Inverted L osteotomy: a new approach via intraoral access through the advances of virtual surgical planning and custom fixation

Hanna's Modified Sagittal Split Osteotomy (HSSO): An Alternative to Inverted L Osteotomy-Merging Function and Aesthetics for Enhanced Stability, Attractiveness, and Nerve Protection

Background: The current high standards in orthognathic surgery demand surgical solutions that are both ⁠ functionally ⁠ effective and aesthetically pleasing. Our approach offers one for enhanced stability, attractiveness, and nerve protection ⁠ with improved accessibility ⁠ in the majority of orthognathic scenarios ⁠ compared to an inverted L osteotomy. Methods: A case series is presented to illustrate the application and outcomes of HSSO, an optimised approach that combines the advantages of a transoral inverted L osteotomy with specific enhancements and increased versatility, ⁠ with accessibility and exposure similar to a BSSO. Results: HSSO as a completely transoral technique, demonstrate the ability to perform significant counterclockwise rotations of the mandible, eliminating the need for trocars or skin incisions. We experinced high postoperative stability when HSSO was performed in conjunction with a three-piece LeFort 1 osteotomy on a dynamic opposing arch. In comparison to an inverted L approach, we postulated that HSSO offers advantages in stability, due to the increased segmental overlap of the proximal and distal segments of the mandible. This approach is designed to enhance the safety of the inferior alveolar nerve compared to traditional sagittal split methods. Furthermore, HSSO represents an alternative to total joint replacement in select cases of idiopathic condylar resorption and is effective for correcting mandibular asymmetries while maintaining jawline aesthetics. This is achieved through the manipulation of the mandibular angle, ramus height, and inferior border without creating a step deformity in the soft tissue. Conclusions: The outcomes of HSSO highlight its capacity to deliver predictable, functional, and aesthetically pleasing results, offering a viable alternative to more traditional orthognathic techniques.

Craniofacial Distraction Osteogenesis

Distraction osteogenesis (DO) of the craniofacial skeleton has become an effective technique for the treatment of both nonsyndromic and syndromic conditions. The advent of craniofacial DO has allowed for earlier intervention in pediatric patients with less complication risk and morbidity compared to traditional techniques. In this review, we will discuss current application and technique for craniofacial DO by anatomical region and explore future applications in craniofacial surgery.

Treatment Strategy for Condyle/Ramus Deficiency Using 3D Virtual Surgery and CAD/CAM Technologies; Total Joint Replacement or Inverted-L Osteotomy

OBJECTIVE

To introduce a guideline for selecting proper surgical modalities for correction of skeletal Class II malocclusion with moderate-to-severe vertical height deficiency (VHD) of the condyle/ramus complex (CRC) using bimaxillary surgery in conjunction with total joint replacement (TJR) or inverted-L osteotomy (ILO) assisted by 3D virtual surgical planning and CAD/CAM technologies.

CASES

Four cases of severe skeletal Class II patients with moderate-to-severe VHD of CRC were presented. They underwent bimaxillary surgery using Le Fort I osteotomy in the maxilla and TJR or ILO in the mandible, with the help of virtual surgical planning (VSP) and computer-aided design/computer-aided manufacturing (CAD/CAM)-printed surgical guides and osteosynthesis plates. Guidelines are as follows: (1) if a patient has a moderate degree of VHD and the function of the temporomandibular joint (TMJ) is normal, ILO would be preferred for vertical elongation of the ramus; (2) if a patient has congenitally small condyle or severe condylar resorption, TJR would be preferred to resolve severe VHD of CRC; and (3) when a patient has a metal allergy, foreign body reaction or anatomic limitations (ie, thin cranial base cortex for fossa fixation), ILO would be a better option than TJR.

RESULTS

TJR or ILO using VSP and CAD/CAM-printed surgical guides, wafers, and customized plates can provide a proper selection of the surgical plan, accurate transfer of surgical plans to actual surgical procedures, and esthetic improvement of the facial profile.

CONCLUSION

This guideline based on the degree of VHD and functional aspects of CRC might help clinicians to select effective surgical modality for correction of skeletal Class II malocclusion with moderate-to-severe VHD of CRC.

