Cheek soft tissue prediction in cleft orthognathic surgery: A 3D computer-assisted investigation with comparative analysis

Clockwise versus counterclockwise rotation in bimaxillary surgery: 3D analysis of facial soft tissue outcomes

PURPOSE

This study aimed to compare facial 3D soft tissue changes in subjects with Class III deformities who underwent bimaxillary clockwise (CW) and counterclockwise (CCW) rotational orthognathic surgery.

METHODS

Asian Class III subjects who completed bimaxillary surgical orthodontic treatments were enrolled and categorized into CW and CCW groups based on maxillary occlusal plane alterations. Preoperative and 9-month follow-up cone-beam computed tomography (CBCT) and 3D stereophotogrammetry were obtained, superimposed, and quantified for skeletal movements and soft tissue changes in six facial regions. Inverse probability of treatment weighting (IPTW) adjusted for potential confounding factors.

RESULTS

Thirty-seven subjects were included (CW group, n = 20; CCW group, n = 17). Postsurgical chin volume significantly reduced in the CW group compared to the CCW group (mean difference 6362 mm3; p = 0.037), and intergonial width significantly decreased in the CW group (mean difference 6.2 mm; p = 0.005). The postoperative alar width increased by 1.04 mm and 1.22 mm in the CW and CCW groups, respectively (p = 0.70). However, these changes were not significantly correlated to the direction of MMC pitch.

CONCLUSION

Clockwise rotation of the bimaxillary complex demonstrated a significant advantage in reducing chin volume and intergonial width compared to counterclockwise rotation, leading to a reduced frontal lower face width among Asian Class III subjects.

Change in Lower Lip Position After Le Fort I Advancement in Patients with Bilateral vs. Unilateral Cleft Lip and Palate

To compare lower lip changes after Le Fort I advancement surgery in patients with a cleft.

Single institution, retrospective review.

Academic tertiary referral hospital.

Skeletally mature patients with a cleft who underwent one-piece Le Fort I advancement surgery who had a lateral cephalogram or cone-beam computed tomography (CBCT) scan preoperatively and at least 6 months postoperatively. Patients who underwent concomitant mandibular surgery or genioplasty were excluded. 64 patients were included: 45 male and 19 female, 25 with BCLP and 39 with UCLP. The mean age at surgery was 18.4 years.

Single jaw one-piece Le Fort I advancement surgery.

Standard lateral cephalometric landmarks of the bony skeleton and soft tissue were compared before and after Le Fort I advancement. Pearson correlation coefficients (r) were calculated to measure the correlation between lower lip position and other soft and hard tissue changes.

After comparable maxillary advancements [BCLP: 7.2 mm (95% CI: 6.2-8.3 mm), UCLP: 6.4 mm (95% CI: 5.7-7.0 mm)] the horizontal upper-to-lower lip discrepancy significantly improved in both groups. The lower lip became thinner and more posteriorly positioned. Changes in lower lip position correlated strongly with mandibular bony landmarks and moderately with upper lip position, but poorly with maxillary landmarks.

Le Fort I advancement results in posterior displacement of the lower lip and better lip competence, thereby improving facial harmony. This lower lip change is not predictable by degree of maxillary advancement, and does not differ in patients with BCLP vs. UCLP.

Long-term treatment outcome of patients with complete bilateral cleft lip and palate: a retrospective cohort study

BACKGROUND

Patients with cleft lip and palate have functional and esthetic impairment and typically require multiple interventions in their life. Long-term evaluation following a treatment protocol, especially for patients with complete bilateral cleft lip and palate (BCLP), is important but was rarely reported in the literature.

PATIENTS AND METHODS

A retrospective review was conducted on all patients with complete BCLP born between 1995 and 2002 and treated at our center. Inclusion criteria were having adequate medical records and receiving continuous multidisciplinary team care at least until 20 years of age. Exclusion criteria were lack of regular follow-up and congenital syndromic abnormalities. The medical records and photos were reviewed, and facial bone development was evaluated using cephalometric analysis.

