Three-dimensional survey of the whole mandibular canal and mandibular morphology by cone beam computed tomography in normal young people / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This research aimed to analyze the three-dimensional position of mandibular canal (MC) and man of MC and its relationship with the surrounding structures dibular morphology of normal young males and females by using data from cone beam computed tomography (CBCT), as well as to provide an anatomical basis for clinical surgery of the mandible.</p><p><b>METHODS</b>Normal occlusion and CBCT scans of 29 normal young people were conducted. InVivo 5 software was used to reconstruct the mandible, anchor the points, and measure the jaw shape and three-dimensional course of MC. All measurements were analyzed with SSPS 17.0 software.</p><p><b>RESULTS</b>The MC lingual bone cortex was thinner than the MC buccal bone cortex, and the distance of the MC to the buccal bone cortex gradually increased. However, the distance of the MC to the tongue bone cortex and alveolar crest gradually decreased from proximal to distal. In addition, the distance of the MC to the mandibular lower margin was minimal at the first molar and reached the maximum at the second premolar. No significant difference was observed among the heights, widths, and thicknesses of the left and right sides of the cortical bone of the mandibular body cross sections. From the midline to the farthest point, the height and lower one-third thickness of the lingual cortical bone of the mandibular body cross sections gradually decreased, whereas the width of the upper cross section and upper one-third thickness of the buccal cortical bone gradually increased. Significant difference was observed in some measured values.</p><p><b>CONCLUSION</b>After MC enter into the mandibular foramen, it moved away from the lingual to the buccal bone but gradually returned to the lingual bone; its general course is closer to the lingual bone. The mandibles of males are thicker than those of females. CBCT can accurately display the course of MC and its relationship with the surrounding structures.</p>

Application of 3D printing technique in bilateral sagittal split osteotomy / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the application of osteotomy template manufactured via 3D printing technique in bilateral sagittal split osteotomy (BSSO).</p><p><b>METHODS</b>The patient group consisted of 32 patients (17 males and 15 females) with mandibular hypoplasia who underwent a BSSO setback (Hunsuck modification; 64 splits). The mean age at the time of surgery was 23.5 years (range 1.9-35 years). All patients were scanned using cone beam computed tomography (CBCT) to create a 3D model of the mandibular, and the osteotomy template of the inner horizontal ramus of mandible bone incision was manufactured via 3D printing technique. All splits underwent operation with or without the osteotomy template by either a young doctor (attending doctor) or a doctor with extensive orthognathic surgery experience (chief doctor). The time it took to perform the mandible bone incision of the inner horizontal ramus of each group was recorded. Postoperative CBCT scan was performed, and the lingual split scale was used to assess the effect of the operation.</p><p><b>RESULTS</b>Primary healing of incisions was observed in all patients, and no serious complications occurred. The time it took to perform the mandible bone incision of the inner horizontal ramus was significantly different in the four groups (F=30.059, P<0.05), and it was longer in the group of the attending doctor without osteotomy template than in the other three groups (P<0.05). No significant difference was observed in the other groups (P>0.05). Although all splits (n=64) were performed according to the standardized protocol, only 59.38% (38/64) of the fracture lines run according to the Hunsuck's description. By contrast, only 21.88% (14/64) run through the mandibular canal and 18.75% (12/64) was split. The database was analyzed using crosstabs and via Fisher exact test. The split pattern was influenced by the application of an osteotomy template (P<0.05).</p><p><b>CONCLUSION</b>The application of osteotomy template manufactured via 3D printing technique in BSSO was effective, which enabled the young doctor to complete the operation faster and with good results.</p>

Inversion of unerupted second deciduous molar and second premolar: a case report / 华西口腔医学杂志

Impacted teeth are usually involved in permanent dentition but not in primary dentition. This paper reports a clinical case of unerupted mandibular second deciduous molar inferior to the second premolar.

Effects of sagital split ramus osteotomy surgery on hyoid position and pharyngeal airway with skeletal mandibular prognathism / 实用口腔医学杂志

Objective:To investigate the changes of hyoid position and pharyngeal airway before and after sagittal split ramus osteotomy (SSRO) of skeletal mandibular prognathism. Methods:Sixteen severe skeletal mandibular prognathism cases(Class Ⅲ, 5 males and 11 females) were chosen. Pre and post operation lateral cephalograms analysis reflecting pharyngeal airway and position of the hyoid bone was performed. Results: ① After SSRO, the width of airway decreased significantly. ② The distance between the mandible and the hyoid bone was also decreased significantly. No significant differences were found regarding measurements of the hyoid bone to the cranial base in male patients. Conclusion: The distance from the mandible to the hyoid bone and the width of airway were decreased significantly after SSRO. It suggests that the tongue and airway might be reformed functionally to new environments following SSRO surgical treatment.

Brain Processing of Nonliteral Language:ERP Researches / 中国临床心理学杂志

The nonliteral language and the literal language may be stored and processed differently in the brain. This review examines studies on idiom,metaphor and prosody processing by event-related brain potentials(ERPs). Many kinds of nonliteral languages,may be automatic speech modulated by the right hemisphere. What are to be further examined is the research paradigm of nonliteral language,the development of automatic speech and the social and emotional interaction.