Three-dimensional surgical management of a patient with Pruzansky I hemifacial microsomia and severe facial asymmetry: A 4-year follow-up

Treatment of hemifacial microsomia is challenging and often requires multiple interventions to restore function and facial esthetics. In this article, the combined orthodontic-surgical treatment of a young patient exhibiting Pruzansky I hemifacial microsomia is reported. The patient was aged 15 years, but his bone age was determined to be 18 years. His facial asymmetry was severe, with the nose and a retrusive chin deviated to the left side and a canted smile. The presurgical phase was aimed at centering the mandibular midline to the center of the chin through the distal movement of the mandibular left buccal dentition. The surgery was planned with 3-dimensional computer-aided surgical simulation and included a LeFort I and unilateral sagittal split osteotomies combined with a genioplasty. This report illustrates the therapeutic stages and a 4-year follow-up of a unique and complex orthognathic surgical approach, chosen among other alternatives and leading to improved function and appearance and stable results.

Three-dimensional comparative evaluation of customized bone-anchored vs tooth-borne maxillary protraction in patients with skeletal Class III malocclusion

INTRODUCTION

The aim of this prospective study was to assess the 3-dimensional skeletal and dental effects induced by a new maxillary protraction approach using customized miniplates for anchorage compared with a control group of traditional tooth-borne maxillary protraction.

METHODS

Forty-one growing patients at prepubescent stage with skeletal Class III malocclusion participated in this study. These patients were randomly split into 2 groups. In group 1 (n = 20), patients underwent maxillary protraction anchored with customized miniplates. The miniplates were individually designed and inserted using the surgical templates. In group 2 (n = 21), patients underwent tooth-borne maxillary protraction. Pretreatment and posttreatment cone-beam computed tomography scans were obtained, and 30 measurements of cone-beam computed tomography images were acquired and calculated. The changes after treatment and the comparison of the 2 groups were assessed.

RESULTS

After maxillary protraction, group 1 showed a greater forward movement of the maxilla than group 2. The maxilla length increased more in group 1 than in group 2. The rotations of the palatal and mandibular planes in group 1 were less than those in group 2. In group 1, the maxillary incisors proclined less, the mandibular incisors retroclined less, and the maxillary first molars extruded less.

CONCLUSIONS

Compared with tooth-borne maxillary protraction, customized miniplates anchored maxillary protraction produced more maxillary growth, fewer dental changes, and less maxillary and mandibular plane rotation.

The inverted-L ramus osteotomy versus sagittal split ramus osteotomy in maxillomandibular advancement for the treatment of obstructive sleep apnea patients: A retrospective study

This study aimed to compare the effectiveness and feasibility of inverted-L osteotomy (ILO) and sagittal split ramus osteotomy (SSRO) on obstructive sleep apnea (OSA) treatment. According to different surgery procedures, 28 OSA patients who underwent maxillomandibular advancement (MMA) were divided into 2 groups (group A: ILO, n = 9; group B: SSRO, n = 19). Polysomnography (PSG) and Epworth sleepiness scale (ESS) on T0, T1and T2 were used to evaluate the effectiveness of OSA treatments. Patients' airway structures and facial appearances were also evaluated. From T0 to T1, the mean apnea-hypopnea index (AHI,/per hour) dropped from 69.2 ± 8.4 to11.2 ± 2.4 (P < 0.01) in group A and from 54.6 ± 14.6 to 9.4 ± 5.4 (P < 0.01) in group B; LSpO2 (lowest pulse oxygen saturation, %) increased from 66.5 ± 7.7% to 88.2 ± 4.6 (P < 0.01) and from 76.6 ± 10.7%to 89.4 ± 2.4% (P < 0.01) while the mean ESS score decreased by 51% in group A and 44% in group B. Most patients (group A: 88.9%; group B: 84.3%) were satisfied with their postoperative appearance. Mild relapse was observed in both groups on T2. This study concluded that MMA containing ILO and MMA containing SSRO are both feasible and effective for selected OSA patients.