Congenital orofacial cleft, the most common birth defect in the maxillofacial region, exhibits a wide range of prognosis depending on the severity of deformity and underlying etiology. Non-syndromic congenital orofacial clefts typically present with milder deformities and more favorable treatment outcomes, whereas syndromic congenital orofacial clefts often manifest with concomitant organ abnormalities, which pose greater challenges for treatment and result in poorer prognosis. This consensus provides an elaborate classification system for varying degrees of orofacial clefts along with corresponding diagnostic and therapeutic guidelines. Results serve as a crucial resource for families to navigate prenatal screening results or make informed decisions regarding treatment options while also contributing significantly to preventing serious birth defects within the development of population.

Geriatric oral health care encounters significant challenges with the increase in the proportion of older individuals. Age-related changes in the dentition, muscles, and joints result in a decline in objective masticatory function, subjective restoration requirements, and acceptability among the elderly population, with individual variations influenced by systemic health. Considering functional requirements, the adaptability of stomatognathic and systemic health conditions, health economics and other factors, the authors believe that it should not be limited to the conventional “one-to-one” strategy for replacing missing teeth in geriatric prosthodontics. There is an urgent need for a precise and adaptable restoration strategy that is more suitable for older individuals. The proposal of a new concept of functional tooth loss updates the minimal restoration standards for elderly patients and establishes the theory of age-friendly functional restoration. Based on the restoration strategy of functional tooth loss, this paper proposes a new concept termed “age-friendly functional restoration of the stomatognathic system”, which integrates treatment considerations including endodontics, periodontology, mucosa, muscles, temporomandibular joint, and systemic health. Efforts should be made in four areas as follows. Firstly, the “assessment of accessible function” should be enhanced by considering the interrelationship between stomatognathic and systemic health. Secondly, the “evaluation of appropriate function” is supposed to be optimised in view of subjective needs and objective evaluation of the stomatognathic system. Moreover, the “formulation of treatment plans” needs to be accomplished with the aid of assistive technologies, such as artificial intelligence, to accurately exert appropriate functional restoration. Lastly, the “management and maintenance of health” is likely to be strengthened through follow-ups, propaganda and education, and preventive healthcare, so as to improve quality of life and ultimately achieve healthy ageing among older individuals.

Objective This study aims to explore the association between single nucleotide polymorphisms (SNPs) loci near the haplotype region hg19 chr9:100560865-100660865 of the forkhead box E1 (FOXE1) gene and the occurrence of non-syndromic cleft lip with or without cleft palate (NSCL/P) in western Han Chinese population. Methods In the first stage, our study recruited 159 NSCL/P patients and performed targeted region sequencing to screen SNPs loci near the haplotype region of the FOXE1 gene associated with NSCL/P. In the second stage, we selected 21 common SNPs and re-enrolled 1 000 non-syndromic cleft lip only (NSCLO) patients, 1 000 non-syndromic cleft palate only (NSCPO) patients, and 1 000 normal controls to verify the association. PLINK software was used to perform Hardy-Weinberg equilibrium (HWE) test. Association analysis for common variants, gene burden analysis for rare mutations, and function prediction of SNPs with non-synonymous mutations were performed using Mutation Taster and other software programs. Results In the first stage, 126 variants, including 76 single nucleotide variants and 50 insertion-deletions were identified. All the included SNPs confirmed to HWE, and the results of gene burden analysis and prediction of functional harmfulness for rare variants were not statistically significant. Association analysis showed that rs13292899 of the FOXE1 gene was significantly associated with NSCL/P (P=1.85E-27) and was also correlated with NSCLO (P=6.41E-23) and non-syndromic cleft lip with cleft palate (NSCLP) (P=2.36E-15) subtypes. In the validation phase, rs79268293 (P=0.013, P=0.022), rs10983951 (P=0.009 2, P=0.007 6), rs117227387 (P=0.009 2, P=0.007 6), rs3758250 (P=0.009 2, P=0.007 6), and rs116899397 (P=0.009 2, P=0.007 6) were significantly associated with NSCLO and NSCPO; rs13292899 (P=0.008 5), rs74606599 (P=0.008 3), rs143226042 (P=0.008 3), and rs117236550 (P=0.01) were associated with the occurrence of NSCLO; and rs12343182 (P=0.008 7), rs10119760 (P=0.012), rs10113907 (P=0.012), and rs13299924 (P=0.012) were associated with the occurrence of NSCPO. Conclusion This study found a new susceptible SNP rs13292899 of the FOXE1 gene that is closely associated with NSCL/P and NSCLO subtype and 13 other SNPs associated with NSCLO or NSCPO.

