Effects of sagittal split Ramus osteotomy on condylar position and Ramal orientation in patients with mandibular asymmetry.

OBJECTIVE: The purpose of this study is to assess the impact of Sagittal Split Ramus Osteotomy (SSRO) on the alignment of the condyle and orientation of the Ramal segment following surgery in patients operated for the correction of mandibular asymmetry. METHODS: A total of 27 patients who underwent SSRO were enrolled in this study, and study groups were defined as asymmetric (study group) and symmetric (control group) using linear measurements from the dental midline based on a three-dimensional coordinate system. Differences on preoperative and postoperative values of anterior (AJS), posterior (PJS) and superior joint spaces (SJS), condylar axial angle (CAA), Sagittal Ramal Angle (SRA), and Coronal Ramal Angles (CRA) of study and control groups were measured and compared. The data was analyzed using the "Wilcoxon signed-ranks test" to identify differences between groups. RESULTS: Differences between preoperative and postoperative values of CRA and SRA of the contralateral group showed statistically significant results with p-values of 0.007 and 0.005, respectively. A statistically significant change in CAA angle was found in the control and deviation groups (p = 0.018 and p = 0.010, respectively). CONCLUSIONS: SSRO has inevitable effects on the condylar and ramal orientation. Individuals with asymmetry require particular attention throughout the planning process and beyond. Conjunctive modalities and modifications should be considered and utilized when necessary. Future studies with larger sample sizes, homogenous follow-up periods, and more comprehensive clinical data are needed to substantiate understanding of the response of the condylar segment. CLINICAL RELEVANCE: Orthognathic surgeries inevitably alter the alignment and harmony of temporomandibular structures and may result in change of AJS, PJS, SJS, CAA, SRA, and LRA, which may change the biomechanics of joint and lead to several complications like temporomandibular disorders. Especially in cases with midline asymmetry needs special consideration from planning till the end of the treatment to achieve best results. In severe cases, conjunctive modalities and modifications and other alternatives such as inverted-L osteotomies should be considered.

Three-Dimensional Evaluation of Upper Airway Changes After Bimaxillary Surgery of Skeletal Class 3 Patients.

The aim of this study was to evaluate the 3-dimensional changes in upper airway space of class 3 patients after surgery with sleep-related breathing disturbance. This is a retrospective cohort study included 25 patients who had undergone bimaxillary orthognathic surgery with maxillary advancement and mandibular setback for skeletal class 3 deformity. The changes in minimum axial area, nasopharyngeal and oropharyngeal airway volume were determined by cone-beam computed tomography images, as well as the sleep parameters by polysomnography preoperatively and postoperatively. The impacts of mandibular setback and maxillary advancement amounts on the airway structures were evaluated and compared with other parameters. The results show that pharyngeal volume measurement means were found to be significantly increased postoperatively ( P <0.05). No significant difference was observed in the mean values of minimum axial area and sleep parameters after the operation ( P> 0.05). A positive relationship was determined between the oropharyngeal volume and minimum axial area changes at a rate of 60% ( r : 0.600). No relationship was revealed between airway volume changes and polysomnographic parameters. An increase in the total airway volume and no postoperative sleep-related disturbance symptoms were observed in the patients treated by maxillary advancement and mandibular setback surgery.

A Novel Use of Buccal Fat Pad Flap for Immediate Reconstruction of Palatal Tumor Resection Defect.

Integrity of the palatal mucosa may be disrupted due to various pathological and congenital factors. In maxillofacial defects, the buccal fat pad has been used frequently to repair the palatal region and close oro-nasal communications. In this case report, the use of buccal fat pad for the closure of a surgical palatal defect is presented with a 3-year follow-up. A 75-year-old female patient visited our clinic with a complaint of a non-adaptive maxillary denture. During clinical and radiographic examination, a well-demarcated mass on the palatal mucosa extending to the soft palate of the left side was observed. Subsequent to resection of the tumor, a defect occurred on the palatal region extending toward the soft palate. The pedicled buccal fat pad was chosen for closure of the defect. The patient was followed-up at 3, 7, 14, and 30 days after surgery. Epithelization and healing of the surgical wound were uneventful. At the 3-year follow-up, functional closure of the left palatal region was observed with no recurrence. Buccal fat pad is an easily manipulated flap with predictable results for the reconstruction of medium-sized defects of the oral and maxillofacial region with minimal postoperative discomfort for the patient.

