Objective:To investigate the relationship between idiopathic condylar resorption （ICR） and arch width disorder. Methods:Thirty-two patients with ICR and twenty patients without condylar resorption were enrolled according to the same inclusion criteria. They were divided into experimental group and control group. The experimental group was divided into unilateral ICR group and bilateral ICR group according to the affected side of condylar resorption, and then experimental group was divided into subgroups ICR Ⅰ, ICRⅡand ICR Ⅲ according to the degree of condylar resorption. Patients with no condylar resorption were used as a control group. The width of anterior, middle and posterior segments of dental arch on cone beam computed tomography（CBCT） was measured and the two groups of measured values were statistically analyzed. Results:Compared with the control group, the width of maxillary anterior, middle and posterior segments in ICR group was significantly reduced, and the difference was statistically significant（P<0.01）. But the width of mandibular segment was not significantly different from that in control group（P>0.05）. There was no significant difference in the width of anterior, middle and posterior dental arch between subgroups（P>0.05）. Conclusion:Almost all patients with ICR have malocclusion of maxillary and mandibular arch width, but there is no significant correlation between the malocclusion width and the severity of condylar resorption.
Humans ; Mandibular Condyle/diagnostic imaging* ; Dental Arch ; Bone Resorption ; Mandible ; Malocclusion

OBJECTIVES: To explore the relationship between the height of alveolar bone resorption and sex and age in the adolescent dentition. METHODS: Multi-slice computed tomography (MSCT) was used to measure the height of alveolar bone resorption at labial, lingual, mesial and distal sites of teeth in 149 adolescents aged from 10 to 20 years. SPSS 25.0 software was used to analyze the relationship between the height of alveolar bone resorption and sex and age. RESULTS: There was no significant difference in the height of alveolar bone resorption between sex (P>0.05). The height of alveolar bone resorption was positively correlated with age in all types of teeth. The model constructed by combining the alveolar bone resorption height data of four sites (y=2.569x₁+3.106x₂+4.108x₃+1.451x₄-0.082, R²_max=0.756)had a better ability to infer age than that of combining two sites (y=5.942x₁+4.489x₂+0.612, R²_max=0.706) and a single site (R²_max=0.638). CONCLUSIONS The height of alveolar bone resorption is positively correlated with the age of adolescents. The combination of four sites has a stronger ability to infer the relationship between the height of alveolar bone resorption and age in adolescents and has higher accuracy in practical application.
Humans ; Adolescent ; Child ; Young Adult ; Adult ; Alveolar Process/diagnostic imaging* ; Cone-Beam Computed Tomography ; Bone Resorption/diagnostic imaging* ; Tomography, X-Ray Computed

Radiographic changes consisting of alterations in mineral content, osteopaenia or destructive neuropathy that occur following successful finger replantation have already been described. We report our experience about four fingers in three individuals in whom bone changes developed in the first three months postoperatively with complete "restitution ad integrum". Three patients, 21-49 years old (average 36 years) sustained a clean-cut amputation of four fingers. The first patient had an amputation at the base of the middle phalanx of the index finger and the second patient at the base of the proximal phalanx of the ring finger. The third had an amputation at the base of the first metacarpal bone and the proximal phalanx of the small finger in a five finger amputation. In the first case, two dorsal veins and two palmar digital arteries and nerves were repaired. In the second case, one palmar artery and one dorsal vein were reanastomosed. In the third case at the thumb, two dorsal veins and two palmar digital arteries and nerves were reconstructed. At the small finger, one dorsal vein, one palmar digital artery and two digital nerves were reconstructed. Bone fixation was achieved with two and three K-wires or tension-band wiring. Replantation was successful in all cases. Three weeks after replantation, the X-rays showed rapid development of osteopaenia in the juxtaarticular region and metaphyses of the bone. These changes were followed by subperiosteal, intracortical and endosteal bone resorption. No further surgical procedures or splintage were needed and hand therapy was not discontinued. At 10-13 weeks (average 12 weeks) postoperatively, the X-rays showed a complete recovery with new periosteal bone formation. We suggest that the radiographic changes after finger replantation are transient, first evident subperiosteally and progressing centrally. They may reflect small-vessel compromise and microinfarction and transient hyperemia secondary to neurovascular damage or to sympathetic progressive recovery.
Adult ; Amputation, Traumatic ; surgery ; Bone Resorption ; etiology ; Female ; Finger Injuries ; diagnostic imaging ; surgery ; Fingers ; surgery ; Humans ; Male ; Middle Aged ; Radiography ; Replantation ; adverse effects

