1. 치아의 맹출 장애는 국소적 또는 전신적 원인에 의하여 발생할 수 있다. 2. 맹출 장애가 있는 치아는 공간소실 또는 인접치아의 치근 흡수, 심미적 문제, 함치성 낭종, 종양 등 합병증을 일으킬 수 있다. 3. 맹출 장애가 있는 치아의 상태 및 합병증의 발생 가능성을 평가하여 조기 치료할지를 판단하는 것이 중요하다.

The aim of this study was to investigate the relationship between the mandibular antegonial notch and the mandibular morphology, and the curve of Spee in anteroposterior skeletal relationship. Pre-treatment lateral cephalograms were obtained from 80(male 34, female 46) adult orthodontic patients and the samples were classified into 3 categories by ANB angle($0^{\circ}$$\leq$ANB< $4^{\circ}$ Class I, $4^{\circ}$$\leq$ANB Class II, ANB< $0^{\circ}$ Class III). The curve of Spee was measured directly from the pre-treatment mandibular study cast of each patient included in this study. Pearson correlation coefficient test and multiple regression analysis in each group revealed the following results; 1. Antegonial notch depth was positively correlated with hoth lower anterior facial height(ANS-Me) in skeletal Class I, II and III groups and Id-Me height in skeletal Class I and II groups. 2. A statistically significant negative correlation was found between the depth of the antegonial notch and the curve of Spee in the Class III group. 3. Significant relationship was not found between the antegonial notch depth and any of the other cephalometric variables such as mandibular body length(Go-Gn) and ramus height(Co-Go). As antegonial notch depth increased, more vertical growth of the mandible was observed. Antegonial notch can be used as a predictor of vertical mandibular growth in the diagnosis and treatment planning of malocclusion.

Deproteinized bovine bone mineral has been widely used as graft material in sinus augmentation procedure. The efficacy of OCS-B(r)(Nibec Inc., Seoul, Korea) as a graft material for sinus augmentaion was evaluated in 10 patients. A total of 13 sinus augmentation procedures were performed, and an average of 6.3 months later 27 implants were placed into the augmentation sinuses. The biopsy specimens were examined histologically and hitomorphometrically. Radiographical evaluation was done also. The average distance form grafted sinus to implant apex at the final evaluation period was $5.7\pm3.1$mm. The average percentage of newly formed bone at an average of 6.3 months was $20.0\pm8.4%$. The degree of bone to graft material contact was $18.7\pm6.4%$. It was shown from both radiographic evaluation and histologic results that sinus augmentation can successfully be performed with $\OCS-B^textcircledR$.