Objective The mechanism of the odontogenic differentiation of apical papillary cells (APCs) stimulated by bioactive glass 45S5 is still unclear. This study aims to investigate the effect of autophagy on the odontogenic differentiation of APCs stimulated by bioactive glass 45S5. Methods APCs were isolated and cultured in vitro, and the cell origin was identified by flow cytometry. The culture medium was prepared with 1 mg/mL 45S5, and its pH and ion concentration were determined. The experiments were divided into control, 45S5, and 3-methyladenine (3-MA) 45S5 groups. In the 45S5 group, APCs were induced to culture with 1 mg/mL 45S5. In the 3-MA 45S5 group, the autophagy inhibitor 3-MA was added to 1 mg/mL 45S5. Protein immunoblotting assay (Western blot) was used to detect the expression of autophagy-associated proteins of microtubule-associated protein 1 light-chain 3β (LC3B) and P62 after 24 h of induction culture in each group. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of bone sialoprotein (BSP), Runt-related transcription factor 2 (Runx2), dentin sialophosphoprotein (DSPP), and dentin matrix protein-1 (DMP-1) after 7 d of induction culture. Cellular alkaline phosphatase (ALP) staining analyzed cellular ALP activity at 7 d of induction, and alizarin red staining evaluated the formation of mineralized nodules at 21 d of induction. Results The pH of the 45S5 extract culture medium was 8.65±0.01, which was not significantly different from that of the control group (P>0.05). The silicon ion concentration of the 45S5 induction culture medium was (1.56±0.07) mmol/L, which was higher than that of the control group (0.08±0.01) mmol/L (P<0.05). The calcium ion concentration of the 45S5 induction culture was (1.57±0.15) mmol/L, which was not significantly different from that of the control group (P>0.05). Western blot results showed that LC3B-Ⅱ/Ⅰ ratio increased and P62 expression decreased in the 45S5 group compared with those in the control group (P<0.05). By contrast, the ratio decreased and the expression increased in the 3-MA 45S5 group compared with those in the 45S5 group (P<0.05). RT-qPCR results showed that the expression of BSP, Runx2, DMP-1, and DSPP enhanced in the 45S5 group compared with that in the control group (P<0.05), but the expression decreased in the 3-MA 45S5 group compared with that in the 45S5 group (P<0.05). Semi-quantitative analysis of ALP staining and alizarin red staining showed that the ALP activity was enhanced, and the formation mineralized nodule increased in the 45S5 group compared with those in the control group. The ALP activity weakened, and the formation mineralized nodules were reduced in the 3-MA 45S5 group compared with that those in the 45S5 group. Conclusion Cell autophagy participates in the odontogenic differentiation of APCs induced by 1 mg/mL 45S5 in vitro.