Complications Associated With Anterior Iliac Bone Grafting for the Reconstruction of Dentoalveolar Defects.

The aim of this study is to evaluate donor- and recipient-site complications of iliac bone grafting for the reconstruction of atrophic jaws.Our study includes 86 consecutive patients with atrophic jaws who underwent iliac bone grafting surgery. At the donor site, hematoma, infection, paresthesia, chronic pain, prolonged gait disturbance, fracture of the ilium, and esthetic concerns; at the recipient site, hematoma, infection, prolonged pain, graft exposure, graft loss, and loss of the implants were evaluated.Grafting was successfully performed in all patients. The mean follow-up period was 35 months. Prolonged gait disturbance (20.9%) and paresthesia (9.3%) were the most frequently observed donor-site complications. At the recipient site, hematoma (8.1%), infection (12.8%), prolonged pain (11.6%), partial graft exposure (33.7%), total graft exposure (7%), partial graft loss (17.4%), and total graft loss (5.8%) were observed.Reconstruction of atrophic jaws can be achieved successfully with iliac bone grafting. However, there are possible donor- and recipient-site complications that have to be taken into consideration.

Clinical Evaluation of the Use of Tibial Bone Grafting in Dentoalveolar Reconstructive Surgery.

OBJECTIVE: The aim of this study was to evaluate the efficacy of tibial autogenous bone grafting in the treatment of patients with alveolar bone defects. MATERIALS AND METHODS: The study subjects consisted of 12 patients (10 male, 2 female, age: 19-51 years) who underwent reconstructive autogenous bone-grafting procedures. The medial approach to the tibial bone was used to harvest autogenous cancellous bone grafts in all the patients. Clinical parameters (complications at the donor and recipient sites, resorption and volume of the grafts) were evaluated retrospectively. RESULTS: The mean age of the patients was 36.25 ± 0.9 years. Of the 12 patients, 5 (41.7%) received bone grafts for sinus augmentation, 3 (25%) for cyst cavity reconstruction and 4 (33.3%) for alveolar cleft reconstruction procedures. The average follow-up period was 28.4 months (range: 21-40 months). An average of 5.2 cm3 of cancellous bone was harvested for grafting procedures. All the grafting procedures were successful, and there were no surgical complications during the harvesting protocol. In all cases, pain and gait disturbance lasted less than 2 weeks. CONCLUSION: The results of this study suggest that the use of tibial autogenous bone graft harvested using a medial approach was a safe, simple and effective method for grafting various alveolar bone defects where high amounts of cancellous bone grafts were needed with low morbidity.

A simple solution for vector control in vertical alveolar distraction osteogenesis.

One of the important and frequent complications in alveolar distraction osteogenesis is vectorial change of the transport segment. This report presents a simple solution for vector angulation control by placing intermaxillary fixation screws intraoperatively. Advantages of the technique are also discussed.

Further Expanding the Mutational Spectrum of Gorlin Syndrome in Three Unrelated Families.

Introduction: Gorlin syndrome is a rare, autosomal dominant multi-systemic disorder with a predisposition to the development of cancers such as medulloblastoma and nevoid basal cell carcinoma. Heterozygous pathogenic variants in PTCH1 are responsible for 90% of Gorlin syndrome cases. Pathogenic variants in PTCH1 cause overstimulation of the sonic hedgehog signaling pathway, which plays a role in the development of embryonic structures and tumorigenesis. Clinical major and minor diagnostic criteria for Gorlin syndrome have been determined. Odontogenic keratocyst (OKC) is the most common reason for medical admission in Gorlin syndrome. In this article, it is aimed to draw attention to the fact that patients with Gorlin syndrome are not very rare in our country and the variability in phenotypic and dysmorphic findings may be a clue for the diagnosis. Methods: Exome sequencing was performed on the Illumina NextSeq550 System platform by using the Ion Ampliseq exome RDY kit for Illumina. Sanger sequencing was performed accordingly for the other affected individuals in both families. Results: In this study, the clinical and molecular findings of 9 Gorlin syndrome patients from three unrelated families are presented. Macrocephaly, calcification of falx cerebri, palmar-plantar pits, rib anomalies, and OKC were detected in decreasing order in more than half of the patients. A novel heterozygous frameshift PTCH1 variant in family 1, a nonsense previously reported PTCH1 variant in family 2, and a novel heterozygous splice-site PTCH1 variant in family 3 were detected. Conclusion: Gorlin syndrome should be kept in mind in patients presenting with macrocephaly, palmoplantar pits, and OKC history. Careful examination of all family members is essential in the timely diagnosis of other affected individuals with minor phenotypic findings.

