Apical surgery for a mandibular molar is still challenging for many reasons. This report describes the applications of computer-guided cortical \'bone-window technique\' using piezoelectric saws that prevented any nerve damage in performing endodontic microsurgery of a mandibular molar. A 49-year-old woman presented with gumboil on tooth #36 (previously endodontically treated tooth) and was diagnosed with chronic apical abscess. Periapical lesions were confirmed using cone-beam computed tomography (CBCT). Endodontic microsurgery for the mesial and distal roots of tooth #36 was planned. Following the transfer of data of the CBCT images and the scanned cast to an implant surgical planning program, data from both devices were merged. A surgical stent was designed, on the superimposed three-dimensional model, to guide the preparation of a cortical window on the buccal side of tooth #36. Endodontic microsurgery was performed with a printed surgical template. Minimal osteotomy was required and preservation of the buccal cortical plate rendered this endodontic surgery less traumatic. No postoperative complications such as mental nerve damage were reported. Window technique guided by a computer-aided design/computer-aided manufacture based surgical template can be considerably useful in endodontic microsurgery in complicated cases.

Pulmonary cement embolism (PCE) is one of several complications of percutaneous vertebroplasty and kyphoplasty. Generally, PCE can be easily diagnosed based on typical chest radiograph findings such as single or multiple radiographically dense opacities with a tubular or branch shape in the lung field along with a recent history of percutaneous vertebroplasty or kyphoplasty. These findings can be alarming and may be encountered on routine chest radiographs, even in asymptomatic patients. One study showed that PCEs that were not visualized on chest radiograph were also not shown on chest computed tomography. However, we encountered a patient with dyspnea who had normal chest radiograph findings but was diagnosed with PCE through only the bone window setting on chest computed tomography. The present case will be beneficial to all physicians examining older patients with dyspnea.

The aim of this case series study was to illustrate the bone lid technique implemented using piezoelectric surgery to access mandibular alveolar bone diseases and to assess the clinical and radiographic outcomes. The technique was used to treat 21 consecutive patients with various conditions: cysts in six cases, impacted teeth with associated cysts in nine, keratocystic odontogenic tumours in three, impacted teeth in two, and an endodontic lesion in one. The bone lid was fashioned using piezoelectric surgery and a thin osteotomy insert. After the surgical procedure, the bone lid was replaced and fixed with miniplates. On clinical and radiological follow-up at 12 months, the outcome measures were bone lid integration and alveolar bone volume recovery. Any complications were also documented. The lesion and bone lid healed completely in 19 cases; one patient experienced permanent mild paresthesia and one experienced trauma-induced bone lid necrosis. Computed tomography volumetric analyses conducted on 11 cases indicated a mean recovery of 93.8% of the volume of bone lost. Based on healthy biological reasoning, the bone lid technique with piezoelectric surgery and rigid fixation may be considered a valid alternative to ostectomy for the purposes of bone tissue healing.