Demographic Factors of Nasal Bone Fractures and Social Reflection.

INTRODUCTION: The nose is the most protruding central part of the face, and nasal bone fractures are the most common of facial bone fractures, leading up to 39%. Despite its high frequency, not many studies handled the etiology of nasal bone fractures, leading to the necessity of a recent demographic study. MATERIALS AND METHODS: A total of 1111 patients diagnosed with nasal bone fracture from 2013 to 2018 at our institute were evaluated. A retrospective review of the various demographic and etiologic characteristics was done. RESULTS: Numerous factors associated with nasal bone fractures were analyzed. Male patients were 3.3 times greater than the number of female patients, and twenties were the most common age range. Violence was the overall most common cause of injury, while slip down was the most common cause for females. Upon monthly distribution, the highest incidence of nasal bone fractures occurred in September, followed by March and December. The authors further divided the patients by time zone of the fractures, and male patients were most commonly injured from midnight to 3 AM, while female patients were 6 PM to 9 PM. CONCLUSION: Our findings represent a recent urban data of various etiologic factors of nasal bone fracture. The concept of school violence has been widely used since 1990s, and our data reflects that violence of the youth is a serious issue of the society. The mechanism of injury differed among sexes and age groups, and such discrepancies will aid physicians to better understand facial bone fracture patients and educate them in the future.

Huge Anterior Skull Base Defect Reconstruction on Communicating Between Cranium and Nasal Cavity: Combination Flap of Galeal Flap and Reverse Temporalis Flap.

INTRODUCTION: Traditionally, galeal flap or cranialization was often used to reconstruct the skull base defect caused by trauma or tumor removal. However, in the case of huge skull base defect, galeal flap is not enough to block the communication between nasal cavity and intracranial space. In this study, authors suggest combination flap of galea and reverse temporalis muscle as a method for reconstruction of huge skull base defect. MATERIALS AND METHODS: From 2016 to 2019, retrospective review was conducted, assessing 7 patients with bone defect which is not just opening of frontal sinus but extends to frontal sinus and cribriform plate. Reconstructions were done by combination of galeal flap and reverse temporalis muscle flap transposition. RESULTS: Defects were caused by nasal cavity tumor with intracranial extension or brain tumor with nasal cavity extension. There was no major complication in every case. During the follow up period, no patient had signs of complication such as ascending infection, herniation and CSF rhinorrhea. Postoperative radiologic images of all patients that were taken at least 6 months after the surgery showed that flaps maintained the lining and the volume well. DISCUSSION: Conventional reconstruction of skull base defect with galeal flap is not effective enough to cover the large sized defect. In conclusion, galeal flap in combination with reverse temporalis muscle flap can effectively block the communication of nasal cavity and intracranium.

Combined Therapeutic Strategies for Keloid Treatment.

BACKGROUND: Recent advances in keloid management favor the administration of combination therapy over monotherapy. OBJECTIVE: The authors evaluated the safety and efficacy of combination therapy to treat keloids using fractional lasers, cryotherapy, and intralesional corticosteroids. MATERIALS AND METHODS: The authors performed a retrospective study involving 35 Korean patients. Each patient underwent treatment using the 1,550 nm nonablative fractional erbium-glass laser, followed by the 10,600 nm ablative fractional carbon dioxide laser. Laser treatment was immediately followed by the administration of superficial cryotherapy and intralesional triamcinolone injection. Therapeutic efficacy was assessed using the Vancouver Scar Scale (VSS) score and the 7-point patient self-assessment score. RESULTS: The mean total and subcategory VSS scores showed statistically significant improvements. The height and pliability scores showed the most significant and quickest responses to the combination therapy. The patients reported remarkable improvement in itching, pain, and limitations of motion after a single combination therapy session. Twenty patients were followed up for 1 year after the discontinuation of the combination treatment, and the recurrence was observed only in one patient. No significant adverse effects were observed throughout the follow-up period. CONCLUSION: Combination keloid therapy using fractional lasers, superficial cryotherapy, and intralesional triamcinolone injection is safe and more effective than individual monotherapies.

Reconstruction for Skull Base Defect Using Fat-Containing Perifascial Areolar Tissue.

