F-Chin/Feminizing the Chin: A Genioplasty Technique with Virtual Planning for Male-to-Female Transgender Patients

The chin is an essential structure in facial harmony and an important gender marker. Advancing a receding chin is fundamental to improve the facial appearance, particularly in male-to-female transgender patients. However, in patients with microgenia and/or retrognathia, desiring a more feminine appearance, a chin advancement can result in a wider, square shape; an undesirable effect. Genioplasty is a versatile procedure used in facial feminization surgery that allows modifying the natural anatomy of the chin in all three spatial dimensions. The technique herein described proposes a simple genioplasty procedure for feminizing the chin (F-chin genioplasty) in transgender patients where anteroposterior advance is required. Virtual planning was used to establish the landmarks for an anteroposterior advancement with transverse reduction in the chin. A perpendicular line to the Frankfurt plane passing through the incisal edge of the upper central incisor was used to plan the anteroposterior movement, and two vertical lines on the outer wall of the nasal cavity  for the chin transverse measurement. The authors present three case reports with the F-chin genioplasty transgender technique with satisfactory results, ensuring a more feminine facial appearance.Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Evaluation of trabecular changes following advancement genioplasty combined with or without bilateral sagittal split osteotomy by fractal analysis: a retrospective cohort study

BACKGROUND

It is aimed to investigate whether there was a difference in radiographic changes in the operational areas between genioplasty alone and genioplasty combined with mandibular advancement and to evaluate the fractal dimension (FD) to assess trabecular changes after genioplasty surgery.

METHODS

Preoperative-(T0) and postoperative-(T1) panoramic radiographs of 26 patients without any complications who underwent genioplasty combined with bilateral sagittal osteotomy and mandibular advancement or genioplasty alone were selected. In the panoramic radiographs of both groups, the genial segment, mandibular angulus, and surgical osteotomy line were examined using FD. The box-counting method was used for FD evaluation.

RESULTS

It was determined that FD values before and after treatment were similar in both groups for all regions where measurements were made. After surgery, the FD values of the middle region of the genial segment were found to be significantly lower than the other regions. At T1, the FD values at the osteotomy area were found to be significantly higher than those in the middle region of the genial segment.

CONCLUSION

Trabecular structure does not differ in patients undergoing genioplasty alone or in combination with mandibular advancement osteotomy. The middle region of the genial segment heals later than other regions.

Total inferior border ostectomy versus T-shape genioplasty for chin narrowing combined with mandibular contouring

The objective of this study was to compare the indications and outcomes of the total inferior border ostectomy and T-shape genioplasty. A retrospective study was conducted using the clinical notes and records of patients who underwent total inferior border ostectomy (group 1, n = 42) and T-shape genioplasty (group 2, n = 60). The outcomes were evaluated by assessment of computed tomography images combined with medical records and photographs. Lower facial height, chin width, chin symmetry, and facial proportions, as well as patient satisfaction and complications were investigated. The data were collected preoperatively and 6-24 months postoperatively. All 102 patients showed an improved lower facial contour. No severe complications were observed during the follow-up period. Although the postoperative lower to midfacial height ratios were similar in the two groups (P = 0.080), both the preoperative and postoperative chin width to lower facial height ratios were lower in group 1 (both P < 0.001). A larger amount of chin narrowing, as well as better chin symmetry were observed in group 1 (P < 0.001). In conclusion, compared to the T-shape genioplasty, the total inferior border ostectomy is well suited for a longer, wider, and more asymmetrical chin. The surgical options should be considered and chosen quantitatively to achieve aesthetically pleasing results.

Three-dimensional analysis of the anterior loop of the inferior alveolar nerve in relation to the growth pattern of the mandibular functional subunit

Background

The purpose of the present study was to investigate the differences in the position and shape of the anterior loop of the inferior alveolar nerve (ALIAN) in relation to the growth pattern of the mandibular functional subunit.

Methods

The study was conducted on 56 patients among those who had undergone orthognathic surgery at the Gangnam Severance Hospital between January 2010 and December 2015. Preoperative computerized tomography (CT) images were analyzed using the Simplant OMS software (ver.14.0 Materialise Medical, Leuven, Belgium). The anterior and inferior lengths of ALIAN (dAnt and dInf) and each length of the mandibular functional subunits were measured. The relationship between dAnt, dInf, and the growth pattern of the mandibular subunits was analyzed.

Results

The length of the anterior portion of ALIAN (dAnt) reached 3.34 ± 1.59 mm in prognathism and 1.00 ± 0.97 mm in retrognathism. The length of the inferior portion of ALIAN (dInf) reached 6.81 ± 1.33 mm in prognathism and 5.56 ± 1.34 mm in retrognathism. The analysis of Pearson’s correlation coefficiency on all samples showed that the lengths of functional subunits were positively correlated with the loop depth. The length of the symphysis area in prognathic patients was positively correlated with the anterior loop depth (p = 0.005).

Conclusions

Both the anterior and inferior length of ALIAN are longer in prognathic patients. Especially, it seems to be associated with the growth of the symphysis area.