Peripheral facial palsy after bilateral sagittal split ramus osteotomy: case report

Cranial Nerve Injuries in Orthognathic Surgery: A Review of Literature

ABSTRACT

Orthognathic surgery is increasingly utilized to correct facial deformities and dental malocclusions, as well as to enhance facial aesthetics. Significant advancements in surgical planning and execution have made it more widespread and accessible. However, unfavorable outcomes or complications can occur, leading to potentially severe and possibly long-term consequences, such as cranial nerve injuries. This literature review investigates the cranial nerve complications associated with orthognathic surgery. We conducted an extensive search across available databases, analyzing relevant studies published up to September 30, 2023. Two authors independently selected articles for full-text review based on their titles and abstracts. The eligible studies reported cranial nerve injuries in individuals who had undergone orthognathic surgery. Our findings highlight the risk of cranial nerve injuries, their possible mechanism, management, and outcomes. It is imperative for surgeons to remain vigilant and informed and to communicate such information during preoperative patient consultation.

Facial palsy after orthognathic surgery: A systematic review

It was the aim of the systematic review to evaluate the incidence of facial palsy following orthognathic surgery, and to assess the possible mechanisms of injury, subsequent management, and eventual outcomes. The protocol of this systematic review was registered in the International Prospective Register of Systematic Reviews. A thorough search of PubMed, Scopus, Cochrane Library, and CINAHL databases up to April 2022 was conducted. In total, 34 articles were selected for this review, including 54 facial palsies in 53 patients. The incidence of facial palsy was estimated to range from 0.04% to 0.77%. Most of the possible etiologies proposed involved intraoperative nerve compression or postoperative edema. Physical therapy and steroid administration were the most frequently employed management approaches. Surgical exploration for the facial nerve was executed in one patient. Forty-three facial palsies (79.6%) attained complete recovery with conservative management, whereas 11 facial palsies (20.4%) continued to show incomplete recovery during the follow-up period. Earlier facial palsy onset (timing after surgery) was related to a higher risk of continuing palsy (p = 0.018). Within the limitations of this review it seems that facial palsy following orthognathic surgery should be treated conservatively whenever appropriate.

Sagittal Split Ramus Osteotomy in the Shortest Buccal Bone Marrow Distances of the Mandible on the Coronal Plane

Purpose

This study investigated the relationship between the shortest buccal bone marrow of the ramus and skeletal patterns.

Materials and Methods

Using cone-beam computed tomography data (specifically, the A point-nasion-B point (ANB) angle), we divided patients into three groups as follows: skeletal class I (0° < ANB < 4°), class II (ANB: ≥4°), and class III (ANB: ≤0°). Sixteen vertical sections in the coronal plane were taken starting from slice 0 (original intact mandibular canal) anteriorly at 2 mm intervals to slice 15 (30 mm). The thickness of the mandible (M) and shortest buccal bone marrow (SBM) were measured. The data of SBM were divided into two groups (SBM ≥ 1 mm and SBM < 1 mm). For each skeletal pattern, an SBM value < 1 mm was considered to indicate a high possibility of postoperative nerve paresthesia and bad split.

Results

The three skeletal pattern groups also did not significantly differ in their M values for all sections. The mean SBM values of class III (0.91–2.11 mm) at 6–16 mm anterior to the mandibular foramen were significantly smaller than those of class II (1.53–3.17 mm). Comparing the occurrence ratio of SBM < 1 mm, the highest and lowest probabilities in class III (55% and 21.7%, respectively) were significantly larger at 6–20 mm anterior to the mandibular foramen than those in class II (28.3% and 5%, respectively).

Conclusion

Class III had a significantly shorter SBM distance and higher SBM occurrence probability than class II at the mandibular ramus region, implying that class III participants are more likely than class II participants to have nerve paresthesia and bad split after sagittal split ramus osteotomy.