Objective This study aimed to observe the effects of initial periodontal therapy on the level of neutrophil extracellular traps (NETs) in gingival crevicular fluid (GCF) of patients with severe periodontitis and to analyze the factors related to the formation of NETs. Methods Thirty-one patients with stage Ⅲ-Ⅳ periodontitis were recruited. Clinical periodontal parameters, including plaque index (PLI), gingival index (GI), probing depth (PD), and clinical atta-chment loss (CAL), were recorded before and 6-8 weeks after initial periodontal therapy. Levels of NETs in GCF were detected by immunofluorescence staining. Quantities of total bacteria, Porphyromonas gingivalis (P. gingivalis), Aggregatibacter actinomycetemcomitans (A. actionomycetemcomitans) and Prevotella intermedia (P. intermedia)in unattached subgingival plaque were determined by real-time quantitative PCR, and levels of tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in GCF were explored by enzyme-linked immunosorbent assay. In addition, the correlations between the level of NETs and the above indicators were analyzed. Results After initial periodontal therapy, the level of NETs in GCF, PLI, GI, PD, and CAL; quantities of total bacteria, P. gingivalis, A. actinomycetemcomitans, and P. itermedia; and levels of IL-8 and TNF-α significantly decreased (P<0.05). We observed strong positive correlations between the level of NETs and PLI, GI, PD, CAL, the amount of total bacteria, P. gingivalis, TNF-α, and IL-8 (P<0.05). Conclusion Initial periodontal therapy might decrease the level of NETs in GCF from patients with severe periodontitis, which might be positively correlated with the quantities of P. gingivalis andthe levels of TNF-α and IL-8 in GCF.

Objective This study aims to compare the effects of two orthodontic treatment modalities for skeletal class Ⅲ malocclusion on specific changes in airway volume, morphology, palatal angle, mandibular rotation, and bone displacement. Results provide scientific evidence for the selection of orthodontic treatment plans and reduce the risk of developing obstructive sleep apnea hypopnea syndrome (OSAHS). Methods Thirty-six patients diagnosed with skeletal class Ⅲ malocclusion at the Department of Orthodontics, the Affiliated Stomatological Hospital of Nanjing Medical University from September 2018 to December 2023 were divided into two groups: orthodontic-orthognathic treatment group (18 patients) and camouflage orthodontic treatment group (18 patients). Changes in airway volume, cross-sectional area, palatal angle, mandibular, and tongue positions were observed through pre- and post-operative cone beam computed tomography and 3D cephalometric measurements. Results In the camouflage orthodontic treatment group, nasopharyngeal volume and oropharyngeal volume statistically increased after treatment (P<0.05). In the orthodontic-orthognathic treatment group, changes in nasopharyngeal volume, nasopharyngeal airway, distance from posterior tongue to pharyngeal wall, palatal angle, mandibular rotation, and hyoid bone displacement were statistically significant after surgery (P<0.05). In the comparison between the two groups after treatment, changes in the distance from posterior tongue to pharyngeal wall, palatal angle, and distance from hyoid bone to sella turcica point were statistically significant (P<0.05). Conclusion Patients in the orthodontic-orthognathic treatment group showed significantly greater changes in oropharyngeal cross-sectional area, palate angle, and tongue position compared with patients in the camouflage orthodontic treatment group. As individuals susceptible to OSAHS often exhibit mandibular retrusion and decreased minimum airway cross-sectional area, special attention should be paid to airway morphology changes when adopting orthodontic-orthognathic treatment to avoid adverse consequences.

Objective This study aims to explore the effect of improving clinical efficiency by replacing traditional impression workflow with centralized digital impression workflow. Methods The department of prosthodontics in Center of Stomatology, Peking University Shenzhen Hospital has improved the clinical workflow by replacing the traditional impression made by doctors using impression materials for each patient with a centralized digital impression made by one technician for all patients in the department. This cross-sectional study recorded the chairside time required for impression taking in patients undergoing single posterior zirconia full crown restoration before clinical process improvement; the time required for centralized digital impression production; the comfort level of patients; and the adjacency relationship, occlusal contact relationship, and time required for prostheses adjusting (i.e., whether centralized digital impressions would compromise the quality of pro-stheses and increase the time of prostheses adjusting). Results The average time to make a traditional impression was (9.98±1.41) min, and the average time required for each patient to make a centralized digital impression was (5.98±1.49) min, which was shorter than that to used make a traditional impression (P<0.05). Centralized digital impression made patients feel more comfortable compared with traditional impression (P<0.05). The adjacency relationship of restorations by centralized digital impression was more appropriate (P<0.05), and no significant difference in occlusal relationship was found (P>0.05). The time required for adjusting prostheses also had no significant differences (P>0.05). Conclusion Centralized digital impression can improve clinical efficiency for patients undergoing single posterior zirconia crown restoration. The time for impression taking is shorter, and patients feel more comfortable without compromising the quality of the prostheses.

