Appraising mandibular prognathism in class III malocclusion following orthognathic surgery: Patient-reported and cephalometry-based outcomes.

Patients with class III malocclusion often exhibit mandibular prognathism and complain of "prognathic appearance". The overall positive effects of orthognathic surgery on facial appearance have been demonstrated using patient-reported outcome measures (PROMs), but studies investigating the correlation between subjective PROMs results and objective measurements of imaging studies are sparse in the literature. This study recruited consecutive patients with skeletal class III malocclusion who underwent two-jaw orthognathic surgery between January 2016 and January 2021. The PROMs survey was conducted focusing on subjective perception of mandibular appearance. Lateral cephalometric images were measured to examine the correlation with the PROMs results. A total of 96 patients were eligible for this study. Of these, 74 patients (77.1%) reported complete correction of prognathic appearance postoperatively, whereas 22 patients (22.9%) perceived residual prognathic appearance. In a comparison of postoperative measurements between completely and incompletely satisfied patients, there were significant differences in SNB, ANB, convexity, facial angle, Nv-B, Nv-Pog, SN'B', soft tissue facial angle, lip-chin-throat angle, N'v-B', and N'v-Pog'. The PROM results were significantly associated with the objective measurements of imaging studies. Investigating the correlation between PROMs and objective measurements enables integration of patients' perception of the outcomes into future therapeutic strategy and surgical planning, contributing to the enhancement of patient satisfaction.

Outcome of patients with complete cleft lip and alveolus: 20-year follow-up.

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 all patients with complete CLA born between January 1995 and August 2002 and treated at our center. Patients who received continuous multidisciplinary team care until 20 years of age were included, and patients with cleft palate and syndromic abnormalities were excluded. Facial bone growth was evaluated using cephalometric analysis. RESULTS: Eighty-seven and 11 patients with unilateral and bilateral CLA (UCLA and BCLA) were included respectively. All patients received one-stage cheiloplasty with primary rhinoplasty. Revisional lip/nose surgery was performed in 21.8 and 27.3% during growing age, and in 51.7 and 72.7% after skeletal maturity. Orthognathic surgery was performed in 20.7 and 27.3%. Compared with UCLA patients, BCLA had larger number of operations (3.0 versus 3.7, p = 0.03) and higher chance of receiving alveolar bone grafting twice (1.1% versus 36.4%, p < 0.01). Patients with complete CLA had less hypoplastic maxilla, and received smaller number of operations than complete cleft lip and palate. CONCLUSION: Complete CLA is a less severe form of cleft, but the patients still require multiple interventions. This review revealed certain suboptimal results, and modifications have been made in the treatment protocol. Longitudinal follow-up and periodic assessment help to establish an ideal therapeutic strategy and improve overall cleft care.

Synergistic benefits of hyperbaric oxygen therapy for postoperative palatal oro-nasal fistula following segmental Le Fort 1 osteotomy.

Segmental maxillary osteotomy, a surgical technique used in orthognathic surgery, involves the risk of palatal mucosa tearing, which can lead to severe complications. Herein, we report the case of a woman with Angle class II malocclusion who underwent multiple elective segmental maxillary osteotomy and augmentation genioplasty procedures for the correction of her malocclusion and the enhancement of her facial profile. A week after surgery, the patient developed a palatal ulcer. We adopted a comprehensive treatment approach involving 14-day hyperbaric oxygen therapy and conventional modalities; this approach resulted in favorable outcomes. Our case underscores the importance of immediate intervention and the synergistic potential of the comprehensive approach against oronasal fistula formation. Our findings indicate that hyperbaric oxygen therapy promotes wound healing, particularly in patients with complications arising from maxillofacial surgery.

Bletilla striata Polysaccharide-Containing Carboxymethyl Cellulose Bilayer Structure Membrane for Prevention of Postoperative Adhesion and Achilles Tendon Repair.

