Implant treatment in the esthetic area requires stable osseointegration and successful esthetic outcomes. Achieving this goal requires careful consideration of accurate implant axis and ideal three-dimensional position. Owing to the high esthetics and the special anatomical structure of the maxillary, a successful implant means a synthesized deli-beration of the residual bone dimensions, soft-tissue thickness, and the relationship of the residual alveolar ridge with the planned restoration. This article offers an in-depth analysis of the clinical decisions and key factors affecting the implant direction in the esthetic area.
Dental Implantation, Endosseous/methods* ; Dental Implants ; Esthetics, Dental ; Alveolar Ridge Augmentation/methods* ; Osseointegration ; Maxilla/surgery* ; Dental Implants, Single-Tooth

OBJECTIVES: To summarize the open-eruption technique of impacted anterior maxillary teeth, this study reports a technically improved operation on surgical exposure based on dental follicles and evaluates post-treatment periodontal health considering the effect of dental follicles. METHODS: Patients who underwent open-eruption technique with unilateral labially impacted maxillary central incisors were selected. The impacted teeth were assigned to the experimental group, and the contralateral unimpacted maxillary central incisors were assigned to the control group. In the surgical exposure, the new technique makes use of dental follicles to manage the soft tissue, so as to preserve soft tissue for better aesthetic results and healthier periodontal tissue. Tooth length, root length, alveolar bone loss, and alveolar bone thickness were recorded after the therapy. RESULTS: A total of 17 patients with unilateral maxillary central incisor impaction were successfully treated. The tooth length and root length of the two groups showed a statistically significant difference between the impacted and homonym teeth, with a shorter length in the impacted tooth (P<0.05). More labial alveolar bone loss was found in the experimental group compared with that in the control group (P<0.05). The outcomes of the cementoenamel junction width, pa- latal alveolar bone loss, and alveolar bone thickness did not indicate statistical significance between the experimental and control groups (P>0.05). CONCLUSIONS In the surgical exposure, the new technique uses dental follicles to manage the soft tissue and preserve it for better aesthetic results and healthier periodontal tissues.
Humans ; Tooth, Impacted/surgery* ; Incisor ; Alveolar Bone Loss/diagnostic imaging* ; Tooth Root ; Dental Sac ; Maxilla/surgery* ; Esthetics, Dental

Objective:To investigate the feasibility and clinical effect of the surgical approach and method of transnasal fenestration under nasal endoscope for the treatment of maxillary odontogenic cyst. Methods:The clinical data of 23 cases with maxillary odontogenic cysts treated by nasal endoscopy through nasal fenestration were retrospectively analyzed. All cases underwent nasal endoscopy and CT examination before the operation. The mucosal membrane of the parietal wall of the cyst was excised through fenestration of the nasal base. The cyst fluid was removed by decompression, and the bony opening of the nasal base was trimmed and enlarged to the edge of the cyst. The intraoperative and postoperative effects were observed. Results:All cases were well exposed under the direct vision of nasal endoscope. The top wall of the cyst was removed to maximize the communication between the cyst cavity and the nasal floor. There were no complications such as nasolacrimal duct injury, turbinate atrophy, necrosis, and facial numbness. All patients were followed up for 6-12 months, and the clinical symptoms gradually disappeared after surgery. The inferior turbinate was in good shape, the cyst cavity was smooth, the cyst wall was determined, and no cyst recurrence was observed. Conclusion:The treatment of odontogenic cyst of maxilla under nasal endoscope through nasal fenestration is convenient. It has less trauma, fewer complications and a satisfactory curative effect, which is worthy of clinical promotion.
Humans ; Maxilla ; Retrospective Studies ; Odontogenic Cysts/surgery* ; Endoscopy ; Turbinates/surgery* ; Endoscopes

