A New Surgical Assistance Aid for Mesiodens Extraction Based on the Ideal Approach.

BACKGROUND: To date, the classification of mesiodens has been based on the location, crown orientation, and morphology; however, there is no assistance aid focusing on choosing surgical approach. PURPOSE: This study aimed to introduce and evaluate a new surgical assistance aid for mesiodens extraction based on surgical approach. STUDY DESIGN, SETTING, SAMPLE: For the retrospective trial part of this study, case data from mesiodens patients who had surgery at the Affiliated Stomatological Hospital was collected, and a new surgical assistance aid was developed. A prospective randomized controlled trial was conducted on mesiodens patients who were seen in our department (patients with one mesiodens were included). PREDICTOR VARIABLE: The predictor variable was surgical approach either with or without the surgical assistance aid. Subjects were randomized to one of the two study groups. For subjects assigned to the group using the surgical assistance guide, the approach was selected according to the aid detailed in this study. For subjects assigned to the group without the surgical assistant aid, 2 residents chose an approach based on their judgment and review of relevant imaging and physical examination. MAIN OUTCOME VARIABLES: The preoperative evaluation time, operative time, and complications associated with surgery were recorded separately for the two groups. COVARIATES: The age and sex were also recorded. ANALYSES: Variables were analyzed using the independent t-test and χ2 test. The level of statistical significance is P < .05. RESULTS: In the retrospective trial part, a new surgical assistance aid for mesiodens extraction was developed based on the ideal surgical approach. In the prospective randomized controlled trial, the experimental group (n = 50) was statistically significant in preoperative evaluation time (4.51 ± 0.34 mins vs 5.43 ± 0.34 mins) and operative time (31.87 ± 5.57 mins vs 36.32 ± 5.28 mins) compared to the control group (n = 50) (P < .001). There was no significant intergroup difference in complications associated with surgery (P > .05). CONCLUSION AND RELEVANCE: The new surgical assistance aid developed in this study guides surgeons to ease the selection of surgical approaches and shorten the operative time.

Application of digital guide plate with drill-hole sharing technique in the mandible reconstruction.

Background/purpose: With the development of computer-assisted surgery, digital guide plate was widely used in vascularized bone flap grafts for mandibular reconstruction. The purpose of this study was to design and manufacture a digital guide plate with drill-hole sharing for mandibular reconstruction and assess for surgical accuracy. Materials and methods: 17 patients that required mandibular reconstruction using fibula free flap or iliac crest free flap were included in the study. The computed tomography (CT) data of the patient's mandible and pelvis or fibula were acquired preoperatively. A surgical simulation was then performed using computer-aided surgical simulation (CASS) technology based on above date, which allowed the design of two cutting guide and a repositioning guide for mandibular reconstruction. After surgery, the accuracy of reconstruction was evaluated by superimposing the postoperative image onto the preoperative image of mandible, recording the linear and angular deviation of landmarks, measuring the differences between the planned and actual outcomes. Results: The osteotomy and repositioning of fibula or iliac crest segments were successfully performed as planned using surgical guides. The digital guide plate with drill-hole sharing showed excellent accuracy, When the iliac crest or the fibula free flap were used for mandibular reconstruction, the largest mean differences between the preoperative and postoperative were 1.11 mm and 2.8° or 1.3 mm and 3.87°. Conclusion: The digital guide plate with drill-hole sharing designed preoperatively provides a reliable method of for the mandibular reconstruction. This can assist surgeons in accurately performing osteotomy and repositioning fibula or iliac crest segments during the mandibular reconstruction.

Design and manufacture of dental-supported surgical guide for genioplasty.

BACKGROUND/PURPOSE: Genioplasty were used widely to correct chin deformities. The purpose of this study was to design and manufacture a dental-supported surgical guide for genioplasty surgery and assess for surgical accuracy. MATERIALS AND METHODS: eleven patients with chin deformities were treated in this study. The computed tomography (CT) data of the patient's skull and the digital dental models of stone dental models were acquired preoperatively. For each patient, a virtual three-dimensional (3D) model of the skull was constructed and enhanced with digital dental models. A surgical simulation was then performed using computer-aided surgical simulation (CASS) technology based on clinical examination and 3D cephalometry. The surgery was simulated preoperatively which allowed the design of a cutting guide and a dental-supported repositioning guide for genioplasty, which was then 3D-printed and used during operation after disinfection. After surgery, the outcome was evaluated by superimposing the postoperative CT model onto the preoperative model, recording the linear and angular deviation of landmarks and plane, then measuring the differences between the planned and actual outcomes. RESULTS: The osteotomy and repositioning were successfully performed as planned using surgical guides. No inferior alveolar nerve damage was seen in this study. The dental-supported surgical guide showed excellent accuracy, with the largest differences between the planned and the postoperative chin segment being 0.9 mm and 3.2°. CONCLUSION: The dental-supported surgical guide designed preoperatively provided a reliable method of transfer genioplasty planning. This can assist surgeons in accurately performing osteotomy and repositioning bone segments during a genioplasty.

[Survey and analysis of tooth extraction anxiety of dental patients].

OBJECTIVE: This study aims to understand the current status and analyze the influencing factors of tooth extraction anxiety of dental patients. METHODS: The General Factor Questionnaire and Modified Dental Anxiety Scale (MDAS) were used to survey and analyze tooth extraction anxiety of 800 dental patients. Single-factor and multi-factor analyses were used for statistical data analysis. RESULTS: A total of 768 qualified questionnaires were received out of 800, the efficiency was 96%. The mean MDAS score was 10.21±3.29. The prevalence percentage of dental anxiety was 14.7%. Significant statistical differences of the incidence of dental anxiety were observed with regard to sex, age, tooth extraction time, accompanying relatives and friends, before tooth extraction, tooth extraction experience for family and friends, pain tolerance, mental health state before tooth extraction, and self-reported oral health status (P<0.05. By contrast, no significant statistical differences in the incidence of dental anxiety were observed with regard to educational level, tooth extraction type, national life experience, profession, and personality (P>0.05). Logistic regression analysis indicated that the risk factors of dental anxiety were sex, accompanying relatives and friends, mental health state before tooth extraction, and self-rated oral health status. CONCLUSIONS: The prevalence percentage of tooth extraction anxiety is high for dental patients. Gender, age, health satisfaction, tooth extraction time, accompanying relatives and friends, before tooth extraction, tooth extraction experience for family and friends, pain tolerance, mental health state before tooth extraction, and self-reported oral health status are the influencing factors of dental anxiety.