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 diglycidyl ether cross-linked with carboxymethyl cellulose (CX)] and an inner layer [1,4-butanediol diglycidyl ether cross-linked with Bletilla striata polysaccharides and carboxymethyl cellulose (CXB)]. The morphology, chemical functional groups, and membrane structure were determined. In vitro experiments revealed that the CX/CXB membrane demonstrated good biosafety and biodegradability, promoted tenocyte proliferation and migration, and exhibited low cell attachment and anti-inflammatory effects. Furthermore, in in vivo animal study, the CX/CXB membrane effectively reduced postoperative tendon-peripheral tissue adhesion and improved tendon repair, downregulating inflammatory cytokines in the tendon tissue at the surgical site, which ultimately increased tendon strength by 54% after 4 weeks.

Comparison of modified Furlow palatoplasty using small double-opposing Z-plasty and conventional Furlow palatoplasty: A long-term outcome study.

BACKGROUND: The aim of palatoplasty is to create a functional palate to achieve normal speech, while minimizing post-operative complications. This study aimed to compare the long-term outcomes of modified Furlow palatoplasty using small double-opposing Z-plasty (small-DOZ) and conventional Furlow palatoplasty (conventional-DOZ) performed in a single center. METHODS: A retrospective review of consecutive patients who underwent Furlow palatoplasty between May 2007 and March 2014 was executed. Non-syndromic patients subjected to palatoplasty prior to 24 months of age and followed-up until at least 9 years of age were included. RESULTS: A total of 196 small-DOZ and 280 conventional-DOZ palatoplasty patients were included in this study. Overall, 14 patients (2.9%) developed oronasal fistula, and 40 patients (8.4%) received velopharyngeal insufficiency (VPI) surgery. In comparisons, oronasal fistula rate was significantly higher in conventional-DOZ (0.5% vs. 4.6%, p = 0.01), and the VPI prevalence was not significantly different (9.2% vs. 7.9%, p = 0.62). Patients who developed fistula had a significantly higher likelihood of developing VPI than patients without oronasal fistula (50.0% vs. 7.1%, respectively; p < 0.01), with an odds ratio of 13.0. CONCLUSION: Both modalities of palatoplasty yielded commendable velopharyngeal function in the long-term follow-up. The small-DOZ with reduced tension lowered the risk of oronasal fistula.

Comparison between one-jaw and two-jaw designs in virtual surgery planning for patients with class III malocclusion.

Orthognathic surgery is highly effective for treating maxillomandibular discrepancies in patients with class III malocclusion. However, whether one- or two-jaw surgery should be selected remains controversial. Our study aimed to evaluate quantitative differences between one-jaw and two-jaw surgical designs. In total, 100 consecutive patients with skeletal class III malocclusion who underwent orthognathic surgery with preoperative three-dimensional simulation between August 2016 and November 2021 were recruited. Based on the same final occlusal setup, a two-jaw surgery design and two types of one-jaw design were created. In total, 400 image sets, including preoperative images and three types of surgical simulation, were measured and compared. The one-jaw mandibular setback design led to improvement in most cephalometric measurements and facial symmetry. Although the one-jaw maxillary advancement design improved the ANB angle and facial convexity, it induced maxillary protrusion and reduced facial symmetry. Compared with the other designs, the two-jaw design provided significantly closer cephalometric measurements to the normative values, better symmetry, and less occlusal cant. Overall, the two-jaw design provided a quantitatively better facial appearance in terms of symmetry, proportion, and profile. Although an optimal surgical design necessitates thorough preoperative evaluation and a shared decision-making process, two-jaw surgery can be considered for improving overall facial esthetics and harmony.

Secondary Bilateral Cleft Rhinoplasty: Achieving an Aesthetic Result.