OBJECTIVE: To evaluate the effect and summarize the characteristics of different treatment methods in repairing zygomatic defect. METHODS: A total of 37 patients with zygomatic defect were reviewed in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from August 2012 to August 2019. According to the anatomical scope of defect, the zygomatic defects were divided into four categories: Class 0, the defect did not involve changes in zygomatic structure or continuity, only deficiency in thickness or projection; Class Ⅰ, defect was located in the zygomatic body or involved only one process; Class Ⅱ, a single defect involved two processes; Class Ⅲa, referred to a single defect involving three processes and above; Class Ⅲb, referred to zygomatic defects associated with large maxillary defects. The etiology, defect time, defect size and characteristics of zygomatic defects, the repair and reconstruction methods, and postoperative complications were collected and analyzed. Postoperative computed tomography (CT) data were collected to evaluate the outcome of zygomatic protrusion. Chromatographic analysis was used to assess the postoperative stability. RESULTS: Among the causes of defects, 25 cases (67.57%) were caused by trauma, and 11 cases (29.73%) were of surgical defects following tumor resection. We performed autologous bone grafts in 19 cases, 6 cases underwent vascularized tissue flap, 5 cases underwent external implants alone, and 7 cases underwent vascularized tissue flap combined with external implants. After the recovery of the affected side, the average difference of the zygomatic projection between the navigation group and the non-navigation group was 0.45 mm (0.20-2.50 mm) and 1.60 mm (0.10-2.90 mm), with a significant difference (P=0.045). Two patients repaired with titanium mesh combined with anterolateral thigh flap had obvious deformation or fracture of titanium mesh; 2 patients with customized casting prosthesis had infection after surgery and fetched out the prosthesis finally. CONCLUSION Autologous free grafts or alloplastic materials may be used in cases without significant structural changes. Pedicle skull flap or vascularized bone tissue flap is recommended for zygomatic bone defects with bone pillar destruction, chronic inflammation, oral and nasal communication or significant soft tissue insufficiency. Titanium mesh can be used to repair a large defect of zygomatic bone, and it is suggested to combine with vascularized bone flap transplantation.
Humans ; Maxilla/surgery* ; Prognosis ; Reconstructive Surgical Procedures/methods* ; Retrospective Studies ; Titanium

OBJECTIVE: To explore the method of measuring root volume with cone-beam computed tomography (CBCT) three-dimensional reconstruction technology, and to study root length and root volume of upper and lower central incisors in patients with skeletal Class Ⅲ malocclusion treated by surgical orthodontic treatment. METHODS: Twenty patients with skeletal Class Ⅲ malocclusion undergoing surgical orthodontic treatment were selected. CBCT data at three time points, before decompensation treatment (T0), after decompensation treatment (before orthognathic surgery, T1), and the end of post-operative orthodontic treatment (T2) were collected. Three-dimensional reconstruction technology was used to measure the root length and root volume of the upper and lower central incisors (including total root volume, cervical root and apical root), calculate the percentage of reduction volume, and measure the distance of tooth movement after orthodontic treatment. Data were statistically analyzed by SPSS 20.0 software. Least significant difference (LSD) method was used for pair comparison between the groups subject to normal distribution, and non-parametric test was used for comparison between the groups not subject to normal distribution. The differences of root length and root volume of upper and lower incisors were compared, and the characteristics of root absorption were analyzed. RESULTS: Root length and root volume of the upper and lower central incisors were reduced during the surgical orthodontic treatment (P < 0.05) in cases. Both the root volume of cervical root and apical root were significantly reduced (P < 0.05), the reduction of apical root was more significant. The percentage of root volume reduction of the upper central incisor was (30.51±23.23)%, and lower central incisor (23.24±11.96)%. Compared with the upper central incisor, the root volume reduction amount and percentage of the lower central incisor were smaller, and apical root volume reduction of the upper central incisor was greater than that of the lower central incisor, which was statistically significant (P < 0.05). During pre-surgical orthodontic treatment, maxillary central incisor palatal moving was in a controlled tipping manner, and the mandibular central incisor tipped labially. CONCLUSION In patients with skeletal Class Ⅲ malocclusion, root length and total root volume of upper and lower central incisors decreased during surgical orthodontic treatment. Root volume measurement indicated that the cervical root also had root resorption. The difference in root resorption of the upper and lower central incisors might be related to the distance and direction of teeth movement. CBCT three-dimensional reconstruction will compensate for the limitation of root length measurement in evaluating root resorption.
Cone-Beam Computed Tomography/methods* ; Humans ; Incisor/diagnostic imaging* ; Malocclusion, Angle Class III/surgery* ; Maxilla/surgery* ; Root Resorption/etiology*

