Heritability of mandibular asymmetries in sagittal direction: A cephalometric study.

AIM OF THE WORK: If we figure out mandible asymmetry etiology, we can inspire further scientific research, create more effective treatment schemas and recommend means of prophylaxis that could stop mandible asymmetry development. The aim of this work was to analyze monozygotic and dizygotic twins' mandibular asymmetry in sagittal direction using cephalometric data and to analyze its dependence of genetic and environmental factors. MATERIAL AND METHODS: Study sample consisted of 80 dizygotic (DZ) and 80 monozygotic (MZ) twins of same sex. 3 cephalometric measurements were made to determine mandible asymmetry in sagittal direction. Indexes of mandibular asymmetry (IMA1, IMA2) were calculated. Data analysis was done using Microsoft Excel (2013). Genetic and environmental factors influencing mandible asymmetry was determined. RESULTS: Mandibular dental asymmetry was bigger in monozygotic twins' group but the results were not statistically significant. Mandibular skeletal asymmetry was significantly bigger in dizygotic twins' group: IMA1(DZ)=3.05±1.94, IMA1(MZ)=1.92±1.05, p=0.005. IMA2(DZ)=3.12±2.04, IMA2(MZ)=1.88±1.04, p=0.004. Distance between distal borders of the ramus is mostly determined by genetic factors. CONCLUSIONS: 1. Mandibular skeletal asymmetry was significantly bigger in dizygotic twins' group. Mandibular dental asymmetry and symmetry did not differ in groups significantly. 2. Skeletal mandible's asymmetry is more determined by genetics than environmental factors, but lower molars' sagittal position is determined more by environment.

Diagnostic methods and treatment strategies of impacted maxillary canines: A literature review.

OBJECTIVE: This study aims to review main diagnostic methods and different treatment strategies of impacted maxillary canines. MATERIALS AND METHODS: A computerised systematic search of studies was conducted on PubMed and Cochrane databases. The systematic search was performed using inclusion and exclusion criteria. RESULTS: 23 publications were identified as relevant to the theme. Nine studies were about the treatment of impacted maxillary canines, and fourteen reviews were about the diagnostic methods of impacted maxillary canines. Seven of these studies analysed samples comprising combined surgical and orthodontic treatment. Two studies were based on a treatment method whereby deciduous maxillary canine was extracted, and maxilla was expanded to avoid the impaction of permanent maxillary canine. Seven studies compared which diagnostic way - a cone-beam computed tomography or conventional radiography - is more accurate. Four studies evaluated only the accuracy of dental panoramic radiograms. Two studies evaluated how accurate the cone-beam computed tomography method is in diagnosing impacted maxillary canines. One study analysed if cephalogram could be useful in early diagnosis of impacted maxillary canines. CONCLUSIONS: Impacted maxillary canines are usually diagnosed by using panoramic imaging or cone-beam computed tomography. Cone-beam computed tomography is the most accurate diagnostic method to identify the localisation of impacted maxillary canines. Palatal expansion can help to avoid the impaction of maxillary canines. Combined surgical and orthodontic treatment is used to treat impacted maxillary canines in permanent dentition.

Types of root resorptions related to orthodontic treatment.

OBJECTIVES: Root resorption is one of the research topics that may be looked into and that may arise during orthodontic treatment. It is necessary to determine the type of root resorption that was caused by the orthodontic treatment, its factors leading to aforementioned issue, and means to eliminate it. MATERIAL AND METHODS: In this work, articles issued in 2008-2018 and found in biomedical systems such as PubMed and Oxford Journal have been used. The articles were selected with the keywords provided, 25 articles met all criteria. Other articles mentioned have been used for such root tooth resorption analysis, where at least one factor may have affected the issue under discussion. RESULTS: The mechanism of tooth movement during orthodontic treatment causes external or internal root resorption due to certain biochemical and biological processes. Factors, that cause root resorption during orthodontic treatment, were divided into local and general. Local factors include mechanisms of teeth movement, teeth vitality, length of treatment procedure - these factors may affect the type and level of resorption. General factors include age and other systemic elements. CONCLUSIONS: Root resorption extent and type depends on local and general factors active during the orthodontic treatment. It is not possible to eliminate all active factors, however the root resorption issue can be controlled during orthodontic treatment.