Pang-Yun Chou

Chang Gung Memorial Hospital | CGMH · Division of Plastic and Reconstructive Surgery

Purpose The authors evaluated pterygomaxillary junction angles across malocclusion patterns and identified the optimal technique for effective pterygomaxillary junction separation during Le Fort I osteotomy, focusing on appropriate osteotome angles and clinical applications. Methods This retrospective study included 211 patients with malocclusion...

Background Plagiocephaly, wherein infants' head exhibits a diagonal asymmetry, is currently diagnosed based on physicians' subjective judgment. Discrepancies between physician and parent perspectives may result in dissatisfaction with treatment outcomes. This problem highlights the need for an objective assessment system aligning with physician-mad...

Introduction Deep, second- and third-degree burn injuries may lead to irreversible damage to the traumatized tissue and to coagulation or thrombosis of the microvessels, further compromising wound healing. Engineered, morphologically gradient drug-eluting nanofiber dressings promote wound healing by mimicking tissue structure and providing sustaine...

Background: Although the human body generally exhibits bilateral symmetry, achieving perfect symmetry is exceedingly uncommon. During preadolescent development, a face that approximates symmetry is considered both aesthetically and functionally ideal. This study aimed to investigate the relationship between craniofacial traits and hand predominance...

Background Patients with cleft have functional and aesthetic impairment, and typically require several interventions as they grow. Long-term evaluation following a treatment protocol is essential, but such reports on patients with complete cleft lip and alveolus (CLA) are sparse in the literature. Methods A retrospective review was conducted to al...

Postoperative tissue adhesion and poor tendon healing are major clinical problems associated with tendon surgery. To avoid postoperative adhesion and promote tendon healing, we developed and synthesized a membrane to wrap the surgical site after tendon suturing. The bilayer-structured porous membrane comprised an outer layer [1,4-butanediol diglyci...

Background Secondary rhinoplasty in patients with bilateral cleft lip poses ongoing challenges and requires a reliable method for achieving optimal outcomes. Objectives The purpose of this study was to establish a safe and effective method for secondary bilateral cleft rhinoplasty. Methods A consecutive series of 92 skeletally matured patients wi...

Introduction The Chang Gung Forum has been dedicated to the care of craniofacial anomalies since 2000. This annual continuing medical education program focuses on orofacial cleft and surgery-first orthognathic surgery by providing up-to-date information and management guidelines. This study explored how the Chang Gung Forum has influenced medical p...

Background In recent years, facial feminization surgery (FFS) has gained increasing popularity because of increases in transgender individuals and the acceptance of diversity in gender identity. However, there is still a scarcity of anthropometric research to guide evidence-based practices for FFS in Taiwan. Aim and Objectives The purpose of this...

Three-dimensional (3D) planning of orthognathic surgery (OGS) improves the treatment of facial asymmetry and malocclusion, but no consensus exists among clinicians regarding technical details. This study verified the consistency of authors’ workflow and strategies between 3D planning and surgical execution for facial asymmetry. This retrospective s...

Background The post-palatoplasty velopharyngeal function needs to be evaluated through long-term follow-up, but such reports are limited in the literature and there has been no consensus as to which surgical technique yields optimal velopharyngeal function with minimum complication rate. This study aimed to evaluate the long-term outcome of the mod...

Background International travel had been radically disrupted by coronavirus disease 2019 (COVID-19), leaving traditional medical conferences on a 2-year hiatus. The International Craniofacial Chang Gung Group (ICC) was thus created to disseminate knowledge related to craniofacial surgery. This study aimed to reveal how webinars fundamentally transf...

Background: The importance of early diagnosis of pediatric malocclusion and early intervention has been emphasized. Without use of radiation, 3D imaging holds the potential to be an alternative for evaluating facial features in school-aged populations. Methods: Students aged 9 and 10 years were recruited. We performed annual 3D stereophotogramme...

Background: The present study evaluated the three-dimensional changes of the pharyngeal airway after orthognathic surgery (OGS) in patients with unilateral and bilateral clefts, and in unilateral cleft patients with and without pharyngeal flap (PF). Methods: Forty-five patients with unilateral or bilateral clefts receiving OGS were enrolled. Con...

Background: Clear aligner therapy has an aesthetic advantage over fixed appliance therapy. However, to our knowledge, no study has objectively compared patient orthodontic and aesthetic outcomes between clear aligner and fixed appliance therapies administered after orthognathic surgery (OGS). Methods: This study included patients with no history...

Background: Patients with cleft lip and palate have functional and aesthetic 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. Materials and...