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 with bilateral cleft lip and nasal deformity were included. All had undergone secondary open rhinoplasty, performed by a single surgeon with a bilateral reverse-U flap and septal extension graft, between 2013 and 2021. Medical records of these 92 patients were reviewed to assess the clinical course. A 3-dimensional (3D) anthropometric analysis and panel assessment of 32 patients were performed to evaluate the aesthetic improvement, with an age-, sex-, and ethnicity-matched normal control group for comparisons. RESULTS: The methods showed statistically significant improvement in addressing a short columella (columellar height), short nasal bridge (nasal bridge length), de-projected nasal tip (nasal tip projection, nasal dorsum angle), poorly defined nasal tip (nasal tip angle, dome height, and panel assessment), and transversely oriented nostrils (columellar height, alar width, nostril type). Importantly, these improvements were accompanied by a low complication rate of 4%. However, upper lip deficiency over the upper lip angle and labial-columellar angle remained without significant improvement. CONCLUSIONS: In this study we described effective secondary rhinoplasty, which was composed of a bilateral reverse-U flap and septal extension graft, with acceptable outcome. The 3D anthropometric analysis and panel assessment clarified that our rhinoplasty procedure could bring the nasal morphology in these patients closer to the normal data.

Two-flap technique with interpositional dermofat graft for anterior oronasal fistula closure in patients with cleft: A case series.

BACKGROUND: Oronasal fistula at the anterior hard palate is one of the common sequelae after cleft surgery, and the leakage negatively affects the patient's quality of life. Although several surgical techniques have been proposed for reconstruction, it remains challenging because of the scarred regional tissue with a high rate of fistula recurrence. In this study, we present the anterior oronasal fistula repair using a two-flap technique with an interpositional dermofat graft (DFG). METHODS: A retrospective review of anterior oronasal fistula repair performed by the senior author between April 2018 and August 2022 at the Craniofacial Center was conducted. Patients who underwent a fistula repair using the technique were further identified and investigated. RESULTS: Thirty-four operations were performed using the technique, and 31 fistulas were completely closed, with a success rate of 91.2%. The fistula symptom improved but persisted postoperatively in 3 patients, of whom 2 patients underwent a second fistula repair using the same procedure, resulting in successful closure. Fistula recurrence was significantly correlated with fistula size (p = 0.04). The DFG was simultaneously utilized for nasal dorsum and/or vermillion reconstruction in 28 cases. CONCLUSION: The two-flap technique enabled tension-free approximation, and the interpositional DFG facilitated watertight closure of the fistula, resulting in a high success rate of anterior oronasal fistula repair. The fistula closure could be combined with other revisional procedures for cleft-related deformities, where the DFG was simultaneously utilized.

Primary rhinoplasty in patients with bilateral cleft lip: Longitudinal results and comparison between closed and semi-open approaches.

BACKGROUND: Although several studies have shown that primary rhinoplasty in patients with cleft lip provides good outcomes with limited effect on nasal growth, the surgical procedure remains to be standardized. The purpose of this study was to evaluate the long-term outcome of primary semi-open rhinoplasty with Tajima reverse-U incision, compared with that of closed rhinoplasty. METHODS: Consecutive nonsyndromic patients with complete bilateral cleft lip and palate (n = 52) who underwent primary semi-open rhinoplasty between 2001 and 2016 were reviewed. Patients who underwent primary closed rhinoplasty (n = 61) and control group individuals were recruited for comparison. Computer-based standardized measurements of 2D photographs and panel assessments by laypersons were collected and statistically analyzed. RESULTS: In the comparative analysis at preschool age, semi-open rhinoplasty significantly improved the typical nasal deformities, including transversely oriented wide nostrils, short columella, and de-projected nasal tip, more effectively than closed rhinoplasty. Without major drawbacks, these parameters in the semi-open group were well maintained closer to those in the control group till skeletal maturity. After primary rhinoplasty, 54% of patients in the closed group and 4% in the semi-open group underwent intermediate rhinoplasty at preschool age. CONCLUSION: This study showed that the patients who underwent primary semi-open rhinoplasty achieved long-term and persistent outcomes that were closer to the normal nasal morphology compared with the patients treated with closed rhinoplasty, while avoiding intermediate rhinoplasty during the preschool to adolescent periods.