Objective: To evaluate the pink and white esthetics of conventional and socket shield technique (SST) immediate implant restoration. Methods: Thirty volunteers were recruited according to preset criteria, and were assigned to 3 groups. Natural teeth group (ten undergraduates or postgraduates from Peking University School and Hospital of Stomatology in January 2020, n=10): all volunteers' maxillary anterior teeth were natural teeth with healthy gingiva, and none of the teeth were restored by crowns or composite. Conventional group and SST group (patients had a maxillary central incisor immediate implant placed in Department of Prosthodontics, Peking University School and Hospital of Stomatology during October 2016 to January 2021, n=10 for each group): the volunteer had an unrestored natural maxillary central incisor, and the contralateral maxillary central incisor was restored by conventional or SST immediate implant placement, temporization and all ceramic final restoration, photos were taken 12 months post-surgery. Three groups of evaluators namely layperson (staff from Second Clinical Division of Peking University School and Hospital of Stomatology and 2 family members, n=10), dental students (class 2015 undergraduates from Peking University School and Hospital of Stomatology, n=10) and prosthodontists (from Department of Prosthodontics, Peking University School and Hospital of Stomatology, n=10) were invited to assess the esthetics using pink esthetic score (PES) and white esthetic score (WES). The results were statistically analyzed. Results: PES and WES of natural teeth group [9(8, 10) and 8(7, 10)] were significantly higher than conventional group [7(6,8) and 7(6,9)] (H=287.08, 132.79,P<0.01) and SST group [7(6, 9) and 8(7, 9)] (H=216.01, 101.21, P<0.01). SST group yielded higher PES than the conventional group (H=-71.06, P<0.01), yet had similar WES (H=-31.57, P>0.05). Dental students had significant lower PES and WES than prosthodontists (H=-120.90, -218.86, P<0.01) and layperson (H=-109.55, 134.97, P<0.01). Prosthodontists and layperson got similar PES (H=-11.36, P>0.05), however yielded different WES (H=-83.89, P<0.01). Conclusions: SST immediate implant placement obtained better pink esthetics than conventional protocol 12-month after implant surgery, profession may have significant impact on evaluators during pink and white esthetic evaluation.
Crowns ; Dental Implants ; Dental Implants, Single-Tooth ; Esthetics, Dental ; Humans ; Immediate Dental Implant Loading ; Maxilla/surgery* ; Treatment Outcome

Recently, among the edentulous patients who undergo dental implants, the proportion of hypertensive patients remains high, which poses a greater challenge for clinicians to operate and to maintain the therapeutic effect. The present review comprehensively summarized clinical researches about the adverse effects on dental implants, outlined molecular mechanisms of the positive effects of various antihypertensive drugs on bone metabolism, and proposed that clinicians should select preventive strategies during preoperative and intraoperative procedures according to the blood pressure of patients with hypertension.
Alveolar Bone Loss ; Dental Implantation, Endosseous/methods* ; Dental Implants ; Dental Prosthesis, Implant-Supported ; Dental Restoration Failure ; Humans ; Hypertension/surgery* ; Jaw, Edentulous ; Maxilla/surgery* ; Risk Assessment

Objective: To select the preferred flaps for the reconstruction of different maxillary defects and to propose a new classification of maxillary defects. Methods: A total of 219 patients (136 males and 83 females) underwent the simultaneous reconstruction of maxillary defects in the Beijing Tongren Hospital, Capital Medical University, between January 2005 and December 2018 were reviewed. Age ranged from 16 to 78 years. Based on the proposed new classification of the maxillary defects, 22 patients with class Ⅰ defects (inferior maxillectomy), 44 patients with class Ⅱ defects (supperior maxillectomy), 132 patients with class Ⅲ defects (total maxillectomy) and 21 patients with class Ⅳ defects (extensive maxillectomy) were enrolled. Survival rate, functional and aesthetic outcomes of flaps were evaluated. Survival analysis was performed in 169 patients with malignant tumor, Kaplan-Meier method was used to calculate the survival rate, and Log-rank method was used to compare the difference of survival rate in each group. Results: A total of 234 repairs for maxillary defects were performed in 219 patients. Fibula flaps were used in 4/13 of class Ⅰ defects; temporal muscle flaps (11/24, 45.8%) and anterolateral thigh flaps (6/24, 25.0%) used in class Ⅱ defects; temporal muscle flaps (71/128, 55.5%), anterolateral thigh flaps (6/24, 25.0%) and fibula flaps (12/128, 9.4%) used in class Ⅲ defects; and anterolateral thigh flaps (8/20, 40.0%) and rectus abdominis flaps (8/20, 40.0%) used in class Ⅳ defects. The success rate of local pedicled flaps was 95.6% (109/114) and that of free flaps was 95.8% (115/120). Thrombosis(10/234,4.3%) was a main reason for repair failure. Among the followed-up 88 patients, swallowing and speech functions recovered, 82 (93.2%) of them were satisfied with appearance, and 75 (85.2%) were satisfied with visual field. The 3-year and 5-year overall survival rates were 66.5% and 63.6%, and the 3-year and 5-year disease-free survival rates were 57.1% and 46.2%, respectively, in the 169 patients with malignant tumors. Conclusion: A new classification of maxillary defects is proposed, on which suitable flaps are selected to offer patients good functional and aesthetic outcomes and high quality of life.
Adolescent ; Adult ; Aged ; Female ; Free Tissue Flaps ; Humans ; Male ; Maxilla/surgery* ; Middle Aged ; Quality of Life ; Reconstructive Surgical Procedures ; Young Adult