Background: Although childhood obesity matters, the association between body mass index (BMI) and bone mineral density (BMD) progression in grafted tissue after secondary alveolar bone grafting (ABG) for children with cleft alveolus is scarcely studied. Accordingly, this study explored the influence of BMI on BMD progression after ABG. Methods:...

Background: Geriatric maxillofacial trauma has become an increasingly pressing clinical issue in Taiwan because of increased life expectancy. Aim and objectives: The purposes of this study were to investigate the anthropometric changes and the posttrauma outcomes in the aging population and to optimize the management strategies for geriatric fac...

Peripheral nerve injuries are commonly encountered in extremity traumas. Their motor and sensory recovery following microsurgical repair is limited by slow regeneration speed (<1 mm/d) and subsequent muscle atrophy, which are consequently correlated with the activity of local Schwann cells and efficacy of axon outgrowth. To promote post-surgical ne...

Peripheral nerve injuries are commonly occurring traumas of the extremities; functional recovery is hindered by slow nerve regeneration (<1 mm/day) following microsurgical repair and subsequent muscle atrophy. Functional recovery after peripheral nerve repair is highly dependent on local Schwann cell activity and axon regeneration speed. Herein, to...

Background: No consensus exists regarding the timing or technique of rhinoplasty for correction of the unilateral cleft lip nose deformity, with few studies examining the long-term effects of a single technique. This study appraised the long-term outcomes of primary rhinoplasty using the Tajima technique for overcorrection in a cohort of patients...

Objective: To evaluate the development of the craniofacial region in healthy infants and analyze the asymmetry pattern in the first year of life. Methods: The participants were grouped by sex and age (1, 2, 4, 6, 9, and 12 months) to receive three-dimensional (3D) photographs. Stereoscopic craniofacial photos were captured and transformed into a...

Background: The pedicled buccal fat flap has recently been applied to cover the lateral raw surfaces during palatoplasty as an attempt to mitigate scar-induced transverse maxillary constriction during growth, but with no formal long-term comparative analysis. This 3D imaging-assisted study assessed its impact on posterior transverse maxillary deve...

Secondary alveolar bone grafting is one of the key surgical procedures performed to restore dental arch continuity and facilitate tooth eruption in patients with cleft lip and palate. Harvest of cancellous bone graft from the iliac crest has become the gold standard; however. there is no consensus regarding the ideal technique. An optimal bone harv...

Objective: In this study, we aim to present a single institution's 25-year experience of employing a comprehensive multidisciplinary team-based surgical approach for treating patients with NF-1. Summary background data: All patients (n = 106) with a confirmed diagnosis of NF-1 who were treated using a multidisciplinary surgical treatment algorit...

An alveolar cleft is a bone defect in the maxillary arch. Although the use of autologous iliac bone grafts to repair alveolar clefts is the preferred treatment method, donor-site morbidity remains a concern. In this study, we incorporated bone morphogenetic protein (BMP), an antimicrobial agent, and an analgesic into nanofibrous scaffolds for alveo...

Despite progress in clinical science, the repair and restoration of alveolar bone defects remains as a challenge, particularly for nonuniform and complex defects. We developed bioresorbable nanofibrous drug-eluting cuboid frames for alveolar bone repair using three-dimensional (3D) printing and electrospinning technologies. The cuboid frames compri...

Pedicled buccal fat flaps have been adopted in primary Furlow double-opposing Z-plasty palatoplasty to reduce oronasal fistula formation or to attenuate maxillary growth disturbance. We combined both goals in a single intervention. This study describes a series of 33 modified Furlow small double-opposing Z-plasty palatoplasties reinforced with a mi...

Patients with maxillomandibular disharmony may present with a flat to concave midface. The effects of orthognathic surgery concomitant with midface fat grafting on facial appearance and midface volumetric and positional change have not formally been assessed to date. The authors' approach for synchronous orthognathic surgery and fat grafting is des...

Healing of ruptured tendons remains a clinical challenge because of its slow progress and relatively weak mechanical force at an early stage. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have therapeutic potential for tissue regeneration. In this study, we isolated EVs from adipose-derived stem cells (ADSCs) and evaluated...

(1) Background: Continuing to observe the grafted bone mineral density (BMD) is essential to ensure the success of alveolar bone grafting (ABG) in patients with cleft lip and palate. This study elaborates on three methods that can be used to evaluate the progressive BMD. (2) Methods: Forty patients with unilateral or bilateral clefts receiving ABG...

