PURPOSE: The aim of this study was to confirm the applicability of YouTube as a delivery platform of lecture videos for dental students and to assess their learning attitudes towards the flipped classroom model. METHODS: Learning experiences after using the YouTube platform to deliver preliminary video lectures in a flipped classroom were assessed by 69 second-year students (52 males, 17 females) at Dankook University College of Dentistry, Korea, who attended periodontology lectures during 2 consecutive semesters of the 2016 academic year. The instructor uploaded the lecture videos to YouTube before each class. At the end of the second semester, the students were surveyed using a questionnaire devised by the authors. RESULTS: Of the students, 53 (76.8%) always watched the lecture before the class, 48 (69.6%) used their smartphones, and 66 (95.7%) stated that they watched the lectures at home. The majority of the students replied that the video lectures were easier to understand than face to face lectures (82.6%) and that they would like to view the videos again after graduation (73.9%). CONCLUSION: Our results indicate that YouTube is an applicable platform to deliver video lectures and to expose students to increased learning opportunities.
Dentistry ; Education, Dental ; Educational Technology ; Humans ; Korea ; Learning ; Lectures ; Male ; Republic of Korea ; Smartphone ; Students, Dental

PURPOSE: The aim of this study was to confirm the applicability of YouTube as a delivery platform of lecture videos for dental students and to assess their learning attitudes towards the flipped classroom model. METHODS: Learning experiences after using the YouTube platform to deliver preliminary video lectures in a flipped classroom were assessed by 69 second-year students (52 males, 17 females) at Dankook University College of Dentistry, Korea, who attended periodontology lectures during 2 consecutive semesters of the 2016 academic year. The instructor uploaded the lecture videos to YouTube before each class. At the end of the second semester, the students were surveyed using a questionnaire devised by the authors. RESULTS: Of the students, 53 (76.8%) always watched the lecture before the class, 48 (69.6%) used their smartphones, and 66 (95.7%) stated that they watched the lectures at home. The majority of the students replied that the video lectures were easier to understand than face to face lectures (82.6%) and that they would like to view the videos again after graduation (73.9%). CONCLUSION Our results indicate that YouTube is an applicable platform to deliver video lectures and to expose students to increased learning opportunities.

Anatomical shape of the mandibular ramus, which includes the area from the rear of the mandibular second molar to the mandibular posterior border and from the mandibular sigmoid notch to the inferior mandibular border, must be carefully considered to perform orthognathic surgery. The locations of the lingula and mandibular foramen in medial side of mandibular ramus are one of the most important factors to decide the location of the horizontal medial osteotomy in sagittal split ramus osteotomy and to select the line of vertical osteotomy in intraoral vertical ramus osteotomy. Sixty-five different Korean human dry mandibles were surveyed. All mandible have permanent dentition including complete eruption of the mandibular second molar. The locations of the lingula and mandibular foramen in medial side of the ramus were identified and following results were obtained. Anterior ramal horizontal distance from lingula was 16.13+/-3.53mm(range:8.6~24.3mm), anterior ramal horizontal distance from mandibular foramen was 23.91+/-4.79mm(range: 14.1~39.7mm), horizontal width of mandibular foramen was 2.79+/-0.95mm(range: 1.5 ~6.1mm), height of lingula was 10.51+/-3.84mm(range: 3.1~22.4mm), vertical distance from sigmoid notch to lingula was 19.82+/-5.11mm(range: 9.1~35.3mm). From this study, the result could be used to select the location of osteotomy lines and to decide amount of periosteal elevation to avoid injury of neurovascular bundle, and to accomplish the appropriate split in Korean patients in mandibular orthognathic surgery.
Colon, Sigmoid ; Dentition, Permanent ; Humans ; Mandible ; Molar ; Orthognathic Surgery* ; Osteotomy ; Osteotomy, Sagittal Split Ramus

PURPOSE: The aim of this prospective pilot study was to compare alveolar ridge preservation (ARP) procedures with open-healing approach using a single-layer and a double-layer coverage with collagen membranes using radiographic and clinical analyses. METHODS: Eleven molars from 9 healthy patients requiring extraction of the maxillary or mandibular posterior teeth were included and allocated into 2 groups. After tooth extraction, deproteinized bovine bone mineral mixed with 10% collagen was grafted into the socket and covered either with a double-layer of resorbable non-cross-linked collagen membranes (DL group, n=6) or with a single-layer (SL group, n=5). Primary closure was not obtained. Cone-beam computed tomography images were taken immediately after the ARP procedure and after a healing period of 4 months before implant placement. Radiographic measurements were made of the width and height changes of the alveolar ridge. RESULTS: All sites healed without any complications, and dental implants were placed at all operated sites with acceptable initial stability. The measurements showed that the reductions in width at the level 1 mm apical from the alveolar crest (including the bone graft) were −1.7±0.5 mm in the SL group and −1.8±0.4 mm in the DL group, and the horizontal changes in the other areas were also similar in the DL and SL groups. The reductions in height were also comparable between groups. CONCLUSIONS: Within the limitations of this study, single-layer and double-layer coverage with collagen membranes after ARP failed to show substantial differences in the preservation of horizontal or vertical dimensions or in clinical healing. Thus, both approaches seem to be suitable for open-healing ridge preservation procedures.
Alveolar Process* ; Bone Regeneration ; Collagen* ; Cone-Beam Computed Tomography ; Dental Implants ; Humans ; Membranes* ; Miners ; Molar ; Pilot Projects ; Prospective Studies ; Tooth ; Tooth Extraction ; Transplants ; Vertical Dimension