Colorectal Cancer-Associated Genes Are Associated with Tooth Agenesis and May Have a Role in Tooth Development

Previously reported co-occurrence of colorectal cancer (CRC) and tooth agenesis (TA) and the overlap in disease-associated gene variants suggest involvement of similar molecular pathways. Here, we took an unbiased approach and tested genome-wide significant CRC-associated variants for association with isolated TA. Thirty single nucleotide variants (SNVs) in CRC-predisposing genes/loci were genotyped in a discovery dataset composed of 440 individuals with and without isolated TA. Genome-wide significant associations were found between TA and ATF1 rs11169552 (P = 4.36 × 10−10) and DUSP10 rs6687758 (P = 1.25 × 10−9), and positive association found with CASC8 rs10505477 (P = 8.2 × 10−5). Additional CRC marker haplotypes were also significantly associated with TA. Genotyping an independent dataset consisting of 52 cases with TA and 427 controls confirmed the association with CASC8. Atf1 and Dusp10 expression was detected in the mouse developing teeth from early bud stages to the formation of the complete tooth, suggesting a potential role for these genes and their encoded proteins in tooth development. While their individual contributions in tooth development remain to be elucidated, these genes may be considered candidates to be tested in additional populations

The effectiveness of a single osteointegrated implant combined with pendulum springs for molar distalization

WOS: 000244235200017PubMed ID: 17276871The aim of this report was to present the clinical efficiency of a single osteointegrated implant combined with pendulum springs for molar distalization. A 15-year-old girl sought treatment for irregular anterior teeth and poor smile esthetics. A novel appliance was designed that combined osteointegrated implants with 0.032-in beta-titanium wire and pendulum springs. The treatment results were evaluated from lateral cephalometric radiographs. Distalization of the maxillary first molars was achieved in 6 months. Total treatment time was 21 months. Facial esthetics improved as a consequence of treatment. This appliance design offers reliable molar distalization, even when absolute anchorage is required

Extraction versus non-extraction: evaluation by digital subtraction radiography

WOS: 000251506100018PubMed ID: 17906308The aim of this study was to investigate the facial profile changes of patients treated with and without extractions of four first premolars using novel computer-based digital subtraction software. The pre- and post-treatment radiographic image pairs of 25 extraction (13 girls and 12 boys, mean age = 12.64 +/- 1.82 years) and 24 non-extraction (12 girls and 12 boys, mean age = 12.48 +/- 1.66 years) Class I patients were subtracted by the software. Student's t-tests were used to determine whether the subtraction values for the linear measurements of radiographic differences registered at various anatomical landmark parameters were statistically different between the groups. To further determine whether any variables related to upper and lower lip changes, regression analyses were performed. The main soft tissue differences between the groups were established at labrale superior, labrale inferior, and sulcus inferior points, with extraction patients showing significantly more retruded upper and lower lips. However, the mean differences between the groups did not exceed 1 mm for these variables. Changes at labrale superior and labrale inferior were associated with sagittal movement of the maxillary (r = 0.549) and mandibular (r = 0.630) incisor midpoints. Changes at sulcus inferior were associated with both sagittal and vertical displacement of mandibular incision point (r = 0.676). Some dentofacial alterations were found but in view of the differences between the groups pretreatment, the inter-group differences reflect different treatment intent rather than differences arising from the extraction and non-extraction modalities

Enhanced Effect of Combined Treatment With Corticotomy and Skeletal Anchorage in Open Bite Correction

WOS: 000263961200015PubMed ID: 19231781Purpose: To determine the effects of combined treatment with corticotomy and skeletal anchorage in open bite correction. Patients and Methods: Ten patients (6 females, 4 males) with ages ranging from 15 to 25 years were involved. All of the individuals received combined subapical corticotomy and skeletal anchorage procedure and intrusion forces of 200 to 300 g were applied on the attachments of each molar and both premolars during 12 to 15 weeks. Mean changes for the measurements for the sample group were evaluated with Wilcoxon signed ranks test. Results: Significant intrusion of maxillary posterior teeth provided counterclockwise rotation of the mandible and open bite was successfully corrected. SNB angle increased and the ANB angle decreased (P < .05). Significant decreases were noted for vertical skeletal characteristics and overbite increased accordingly (P < .05). Conclusions: our results indicated that the use of combined treatment with corticotomy and skeletal anchorage provided safe and noncompliance intrusion of posterior teeth in a short period and may be regarded as an alternative method for skeletal open bite correction in adults who reject orthognathic surgery. (C) 2009 American Association of Oral and Maxillofacial Surgeon

