Due to the increase of osteoporotic patients, it is predicted that the number of implant patients who are suffering from osteoporosis will increase. If the condition of jaw and skeletal bones in implant patients is evaluated preoperatively, it may be useful for implant treatments.The aim of this study was to determine the relationship between the mandibular cortical assessments on panoramic radiographs, as screening for osteoporosis and the bone densities of jaw and skeletal bones.
The patients were 186 women,88 premenopausal and 98 postmenopausal, who desired implant treatment.They underwent both panoramic radiography and bone mineral measurements of jaw and skeletal bones. Panoramic radiographs were particularly assessed on mandibular cortical width (MCW) as well as mandibular cortical index(MCI:C1-C3). Bone mineral density (BMD) of the mandible and the maxilla was measured by quantitative computed tomography(QCT). To assess skeletal status, the ΣGS/D of the second metacarpal by microdensitometry (MD) and osteosono-assessment index (OSI) of the calcaneus by quantitative ultrasound (QUS) were used. Furthermore, the mandibular cortical bone was classified according to the bone rarefaction by using MCW and MCI. The bone densities of the jaw and the skeletal bones were compared between two groups, a normal or low rarefaction group and a high rarefaction group, by the classification of the bone status.
The results were as follows:In the postmenopausal women, MCI was significantly correlated with maxillary BMD, mandibular BMD,ΣGS/D and OSI respectively (r=0.43-0.68, p<0.01), although the correlation in the premenopausal women was lower. Maxillary BMD, mandibular BMD, ΣGS/D and OSI in the postmenopausal women with C3 were significantly lower than those with C1 and C2(p<0.05). The bone densities of the high rarefaction group were significantly lower than those of the normal or low rarefaction group(p<0.01).
It was shown that the mandibular cortical assessments on the panoramic radiographs reflected the bone densities of the jaw and the skeletal bones, particularly in the postmenopausal women. The classification of bone rarefaction through panoramic radiographs may be valuable when predicting low bone densities before implant treatment, but it is necessary to further examine the bone densities of different regions of the jawbone in detail and to evaluate the validity of this classification.
A statistical survey was conducted in a total of 2,122 new patients seen in our Oral Implant Clinic during the period from January 1997 to December 2003 to assess their demographic characteristics and trends and to give clinical considerations. The following results were obtained.
1. There were more female patients than male patients in the population with the male-to-female ratio of 2:3. The mean age of all the patients was 50.2 years.
2. Including those referred by dentists in different departments of the university hospital and those personally introduced by university personnel, 73% of the patients were referred to our clinic.
3. As to the reason for their visit, 81% of the patients hoped to receive dental implants while 14% had complaints about their dental implants provided by other dentists.
4. In 1,728 patients expecting dental implants, 1,002 had missing teeth in the maxilla and 1,010 in the mandible.
5. The most frequently observed pattern of missing teeth was loss of posterior teeth, more particularly unilateral free-end saddle, which accounted for 39%. Single-tooth missing cases amounted to 13% of the jaws of the patients hoping to receive implants, among which a single missing maxillary anterior tooth was most frequently seen.
6. Among 2,012 jaws of the patients expecting dental implants, 120 upper jaws (12.0%) and 337 lower jaws (33.4%) had already been treated by dental implants.