Sub total unilateral oculomotor nerve palsy in a Le Fort I osteotomy

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.

Strain Distribution and Amount of Force Required During Pterygomaxillary Dysjunction: A Comparison of Pterygoid Versus Shark-fin Osteotome

Objective

This study was conducted to compare the efficacy of Obwegeser's pterygoid osteotome and Laster shark-fin osteotome by measurement of strain adjacent to the pterygomaxillary suture and the amount of force required for dysjunction.

Materials and Methods

Two popular instruments Obwegesser's pterygoid and shark-fin osteotome were tested on dry human skulls. The external force required for separation of the pterygomaxillary suture with these osteotomes was generated by an electronically controlled 'Instron' tester Bi-06-108. Tests were performed with pterygoid osteotome placed on one randomly chosen side and shark-fin osteotome on the other side of the same specimen. The amount of strain developed by each of these instruments was recorded using two strain gauges on the right and left lateral pterygoid plates.

Results

[Table: see text].

Conclusion

Based on the distribution of strain, from this study, we conclude that Laster shark-fin osteotome is efficacious over Obwegeser's Pterygoid osteotome, in Le fort I osteotomy.

Evaluation of strain values of critical anatomic regions for two different pterygomaxillary approaches in Le Fort I osteotomy: An experimental study

Background

The purpose of this experimental study was to measure stresses both on the pterygoid plates and the skull base following two different pterygomaxillary approaches in Le Fort I osteotomy.

Material and Methods

The prepared skull models were randomly divided into 2 groups of 7. In the first group (A), the pterygomaxillary area was left intact. In the second group (B), pterygomaxillary separation was performed with a fine bur. The stresses were measured by using strain gauges. These strain gauges were attached to 6 different anatomical sites. The skull models were mounted on a servo-hydraulic testing unit. Each model was then subjected to a continuous linear tension until a plastic deformation was seen.

Results

The statistical analyses showed that there were no significant differences (p >.05) between the 2 groups regarding the strain values. Moreover, no statistical differences (p >.05) were found between the two groups in terms of maximum applied forces.

Conclusions

Considering the clinical conditions, the present study shows that when Le Fort I osteotomy performed without pterygomaxillary separation, there is no significant stress on the skull base during the downfracture. Moreover, it is considered that there is no need for an excessive force applied to perform downfracture in Le Fort osteotomies without pterygomaxillary separation.

Key words:Le Fort I, osteotomy, strain, base of skull, pterygoid process.

Intracranial subdural hygroma after Le Fort I osteotomy

Various intra- and postoperative complications have been well-documented after Le Fort I osteotomies; however, an intracranial subdural hygroma has not yet been reported in oral and maxillofacial studies. We report a unique case of an intracranial subdural hygroma requiring neurosurgical intervention after Le Fort I advancement.

LeFort I Osteotomy

The LeFort I osteotomy is one of the most commonly used procedures to correct midface deformities. It allows for correction in three dimensions including advancement, retrusion, elongation, and shortening. It is indicated, often in conjunction with mandibular surgery, for class II and III malocclusion, facial asymmetry, obstructive sleep apnea, and maxillary atrophy. Before surgery, proper orthodontics and surgical planning should be undertaken to ensure adequate outcomes. Overall, the surgery is widely used due to its low complication profile and reliable long-term results.

Screw implantation in the globe: the risk of delayed hardware migration from craniofacial repair

Plating system modification has enabled the use of rigid fixation in younger patients having maxillofacial surgery. One of the common reported complications of the use of plates and screws in children is screw migration due to skeletal maturation. Ophthalmic complications due to maxillofacial surgery reported to date include oculomotor and abducens palsies, lacrimal damage and vision loss due to infection, retrobulbar hemorrhage, and compartment syndrome. We describe a complication unique to screw migration resulting in orbital fixation and near-globe rupture in a patient with Treacher Collins syndrome. We hope to alert our colleagues to the potential risk of screw and hardware migration and breakage, particularly in the setting of craniofacial surgery performed on a child before maturation of craniofacial osseous structures.

Intra- and perioperative complications of the LeFort I osteotomy: a prospective evaluation of 1000 patients

The LeFort I osteotomy has become a routine procedure in elective orthognathic surgery. The authors report the occurrence of intra- or perioperative complications in a series of 1000 consecutive LeFort I osteotomies performed within a 20-year period. In total, 64 (6.4%) patients experienced complications. Anatomical complications affected 26 (2.6%), patients, including 16 (1.6%) with a deviation of the nasal septum and 10 (1.0%) with non-union of the osteotomy gap. Extensive bleeding that required blood transfusion occurred in 11 (1.1%) patients exclusively after bimaxillary corrections; in 1 patient a ligation of the external carotid artery became necessary. Significant infections such as abscesses or maxillary sinusitis occurred in 11 (1.1%) patients. No patient experienced an osteomyelitis. Ischemic complications affected 10 (1.0%) patients, including 2 (0.2%) who experienced an aseptic necrosis of the alveolar process and 8 (0.8%) who, under critical revision, were affected by retractions of the gingiva. Five (0.5%) patients experienced an insufficient fixation of the osteosynthesis material. The risk and the extent of complications was enhanced in patients with anatomical irregularities (eg, in patients with craniofacial dysplasias, orofacial clefts, or vascular anomalies). The risk of ischemic complications was enhanced in extensive dislocations or transversal segmentation of the maxilla. The authors conclude that patients with major anatomical irregularities should be informed about an enhanced risk of Le-Fort I osteotomies. Preoperative planning avoiding transversal segmentation or extensive dislocations of the maxilla should reduce the occurrence of complications. For healthy individuals, the risk of complications with the LeFort I osteotomy is considered low.

Ocular palsy following Le Fort 1 osteotomy: a case report

A 33-year-old female patient developed an ipsilateral sixth nerve palsy and partial third nerve palsy following a Le Fort 1 osteotomy. Complete resolution occurred at 10 weeks. The likely mechanism of injury secondary to pterygo-maxillary dysjunction is highlighted, with description of the relevant anatomy. Previous cases of ocular motility complications following Le Fort 1 osteotomy are discussed. We recommend that significant care be taken in osteotome placement in the pterygo-maxillary fissure, particularly in those prone to unpredicted fractures such as older patients, or where the anatomy is congenitally abnormal or altered by previous surgery.