Should dentistry be a specialty of medicine? Two viewpoints

Dentistry and dental education are well-established domains with deep-rooted institutions, educational programs, organizational structures, and advanced specialty fields. Almost 100 years ago, Dr. William Gies, founder of the Columbia University College of Dental Medicine, stated that to best serve the oral health needs of the population, dentistry should be considered a specialty of medicine, and dental students should have the same solid foundation in the basic and clinical sciences as medical students. More recently, the report on “Advancing Dental Education in the 21st Century” recommends an increase in the integration of dental and medical education as a means to address 2 of its key challenges: “shrinking demand for dental services” and “shifting practice environment.” However, it has also been argued that making dentistry and dental education a subspecialty of medicine and medical education will create logistical, structural, regulatory, and financial dilemmas. Instead of a drastic change to current dental educational, organizational, and institutional models, some argue a contemporary approach to dental education is required to ensure dentists are well prepared to address the healthcare needs of the population and future healthcare delivery systems and practice models. Recognizing the need for change in dental education to keep pace with changes in patient demographics and healthcare systems, the dental profession has the responsibility and opportunity to develop new models and paradigms that improve educational and clinical outcomes in our educational programs and future practice

Evaluation of miniscrew-supported rapid maxillary expansion in adolescents: A prospective randomized clinical trial

WOS: 000448802300006PubMed ID: 30102085Objectives: To evaluate and compare the dental and skeletal changes with conventional and miniscrew-supported maxillary expansion appliances in adolescents. Materials and Methods: Forty patients were divided into two groups, with one group receiving a tooth-borne expander and the other group receiving an expander supported by four miniscrews (bone-borne). Multiplanar coronal and axial slices obtained from cone-beam computed tomography images were used to measure the changes in transverse skeletal widths, buccal bone thickness, tooth inclination, and root length. Paired t-tests and independent-sample t-tests were used to compare the two expansion methods. Results: Bone-borne expansion increased the maxillary suture opening more than 2.5 times than tooth-borne expansion both anteriorly and posteriorly. Between the maxillary first premolars, sutural expansion accounted for 28% and 70% of the total transverse width increase in the tooth-borne and bone-borne expander groups, respectively. Similarly, 26% and 68% of the total expansion was of skeletal nature in the tooth-borne and bone-borne expander groups between the maxillary first molars. The pattern of expansion was variable, with most of the patients in both groups demonstrating a triangular-shaped sutural opening that was wider anteriorly. Subjects in the conventional group experienced significantly more buccal bone reduction and greater buccal inclination of the teeth. No significant differences were observed for root length measurements between the two groups. Conclusion: Use of bone-borne expansion in the adolescent population increased the extent of skeletal changes in the range of 1.5 to 2.8 times that of tooth-borne expansion and did not result in any dental side effects

Evaluation of Dental Root Development Regarding Maxillary Canine Eruption Status after Secondary Alveolar Bone Grafting in Patients with Cleft Lip and Palate

In children born with cleft lip and palate, the timing of the secondary alveolar bone graft (SABG) is crucial to its success; this involves estimating the eruption of the permanent maxillary canine. Altered dental eruption in this patient group gives impetus to the identification of dental developmental factors concerning maxillary canine eruption, which may steer the clinical decision of SABG timing. Records of over nine hundred patients who received SABG with pre- and post-operative cone beam computed tomography (CBCT) scans were analyzed for inclusion and divided into two groups (erupting or non-erupting canine after SABG). Roots of the maxillary canines and premolars were segmented from the cementoenamel junction then linear and volumetric measurements were performed. The pre- and post-operative root length and volume differences were calculated and compared statistically using independent sample tests and paired t-tests. No statistically significant differences were found in the volume change (%), or reciprocal of mean root length in the erupted and unerupted groups in the canine, first premolar, or second premolar roots except for an association between the post-operative dental root length of the canine and the maxillary canine eruption status. Therefore, assessment of root development from pre-treatment CBCT scans was not deemed worthy from a diagnostic perspective