Facial Anthropometric Analysis of Gender-Related Characteristics in Computed Tomography.

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 study was to provide a reference for surgeons to achieve optimal outcomes for patients undergoing FFS. The anthropometric analysis could help surgeons meet patients' specific requirements and improve patients' alignment with their gender identity. MATERIALS AND METHODS: The study group consisted of 100 patients (50 males and 50 females) who had undergone cranial computed tomography at Chang Gung Memorial Hospital in Taiwan because of the indication of blunt injuries to the head and face with suspected skull and facial fractures. The computed tomography images were imported into the OsiriX image software to conduct an anthropometric evaluation. The parameters used in the measurements included 2 aspects: bone and soft tissue anthropometric analysis. RESULTS: Anthropometric data were obtained from 50 males (age 32.6 ± 11.4 years) and 50 females (age 33.7 ± 10.3 years). The results for bone measurements showed that both the forehead bossing length and nasal bone width in the male group were significantly greater. The frontal angle in both bone and soft tissue in the male group was significantly smaller. The chin height and bigonial width in both bone and soft tissue in the male group were significantly greater. Although the average gonial angle was greater in the female group, the difference was not significant. For the measurements of lip projection, the results showed that there was no significant difference. Although this group of Asian males had more acute nasolabial angles, the difference was not statistically significant. However, the average nasofrontal angle among females was significantly more obtuse than among males. CONCLUSION: The results revealed that Asian males tend to have more prominent superior orbital rims, wider nasal bones, and wider and taller mandibles compared with Asian females. Despite showing some trends, the gonial angle and lip projections did not reveal any significant differences, which is likely because of a large amount of variation.

Chang Gung Forum: An Exemplary Strategy for Implementing a Multidisciplinary Network of Experts in Craniofacial Anomalies.

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 perspectives, decisions, and practices in a multidisciplinary craniofacial team. METHODS: Between 2000 and 2022, 20 Chang Gung Forums have been held. A questionnaire was distributed among 170 attendees who had participated in the forum more than once. The questionnaire collected information on the participants' experiences and levels of satisfaction with the educational program and whether or how it had influenced their clinical practice. RESULTS: Valid responses from 86 attendees (response rate, 50.6%) who had participated more than once were collected and analyzed. The overall satisfaction rate of the Chang Gung Forum based on the respondents' most recent visits was 4.28 ± 0.63 out of 5. Of the respondents, 90.9% acknowledged changes in their clinical practice, with modifications in surgery plans and decisions being the most notable (48.5%). In addition, comprehension increased throughout years of attending the annual forum (P < 0.001). CONCLUSION: The Chang Gung Forum has contributed markedly to the community of congenital craniofacial anomalies. The program will continue providing updated information and influencing the clinical decision-making of health care professionals.

Modified Furlow palatoplasty using small double-opposing Z-plasty: Long-term outcome and comparison with two-flap palatoplasty.

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 modified Furlow palatoplasty using small double-opposing Z-plasty (small-DOZ). METHODS: A retrospective review of consecutive patients who received palatoplasty performed by the senior author between January 2000 and March 2014 was conducted. Non-syndromic patients who underwent palatoplasty before the age of 18 months and followed-up until at least 9 years of age were included. Comparisons between the small-DOZ and two-flap methods for soft palate repair were made. RESULTS: A total of 196 small-DOZ and 167 two-flap palatoplasty patients were eligible in the study. Among the small-DOZ palatoplasty patients, 1 patient (0.5%) developed oronasal fistula, and 18 patients (9.2%) received velopharyngeal insufficiency (VPI) surgery (10 patients at preschool age and 8 at nine years of age). Compared with the small-DOZ palatoplasty, the oronasal fistula rate, VPI surgery rate, and the need for myringotomy tube insertion were significantly higher in the two-flap group (p =0.01, <0.01, <0.01, respectively). Patients who developed oronasal fistula had significantly higher likelihood of having velopharyngeal insufficiency (p < 0.01). CONCLUSION: The small-DOZ provided successful palatal repair with low rates of oronasal fistula and VPI in the long-term. Wound closure under minimal tension facilitated to avoid oronasal fistula. Reconstruction of the functional muscle sling enabled to achieve normal velopharyngeal function with favorable speech outcome and middle ear function.