The aim of this retrospective study was to quantitatively evaluate the treatment effects of intrusion of overerupted maxillary molars using miniscrew implant anchorage and to investigate the apical root resorption after molar intrusion. The subjects included 30 patients whose average ages were 35.5±9.0 years. All patients had received intrusion treatments for overerupted maxillary molars with miniscrew anchorage. There were 38 maxillary first molars and 26 maxillary second molars to be intruded. Two miniscrews were inserted in the buccal and palatal alveolar bone mesial to the overerupted molar. Force of 100-150 g was applied by the elastic chains between screw head and attachment on each side. Lateral cephalograms and panoramic radiographs taken before and after intrusion were used to evaluate dental changes and root resorption of molars. Only 6 of the 128 miniscrews failed. The first and second molars were significantly intruded by averages of 3.4 mm and 3.1 mm respectively (P<0.001). The average intrusion time was more than 6 months. The crown of the molars mesially tilted by averages of 3.1 degrees and 3.3 degrees (P<0.001) for first and second molars. The amounts of root resorption were 0.2-0.4 mm on average. The intrusion treatment of overerupted molars with miniscrew anchorages could be used as an efficient and reliable method to recover lost restoration space for prosthesis. Radiographically speaking, root resorption of molars was not clinically significant after application of intrusive forces of 200 to 300 g.
Adult ; Bone Screws ; Cephalometry ; Dental Implantation ; Female ; Humans ; Male ; Maxilla ; Middle Aged ; Molar ; diagnostic imaging ; surgery ; Orthodontic Anchorage Procedures ; instrumentation ; methods ; Radiography, Dental ; methods ; Retrospective Studies ; Root Resorption ; diagnostic imaging ; surgery ; Tooth Movement Techniques ; instrumentation ; methods ; Young Adult

OBJECTIVETo investigate the effect of ridge preservation with Bio-Oss Collagen and Bio-Gide in posterior sites.

METHODSFrom May 2010 to July 2013, 16 patients with bilateral posterior teeth planned to be extracted and replaced by implants were enrolled. One of the sockets was randomly selected and presserved with Bio-Oss Collagen and Bio-Gide (intervention group). The contralateral socket was left to heal spontaneously (control group). Cone-beam (CBCT) scans were performed immediately after the extraction and 6 month later. The bone cores were collected during the implant placement surgery and analyzed by micro-computed tomography.

RESULTSAfter 6 month healing, the vertical and horizontal dimensional alteration of the treatment group were (0.55 ± 1.05) mm and (-0.99 ± 0.94) mm respectively, while the vertical and horizontal change of control group were (-0.71 ± 1.41) mm and (-2.26 ± 1.29) mm respectively. The micro-computed tomography results showed that there was no significant difference in new bone volume between control and intervention groups.

CONCLUSIONSApplying Bio-Oss Collagen and Bio-Gide for ridge preservation in posterior sites resulted in less vertical and horizontal bone resorption of sockets following extraction.

Alveolar Process ; diagnostic imaging ; Biocompatible Materials ; therapeutic use ; Bone Resorption ; prevention & control ; Collagen ; therapeutic use ; Heterografts ; Humans ; Minerals ; therapeutic use ; Organ Sparing Treatments ; methods ; Tooth Extraction ; Wound Healing ; X-Ray Microtomography