Frequency of Root Surface Microgrooves Associated with Periodontal Destruction.

Small linear microgrooves have been observed on root surfaces associated with osseous defects when videoscope-assisted minimally invasive surgery (V-MIS) is performed. The aim of this study was to evaluate the frequency of occurrence of these microgrooves associated with osseous defects. Videos of dry skulls from an anatomy department collection and videos made during consecutive V-MIS procedures on patients were evaluated to determine the presence or absence of microgrooves associated with osseous defects.

Specific inactivation of Twist1 in the mandibular arch neural crest cells affects the development of the ramus and reveals interactions with hand2.

Background: The basic helix-loop-helix (bHLH) transcription factor Twist1 fulfills an essential function in neural crest cell formation, migration, and survival and is associated with the craniosynostic Saethre-Chotzen syndrome in humans. However, its functions during mandibular development, when it may interact with other bHLH transcription factors like Hand2, are unknown because mice homozygous for the Twist1 null mutation die in early embryogenesis. To determine the role of Twist1 during mandibular development, we used the Hand2-Cre transgene to conditionally inactivate the gene in the neural crest cells populating the mandibular pharyngeal arch.