Significance of osteoporosis in facial bone density using computed tomography.

OBJECTIVES: The objectives of this study were to compare the variations of bone density in the midfacial bones as measured by computed tomography (CT) scans between the osteoporosis and control groups and to evaluate the regions that facial trauma and iatrogenic problem often occur in the midface. METHODS: The 96 patients who underwent both osteomeatal unit CT scans and dual-energy x-ray absorptiometry at our hospital were included in this study retrospectively. Seven skeletal regions were chosen for evaluation: group A (orbital floor, nasal bone), group B (zygomaticomaxillary suture, zygomatic arch, zygomaticofrontal suture), and group C (anterior wall of the maxillary sinus, maxillary process). Forty-seven patients were in the osteoporosis group, and 49 patients were in the control group. On a PACS (picture archiving communication system), the region of interest was analyzed, and the Hounsfield units were measured. RESULTS: There was a significant difference in the mean bone density of the midfacial bones between the osteoporosis group and the control group (P < 0.01). For both groups, each of comparison of the 7 skeletal regions was greater as group A < group B < group C in this order (P < 0.01). CONCLUSIONS: We can see the independent effects of osteoporosis on the midfacial bones using CT scans. Estimated Hounsfield unit through CT scan is able to explain osteoporosis, which may be useful in the clinical fields in the future.

Clinical Significance of ß-Tricalcium Phosphate and Polyphosphate for Mastoid Cavity Obliteration during Middle Ear Surgery: Human and Animal Study.

OBJECTIVES: Mastoid obliteration is used to obliterate the mastoid cavity following a mastoidectomy or to prevent the formation of a retraction pocket. This study evaluated the effectiveness of ß-tricalcium phosphate and polyphosphate (ß-TPP) for mastoid obliteration in middle ear surgeries in prospective human and animal studies. METHODS: Twenty patients with chronic otitis media underwent mastoid obliteration using ß-TPP after a intact canal wall mastoidectomy or simple mastoidectomy. The clinical data were prospectively evaluated including: the diagnosis, temporal bone computed tomography (TBCT), otoscopic findings, pure tone audiogram, and complications. In the animal experiment, ß-TPP was applied into the right bulla in five rats, and the opposite bulla was used as the control in the non-obliterated state. The skulls of five other rats were drilled out and the holes were obliterated with ß-TPP. TBCT were obtained at 3, 6, and 9 months after the obliteration and histologic analysis was done at 3 and 9 months after surgery. RESULTS: In the human study, fourteen TBCTs were obtained at 12 months after the surgery. All demonstrated no bone resorption in the obliterated mastoids. Among the 15 cases displaying retracted tympanic membranes preoperatively, 11 showed no retraction, 2 showed retraction postoperatively, 1 was lost to follow-up and 1 was a case of postoperative wound infection. Among 20 cases, one case developed a postoperative infection that necessitated a second operation. Sixteen underwent ossiculoplasty; hearing improvements were obtained in 15 cases and 1 case showed decreased hearing. In the animal study, new bone formation without significant bone resorption in the radiologic and histologic findings were noted in both the skull and bulla groups. CONCLUSION: Although ß-TPP is a foreign material having the possibility of infection, mastoid obliteration with it can be a treatment option in middle ear surgeries to prevent retraction pockets or the recurrence of diseases.