Single-Splint, 2-Jaw Orthognathic Surgery for Correction of Facial Asymmetry: 3-Dimensional Planning and Surgical Execution.

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 study recruited consecutive patients (n=54) with nonsyndromic facial asymmetry associated with malocclusion. The stepwise workflow included orthodontic treatment, 3D imaging-based evaluation, planning, and transferring the virtual of single-splint 2-jaw OGS to actual surgery in all patients. Seven landmark-based measurements were selected for postoperative assessment of facial symmetry. Fifty patients had no anesthetic/surgical-related episode and procedure-related complications. Others experienced wound infection (n=1), transient TMJ discomfort (n=1), and facial numbness (n=3). Two cases had minor residual asymmetry (cheek and chin, respectively), but did not request revisionary bone or soft tissue surgery. Comparisons between the planned and postoperative 3D images with quantitative measurement revealed acceptable outcome data. The results showed a significant increase in facial symmetry at 7 landmark-based postoperative measurements for both male and female. This 3D-assisted pathway of OGS permitted achievement of consistent satisfactory results in managing facial asymmetry, with low rate of complications and secondary management.

The Rise of Online Medical Education in Craniofacial Surgery.

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 transformed the traditional format of medical conferences. MATERIALS AND METHOD: In total, 64 ICC webinars held between December 13, 2020, and May 21, 2023, were documented and reviewed. A questionnaire was designed and sent to ICC members. The questionnaire collected information on attitudes and habits relating to videoconferencing in general before and after the start of COVID-19 and on the ICC webinars specifically. Responses were analyzed to inform our understanding of respondents' experience and satisfaction with the webinars. RESULTS: The webinars covered a variety of topics related to craniofacial surgery. In total, 64 webinars were included for analysis. The mean number of attendees at each webinar was 86.7. In total, 111 respondents were more satisfied (4.25 ± 0.72 out of 5) with ICC webinars than with other media of online meetings ( P < 0.001). In total, 89.2% of respondents were willing to continue attending ICC webinars after COVID-19 restrictions have been lifted. CONCLUSIONS: Webinars are an effective format for imparting knowledge, especially in the ICC, and will become key in continuing medical education.

Occlusion-Based Three-Dimensional Craniofacial Anthropometric and Symmetric Evaluation in Preadolescences: A Comparative COHORT Study.

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 stereophotogrammetry of the participants' heads. A total of 37 recognizable anatomical landmarks were identified for linear, angular, and asymmetric analyses using the MATLAB program. RESULTS: This study included 139 healthy Taiwanese children with a mean age of 9.13, of whom 74 had class I occlusion, 50 had class II malocclusion, and 15 had class III malocclusion. The class III group had lower soft-tissue convexity (p = 0.01) than the class II group. The boys with class II malocclusion had greater dimensions in the anteroposterior position of the mid-face (p = 0.024) at age 10. Overall asymmetry showed no significance (p > 0.05). Heat maps of the 3D models exhibited asymmetry in the mid-face of the class II group and in the lower face of the class III group. CONCLUSION: Various types of malocclusion exhibited distinct facial traits in preadolescents. Those with class II malocclusion had a protruded maxilla and convex facial profile, whereas those with class III malocclusion had a less convex facial profile. Asymmetry was noted in facial areas with relatively prominent soft-tissue features among different malocclusion types.

Effect of body mass index on progressive bone mineral density in patients with cleft after secondary alveolar bone grafting.