Objective This study aims to evaluate the clinical effect of low-energy semiconductor laser treatment on the promotion of wound healing after maxillofacial fracture surgery. Methods A prospective randomized controlled study was conducted. Patients with maxillofacial fractures who were hospitalized in the Department of Trauma and Plastic Surgery, West China Hospital of Stomatology, Sichuan University, from August 2021 to June 2023 were selected as the study subjects and randomly divided into experimental and control groups. The experimental group was treated with a low-energy semiconductor laser once a day for six consecutive days after daily routine dressing change on the first day after surgery. The control group only underwent routine dressing change treatment and did not receive low-energy semiconductor laser treatment. Wound healing times, wound healing conditions, modified Stony Brook scar evaluation scale (mSBSES) scores, pain indices, and wound infection rates were compared between the two groups. Results A total of 211 patients were included in this study. A total of 104 and 107 cases comprised the experimental and control groups, respectively. A total of 128 males and 83 females were included. After low-energy semiconductor laser treatment, the facial skin wound healing time of the experimental group was found to be significantly shorter than that of the control group (P<0.05). Moreover, the wound grade A healing rate of the experimental group was higher than that of the control group on the seventh day after surgery (P<0.05). Among postoperative facial skin wound evaluation indices, the mSBSES scores of the experimental group at all observation points were higher than those of the control group (P<0.05), and the scores of the experimental group were higher than those of the control group in terms of wound width reduction, height reduction, color lightening, and incision line loss (P<0.05). In postoperative wound pain evaluation, the pain index of the experimental group after low-energy semiconductor laser treatment was significantly lower than that of the control group (P<0.05). No significant difference in wound infection rates was found between the two groups (P>0.05). Conclusion For facial skin wounds in maxillofacial fracture surgery, low-energy semiconductor laser treatment can effectively promote wound healing, improve wound healing quality, fade scars, and relieve wound pain.

Objective To study the clinical effect of the L-shape technique combined with concentrated growth factor on the horizontal bone defects of maxillary anterior teeth. Methods Twenty-five implants from 25 patients who underwent single maxillary anterior tooth implantation with simultaneous bone grafting were selected as the study subjects. Based on the bone grafting techniques, the patients were divided into a test group (L-shaped technique with guided bone regeneration combined with concentrated growth factor, 11 cases) and a control group (traditional guided bone regeneration combined with concentrated growth factor, 14 cases). The early discomfort and wound healing conditions in the two groups at two weeks after surgery were compared. The horizontal bone thickness, vertical bone thickness, and grayscale values in the augmentation area were measured immediately postsurgery and six months after surgery. Implant stability, hard tissue resorption within six months, and grayscale values were compared between the two groups. Results Differences in early discomfort, wound healing, implant stability, and grayscale values between the two groups were not statistically significant (P>0.05). Vertical bone thickness in the test group was significantly better than that in the control group at six months after surgery (P<0.05). The variation in horizontal bone thickness in the test group was significantly higher than that in the control group (P<0.05). Conclusion The application of the L-shape technique with concentrated growth factor for horizontal bone defects in the anterior maxillary area yielded satisfactory short-term results in terms of bone augmentation, early discomfort, wound healing, and implant stability at six months after surgery.

Objective This study aims to explore the current status and risk factors of oral health-related quality of life OHRQoL in patients with mental disorders and provide evidence for effective intervention measures. Methods A total of 397 patients diagnosed with mental illness were selected by convenience sampling, and investigation was carried out using general data questionnaire, health literacy in dentistry-14 (HeLD-14), oral health impact profile-14 (OHIP-14), and oral health status checklist. Results The total score of OHIP-14 in patients with mental disorders was 8(2, 14). The score of HeLD-14 was negatively correlated with the score of OHIP-14 (r=-0.142, P<0.01). The results of multiple linear regression showed that six variables including annual family income, schizophrenia, sweets, frequency of visits to the dentist, dental caries, and missing teeth affected OHRQoL of patients with mental disorders (P<0.05). Conclusion The poor OHRQoL of psychiatric patients is associated with many factors. Medical personnel should pay attention to their oral health problems and develop targeted oral care programs throughout the course of disease to improve oral health and related quality of life of patients.