Skull base reconstruction is a challenging task. The method depends on the anatomical complexity and size of the defect. We obtained tissue by harvesting fat-containing perifascial areolar tissue (PAT) for reconstruction of limited skull base defects and volume augmentation. We demonstrated the effective option for reconstruction of limited skull base defects and volume augmentation. From October 2013 to November 2015, 5 patients underwent operations using fat-containing PAT to fill the defect in skull base and/or perform volume replacement in the forehead. Perifascial areolar tissue with 5- to 10-mm fat thickness was harvested from the inguinal region. The fat-containing PAT was grafted to the defect contacting the vascularized wound bed. Patients were followed up in terms of their clinical symptoms and postoperative magnetic resonance imaging findings. Four patients were treated using fat-containing PAT after tumor resection. One patient was treated for a posttraumatic forehead depression deformity. The fat-containing PAT included 5- to 9-mm fat thickness in all cases. The mean size of grafted PAT was 65.6 cm (28-140 cm). The mean follow-up period was 18.6 months (12-31 months). There was no notable complication. There was no donor site morbidity. We can harvest PAT with fat easily and obtain the sufficient volume to treat the defect. It also could be used with other reconstructive method, such as a free flap or a regional flap to fill the left dead space. Therefore, fat-containing PAT could be additional options to reconstruction of skull base defect.

Botulinum toxin A affects early capsule formation around silicone implants in a rat model.

Capsular contracture is one of the most common complications resulting from implants placed during mammoplasty and rhinoplasty, and there is no definitive solution or a method for preventing it. Recent reports suggest that botulinum toxin A (BoTA) is effective at reducing keloid scars clinically. Peri-implant capsules are histologically similar to keloid scars and hypertrophic scars. Therefore, we hypothesized that BoTA may reduce peri-implant capsule formation.To test our hypothesis, we divided 24 male Sprague-Dawley rats into an experiment group and a control group. We created two 15 × 15-mm subpanniculus pockets in each rat. Botulinum toxin A (0.5 mL; 5 U) was injected into the carnosa layer of the experimental group's pockets and 0.5 mL normal saline was similarly injected in the control group. Hemispherical silicone implants, 15 mm in diameter, were inserted into the pockets. After 6 weeks, the peri-implant capsule was excised and examined by histologic evaluation, immunohistochemical stain, scanning electron microscope, and real-time polymerase chain reaction.Capsular thickness, number of inflammatory cells, number of vessels, and transforming growth factor ß1 expression were reduced in the experimental group compared to the control group (P < 0.01). The experimental group's collagen pattern was loose and well organized. The total myofibroblast content was lower in the experimental group than in the control group; however, this difference was not statistically significant (P = 0.32). Additionally, the experimental group had a smaller fibrosis index than the control group (P < 0.05).Our results suggest that BoTA may provide an alternative treatment for reducing capsule formation and preventing contracture, and further studies may reveal the mechanism of action.

The abdominal fascial closure in a double-breasted jacket pattern following a TRAM free flap breast reconstruction.

The primary closure of abdominal fascia after breast reconstruction with transverse rectus abdominis myocutaneous (TRAM) flap has been reported to be the most effective way to reduce these complications. A total of 108 patients who underwent immediate unilateral breast reconstruction with muscle-sparing TRAM flap were included in the study. We compared complications between 56 patients who underwent conventional primary fascial closure (group 1) and 52 who underwent fascial closure in a new double-breasted jacket pattern (group 2), retrospectively. Abdominal bulging occurred in four patients (7.1%) in group 1 and one patient (1.9%) in group 2 (p = 0.01). An abdominal wound dehiscence occurred in three (5.4%) patient in group 1 and two (3.8%) patient in group 2 (p = 0.12). After conventional or muscle-sparing TRAM free flap reconstruction, closing the abdominal fascia in a double-breasted jacket pattern can help reinforce the lower abdominal fascia and prevent abdominal bulging caused by abdominal fascia tensional imbalance.

A Retrospective study of anatomical differences in levator aponeurosis angle and length in East-Asian blepharoplasty.

This study aimed to analyze the anatomical differences in levator aponeurosis angle and length between both sides in double eyelidplasty in East Asians. The retrospective study included patients with mild blepharoptosis who underwent upper blepharoplasty with levator aponeurosis. In the study, 140 patients were enrolled, 126 females and 14 males, with an age range of 16-73 years. The mean levator aponeurosis angle was 19.2 ± 2.9° on the right and 17.0 ± 3.8° on the left, which was significantly different (95% CI, p < 0.001). The mean length was 24.1 mm on the right and 23.2 mm on the left, a difference that was also statistically significant (95% CI, p < 0.001). The relationship between the dominant eye and levator aponeurosis prominence was also investigated, although there was no apparent correlation. Within the limitations of the study, it seems that this is the first study of the anatomical differences of the levator aponeurosis between both sides, leading to a greater predictability of surgery to maximize postoperative symmetry.

