Orthognathic surgery in cleft patients

Distraction force promotes the osteogenic differentiation of Gli1+ cells in facial sutures via primary cilia-mediated Hedgehog signaling pathway

BACKGROUND

Trans-sutural distraction osteogenesis (TSDO) involves the application of distraction force to facial sutures to stimulate osteogenesis. Gli1+ cells in the cranial sutures play an important role in bone growth. However, whether Gli1+ cells in facial sutures differentiate into bone under distraction force is unknown.

METHODS

4-week-old Gli1ER/Td and C57BL/6 mice were used to establish a TSDO model to explore osteogenesis of zygomaticomaxillary sutures. A Gli1+ cell lineage tracing model was used to observe the distribution of Gli1+ cells and explore the role of Gli1+ cells in facial bone remodeling.

RESULTS

Distraction force promoted bone remodeling during TSDO. Fluorescence and two-photon scanning images revealed the distribution of Gli1+ cells. Under distraction force, Gli1-lineage cells proliferated significantly and co-localized with Runx2+ cells. Hedgehog signaling was upregulated in Gli1+ cells. Inhibition of Hedgehog signaling suppresses the proliferation and osteogenesis of Gli1+ cells induced by distraction force. Subsequently, the stem cell characteristics of Gli1+ cells were identified. Cell-stretching experiments verified that mechanical force promoted the osteogenic differentiation of Gli1+ cells through Hh signaling. Furthermore, immunofluorescence staining and RT-qPCR experiments demonstrated that the primary cilia in Gli1+ cells exhibit Hedgehog-independent mechanosensitivity, which was required for the osteogenic differentiation induced by mechanical force.

CONCLUSIONS

Our study indicates that the primary cilia of Gli1+ cells sense mechanical stimuli, mediate Hedgehog signaling activation, and promote the osteogenic differentiation of Gli1+ cells in zygomaticomaxillary sutures.

Effectiveness of tranexamic acid in orthognathic surgery: A systematic review of systematic reviews

PURPOSE

This study aimed to review the currently available evidence on the effectiveness of administering tranexamic acid (TXA) to patients undergoing orthognathic surgery.

METHODS

A study protocol was developed in accordance with the Preferred Reporting Guideline for Overviews of Reviews (PRIOR) and registered on the International Prospective Register of Systematic Reviews (PROSPERO) under Registration No. CRD42021232931. Furthermore, the reporting of the present systematic review was performed based on the PRISMA checklist.

RESULTS

The search strategy yielded a total of 50 articles. After reading the abstracts, 28 articles were excluded, and the English full texts of the remaining 22 studies were separately examined for eligibility by two authors; 15 articles were excluded because they did not meet the inclusion criteria. Finally, seven systematic reviews and meta-analysis satisfied the criteria for inclusion and were processed for critical review evaluation.

CONCLUSIONS

Within the limits of the present study and the reviews of the 7 articles included, it is observed that TXA is able to reduce the amount of intraoperative blood loss and the amount of irrigation fluids required. However, it does not influence postoperative levels of hemoglobin or hematocrit, nor does it affect the requirement for blood transfusions. It was interestingly discovered that TXA could increase the quality of the surgical site. These data imply that TXA may be an effective adjuvant in lowering bleeding during orthognathic surgery. As a result, the potential risk of problems related with considerable blood loss may be minimized.

Unilateral Cleft Lip and Palate Has Asymmetry of Bony Orbits: A Retrospective Study

Facial asymmetry is common in unilateral clefts. Since virtual surgical planning (VSP) is becoming more common and automated segmentation is utilized more often, the position and asymmetry of the orbits can affect the design outcome. The aim of this study is to evaluate whether non-syndromic unilateral cleft lip and palate (UCLP) patients requiring orthognathic surgery have asymmetry of the bony orbits. Retrospectively, we analyzed the preoperative cone-beam computed tomography (CBCT) or computed tomography (CT) data of UCLP (n = 15) patients scheduled for a Le Fort 1 (n = 10) or bimaxillary osteotomy (n = 5) with VSP at the Cleft Palate and Craniofacial Center, Helsinki University Hospital. The width, height, and depth of the bony orbit and the distance between the sella turcica and infraorbital canal were measured. A volumetric analysis of the orbits was also performed. The measurements were tested for distribution, and the cleft side and the contralateral side were compared statistically with a two-sided paired t-test. To assess asymmetry in the non-cleft population, we performed the same measurements of skeletal class III patients undergoing orthognathic surgery at Päijät-Häme Central Hospital (n = 16). The volume of bony orbit was statistically significantly smaller (p = 0.014), the distance from the infraorbital canal to sella turcica was shorter (p = 0.019), and the anatomical location of the orbit was more medio-posterior on the cleft side than on the contralateral side. The non-cleft group showed no statistically significant asymmetry in any measurements. According to these preliminary results, UCLP patients undergoing orthognathic surgery show asymmetry of the bony orbit not seen in skeletal class III patients without a cleft. This should be considered in VSP for the correction of maxillary hypoplasia and facial asymmetry in patients with UCLP.

