Sagittal Genioplasty: New Techniques

Injury Risk Estimation in Mandible-Related Surgical Procedures: A CBCT Study Based on Vital Interforaminal Anatomical Structures

The mandibular interforaminal region has been considered safe for surgical procedures; nevertheless, the risk of injury to neurovascular structures, such as the mental foramen (MF) and its related structures (anterior loop [AL] and lingual foramina [LF]) should not be overlooked. The study aimed to evaluate the relative risk of injury to these structures during surgical procedures in the anterior region of the mandible based on cone-beam computed tomography (CBCT) scans. A retrospective cross-sectional and observational study was performed on 250 CBCTs from adults (18-69 years) with dentate jaws. Linear measurements of the MF, AL, and LF were evaluated to estimate the risk of injury to these structures during chin-related surgical procedures. The most frequent distance between the base of the mandible (BM) and MF was 8 mm (30.2%). In addition, 20.4% of the CTs had 6 mm from the vestibular cortical bone to the LF. The commonly found measurement from LF to the apex of the nearest tooth was 7 mm (24.0%); 64.2% of the CTs showed a 2-mm distance between the most distal point of the dental implant site to the most anterior point of the AL. Safety distances for genioplasty techniques (MF to mandible base > 6 mm, 96.6% [CI 95%, 95.0%-98.2%]) were observed. Considering the 5-mm cut-off point between the lower limit of a hypothetical bone graft and the chin, 65.4% (CI 95%, 58.9%-71.9%) of CTs were within this distance. Regarding the safety margin of 8 mm, 85.6% (CI 95%, 80.8%-90.4%) were up to this value. This study found safety margins for genioplasty and chin bone grafting surgical techniques that adopt a 5-mm cut-off point. Further similar studies assessing other surgical methods and employing larger samples from different geographical origins may contribute to this field of investigation.

Clinical and Cephalometric Changes in Long-face Patients With Retrogenia Following the Novel B-genioplasty Technique

BACKGROUND

The chin plays a fundamental role in facial attractiveness. Accordingly, several surgical procedures have been proposed for chin contouring. This study aimed to introduce "B-genioplasty" as a novel genioplasty technique and assess the clinical and cephalometric changes in long-face patients with retrognathia following the novel B-genioplasty.

METHODS

This is a cross-sectional study. Subjects with class I occlusion increased lower facial height and retrognathia underwent B-genioplasty in this prospective experimental study. Soft and hard tissue cephalometric measurements were made, and the depth of the notch in the lower border of the mandible was measured on lateral cephalograms at 6 months postoperatively and compared with baseline. Patient satisfaction with the outcome was also assessed.

RESULTS

Seventeen subjects were studied. Ten (58%) patients underwent rhinoplasty plus genioplasty. All patients were satisfied with the outcome. The step/notch in the lower border of the mandible was not detected in clinical examination in any patient. The mean notch depth was 0.5±0.83 mm on lateral cephalograms. The change in all soft and hard tissue cephalometric parameters was significant at 6 months postoperatively compared with baseline ( P <0.001 for all).

CONCLUSION

B-genioplasty caused satisfactory clinical and cephalometric changes in long-face patients with retrognathia, including prevention of step/notch in the inferior border of the mandible, significant reduction of gonial angle, correction of the mandibular plane, and reduction of lower facial height.

Satisfaction Level of Patients with the Outcome of Genioplasty

Background

We aimed to assess the satisfaction level of patients with the outcome of genioplasty and the influential parameters in this respect.

Methods

This retrospective study was conducted on 70 patients between 18 to 59 years, who underwent genioplasty in the Oral and Maxillofacial Surgery Department at Shariati and Sina Hospitals, Tehran, Iran, between 2010 and 2020. Patient records were evaluated and a questionnaire was filled out over the phone to assess the influential parameters on the satisfaction level of patients with the outcome of genioplasty. Data were analyzed by PASS 11 (alpha=0.1).

Results

Seventy patients were evaluated including 56 (80%) females and 14 (20%) males. Forty patients (52.6%) had no complaint with regard to the outcome of genioplasty. Postoperative chin deviation (not correcting the initial complaint) (10.52%), postoperative pain in the chin area (10.52%), and lower lip paresthesia (9.21%) were the most common patient complaints. The minimum and maximum satisfaction scores were 22 and 80, respectively. Number of follow-up sessions had a significant effect on satisfaction with the outcome of genioplasty (P=0.076). Patients who underwent advancement genioplasty alone had the highest level of long-term satisfaction with the outcome while those who underwent setback genioplasty alone had the lowest level of long-term satisfaction.

Conclusion

Advancement genioplasty had the highest rate of patient satisfaction, and chin asymmetry in the frontal view was the most common patient complaint after genioplasty.