Reaching New Heights: A Comprehensive Study of Hand Transplantations in Korea after Institutionalization of Hand Transplantation Law.

PURPOSE: With the revision of the Organ and Transplantation Act in 2018, the hand has become legal as an area of transplantable organs in Korea. In January 2021, the first hand allotransplantation since legalization was successfully performed, and we have performed a total of three successful hand transplantation since then. By comparing and incorporating our experiences, this study aimed to provide a comprehensive reconstructive solution for hand amputation in Korea. MATERIALS AND METHODS: Recipients were selected through a structured preoperative evaluation, and hand transplantations were performed at the distal forearm level. Postoperatively, patients were treated with three-drug immunosuppressive regimen, and functional outcomes were monitored. RESULTS: The hand transplantations were performed without intraoperative complications. All patients had partial skin necrosis and underwent additional surgical procedures in 2 months after transplantation. After additional operations, no further severe complications were observed. Also, patients developed acute rejection within 3 months of surgery, but all resolved within 2 weeks after steroid pulse therapy. Motor and sensory function improved dramatically, and patients were very satisfied with the appearance and function of their transplanted hands. CONCLUSION: Hand transplantation is a viable reconstructive option, and patients have shown positive functional and psychological outcomes. Although this study has limitations, such as the small number of patients and short follow-up period, we should focus on continued recovery of hand function, and be careful not to develop side effects from immunosuppressive drugs. Through the present study, we will continue to strive for a bright future regarding hand transplantation in Korea.

Ischemic oculomotor nerve palsy and skin necrosis caused by vascular embolization after hyaluronic acid filler injection: a case report.

Hyaluronic acid filler injection is widely used for soft tissue augmentation. However, there can be disastrous complications by direct vascular embolization. We present a case of ischemic oculomotor nerve palsy and skin necrosis after hyaluronic acid filler injection on glabellar.blepharoptosis, exotropia and diplopia developed suddenly after the injection, and skin necrosis gradually occurred. Symptoms and signs of oculomotor nerve palsy continuously improved with steroid therapy. Skin defects healed with minimal scars through intensive wound care.Percutaneous filler injection of periorbital areas should be performed carefully by experienced surgeons, and the possibility of embolization should be considered promptly if symptoms develop.

Endoscopic thyroidectomy via a transaxillary approach is a safe procedure in patients with breast augmentation.

INTRODUCTION: Breast augmentation with implants is a common cosmetic procedure. Some endoscopic thyroid procedures can pose a risk of damage to the augmented breast. The aim of this study was to evaluate the safety of transaxillary gasless endoscopic thyroidectomy in patients with augmented breast. MATERIALS AND METHODS: Between January 2009 and December 2010, 120 patients underwent endoscopic thyroidectomies. Of those, 6 patients had previously undergone breast augmentation. Augmented breasts were evaluated preoperatively and postoperatively in terms of shape and stability. RESULTS: All patients were female, and the mean age was 40.8 years. All patients received breast augmentation with silicone cohesive gel 2 to 10 years prior to thyroidectomy. Postoperatively, the authors found that there were no changes to the breasts in terms of anterior-posterior projections and internal angles. The augmented breasts remained stable. CONCLUSIONS: Endoscopic thyroidectomy via a transaxillary approach is safe and effective for patients who have undergone silicone breast implant augmentation.

Is conservative management of partial zone II flexor tendon laceration possible? A systematic literature review and meta-analysis.

Background: There is still no consensus on managing zone II level partial flexor tendon lacerations, and the management of zone II partial flexor tendon injuries is controversial. No reliable large cohort studies or metaanalysis papers on partial flexor tendon laceration management are available in PubMed or Embase.Methods: We searched PubMed, Embase, Cochrane Library, Insight, Scopus, and Web of Science databases for primary research articles investigating outcomes of patients with partial flexor tendon injuries. The initial search was limited to human studies that were published from 1970-2021 and indexed as randomized controlled or clinical trials or observational, cross-sectional, or cohort studies. We used statistical package R version 4.1.2 for this meta-analysis.Results: The Standardised mean difference (SMD) of the common effects model was 2.020 (95% CI; 1.583-2.457; P < 0.0001), indicating that the results of conservative treatment without surgical intervention are similar to surgical intervention or better in some articles. The SMD of the random effect model was 7.093 (95% CI; 1.090-13.096; P < 0.0206), indicating the same result. Higgins' I2 value was 97.6%, indicating serious heterogeneity.Conclusions: In this first meta-analysis on flexor zone II conservative treatment, five papers with publication bias were analyzed. It is meaningful to verify the result of conservative treatment statistically. Even though this is a heterogeneous paper, conservative treatment seems to have a lot of benefits for the patient, including offering a fairly solid longterm prognosis with very few complications.