Intravenous ibuprofen versus diclofenac plus orphenadrine in orthognathic surgery: a prospective, randomized, double-blind, controlled clinical study

Objectives

The aim of this prospective, randomized, double-blind, controlled clinical study was to evaluate the analgesic effect of ibuprofen versus diclofenac plus orphenadrine on postoperative pain in orthognathic surgery.

Material and methods

Patients who underwent orthognathic surgery were randomized into two groups to receive intravenously either 600 mg of ibuprofen (I-group) or 75 mg diclofenac plus 30 mg orphenadrine (D-group), both of which were given twice daily. Additionally, both groups were given metamizole 500 mg. Rescue pain medication consisted of acetaminophen 1000 mg and piritramide 7.5 mg as needed. To assess the pain intensity, the primary end point was the numeric rating scale (NRS) recorded over the course of the hospital stay three times daily for 3 days.

Results

One hundred nine patients were enrolled (age range, 18 to 61 years) between May 2019 and November 2020. Forty-eight bilateral sagittal split osteotomies (BSSO) and 51 bimaxillary osteotomies (BIMAX) were performed. Surgical subgroup analysis found a significant higher mean NRS (2.73 vs.1.23) in the BIMAX D-group vs. I-group (p = 0.015) on the third postoperative day. Additionally, as the patient’s body mass index (BMI) increased, the mean NRS (r = 0.517, p = 0.001) also increased. No differences were found between age, gender, length of hospital stay, weight, operating times, number of patients with complete pain relief, acetaminophen or piritramide intake, and NRS values. No adverse events were observed.

Conclusion

The results of this study demonstrate that ibuprofen administration and lower BMI were associated with less pain for patients who underwent bimaxillary osteotomy on the third postoperative day. Therefore, surgeons may prefer ibuprofen for more effective pain relief after orthognathic surgery.

Clinical relevance

Ibuprofen differs from diclofenac plus orphenadrine in class and is a powerful analgetic after orthognathic surgery.

One-Year Stability of LeFort I Advancement in Patients With Complete Cleft Lip and Palate Using a Standardized Clinical and Surgical Protocol

AIM

To assess treatment outcome and 1-year stability of LeFort I advancement in patients with complete cleft lip and palate.

METHODS

Thirty-five patients (age 20.65 ± 2.20 years) with unilateral (n = 25) or bilateral (n = 10) complete cleft lip and palate who underwent LeFort I advancement were included.Lateral cephalograms before surgery (T1), immediately postsurgery (T2), and at 1-year follow-up (T3) were superimposed, and the position of anterior nasal spine (ANS), A-point, and U1 Tip assessed using an x, y coordinate system. Differences between landmark positions at the 3-time points were analyzed using paired sample t-tests, with a significance defined as α ≤ 0.05.

RESULTS

The mean surgical advancement in the horizontal direction (T2-T1) was 6.50 ± 2.62 mm at ANS (P < 0.001) and 7.05 ± 2.51 mm at A-point (P < 0.001). At a 1-year follow-up (T3-T2), the mean horizontal relapse at ANS was -1.41 ± 1.89 mm (P < 0.001) and -0.79 ± 1.48 mm at A-point (P 0.003). Mean horizontal relapse was 21.7% and 11% of surgical advancement when assessed at ANS and A-point, respectively. The central incisor tip position remained stable during the postsurgical period (0.12 ± 2.11 mm, P 0.732). At A-point, the mean vertical surgical change (T2-T1) was -0.96 ± 2.57 mm (P < 0.001). No significant post-treatment (T3-T2) vertical changes were detected at ANS or A-point. Phenotypic stability was excellent, with all patients maintaining positive overjet at 1-year follow-up.

CONCLUSIONS

LeFort I advancement in complete cleft lip and palate is stable, with less than a 2 mm relapse after 1-year. Surgical overcorrection by 10% to 20% is recommended to compensate for the expected skeletal relapse.

Influence of pharyngeal flap surgery on maxillary outgrowth in cleft patients

The aim of this study was to investigate the influence of the pharyngeal flap procedure on the frequency of Le Fort I osteotomies in full-grown nonsyndromic cleft patients. A retrospective review of 508 full-grown cleft patients born between 1 January 1983 and 31 December 1992 was performed. Following data analysis, 140 males older than 18 years and 111 females over the age of 16 years were included. 69 of the 251 included cleft patients required pharyngeal flap surgery (27.5%). Revision flap surgery was performed in 17.4% of the cases. A significantly lower age at time of the initial pharyngeal flap procedure was found in patients requiring revision surgery (5.6 years versus 6.8 years). The frequency of Le Fort I osteotomies was significantly higher in the patients with a pharyngeal flap (19%) compared to those without (8%) (p<0.05). The results of this study point towards the pharyngeal flap procedure being one of the possible limiting factors for maxillary antero-posterior growth in cleft patients.