# Maximally Deficiency: Treatments and Applications for Adolescents
## 3 Orthognathic Surgery Approaches
### Adolescents with Congenital Conditions or Treatment Challenges
#### 3.2.2 Distraction Osteogenesis  
With conventional surgical methods, there are limitations of the extent of possible movement, and reliance on the comprehensive conditions of patients. Apart from bony status, soft tissues, particularly in cases involving clefts or scar tissue from multiple surgeries, can present further challenges. Therefore, distraction osteogenesis offers an alternative surgical approach, providing optimized outcomes with improved stability and simplified procedures [125]. Although the primary goal of distraction osteogenesis is to address sagittal deficiencies, clinical cases have demonstrated incidental transverse expansion during the process. * Extraoral vs. internal maxillary distractors: Two primary approaches to distraction osteogenesis in the craniofacial region have been described: extraoral and internal maxillary distractors [103; 126]. Extraoral distractors typically involve a semicircular metal frame affixed to the skull using multiple screws. A vertical bar connects this frame to facial plates via wires and coils, generating the anteroposterior forces required to advance the midface. Various modifications have been introduced by manufacturers to enhance skull stability, vector control, attachment methods, and connectors. However, these devices come with significant drawbacks, including social inconvenience, facial scarring, and, critically, the premature removal of distractors before completing the distraction consolidation phase. This latter issue, especially in cases requiring large movements and extended treatment durations (up to a year), compromises long-term stability. In contrast, internal maxillary distractors consist of a compact design with a barrel mechanism activated between anterior and posterior plates for bone fixation. Continuous innovations in design aim to improve bone anchorage, simplify activation and removal, and enhance vector control. Trans-suture distraction osteogenesis:  
Distraction osteogenesis can also be classified into two types based on whether osteotomy is performed. Trans-suture distraction osteogenesis (TSDO), which the growth potential of cranial sutures is taken advantage of without an osteotomy, is a minimally invasive, non-osteotomy traction technique designed to effectively address midfacial dysplasia [105]. By utilizing a rigid external distraction system equipped with a nickel-titanium-shape memory alloy spring and bone-borne traction hooks anchored to the lateral nasal wall, this approach allows for significant advancement of the midfacial skeleton along with concurrent maxillary expansion (Figure 3). Osteotomy-assisted distraction, where bone is surgically separated, is common for achieving maxillary advancement in adolescent patients with severe maxillary deficiencies, sleep apnea, prior failures in maxillary advancement, anatomical limitations for traditional surgery, or syndromic deficiencies [108]. According to a systematic review evaluating 129 cases of maxillary distraction osteogenesis, approximately 55.7% of patients aged 5-13 underwent incomplete Le Fort I osteotomy [109]. In contrast, for other age groups, maxillary distraction osteogenesis with complete Le Fort I osteotomy remains the predominant approach. Regarding the transverse effects of maxillary distraction osteogenesis, reports indicate that even with incomplete Le Fort I osteotomy, where the anterior (piriform aperture), lateral (zygomatic buttress), and median (mid-palatal suture) bony supports of the maxilla are osteotomized, transverse maxillary expansion can be achieved. Another study involving 276 cases found that 10 cases specifically focused on transverse maxillary expansion, with  
Figure 3: Rigid external distraction system of TSDO. **(a)** Patient wearing a rigid external distraction system featuring a nickel–titanium-shape memory alloy spring and bone-borne traction hooks; **(b)** cephalometric radiographic image displaying the traction hooks anchored to the lateral nasal wall of the maxillary sinus. the majority achieving 5-9 mm of expansion [110].