Objective This study aimed to investigate the clinical characteristics of deciduous fused teeth and their inherited permanent-tooth performance type by using panoramic radiographs. Methods A total of 14 404 panoramic radiographs of 3- to 6-year-old children with deciduous dentition were collected from January 2023 to July 2024. The incidence of deciduous fused teeth was observed, and the abnormality of permanent teeth was recorded. SPSS 24.0 software was used for statistical analysis. Results The incidence of deciduous fused teeth was 3.06% (441/14 404). The order of dental position was as follows: mandibular deciduous incisors and cusp teeth fused (58.18%) > mandibular deciduous central and lateral incisors fused (30.91%) > maxillary deciduous central and lateral incisors fused (8.89%) > deciduous incisors and supernumerary teeth fused (2.02%). Deciduous fused teeth were found in 226 boys and 215 girls, with no significant difference between the sexes (P>0.05). We observed one pair (87.76%, 387/441) and two pairs (12.24%, 54/441) of fused teeth (54/441), respectively. A total of 287 pairs of fusion teeth on the right side more than 208 pairs on the left side, and the difference between them was statistically significant (P<0.01). More fusion teeth existed in mandibular deciduous teeth (443 pairs) than in maxillary ones (54 pairs), and the difference between them was statistically significant (P<0.01). More unilateral deciduous teeth (387 subjects) were found than bilateral ones (54 subjects), and the difference between them was statistically significant (P<0.01). Three types of deciduous fused teeth with inherited permanent teeth were observed as follows: 1) 49.49% (245/495) of inherited permanent teeth was absent, 2) 46.67% (231/495) of inherited permanent teeth was not absent, and 3) the number of fused permanent teeth accounted for 3.84% (19/495). Conclusion The incidence of deciduous fused teeth was 3.06%, mostly occurring in the lower anterior teeth region, with no gender difference. One pair of fused teeth is commonly observed, more often on the right than the left. These fusions occur more frequently in the mandible than the maxillary, and unilateral cases are more common than bilateral ones. Deciduous fused teeth had a certain impact on inherited permanent teeth. Pediatric dentists should pay attention to and closely observe whether any abnormality exists in the permanent dentition for early detection to prevent the harm caused by deciduous fused teeth.

Objective This study aimed to analyze the influence of drug factors on the efficacy of bisphosphonate for chronic nonbacterial osteomyelitis to provide a reference for clinical treatment and promote clinical rational drug use by evaluation of effectiveness and safety of bisphosphonate treatment of chronic nonbacterial osteomyelitis. Methods Literature on the treatment of chronic nonbacterial osteomyelitis by using bisphosphonate was collected and analyzed from PubMed, Medline, Embase, Cochrane, ISI Web of Knowledge, CNKI, VIP, and Wanfang databases. Results A total of 489 cases were collected, with an average complete response rate of clinical presentation, laboratory tests and imaging findings of 80.37%, 80.56% and 79.22%, respectively. Except for opadronate, risedronate, ibandronate, pamidronate, alendronate, neidronate and zoledronate showed good efficacy, and the average complete response rates were 100%, 100%, 81.64%, 87.50%, 69.23% and 69.23%, respectively.The study found that in the pamidronate group, the average complete response rate of 0.5-1 mg/kg (maximum single dose≤60 mg) subgroup and the frequency of administration once every 3 months subgroup were better than other subgroups. Conclusion Bisphosphonate could be used to treat chronic nonbacterial osteomyelitis, which of efficacy were affected by different drug types, dose and frequency of administration. The optimal dose and frequency of administration of pamidronate were 0.5-1 mg/kg (maximum single dose≤60 mg) and once every 3 months, respectively.