One Year Experience of the Hand Allotransplantation First Performed after Korea Organ Transplantation Act (KOTA) Amendment.

The revision of the Korea Organ Transplantation Act (KOTA) in 2018 included hand/arm among the organs that can be transplanted. The first hand transplantation since the revision of KOTA took place in January 2021. A 62-year-old male patient experienced hand amputation on July 13, 2018, by a catapult injury. The patient first visited our institute 3 months after the injury. After serial interviews and an overall evaluation, the patient was registered on the hand transplantation waiting list in January 2020. On January 9, 2021, the patient underwent hand transplantation at the right distal forearm level. The total operation time was 17 hours 15 minutes, and the cold ischemic time was 4 hours 9 minutes. Postoperative immunosuppression was administered based on the protocol used for kidney transplantation. Two acute rejection episodes occurred, on postoperative days 33 and 41. Both rejection episodes were reversible with rescue therapy of a higher tacrolimus trough level, steroid pulse therapy, and topical immunosuppressants. Controlled passive range of motion exercise was started on postoperative day 10. Dynamic splint was applied on postoperative day 18. At 1 year, graft maintenance and functional improvement were satisfactory, and the patient showed a Disabilities of Arm, Shoulder and Hand score of 25.8. We successfully performed the first hand transplantation surgery under the KOTA amendment. It came from the organic and effective cooperation of plastic, orthopaedic, and transplantation departments and we believe it will guarantee the future ongoing success.

A bipedicled keystone perforator island flap: Pedicle division technique with enhanced advancement potential for chronic wound coverage.

Since the first description of the keystone perforator island flap (KPIF) in 2003, several modifications have been suggested to enhance its coverage ability. However, locoregional flaps have limited its use in chronic wounds due to decreased elasticity around the defect. We investigated the use of a bipedicled KPIF (bKPIF), which covers a defect while completely elevating the median part of the flap from the fascia. A retrospective chart review of 20 consecutive patients who underwent classical type I KPIF (n = 10) or bKPIF (n = 10) reconstruction from June 2020 to December 2022 was performed. Baseline characteristics, indications, operative details, healing time, and complications were analyzed and compared between the two groups. The average defect size was 30 cm2 in type I KPIF and 36.6 cm2 in bKPIF, and an average flap size of 86.5 cm2 was covered in type I KPIF, larger than bKPIF at 73.8 cm2. The flap/defect ratio was significantly lower in the bKPIF group (p < 0.02), with an average of only 55% pedicular area. The average advancement distance in the bKPIF group was 1.85 cm (standard deviation 0.78) greater than that in the type 1 KPIF group. There was no significant difference between the groups in terms of operation time, complete healing time, and complications. All ten bKPIFs were successful without any flap necrosis. Even though the mean pedicular area in the bKPIF group was nearly half compared with that in the type I KPIF group, it was sufficient to perfuse the entire flap without any major complications. This novel technique using bKPIF has potential clinical relevance, as evidenced by the enhanced ability to cover chronic defects with severe scarring. Lateralizing the hotspots to the bilateral corners of the flap is the mechanism that facilitates this potential.

Perforating patterns of cutaneous perforator vessels in anterolateral thigh flaps for head and neck reconstruction and clinical outcomes.