Background: Non-absorbable materials (nylon) are always used in cinch sutures to maintain nasal width and to improve harmonious facial symmetry in orthognathic surgery. However, a few drawbacks of nylon materials have been clinically reported following orthognathic surgery, such as nasal irritation and exposure of the sutures. An absorbable materia...

Background Orthognathic Surgery (OGS) is a surgery for patients with dento-facial deformity but not all patients are satisfied with its outcome. The purpose of this study is to find out the short-term and long-term psychological impact and quality-of-life of OGS. Methods 77 participants receiving OGS and 32 age and gender-matched controls were enr...

Background: Le Fort I maxillary repositioning influences nasal morphology. In Asian cultures, upward nasal tip rotation with increased nostril exposure is considered aesthetically unpleasant and can have psychosocial consequences. This three-dimensional imaging-based study evaluated the effect of different Le Fort I maxillary movements on nasal ti...

Millard's rotation-advancement principle, first-described 60 years ago, continues to guide surgeons in reconstruction of the unilateral cleft lip. Modifications of the rotation-advancement repair are commonly used; however, distinction between the complete and incomplete forms of cleft lip has received less emphasis in surgical procedure descriptio...

Background: The helmet worn after sagittal strip craniectomy must be customized to the surgical procedure and the patient's anatomy to achieve optimal outcomes. This study compares three-dimensional head shape outcomes obtained from a novel virtual helmet design and from a traditional helmet design. Methods: Twenty-four patients underwent extend...

Background: Le Fort I maxillary movements affect nasal width, but nasal width changes with specific movement types have not been formally addressed to date. Objectives: The purpose of this study was to analyze and compare the changes in nasal width with different maxillary movements. Methods: A retrospective study was performed among consecuti...

Polycaprolactone/nano-hydroxylapatite (PCL/nHA) nanocomposites have found use in tissue engineering and drug delivery owing to their good biocompatibility with these types of applications in addition to their mechanical characteristics. Three-dimensional (3D) printing of PCL/nHA nanocomposites persists as a defiance mostly because of the lack of co...

Background The surgical management of hypertelorism is challenging for plastic surgeons, and limited long-term outcome data are available. The purpose of this long-term study was to report a single-surgeon experience with a staged reconstructive protocol for hypertelorism correction. Methods This retrospective study reviewed the records of patient...

Surgeons-in-training learning how to perform cleft surgery should not only acquire a broad repertoire of technical details but also master the proper execution of techniques based on the modern principles of bilateral cleft lip repair with synchronous reconstruction of cleft nose deformity. This article describes a bilateral complete cleft lip repa...

Tendon healing after injury is relatively slow, mainly because of the weak activity and metabolic properties of tendon cells (tenocytes). Bletilla striata polysaccharide (BSP) has been reported to enhance cell proliferation. Here, we aimed to increase tendon cell proliferation by BSP treatment. We isolated tenocytes from the flexor tendon of human...

Background: Surgical mobilization of the maxillary segment affects nasal morphology. This study assessed the impact of the type of maxillary mobilization on the three-dimensional (3D) nasal morphometry. Methods: Pre- and postsurgery cone beam computed tomography-derived facial image datasets of consecutive patients who underwent two-jaw orthogna...

Peripheral nerve injuries mainly occur in the extremities and result in functional deficits, and recovery after microsurgical repair is slow (<1 mm/day) and frustrating. To improve the results of nerve repair, it is crucial to promote local Schwann cell (SC) function, neurite outgrowth, and to reduce perineural adhesion. In this study, a nerve wrap...

Background Primary reconstruction of complete bilateral cleft lip and palate (BCLP) with protruding premaxilla in one-stage surgery is challenging because of the tension on muscle repair. Such patients are also common in the developing countries. For this condition, we have applied intraoperative “rapid premaxillary molding (RPM)” technique and obt...

Cold atmospheric plasma jet (CAPJ) or non-thermal plasma jet has been employed in various biomedical applications based on their functions in bactericidal activity and wound healing. However, the effect of CAPJ generated by a particular composition of gases on wound closure and the underlying mechanisms that regulate wound healing signals remain el...

Background: No consensus exists on the selection of procedures for the treatment of submucous cleft palate, with scarce reports on long-term outcomes from single-surgeon experience. This study assessed the outcomes of using extended indication criteria of Furlow palatoplasty as the first-line procedure for the management of submucous-cleft-palate-...

Background: A recent artificial intelligence-based investigation has shown the impacts of orthognathic surgery on the patient's facial appearance and apparent age. However, appearance and age perception as reported by patients and surgical professionals have not been addressed in the same cohort to date. Methods: FACE-Q facial appraisal (appeara...

