly suffering from dental caries. Therefore, early diagnosis and lifelong stomatological interventions are important. Due to the complex nature of AI family history, stomatological, radiographic, and molecular genetic examinations should be part of the diagnostic portfolio. Additionally, we utilized new visualization methods for the assessment of teeth demineralization. We present a case report of two affected Czech sisters (6 and 8 years old) with clinically defined AI. These are the first Czech cases in which comprehensive clinical and genetic analysis had been carried out and reflect the complex clinical nature, positive treatment options, and limitations of candidate-gene molecular genetic testing.

Evaluation of dental morphometrics during the orthodontic treatment.

BACKGROUND: Diagnostic orthodontic and prosthetic procedures commence with an initial examination, during which a number of individual findings on occlusion or malocclusion are clarified. Nowadays we try to replace standard plaster casts by scanned objects and digital models. METHOD: Geometrically calibrated images aid in the comparison of several different steps of the treatment and show the variation of selected features belonging to individual biomedical objects. The methods used are based on geometric morphometrics, making a new approach to the evaluation of the variability of features. The study presents two different methods of measurement and shows their accuracy and reliability. RESULTS: The experimental part of the present paper is devoted to the analysis of the dental arch objects of 24 patients before and after the treatment using the distances between the canines and premolars as the features important for diagnostic purposes. Our work proved the advantage of measuring digitalized orthodontic models over manual measuring of plaster casts, with statistically significant results and accuracy sufficient for dental practice. CONCLUSION: A new method of computer imaging and measurements of a dental stone cast provides information with the precision required for orthodontic treatment. The results obtained point to the reduction in the variance of the distances between the premolars and canines during the treatment, with a regression coefficient RC=0.7 and confidence intervals close enough for dental practice. The ratio of these distances pointed to the nearly constant value of this measure close to 0.84 for the given set of 24 individuals.

Comprehensive treatment of temporomandibular joint disorders.

AIMS: Changing lifestyles, decreasing physical activity, which is increasing the number of degenerative joint diseases of various etiology, and certain dental procedures are increasing the number of patients complaining of pain in their temporomandibular joints. The aim of the study was to assess the benefits of comprehensive physiotherapy sessions in order to decrease the number of temporomandibular joint problems, thereby improving the patient's quality of life. METHODOLOGY: An examination by a dentist determined each patient's treatment plan, which consisted of a medical exam, physical therapy and education. Each form of treatment was applied 10 times at intervals of 7-14 days. The main goal of the therapeutic physical education was to redress the muscle imbalance in the mandibular joint. This was achieved by restoring balance between the masticatory muscles, along with releasing the spastic shrouds found in the masticatory muscles. The aim of education was to teach the patient exercises focused on the temporomandibular joint and masticatory muscles. The intensity of the exercises and their composition were individually adjusted and adapted to their current state. Physical therapy consisted of the application of pulsed magnetic therapy, laser therapy, and non-invasive positive thermotherapy. RESULTS: The above procedure was conducted on a therapeutic group of 24 patients (3 men and 20 women). In the course of therapy, there were no complications, and all patients adhered to the prescribed regime. None reported any side effects. The mean treatment duration was 123 +/- 66 days. The outcome of the therapy was evaluated as described in the methodology, the degree of pain affecting the joint, and the opening ability of the mouth. In both parameters, there was a significant decline in patient pain. CONCLUSIONS: In a study devoted to tactics of rehabilitation treatment for temporomandibular joint disorders, the need for comprehensive long-term therapy, involving education, and learning proper chewing habits was made apparent for recovery and pain reduction. A priority in physical therapy, and combinations of pulsed magnetic therapy and hyperthermia-positive peloids, are also beneficial.

Possibility of reconstruction of dental plaster cast from 3D digital study models.

OBJECTIVES: To compare traditional plaster casts, digital models and 3D printed copies of dental plaster casts based on various criteria. To determine whether 3D printed copies obtained using open source system RepRap can replace traditional plaster casts in dental practice. To compare and contrast the qualities of two possible 3D printing options--source system RepRap and commercially available 3D printing. DESIGN AND SETTINGS: A method comparison study on 10 dental plaster casts from the Orthodontic department, Department of Stomatology, 2nd medical Faulty, Charles University Prague, Czech Republic. MATERIAL AND METHODS: Each of 10 plaster casts were scanned by inEos Blue scanner and the printed on 3D printer RepRap [10 models] and ProJet HD3000 3D printer [1 model]. Linear measurements between selected points on the dental arches of upper and lower jaws on plaster casts and its 3D copy were recorded and statistically analyzed. RESULTS: 3D printed copies have many advantages over traditional plaster casts. The precision and accuracy of the RepRap 3D printed copies of plaster casts were confirmed based on the statistical analysis. Although the commercially available 3D printing enables to print more details than the RepRap system, it is expensive and for the purpose of clinical use can be replaced by the cheaper prints obtained from RepRap printed copies. CONCLUSIONS: Scanning of the traditional plaster casts to obtain a digital model offers a pragmatic approach. The scans can subsequently be used as a template to print the plaster casts as required. Using 3D printers can replace traditional plaster casts primarily due to their accuracy and price.

3D reconstruction of TMJ after resection of the cyst and the stress-strain analyses.

The aim of this article is 3D analysis of the temporomandibular joint (TMJ) patient, who underwent surgery, during which the right TMJ was resected along with the ramus of mandible and consequently the joint was reconstructed with subtotal replacement. The main goal is to give a suitable formulation of mathematical model, which describes the changes of stresses in TMJ incurred after the surgery. The TMJ is a complex, sensitive and highly mobile joint which works bilaterally so each side influences the contralateral joint and because of this the distribution of the stresses is changed in the healthy joint as well. Detailed knowledge about function these are necessary for clinical application of temporomandibular joint prosthesis and also help us estimate the lifetime of the prosthesis a possibilities of alteration in the contra lateral joint components. The geometry for the 3D models is taken from the CT scan date and its numerical solution is based on the theory of semi-coercive unilateral contact problems in linear elasticity. This article provides medical part with case report, discretion of treatment, than the methods of mathematical modeling and his possibilities are described and finally results are reported.