Review of Various Techniques

Onizuka ⁸ was the first author to publish his technique for reduction malarplasty in 1983. He described an entirely intraoral approach to shave the prominent zygoma with a broad chisel. Whitaker ⁹ described a coronal approach, reducing both the zygomatic arch and the malar prominence with a bur, at the same time, also carrying out temporal augmentation with an implant.

Other authors such as Ung and Lew ¹⁰ and Yang and Park ¹¹ have described a combination of shaving the malar prominence through an intraoral incision, and either a single greenstick fracture or multiple osteotomies of the zygomatic arch through a preauricular or coronal incision.

Rhee et al ¹² described utilizing only a preauricular incision to perform shaving of the zygoma body, osteotomy of the zygomatic arch, and lateral corticotomy of the arch.

A more popular method in recent times is to create an L-shaped ¹³ , ¹⁴ , ¹⁵ or I-shaped ¹⁶ osteotomy via an intraoral approach, combined with osteotomy of the zygomatic arch. Kim and Seul ¹⁴ first described the L-shaped osteotomy in 2000, which was carried out via an intraoral approach. Two parallel oblique osteotomies enabled the removal of a small 3–8 mm segment of bone and a transverse osteotomy of the arch was done with a curved osteotome through the same intraoral incision.

Ma ¹² removed a segment of bone along the short arm of the L about 4–6 mm wide, and fixed the remnant fragment with bicortical screws.

Wang ¹³ resected a 3–7 mm segment of bone along the short arm of the L, and fixed the fragment with microplates and screws.

Authors’ Technique

The authors’ approach utilizes both preauricular and sublabial incisions. Small preauricular stab incisions are made in the hairline of the sideburns. The soft tissue and periosteum are dissected off the zygomatic arch. A chisel is then used to osteotomize the zygomatic arch.

Next, sublabial incisions are made, and the periosteum is elevated off the anterior face of the maxillary sinus, as well as the body of the zygoma. The authors use an oscillating saw to create an L-shaped osteotomy of the body of the zygoma ( Fig. 30.3 ).

Resection of a 3–5 mm segment of bone along the long arm of the L is done for patients who require it.

The zygoma is then infractured with a mallet. Fixation is achieved with a three-hole miniplate and screws ( Fig. 30.4 ). The preauricular incisions are closed with polypropylene suture, and the sublabial incisions are closed with an absorbable polyglactin suture. Bulky compressive dressings are kept for 3 days, and then replaced with an elastic headband.

Complications

Most surgeons would now avoid using the coronal incision with its attendant risks of alopecia and longer operating time. The intraoral and preauricular incisions would be the main approaches for most authors currently, as the scars are hidden, with quick access to the zygoma.

The main concern for the intraoral approach is that of cheek drooping due to dissection of the masseter muscle; as such, it is important to limit the dissection and detachment of the masseter from the zygoma.

The criticism of using shaving alone as a reduction technique is insufficient reduction as well as periosteal proliferation, causing a high recurrence rate.

Breach of the maxillary sinus mucosa will almost always occur when performing the L-shaped osteotomy; however, sinusitis has rarely been reported. There have been isolated case reports of chronic sinusitis ¹⁷ and mucocele ¹⁸ occurring after reduction malarplasty.

Despite the proximity of the facial nerve to the zygomatic arch, to the best of the authors’ knowledge, there has been only one published report ¹⁹ of facial nerve palsy. This patient also had iatrogenic lateral rectus muscle injury, orbital fracture, and limited jaw opening.

Other reported complications include asymmetry, numbness in the distribution of the infraorbital nerve, hematoma, and malunion.

Review of Various Techniques

Idiopathic masseter muscle hypertrophy was first described by Legg in 1880. The earliest reports of management of a wide jawline were in the 1940s. Gurney ²⁰ described his method of hypertrophic masseter resection in 1947. Two years later, Adams ²¹ described the resection of the medial portion of the masseter muscle and simultaneous mandibular angle through an external approach.

It is now widely acknowledged that a wide, square jaw is not only due to masseter hypertrophy, but also due to the underlying skeletal structure of the mandible, ²² , ²³ and this is especially so in Asians.

It is important to note that in the assessment of the patient, the surgeon must consider both the gonial angle on lateral view, as well as the bigonial width on frontal view, as the surgical techniques to address each are different.

The early techniques were that of ostectomy of the angle, but as it was found that ostectomy of the angle alone was insufficient to address bigonial width, the addition of corticectomy or sagittal split procedures became more common for suitable patients. Baek et al, ²¹ in 1989, first reported using intraoral incisions to resect prominent mandibular angle using an oscillating saw, along with resection of the medial aspect of the masseter in some patients.

Later, they refined their contouring method by including tangential osteotomy for patients with lateral flaring of the angle. ²⁴ They also moved away from excision of the masseters, finding that doing so caused more bleeding, swelling, as well as a risk of facial nerve injury.

Pu et al ²⁵ described using either an intraoral incision to perform ostectomy for a flared or wide mandibular angle on frontal view, or a postauricular incision to address retroprotrusion of the ramus on lateral view. Shao et al ²⁶ described a combined method of a long, curved fullthickness ostectomy to correct the incline of the mandibular plane angle, as well as a mandible corticectomy to reduce bigonial width.

Multistage angle ostectomy was described by Ying et al ²⁷ in 2011 to achieve a smooth, natural jaw contour from the lateral view. The first cut is made from the mandibular notch to the ascending ramus. The following cuts are made more anteriorly and progressively less inclined to create a smooth inferior mandibular border.