Prevalence of different types of interproximal contacts in the permanent dentition - a study cast evaluation.

Background: A new classification called OXIS was proposed for categorizing the interproximal contacts of primary molars, modified for the primary canines and its prevalence was established. No such information is available for the permanent dentition. Hence, the aim was to establish the variations in interproximal contacts of the permanent dentition and thereby modify the OXIS classification of primary molars and primary canines to the permanent dentition. Methods: We propose a study-cast-based classification of interproximal contacts of the permanent dentition. Three hundred and forty-three pretreatment casts of patients based on an inclusion and exclusion criteria were selected. Contacts of posterior teeth were classified based on OXIS classification of interproximal contacts, and its modification was used for anterior teeth. Results: Among the posterior contacts, the 'O' type of contact was least prevalent, while most prevalent was the 'S' type for second molar-first molar contact, 'I' type for the first molar-second premolar contact, and 'X' type for the second premolar-first premolar contact. Among the anterior contacts, least prevalent was 'S1' type for the first premolar-canine contact, and I type for the canine-lateral incisor and the lateral incisor-central incisor contacts. There was no statistical significance between right- and left-side contacts ( P > 0.05) while significance was seen between maxillary and mandibular contacts ( P < 0.05). Similarity of contacts ranged from 5.17% to 10.05%. Conclusion: The OXIS classification is applicable to posterior permanent teeth, and its modification is representative of anterior permanent teeth.

In Silico Molecular Docking and Simulation Studies of Protein HBx Involved in the Pathogenesis of Hepatitis B Virus-HBV.

Current drug discovery involves finding leading drug candidates for further development. New scientific approaches include molecular docking, ADMET studies, and molecular dynamic simulation to determine targets and lead compounds. Hepatitis B is a disease of concern that is a life-threatening liver infection. The protein considered for the study was HBx. The hepatitis B X-interacting protein crystal structure was obtained from the PDB database (PDB ID-3MSH). Twenty ligands were chosen from the PubChem database for further in silico studies. The present study focused on in silico molecular docking studies using iGEMDOCK. The triethylene glycol monoethyl ether derivative showed an optimum binding affinity with the molecular target HBx, with a high negative affinity binding energy of -59.02 kcal/mol. Lipinski's rule of five, Veber, and Ghose were followed in subsequent ADMET studies. Molecular dynamic simulation was performed to confirm the docking studies and to analyze the stability of the structure. In these respects, the triethylene glycol monoethyl ether derivative may be a promising molecule to prepare future hepatitis B drug candidates. Substantial research effort to find a promising drug for hepatitis B is warranted in the future.

Prevalence and measurement of anterior loop of the mandibular canal using CBCT: A cross sectional study.

BACKGROUND: Anterior loop of the mental nerve is a very important anatomic landmark in implant placement and anterior mandibular osteotomies. PURPOSE: Two-dimensional imaging techniques are not competent enough to locate and measure the mental nerve loop in majority of the cases. Any injury to this loop results in pain/paresthesia/numbness in the region supplied by the mental nerve. The aim of this study is to analyze the prevalence and measure the length of the loop using cone beam computerized tomography (CBCT) and calculate the average length and prevalence so that a safe margin can be given while placing the implants or the osteotomy cuts in the premolar region. MATERIALS AND METHODS: A cross-sectional study was done using CBCT images of 85 patients taken for impaction surgery. The length of the loop was measured in mm using standardized lines drawn along specific anatomic landmarks. RESULTS: In our study 11.76% of patients had anterior loop in their mental nerve. Mean length of the mental nerve loop was calculated and found to be 2.79 mm. CONCLUSION: A margin of 4 mm anterior to the mental foramen should be safe to avoid any damage to the mental nerve loop bundle in majority of the cases where the loop is present.

Localized multiple cemental excrescences: a rare presentation of hypercementosis.

Hypercementosis is an abnormal thickening of cementum which may be generalized or localized. Localized hypercementosis is usually characterized by nodular enlargement of apical third of root. Hypercementosis in the form of multiple cemental spikes distributed throughout the entire length of root is a very rare finding. In this article, we report such a rare manifestation of localized hypercementosis affecting right maxillary third molar in a 24-year-old male. This finding was an accidental observation following a difficult extraction procedure as the spikes were not evident in the orthopantamogram. It is imperative that every dental practitioner be aware of several presentations of hypercementosis and ensure that such an entity is considered in the differential diagnosis of difficult extraction procedures as an Intraoral Periapical (IOPA) radiograph or even an Orthopantamogram (OPG) could not differentiate the root morphology.