Epidermal Growth Factor Receptor and Nerve Growth Factor Receptor in the Rat Mandibular Molar and Incisor after Submandibular Sialadenectomy / 대한해부학회지

Immunohistochemical changes of epidermal growth factor receptor (EGFR) and nerve growth factor receptor (NGFR) were investigated in the rat mandibular molar and incisors after submandibular sialadenectomy. In the sham operated rat, any EGFR immunoreactivity was not observed in the teeth but NGFR immunoreactivities were observed exclusively in the periodontal ligament and ameloblasts of incisor. In the sialadenectomized rat, EGFR immunoreac-tivities were observed in the odontoblasts of the mandibular first molar, periodontal ligament cells, ameloblasts of incisor and some cells of bone marrow. NGFR immunoreactivities were more intense and widely distributed in alveolar bone, periodontal ligaments and odontoblasts of the sialadenectomized rat than in the sham operated rat. Both of EGFR and NGFR immunoreactivities gradually increased in their intensities in a time-dependent manner after submandibular sialadenectomy. The results show that expression of EGFR and NGFR in the mandibular molar and incisor is enhanced by submandibular sialadenectomy. Therefore, it is suggested that EGF and NGF derived from submandibular gland may affect to the mandibular molar and incisors by direct and/or indirect mechanism.

The relations between craniofacial morphology and dental aesthetic index(DAI) / 대한치과교정학회지

Multple features of occlusion have been combined by epodemiologists in attemps to objectively to determine malocclusion severity and treatment priorty. Jenny et al were developed DAI(Dental Aesthetic Index), which is an orthodontic index based on socially defined aesthetic stamdards. This stydy aimed to evaluate association between 10 occlusal componets of DAI and individual measures of skeletal morphology by use of univariate and multivariate analysis. In addition the relationship between a Dental Aeathetic Index score and skeletal mophology was evaluated. The data for this study were obtained from cephalometric radiographs and dental casts of 182 korean patients(79 men, 103 women) with permanent dentition who had been acccepted for the orthodontic treatment at Department of Orthodontics, Chonbuk National University. The results are as follows : 1. Several occusal components of DAI(missing, crowding and spacing in the incisal segment, diastema, largest anterior irregularity on upper and lower arch) were not associated with individual measures of craniofacial morphology. 2. Sagittal occlusal components of DAI were associated with anteroposterior skeletal measures. 3. The relation between vertical occlusal components of DAI and vertical skeletal measures was low magnitude. 4. A Dental Aesthetic Index, which is based on several aspects of occlusion, did not identify craniofacial morphology. We can conclude that combination of certain occlusal components of the DAI may be related with specific skeletal morphology: but, this concept could not be accepted generally.

The effects of mandibular setback osteotomy on the oropharyngeal airway space in mandibular prognathic patients / 대한치과교정학회지

As a result of surgical orthodontic treatment of mandibular prognathism, changes take place in the skeletal and soft orofacial components. Although some investigators had stated that permanent reduction of airway space was observed agter mandibular setback surgery, it was not clear thath this permanent reduction was sustained during long-term follow-up. The purpose of this study was to assess the changes in oropharyngeal airway space and soft tissue orofacial compoment following the mandibular setback surgery and during the follow-up period. The correlation between the changes of the oropharyngeal airway space and the changes of other soft tissue orofacial component was also assessed. The findings of this study were as follows ; 1. The ofoharyngeal airway space area fecreased following mandibular setback surgery for mandibular prognathism and continued to decrease during the follow-up period(p<0.05). 2. The pharyngeal depth at Xi point level and the 2nd cervical vertebra point level decreased agter the surgery and remained during the follow-up period(p<0.05). The decrease of these pharyngeal depth was correlated with the decrease of oropharyngeal airway space area(p<0.01). 3. The decrease of pharyngeal depth at the 3rd and 4th cervical vertebra point level was not significant after the surgery and during the follow-up period. 4. The hyoid bone moved downwasd after the surgery(p<0.05), but returned to its original position during the follow-up period. 5. The length & height of tongue and the position of epiglottis base did not change significantly(p<0.05). 6. The soft palate was displaced posteriorly after the surgery and remained to its changed position during the follow-up period(p<0.05) due to posterior displacement of tongue. The changes of soft palate were significantly correlated with the decrease of oropharyngeal airway space area(p<0.01). 7. The narrowing of oropharyngeal airway space was due to the posterior displacement of tongue above the level of epiglottis tip. The posterior displacement of tongue following mandibiular setback osteotomy remained during the follow-up period.