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The aim of this study was to introduce and report on a 3D-printed perforator navigator and its clinical application. Integrated imaging and 3D printing techniques were employed for the design and manufacture of a perforator navigator. Key techniques included establishing a digital image coordinate system, localizing perforator fascia piercing points, creating a reference plane for the perforator course, and projecting the perforator course onto the body surface. All cases of maxillofacial defect repaired with free fibular myocutaneous flaps, from January 2019 to January 2022, were reinvestigated. Patients treated using traditional perforator localization methods were assigned into group Ⅰ, while those who had a navigator used during treatment were allocated to group Ⅱ. Outcome measurements included perforator positioning accuracy, perforator preparation time (PT), and flap growth score. Capillary refilling time and degree of flap swelling were recorded on the 1st, 3rd, and 7th days after surgery. On the 10th day after surgery, the flap survival situation was graded. In total, 25 patients were included in the study. Perforator preparation time for group Ⅱ was significantly less (p ＝ 0.04) than for group Ⅰ (1038.6 ± 195.4 s versus 1271.4 ± 295.1 s. In group Ⅱ, the mean positioning deviation for the perforator navigator was 2.12 cm less than that for the high-frequency color Doppler (p ＝ 0.001). Group Ⅱ also had a higher score than group Ⅰ for overall flap growth evaluation (nonparametric rank sum test, p ＝ 0.04). Within the scale of the study, it seems that perforator localization and navigation using a 3D-printed navigator is technically feasible, and helps to improve the clinical outcome of free fibular flaps. The perforator navigator will play a useful role in displaying the perforator course, improving the accuracy of perforator localization, reducing surgical injury, and ultimately enhancing flap success rate. • 3D-printed navigators are convenient and reproducible. • The establishment of a visualized coordinate system enabled precise and intuitive perforator localization. • The navigator offered a clear and entire pathway map for the perforator. • There was improvement in flap success with the use of the perforator navigator. [ABSTRACT FROM AUTHOR]

Implant placement in the mandibular molar sites plays a crucial role in the restoration of edentulous mandibles. However, the evaluation of bone quantity before implant surgery using cone beam computed tomography (CBCT) is lacking. The purpose of this clinical study was to evaluate CBCT images of edentulous patients to analyze the feasibility of implant placement in healed mandibular molar sites. The CBCT data of 138 patients were analyzed in the sagittal plane for measurements of mandibular bone height (MBH), superior bone height (SBH), inferior bone height (IBH), buccal bone width (BBW), lingual bone width (LBW), and alveolar bone widths (ABWs). The edentulous sites were categorized according to the bone quantity and complexity of the implant surgery. Multivariate analysis of variance (MANOVA) was used to analyze the site, sex, and age-related variations. An independent t test was used to compare the difference of bone dimension in different sites and between sexes. One-way ANOVA followed by post hoc tests were used to analyze the difference between different age groups. Categorical variables were presented as number of events and percentages. The chi-squared test was used to compare categorical variables (α=.05). A total of 534 sites of interest were recorded, including 274 hemimandibles. A significant difference in BBW was found between the first and second molar sites. Men had higher MBH, SBH, IBH, and BBW than women. The distribution of implant surgical complexity in the conventional group was 63.5%, while the buccolingual tilted implant group accounted for 17.0%, and the complicated group accounted for 19.5%. Of the 274 hemimandibles, an implant could be placed directly at molar sites in 88% of situations. The BBW at the mandibular second molar site was greater than that at the first molar site. The amount of available bone in the SBH and BBW was greater in men than in women at the healed molar sites. Age did not significantly affect the complexity of the implant surgery. Implants can be placed directly in healed mandibular molar sites in most patients who require a complete arch mandibular implant-supported restoration. [ABSTRACT FROM AUTHOR]