Objective This study aims to evaluate the changes in the mandibular canal following the treatment of large odontogenic keratocysts through decompression and curettage, providing a theoretical basis for sequential treatment. Methods Twenty patients were selected for each decompression and curettage treatment of large odontogenic keratocysts in the mandible. Postoperative follow-up with was conducted every three months, during which cone beam computed tomography (CBCT) scans were performed. Then, the data were imported into MIMICS software to observe 3D changes in the position and structure of the mandibular nerve canal, followed by a comparative analysis. Results The total displacement of the mandibular canal was (1.89±0.21) mm on the decompression side and (0.80±0.19) mm on the curettage side. Vertically, the displacement range of the mandibular canal on the decompression side (M=1.03, SD=0.17) was larger than on the curettage side (M=0.52, SD=0.010) within nine months post-operation. In the buccal-lingual direction, the ratio of the thickness of the buccal plate to the lingual plate gradually increased with time. The amount of bone reconstruction at the part of the mandibular nerve canal closest to the cyst was (1.75±0.15) mm on the decompression side and (1.45±0.09) mm on the curettage side after nine months. Conclusion The mandibular nerve canal showed varying degrees of recovery and “relocation” after two surgical procedures. Osteogenesis around the mandibular nerve canal was more remarkable after decompression than after curettage. Therefore, for large odontogenic keratocyst, decompression is recommended as the initial treatment, followed by secondary curettage nine months later.

Objective The objective of this study is to measuring the morphology and position of bilateral temporomandibular joints in patients with unilateral and bilateral molar scissor bite and simulating the deformation of the mandible during occlusion, in order to provide thesis for the diagnosis of temporomandibular joint disease in patients with unilateral and bilateral molar scissor bite. Methods This study was a retrospective study. A total of 10 patients with unilateral molar scissor bite (the unilateral molar scissor bite group) and 10 patients with bilateral molar scissor bite (the bilateral molar scissor bite group) were selected as the experimental group, and 20 adult patients with classⅠ of angle classification of similar ages were selected as the control group. All patients underwent cone beam computed tomography scans, by measuring the width of the fossa, height of the fossa, articular eminence inclination, long axis of the condyle, minor axis of the condyle, horizontal angle of the condyle and the space of the temporomandibular joint, compare temporomandibular joint morphology and position. The three-dimensional finite element analysis of the mandible morphology was carried out to evaluate the force and deformation of the mandible by using software to simulate the occlusion of the patients. It was further explored the relationship between the force of the mandible morphology and the possible temporomandibular joint disorder symptoms of the patients. Results Intergroup comparisons for the unilateral molar scissor bite group and left sides of the other groups revealed that the superior articular space in the group with unilateral molar scissor bite was shorter than that in the control group (P<0.05); the long axis of the condyle in the unilateral and bilateral molar scissor bite group were both shorter than that of the control group (P<0.05); among which the unilateral group was larger than the bilateral group, and the minor axis of the condyle in bilateral molar scissor bite group was smaller than in the control group (P<0.05), and the unilateral and bilateral condylar groups were larger than the control group (P<0.05); and the condylar horizontal angle in the unilateral and bilateral groups were larger than that in the control group (P<0.05). The normal sides of the unilateral molar scissor bite group and right sides of the other groups had smaller superior articular space than the control group (P<0.05); and the condylar long-axis in bilateral group was smaller than the control group (P<0.05); and the normal side of the condylar short-axis unilateral group was larger than that of the bilateral condylar group. Three-dimensional finite element analysis: the condyle of patients with molar scissor bite was a concentrated area of deformation during the bite of the mandible, when the first molar occlusion of the scissors bite side was simulated, the maximum deformation was located in the condyle in the X-axis and Z-axis directions. The amount of deformation was greater than that of the scissor bite side in the X-axis direction, while in the Z-axis direction, the normal side was greater than the scissor bite side. The maximum sites of local deformation in the X-axis direction were located in anterior and posterior the transverse crest of scissor bite side, and the minimum sites of local deformation was at 1/3 of the anterior slope of the inner pole of the normal side, the maximum local deformation sites in the Z-axis direction were located in the outer pole and below the outer pole of the normal side. The X-axis deformation value was the largest in the molars occlusion on the normal side, the Y-axis deformation value was in the premolars occlusion on the normal side, and the Z-axis deformation value was the largest in the centric occlusion, the deformation value of the condyle was not most significant in molar scissor bite. Conclusion Unilateral and bilateral molar scissor bite resulting in a short condyle morphology, and the bilateral group had a shorter condylar morphology than the unilateral group. The condyle of the patient with molar scissor bite is a concentrated area of poor occlusal deformation, and the largest sites of deformation are distributed near the transverse ridge of the inner and outer poles of the condyle. Different occlusion conditions have an effect on condylar deformation values, but do not indicate whether there is a clear association between them.