BACKGROUND: Anterolateral thigh (ALT) flaps are versatile soft tissue flaps that have become the standard soft-tissue flaps used for head and neck reconstruction. They provide a long vascular pedicle, constant vessel diameter, abundant soft tissue coverage, and minimal donor site morbidity. The ALT flap was initially designed on the basis of a septocutaneous (SC) perforator. However, more recent research has shown that a substantial number of ALT flaps are now based on musculocutaneous (MC) perforators, and the ratio between MC and SC perforators varies among studies. In this study, we analyzed the perforating pattern of ALT flaps along with their clinical outcomes during head and neck reconstruction in the Korean population. METHODS: From October 2016 to July 2020, 68 patients who had undergone an ALT flap procedure for head and neck reconstruction were enrolled retrospectively. The perforating pattern of the cutaneous perforator vessel (MC perforator/SC perforator/oblique branch), pedicle length, and flap size were analyzed intraoperatively. Patient demographics and flap necrosis rates were also calculated. RESULTS: The highest number of cutaneous perforator vessels supplying the ALT flap were the MC perforators (87%). The proportion of MC perforators was significantly higher than that of the SC perforators and oblique branches. Flap necrosis occurred in seven cases (11.86%); sex, hypertension, diabetes mellitus, coronary artery disease, perforator course, and history of radiotherapy did not significantly affect flap necrosis. CONCLUSION: The ALT free flap procedure remains popular for reconstruction of the head and neck. In this study, we observed that the majority of cutaneous vessels supplying the flaps were MC perforators (87%). When using the MC perforator during flap elevation, careful dissection of the perforator is required to achieve successful ALT flaps because intramuscular dissection is difficult. Perforator pattern and history of radiotherapy did not affect flap necrosis.

Super-thin ALT flap elevation using preoperative color doppler ultrasound planning: Identification of horizontally running pathway at the deep adipofascial layers.

INTRODUCTION: Presently, super-thin ALT flap, which is elevated above the superficial fascial plane, is gaining popularity. Although there is a huge demand for thin flaps for various types of extremity reconstruction, the technique for ALT flap thinning remains controversial. In this study, we investigated the distance and vector between penetrating points of perforators in deep and superficial fascia using color duplex and clinical measurement to suggest a reliable super-thin flap elevation technique. MATERIALS AND METHODS: From June 2018 to February 2020, 44 patients with various types of defects who were treated using super-thin ALT flaps were enrolled; 69 surgically detected perforators were analyzed. All patients' flap outcomes and characteristics of the perforators were analyzed. In addition, the effects of patients' body mass index (BMI) and thickness of super-thin flap were evaluated. RESULTS: The average traveling length of perforator at the deep adipofascial layer (DAL) was 2.43 cm, and the vector of traveling was randomly arranged. The mean thickness of super-thin ALT flap was 6.8 mm. The thickness of super-thin flap was not significantly correlated with patients' BMI (ranged from 17.4 to 34.2 kg/m2; p = 0.183). CONCLUSION: The novel elevation technique for super-thin ALT might be useful, as evidenced by perforator traveling distance and vector in DAL. Preoperative color duplex ultrasonography is helpful to detect the running course of the perforators during elevating the flap. This anatomic concept must be considered to obtain the reliability of the super-thin ALT flap.

Medical students' perceived stress and perceptions regarding clinical clerkship during the COVID-19 pandemic.

BACKGROUND: It is important to ensure that both the qualitative and quantitative aspects of clinical education are maintained during the pandemic. Understanding students' views on clinical rotations and the extent of their perceived pandemic-related stress would thus be useful for designing and implementing effective clerkship programs. Therefore, this study aimed to investigate perceived stress and perceptions regarding clinical clerkship among incoming clinical students (third year) and senior clinical students (fourth year) during the COVID-19 pandemic. METHODS: After completing orientation programs at the beginning of the academic year, we surveyed students on their perceived stress, their general perspectives regarding the appropriate scope of clinical clerkship, and their preferences regarding level of participation in clerkship. We examined the differences in stress and clerkship-related perceptions based on the students' study year and sex using independent t-test, chi-squared test, and Fisher's exact test. In addition, the influences of stress, sex, and study year on clerkship-related perceptions were examined using multinomial logistic regression. RESULTS: The independent t-test indicated that third-year students experienced lower stress than did fourth-year students. Clerkship-related perceptions also differed significantly between third- and fourth-year students. Multinomial logistic regression analyses on the scope of and participation levels in clinical clerkship revealed that third-year students had significantly lower odds of preferring a limited range of clinical rotations and lower engagement in clerkships compared to fourth-year students. CONCLUSION: The COVID-19 pandemic has affected clinical education and, consequently, medical students' inclination toward active participation in clinical rotations. It is thus essential to understand students' views and provide them with relevant intra-pandemic educational supports.

Combined use of energy-based interventions with low-dose isotretinoin for the treatment of inflammatory acne: An retrospective cohort analysis.

