The alveolar ridge is resorbed gradually after tooth extraction, and its degree is different according to each person and each tooth. The resorption of alveolar ridge is caused by the systemic and local factors, and is mainly influenced by the method of tooth extraction.
The study of prevention of alveolar ridge resorption after tooth extraction, have been performed by a lot of researchers.
In order to prevent resorption of alveolar ridge after extraction, the extraction socket should be closed immediately with the soft tissue. The closure of extraction socket is often performed by the free soft tissue graft or the pedicle graft, and the pedicle graft is mainly used.
The pedicle flap is performed as the rotation flap, which is divided into the closure method with the full-thickness flap and method with the split-thickness flap.
The closure method with the full-thickness/split-thickness flap is to close the extraction socket with the periosteal membrane, and the donor site is closed with the epithelium and subepithelial connective tissue.
This study is good for the closure of extraction socket and can preserve the alveolar bone of donor site, due to elevate the flap with full-thickness or split-thickness flap to remain the periosteal membrane and replace the flap to closure the extraction socket.
In the department of periodontology Pyongyang medical college,
In study, 140 patients (male 74, female 66, ages 27~59 mean ages 41) were subjected. Teeth to be extracted were the teeth which have severe alveolar bone resorption with periodontal diseases, root fracture, hopeless caries or apical diseases. Extracted teeth are one or adjacent two teeth. The study group (n=69) was performed with the semi-lunar coronally positioned flap, and the control group was performed with only suture.
The semi-lunar coronally positioned flap is mainly used in maxillary incisors, which are applied with temporary prosthesis after operation. The examination according to the surgery process was performed after 1 week, 3 months, 6 months, 9 months after surgery, and was compared with control group.
The standard periodontal probe with 1mm scale was used for detection.
After surgery the closure state of extraction socket in study group(91.30%) was significantly higher than the control group(33.80%). In this study, the researchers examined the change state of alveolar ridge height after soft tissue graft. Sequently, the height change of alveolar ridge after soft tissue graft was 1.2±0.14mm on 3 months in study group compared with 2.0±0.15mm in control group, and there was significant difference between the study group and control group on 3, 6, 9 months.
Additionally, the width change of alveolar ridge after soft tissue graft was 1.4±0.14mm on 3 months in study group compared with 2.9±0.15mm in control group, and there was significant difference between the study group and control group on 3, 6, 9 months.
In this study, we concluded that the closure of extraction socket with semi-lunar coronally positioned flap was 2.5 times higher than control group, and the preservation of alveolar ridge was also 1.5 times higher than the control group.
We keep studying to close the extraction socket with the semi-lunar coronally positioned flap for preserve the alveolar ridge.