RESULTS

A total of 122 patients were included, with a mean age of 22.1 years at the final evaluation in this study. Primary one-stage cheiloplasty was performed in 91.0% of the patients, and 9.0% underwent two-stage repair with an initial adhesion cheiloplasty. All patients underwent two-flap palatoplasty at an average of 12.3 months. Surgical intervention for velopharyngeal insufficiency was required in 59.0% of patients. Revisional lip/nose surgery was performed in 31.1% during growing age and in 64.8% after skeletal maturity. Orthognathic surgery was applied in 60.7% of patients with retruded midface, of which 97.3% underwent two-jaw surgery. The average number of operations to complete the treatment was 5.9 per patient.

CONCLUSION

Patients with complete BCLP remain the most challenging group to treat among the cleft. This review revealed certain suboptimal results, and modifications have been made to the treatment protocol. Longitudinal follow-up and periodic assessment help to establish an ideal therapeutic strategy and improve overall cleft care.

Application of 3-Dimensional Technology for Evaluating Muscular Type and Muscle-Fat Pad Mixed-Type Nasolabial Folds With Botulinum Toxin-A Treatment

BACKGROUND

Botulinum toxin-A (BTX-A) is used in the treatment of nasolabial folds (NLFs). However, lighting and clinician subjectivity play a major role in evaluating the efficacy of this treatment.

OBJECTIVES

By applying 3-dimensional (3D) technology, this study aimed to quantitatively evaluate the effects of BTX-A injection on muscular (M) and muscle-fat pad mixed-type (MF) NLFs.

METHODS

BTX-A was injected into bilateral marked points on the NLFs, where the levator labii alaeque nasi, zygomaticus minor, and zygomaticus major pull the skin to form the NLF (2 U at each injection site). Pretreatment and posttreatment 3D facial images were captured with static and laughing expressions. The curvature, width, depth, and lateral fat volume of the NLFs were measured to compare the therapeutic efficacy for type M and MF NLFs.

RESULTS

Thirty-nine patients with type M and 37 with type MF NLFs completed the follow-up data. In these patients, the curvature, width, and depth of the NLF showed a significant reduction at 1 month and gradually recovered at 3 and 6 months after treatment, with more significant improvement when laughing than when static. Variations compared to the pretreatment values of type MF were greater than those of type M at each time point. The lateral fat volume of the type MF NLF was significantly reduced (P < .05).

CONCLUSIONS

3D technology can quantitatively evaluate the effects BTX-A injection for treating type M and type MF NLFs. BTX-A is more effective on type MF than on type M NLFs.

LEVEL OF EVIDENCE: 4

Clinical Application of Individualized 3D-Printed Templates in the Treatment of Condylar Osteochondroma

BACKGROUND

Osteochondroma (OC) is one of the most common benign tumors of the long bones, but it rarely occurs in the maxillofacial skeleton. However, mandibular condylar OC often leads to severe facial deformity in affected patients, including facial asymmetry, deviation of the chin, and malocclusion. This study aimed to explore the clinical application of individualized 3D-printed templates to accurately and effectively treat condylar OC.

METHODS

A total of 8 patients with mandibular condylar OC were treated from July 2015 to August 2021. The enrolled patients (5 women and 3 men) had a median age of 27 years (range: 21-32 years). All patients exhibited symptoms of facial asymmetry and occlusal disorders preoperatively. The digital software used to virtually design the process consisted of three-dimensional reconstruction, 3D-cephalometry analysis, virtual surgery, individualized templates, and postoperative facial soft-tissue prediction. A set of 3D-printed templates (DOS and DOT) were used in all cases to stabilize the occlusion and guide the osteotomy. Then, pre- and post-operative complications, mouth opening, clinical signs, and the accuracy of the CT imaging analysis were all evaluated. All the measurement data were presented as means ± SD; Bonferroni and Tamhane T2 multiple comparison tests were used to examine the differences between the groups.

RESULTS

All patients healed uneventfully. None of the patients exhibited facial nerve injury at follow-up. In comparing the condylar segments with T0p and T1, the average deviation of the condylar segments was 0.5796 mm, indicating that the post-operative reconstructed condyles showed a high degree of similarity to the reconstruction results of the virtual surgical plan.

CONCLUSIONS

Individualized 3D-printed templates simplified surgical procedures and improved surgical accuracy, proving to be an effective method for the treatment of patients with slight asymmetric deformities secondary to condylar OC.