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: In total, 39 patients with cleft alveolus receiving ABG at the mixed dentition stage were enrolled. Patients were classified as underweight, normal weight, or overweight or obese according to age- and sex-adjusted BMI. BMD was measured in Hounsfield units (HU) from cone-beam computed tomography scans obtained 6 months (T1) and 2 years (T2) postoperatively. Adjusted BMD (HUgrafted tissue/HUpogonion, BMDa) was used for further analysis. RESULTS: For underweight, normal-weight, and overweight or obese patients, BMDaT1 values were 72.87%, 91.85%, and 92.89%, respectively (p = 0.727); BMDaT2 values were 111.49%, 112.57%, and 113.10% (p = 0.828); and density enhancement rates were 29.24%, 24.61%, and 22.14% (p = 0.936). No significant correlation was observed between BMI and BMDaT1, BMDaT2, or density enhancement rates (p = 0.223, 0.156, and 0.972, respectively). For patients with BMI < 17 and ≥ 17 kg/m2, BMDaT1 values were 89.80% and 92.89%, respectively (p = 0.496); BMDaT2 values were 111.49% and 113.10% (p = 0.216); and density enhancement rates were 23.06% and 26.39% (p = 0.573). CONCLUSION: Patients with different BMI values had similar outcomes (BMDaT1, BMDaT2, or density enhancement rate) after our ABG procedure in the 2-year postoperative follow-up.

Comparative assessment of orthodontic and aesthetic outcomes after orthognathic surgery with clear aligner or fixed appliance therapy.

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 of congenital craniofacial deformities who underwent surgery-first OGS and received clear aligner or fixed appliance therapy. The patients' grades on the Dental Health Component (DHC) and Aesthetic Component (AC) of the Index of Orthodontic Treatment Need and scores on the Peer Assessment Rating (PAR) index were calculated before OGS (T0), after OGS (T1), and after orthodontic therapy (T2). RESULTS: This study included 33 patients (clear aligner therapy, 19; fixed appliance therapy, 14). No considerable between-group differences were noted in the DHC and AC grades at T0, T1, or T2. Furthermore, %reduction in the PAR index score was more significant in the clear aligner group (74.4%) than in the fixed appliance group (63.2%) from T0 to T1 (p = .035); however, no between-group differences were noted from T1 to T2 or from T0 to T2. Both groups exhibited substantially improved DHC grades, AC grades, and PAR index scores at T1 and T2. CONCLUSIONS: Patient outcomes were similar between the clear aligner and fixed appliance groups after orthodontic therapy. However, the former group exhibited more favorable immediate results after OGS than did the latter group. Thus, as an adjunct therapy for patients with malocclusion, clear aligner therapy may be more effective than fixed appliance therapy.

Three-dimensional comparative changes in the pharyngeal airway of patients with cleft after two-jaw orthognathic surgery.

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. Cone-beam computed tomography images were obtained before (T0) and after (T1) OGS. We measured the pharyngeal airway volumes, minimal cross-sectional area, and the horizontal displacement of facial landmarks. RESULTS: The patients with bilateral cleft exhibited smaller initial velopharyngeal volume (unilateral: 8623 mm 3; bilateral: 7781 mm 3; p = 0.211), while the velopharyngeal volume increased significantly with median of 744 mm 3 after OGS (p = 0.031). The median horizontal displacement of A point was 2.9 and 2.6 mm among the patients with unilateral and bilateral clefts, respectively (p = 0.276), and the median horizontal displacement of B point was -2.9 and -3.3 mm among patients with unilateral and bilateral clefts, respectively (p = 0.618). The unilateral cleft patients with PF exhibited lower initial velopharyngeal volume (PF+: 7582 mm 3; PF-: 8756 mm 3; p = 0.129) and a lower increase in velopharyngeal volume (PF+: 437 mm 3; PF-: 627 mm 3; p = 0.739) after OGS. CONCLUSIONS: Midface hypoplasia and the decrease in the velopharyngeal volume were more prominent among the bilateral cleft patients and the unilateral cleft patients with PF. After OGS, the velopharyngeal volume considerably increased among the bilateral cleft patients, but no considerable differences were noted among the unilateral cleft patients with PF.