Occlusion-Fit V-Line Guide and Gooseneck Saw for Safe and Accurate Mandibuloplasty in Asians

The Accuracy of a Patient-Specific Three-Dimensional Digital Ostectomy Template for Mandibular Angle Ostectomy

BACKGROUND

Although three-dimensional (3D)-printed digital ostectomy templates (DOTs) can help surgeons perform mandibular angle ostectomy (MAO) more precisely and safely, the clinical application of such templates is problematic.

OBJECTIVES

The aim of this study was to evaluate the accuracy of a novel DOT and improve the precision of MAO.

METHODS

A total of 20 patients with a prominent mandibular angle (PMA) were allocated into 2 groups (10 patients per group). A conventional DOT and a novel DOT were applied to guide MAO in Groups A and B, respectively. The mean time taken for curved osteotomy and the volume of postoperative drainage on 1 side within 24 hours were recorded. The deviations between the simulated and postoperative lower border of the mandible were measured on both sides.

RESULTS

All the patients were satisfied with the cosmetic outcomes. Statistical results showed that the mean time taken for curved osteotomy was shorter in Group B than in Group A, and that the volume of postoperative drainage on 1 side within 24 hours was similar between the 2 groups. The deviations at the anterior and posterior parts of the inferior border showed that the accuracy of osteotomy was higher in Group B than in Group A, and that there was no significant difference between the 2 groups in the middle part.

CONCLUSIONS

The novel DOT is easy to locate and fix tightly, which reduced the operating time and increased the safety and precision of the procedures.

LEVEL OF EVIDENCE: 4

Strategies of Mandibular Revision: A Retrospective Study of Revisional Mandibular Surgery for Unaesthetic Results of Previous Mandibular Reduction

BACKGROUND

Mandibular reduction has been developed and popularized in Asia for decades. Despite the technical advancement and experience accumulation, complications and unaesthetic results still occur, and some need a revision surgery. This study aims to introduce the experience of revision surgery to reshape the unaesthetic mandibular contour after previous mandibular reduction.

METHODS

From May 2011 to September 2017, patients dissatisfied with the result of previous mandibular reduction and who received a secondary mandibular revision were retrospectively reviewed and analyzed.

RESULTS

Twenty-five patients were included in this study. Under-correction (88%, 22/25) was the most common aesthetic problem requiring revision, followed by asymmetry (56%, 14/25), broad chin (40%, 10/25), second mandibular angle (32%, 8/25), and over-correction (8%, 2/25). As revision techniques, long-curve mandibular reduction, simple mandibular reduction, and mandibular grinding were performed on 60% (15/25), 36% (9/25), and 4% (1/25) of the patients, respectively. All the patients were satisfied with the results. Cephalometric measurements indicated a significant bone removal after revision.

CONCLUSIONS

When performing a revision surgery to reshape the mandibular contour, the surgeon should have a clear surgical plan based on comprehensive evaluation, focus on the balanced harmony of the entire face, use proper technique and instruments, and avoid concomitant injury and complications. The one-staged technique that treats the whole mandible as an entirety is superior than multistaged techniques to improve the aesthetic outcomes to the largest extent.

LEVEL OF EVIDENCE IV

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One-Piece Mandibuloplasty Compared to Conventional Mandibuloplasty With Narrowing Genioplasty

BACKGROUND

Recently, the mandibular body and chin shape are known to be important issue as well as the mandibular angle. The authors have performed the one-piece mandibuloplasty from the mandibular angle to the most anterior part of chin to achieve the change of the whole mandibular shape as a one-piece.

METHODS

All of 14 patients who complaint prominent mandibular angle and chin were randomly allocated into 2 groups. Group I (n = 7) was treated with conventional mandibuloplasty with narrowing genioplasty and Group II (n = 7) was treated with one-piece mandibuloplasty. Pre- and postoperative clinical photography, cephalometry, computed tomography scan, 3-dimensional photography were taken and occurrence of secondary angle, patient's satisfaction, and operative time were evaluated.

RESULTS

The mean volume reduction per side was 41.8 cc on one-piece mandibuloplasty and 36.5 cc on conventional mandibuloplasty with narrowing genioplasty. Furthermore, average lower facial decreased from 64.3 to 61.0 after 6 months postoperatively and was maintained until 3 years on average after the operation. In one-piece mandibuloplasty group shows a little higher satisfaction about mandible body, and it was estimated that the presence of secondary angle makes dissatisfaction. The authors' treatment approach resulted in a shorter total surgery time than conventional technique (70.57 versus 105.14 min, P = 0.002).

CONCLUSIONS

One-piece mandibuloplasty based on 3-dimensional printing model turned out to be very successful for the natural shaping of the lower jaw in the patients with the prominent mandible in terms of the technical efficiency and the aesthetic point of view.