BACKGROUND: The combined use of oral isotretinoin with energy-based interventions including fractional microneedle radiofrequency, pulsed dye laser, and ablative fractional laser is an effective way to treat moderate-to-severe inflammatory acne lesions. However, studies regarding its efficacy and safety are limited. AIMS: This study aimed to assess the efficacy and safety of a treatment using low-dose isotretinoin with energy-based interventions for inflammatory acne. PATIENTS AND METHODS: This retrospective cohort study included 126 patients who were diagnosed with inflammatory acne and were treated with systemic isotretinoin for at least 3 months. Patients were divided into EBD (energy-based intervention) (n = 82) and non-EBD groups (n = 44). Clinical outcomes of both groups were assessed using medical records and digital photographs. RESULTS: After treatment, the modified Global Acne Grading Score of the EBD and non-EBD groups decreased by 35.1 ± 17.2 and 25.6 ± 10.1, respectively. The improvement in acne severity was significantly greater in the EBD group than in the non-EBD group. Cumulated isotretinoin dose and frequency of drug-related side effects were significantly higher in the non-EBD group than in the EBD group. CONCLUSION: Combined treatment with low-dose isotretinoin and energy-based intervention is well tolerated and associated with positive responses in patients with inflammatory acne.

Methodology in Conventional Head and Neck Reconstruction Following Robotic Cancer Surgery: A Bridgehead Robotic Head and Neck Reconstruction.

PURPOSE: Robotic head and neck surgery is widespread nowadays. However, in the reconstruction field, the use of robotic operations is not. This article aimed to examine methodologies for conventional head and neck reconstruction after robotic tumor surgery in an effort to obtain further options for future reconstruction manipulations. MATERIALS AND METHODS: A retrospective review of all patients who received head and neck robot surgery and conventional reconstructive surgery between October 2016 and September 2021. RESULTS: In total, 53 cases were performed. 67.9% of the tumors were greater than 4 cm. Regarding defect size, 47.2% of the lesions were greater than 8 cm. In terms of TNM stage, stage 3 disease was recorded in 26.4% and stage 4 in 52.8%. To make a deep and narrow field wider, we changed the patient's posture in pre-op field, additional dissection was done. We used radial forearm flap mostly (62.2%). CONCLUSION: Conventional head and neck reconstruction after robotic ENT cancer surgery is possible. One key step is to secure additional space in the deep and narrow space left after robotic surgery. For this, we opted for a radial forearm flap mostly. This can be performed as a bridgehead to perform robotic head and neck reconstruction.

Descending necrotizing mediastinitis and facial palsy as serial complications in orthognathic surgery.

Orthognathic surgery is one of the most commonly performed cosmetic surgical procedures. Hemorrhage, infection, and facial palsy have been reported as complications of the surgery, but the occurrence is low. Our patient presented with facial palsy, postoperative bleeding, wound dehiscence, and descending necrotizing mediastinitis in a sequence. This is the first report of descending necrotizing mediastinitis after orthognathic surgery. Although these are very rare complications, awareness of the clinical presentation and the management of these conditions are important.

Transport disc distraction osteogenesis for the reconstruction of a calvarial defect.

PURPOSE: According to previous reports about the experimental study of transport disk distraction osteogenesis (TDDO) for the reconstruction of bone defects, TDDO showed great feasibility of successful bone regeneration. However, those studies had some limitations in their design and analysis of the results, either. In this report, we intended to verify the effect of TDDO in the reconstruction of skull defects with a combined result of distraction osteogenesis and bone graft of transported disk (TD). METHODS: Six female dogs were operated on and were given a 35×15-mm bilateral skull defect. In the experimental group, TDDO with internal distractors (7×14-mm TD) was performed. On the other side, in the control group, the bone defects were left to heal naturally. The distraction was performed from the postoperative fifth day at a rate of 1 mm/d. The distraction progressed for 14 days, and then the TD was maintained in the middle of the bone defect area. The 40% of the original bone defect area was left the same as the control side. The TD was expected to be survived as a bone graft during the consolidation period. After 3½ months of a consolidation period, the remained bone defects were measured by three-dimensional computed tomography. The solidity of the new bone was compared with the bone tissue of the normal skull bone. RESULTS: In the study group, the new bone formation was estimated to be 62.3% (SD, 25.1%) of the defect area, and in the control group, it was 44.8% (SD, 27.3%). The difference between the 2 groups was significant (P=0.04). The solidity of the newly generated bone by TDDO was not different from the normal skull (P=0.74). CONCLUSIONS: In this study, the concept of TDDO and bone graft seemed to promote new bone formation. The role of the TD could include bone regeneration from distraction osteogenesis as well as autogenous bone graft, although it needs more investigation. The relationship between the duration of distraction and the positive role of the TD as an autogenous bone graft in TDDO for better clinical application may be investigated.