Patient satisfaction with the shape and appearance of their nose after orthognathic surgery-based skeletofacial reconstruction is an important, but often overlooked, outcome. We assessed the nose-related outcomes through a recently developed patient-reported outcome instrument and a widely adopted 3D computer-based objective outcome instrument, to...

Since the original description of Millard rotation advancement principle for cleft lip repair, many important contributions have subsequently been described by other surgeons worldwide. However, the reconstruction of the nasal floor and intraoral lining has received less attention over time. This article demonstrates a modified unilateral complete...

Necrotizing fasciitis (NF) is uncommon but potentially lethal when it is associated with systemic disorders. We report a case of odontogenic NF in a patient with uncontrolled diabetes mellitus. The patient was referred on day 10 since the onset of odontogenic NF. Protective tracheostomy, local facial-cervical fasciotomy were conducted and broadspec...

Skeletofacial reconstruction in skeletally mature patients with cleft lip/palate can be challenging because of multifaceted condition-specific anatomical features in addition to several repercussions from surgical intervention during the growing period. This surgical report presents the history and evolving philosophy of cleft-skeletofacial reconst...

Introduction Facial normalcy, as measured with 2-dimensional or 3-dimensional photographs, has been documented in the healthy pediatric population. However, static images convey far from a complete representation of an individual’s daily interactions with peers. Craniofacial surgery induces changes to soft or osseous tissues and thereby affects dyn...

Longitudinal epidemiological studies are considered the gold standard for understanding craniofacial morphologic development, but participant recruitment and retention can be challenging. This study describes strategies used to recruit and maintain a high level of participation in a longitudinal study involving annual three-dimensional (3D) craniof...

Using the Taguchi method to narrow experimental parameters, the antimicrobial efficiency of a cold atmospheric plasma jet (CAPJ) treatment was investigated. An L9 array with four parameters of CAPJ treatments, including the application voltage, CAPJ-sample distance, argon (Ar) gas flow rate, and CAPJ treatment time, were applied to examine the anti...

Orthognathic surgery (OGS) has been successfully adopted for managing a wide spectrum of skeletofacial deformities, but patients with underlying conditions have not been treated using OGS because of the relatively high risk of surgical anesthetic procedure-related complications. This study compared the OGS outcomes of patients with and without unde...

A precise volumetric assessment of maxillary alveolar defects in patients with cleft lip and palate can reduce donor site morbidity or allow accurate preparation of bone substitutes in future applications. However, there is a lack of agreement regarding the optimal volumetric technique to adopt. This study measured the alveolar bone defects by usin...

Background: Defining three-dimensional (3D) normal craniofacial morphology in healthy children could provide craniofacial surgeons a reference point to assess disease, plan surgical reconstruction, and evaluate treatment outcome. The purposes of this study were to report normal craniofacial form and quantify craniofacial asymmetry of healthy child...

Background: Scalp angiosarcoma is a rare and highly aggressive cutaneous malignancy with poor prognosis and high recurrence rate. Multimodality approach is currently the treatment protocol for resectable angiosarcoma, including wide local excision and postoperative radiation. This single-institution study reviews the 18-year experience of the surg...

Outcome measures reported by patients, clinicians, and lay-observers can help to tailor treatment plans to meet patients’ needs. This study evaluated orthognathic surgery (OGS) outcomes using pre- and post-OGS patients’ (n = 84) FACE-Q reports, and a three-dimensional facial photograph-based panel assessment of facial appearance and psychosocial pa...

This study measured three-dimensional facial fluctuating asymmetry in 600 normal and healthy Taiwanese individuals (6 to 12 years old) and assessed the perceptions of increasing levels of facial fluctuating asymmetric severity by using a panel composed of 20 clinicians (surgical professionals), as well as 20 adult and 40 pre-adolescent observers. O...

Peritendinous adhesion is a major complication after tendon injury and the subsequent repairs or reconstructions. The degree of adhesion can be reduced by the interposition of a membranous barrier between the traumatized tendon and the surrounding tissue. In the present study, electrospun water-borne polyurethane (WPU) nanofibrous membranes (NFMs)...

Background: Cleft lip/palate is a congenital craniofacial anomaly affecting patients physically and psychosocially and has contributed to the global burden of surgical disease, especially in underprivileged areas. For 20 years, Noordhoff Craniofacial Foundation (NCF) and the Chang Gung Craniofacial Center (CGCFC) have carried out missions to these...