To explore the efficacy and value of personalized surgical schemes in the repair of maxillary sinus perforation and maxillary sinus fistula based on the size of the maxillary sinus perforation and maxillary sinus fistula. A total of 28 patients with maxillary sinus perforation and maxillary sinus fistula who were admitted to the Department of Oral and Maxillofacial Surgery, Stomatology Hospital of Kunming Medical University from July 2017 to May 2020 were included to conduct a prospective case clinical study. After the inflammation in the maxillary sinus was controlled, a proper surgical repair method was selected according to the size of the perforation and fistula based on the double-layer closure technique. The diameter of the perforation and fistula was measured with the assistance of cone-beam CT. After that, the platelet rich fibrin (PRF) repair was performed on the perforation and fistula with 3 mm≤diameter<7 mm in size in 14 patients. The PRF repair and buccal flap repair were performed on the perforation and fistula with 7 mm ≤diameter<15 mm in size in 7 patients. The adjacent buccal pad repair, palatine flap repair, and buccal flap repair were performed on the perforation and fistula with 15 mm≤ diameter<25 mm in size in 4 patients. The nasolabial axial flap repair and nasolabial free flap repair were performed on the perforation and fistula with a diameter ≥25 mm in size in 3 patients. The medical follow-up was conducted in all patients in the 1st, 2nd, and 4th week after surgery, with an overall success rate reaching 96.4% (27/28) after the initial intervention. The relapse of disease occurred in one patient (4.6%) with diabetes and a smoking history in the 2nd week after surgery. Identifying a proper surgical repair method according to the size of the oral and maxillary sinus perforation and maxillary sinus fistula based on the double-layer closure technique can improve the one-time cure rate in these patients under the premise that the inflammation in the maxillary sinus can be controlled.
Fistula/surgery* ; Humans ; Inflammation ; Maxilla ; Maxillary Sinus/surgery* ; Oroantral Fistula/surgery*

Objective: To construct a virtual reconstruction method including midspan maxillary defects and provide clinical reference by training a generative adversarial network (GAN) model. Methods: The CT data of middle-aged Han patients with oral diseases who visited the Department of Radiology, West China Hospital of Stomatology, Sichuan University from June 2015 to June 2022 were collected, where the CT data of 100 healthy maxilla and 15 maxillary defects (5 simple unilateral defects, 5 unilateral defects involving zygomatic bone, 5 midspan defects) were selected. Mimics was used to create spherical phantom and simulate bone defects around the healthy maxillas, including simple unilateral defects, unilateral defects involving zygomatic bone and midspan defects. The original image was set as the correct reference for the reconstruction: artificial defects paired with the correct reference were divided into training set (n=70), validation set (n=20) and test set (n=10), where the first two were used to train the GAN model, and the test set was used to evaluate the GAN performance. Data from 15 clinical defects were imported into the trained GAN model for reconstruction, with mirroring and GAN-based virtual reconstruction for unilateral clinical defects, and only the latter method was adopted for midspan defects. The reconstruction results were divided into mirror reconstruction group (n=10), unilateral defect GAN reconstruction group (n=10) and midspan defect GAN reconstruction group (n=5). The test set, mirror reconstruction group, and unilateral defect GAN reconstruction group were quantitatively evaluated, whose quantitative indicators were Dice similarity coefficient (DSC) and 95% Hausdorff distance (HD95), and the group results were subjected to one-way ANOVA and Tukey test. The test set, mirror reconstruction group, unilateral defect GAN reconstruction group and midspan defect GAN reconstruction group were qualitatively scored, and Kruskal-Wallis test and Bonferroni correction were used for the total score of each group. Results: The total differences in the test set, mirror reconstruction group, unilateral defect GAN reconstruction group DCS (0.891±0.049, 0.721±0.047, 0.778±0.057, respectively) and HD95 [(3.58±1.51), (5.19±1.38), (4.51±1.10) mm, respectively] were statistically significant (F=28.08, P<0.001; F=3.62, P=0.041); among them, the test set DSC was significantly larger than the mirror reconstruction group (P<0.05), and the test set HD95 was significantly less than the mirror reconstruction group (P<0.05). Overall difference in qualitative total scores [8 (1), 6 (2), 6 (2), and 4 (2) points, respectively] in the test set, mirror reconstruction group, unilateral defect GAN reconstruction group, and midspan defect GAN reconstruction group were statistical significance (H=18.13, P<0.001); pairwise comparison showed that the total score of the test set was significantly higher than that of the mirror reconstruction group (P<0.05). Conclusions: The virtual reconstruction method based on GAN proposed in this study has better virtual reconstruction effect of unilateral defect than mirror technique, and can also realize virtual reconstruction of maxillary midspan defect.
Humans ; Middle Aged ; Maxilla/surgery* ; Deep Learning ; China