Objective This study aims to analyze the biomechanics of three kinds of rigid internal fixation methods for condylar head fractures. Methods A three dimensional finite element model of the normal mandible was constructed. It was then used to prepare condylar head fracture finite element model and three kinds of rigid internal fixation finite element model (unilateral tension screw, bilateral tension screw, tension screw+titanium plate). The mechanical characteristics and changes of the mandible condyle under the same mechanical conditions were compared among the three different rigid internal fixation methods. Results The maximum equivalent stress and displacement of the non-free end of condyle under the rigid internal fixation method of unilateral tension screw were 71.03 MPa and 4.72 mm, respectively. The maximum equivalent stress and displacement of the free end of condyle were 78.45 MPa and 4.50 mm, respectively. The maximum stress of fracture suture was 3.27 MPa. The maximum equivalent stress and displacement of the non-free end of condyle under the rigid internal fixation method of bilateral tension screw were 70.52 MPa and 4.00 mm, respectively. The maximum equivalent stress and displacement of the free end of condyle were 72.49 MPa and 3.85 mm, respectively. The maximum stress of fracture suture was 2.33 MPa. The maximum equivalent stress and maximum displacement of the non-free end of condyle under the rigid internal fixation method of tension screw+titanium plate were 67.26 MPa and 2.66 mm, respectively. The maximum equivalent stress and maximum displacement of the free end of condyle were 69.66 MPa and 2.50 mm, respectively. The maximum stress of fracture suture was 2.18 MPa. Conclusion The tension screw+titanium plate rigid internal fixation method is the most conducive to biomechanical distribution for condylar head fractures.

Peri-implantitis is a pathologic condition associated with dental plaque that occurs in the implant tissue and is characterized by inflammation of the mucous membrane surrounding the implant, followed by the progressive loss of supporting bone. In this study, a case of guided bone regeneration therapy based on plaque control of peri-implant inflammation was reported. Four years after surgery for the left second premolar implant, the patient presented with “left lower posterior tooth swelling and discomfort for more than 2 years”. The X-ray periapical film showed a decrease in distal bone mineral density of implant, and the clinical diagnosis was peri-implantitis of the left second premolar. Implants underwent guided bone regeneration and regular periodontal maintenance treatment. Re-examination at 3.5 months, 11 months, 18 months, and 7 years showed that the alveolar bone height and bone mineral density were stable, and the periodontal depth became shallow. However, the gingival recession was mild. In the present case, follow-up at 7 years demonstrated that the clinical periodontal indexes could be remarkably improved after complete periodontal treatment for peri-implantitis, and the alveolar bone could be well restored and regenerated.

Stafne bone cavity, also known as static bone cavity, is a rare bony defect on the lingual side of the mandible. It rarely shows progressive changes, and requires only follow-up bservation. This article described a case of progressive enlargement of a Stafne bone cavity and analyzed the causes of its progress by reviewing relevant literature.

Pathological fractures after jaw cyst surgery are rare clinically but are a serious complication. Once a pathological fracture occurs, treatment time and economic costs increase, and doctors face difficulty in handling it. This article reports a case of a patient with mandibular pathological fractures after multiple odontogenic keratocyst surgery of the jaw. Mandibular lesions were located in the bilateral mandibular angles and had macrocystic changes. We adopted a conservative treatment plan, and the treatment effect was good. We also discussed and analyzed relevant literature to provide a reference for clinicians.