Evaluation of clinical signs and magnetic resonance imaging findings in patients with temporomandibular disorders.

This study assessed the relationship between clinical symptoms and magnetic resonance imaging (MRI) findings in temporomandibular disorders (TMD). A total of 324 temporomandibular joints (TMJs) from 162 patients were included. The TMJs were divided into three groups based on disc positions on MRI: normal disc position, anterior disc displacement with reduction (ADDwR), and anterior disc displacement without reduction (ADDwoR). Clinical findings included TMJ pain, TMJ noise, and maximum mouth opening (MMO). The disc configuration, disc positions, condylar morphology, and joint effusion were evaluated in proton density-weighted and T2-weighted open and closed-mouth sagittal sections. Patients comprised 135 females and 27 males, with a mean age of 37.63 ± 13.86 years. The VAS score was significantly higher in ADDwoR than in ADDwR (p = 0.007). Condylar sclerosis (ß coefficient: 1.449, 95% confidence interval (CI): 0.505-2.393, p = 0.003) and condylar flattening (ß coefficient: 1.024, 95% CI: 0.209-1.840, p = 0.014) had higher VAS scores than the other MRI findings in multiple regression analyses. Limited mouth opening (MO) was independently associated with ADDwoR. ADDwoR had a higher risk of having limited MO than normal disc position (odds ratio: 5.268), while there were no associations between limited MO and other MRI findings. None of the MRI findings showed significant performance in predicting TMJ noise. The convex and folded disc configuration percentages, the frequencies of osteophyte formation, and grade 3 effusion were significantly higher in the ADDwoR group. More severe clinical symptoms and a higher degree of disc deformity, osteophyte formation, and high-grade effusion were shown to be associated with ADDwoR.

Piezosurgery versus conventional surgery in radicular cyst enucleation.

OBJECTIVE: This study compared the use of piezosurgery and conventional surgery in radicular cyst enucleation. STUDY DESIGN: The study was conducted with 29 patients who were radiologically and cytologically prediagnosed with radicular cysts in the jaw region. Nineteen patients were treated using piezosurgery, and 10 were treated using conventional surgical procedures. Surgical procedures were evaluated according to the following criteria: hemorrhage, soft-tissue damage, manipulation complexity, major perforation areas on the enucleated cyst tissue, and approximate operation duration. Patients were monitored postoperatively and evaluated for hemorrhaging at 24, 48, and 72 hours following surgery. Follow-up was conducted to check for recurrences and ranged from 5 to 24 months. RESULTS: No complications were observed in any of the 20 patients treated using piezosurgery, although the duration of surgery was longer than expected. Of the 10 patients treated using conventional methods, hemorrhaging that affected the operation occurred in 3 cases, perforation of the cyst epithelium and difficulties in enucleation occurred in 5 cases, postoperative hemorrhage occurred in 2 cases, and recurrence was observed in 2 cases. CONCLUSIONS: Piezosurgery may be considered effective in procedures such as enucleation that require sensitive manipulation, despite the increase in the length of the overall surgical procedure. Given the results of the present study and the current lack of information in the literature regarding postoperative pain, infection, and long-term success rates associated with the use of piezosurgery in cyst enucleation, further study in this area is recommended.

Correction of postsurgical alveolar ridge defect with vertical alveolar distraction of the onlay block graft.

Alveolar bone augmentation for dental implant rehabilitation is one of the greatest challenges for oral and maxillofacial surgeons. Bringing out an inadequate quantity of vertical bone during augmentation compromises correct implant positioning and the resulting prosthetic restoration. Alveolar distraction osteogenesis is now generally used in correcting alveolar ridge atrophy due to trauma, congenital defects, or periodontal defects. Onlay block grafting is a suitable method for restoring the alveolar bony defects. However, it sometimes can become a complicated procedure to repair the horizontal defect accompanying a vertical defect using only bone blocks. This clinical report presents a successful reconstruction of a severe anterior mandibular alveolar bony defect as a result of impacted teeth extraction and periodontal problem in a 50-year-old healthy female patient. The defect was reconstructed with symphysis graft and platelet-rich fibrin in the first step. Vertical alveolar distraction was performed on the grafted site to maintain the suitable bony height 3 months later. Grafted bony segment distraction and the treatment options in similar cases were also discussed in this clinical report among with the literature.

Effect of suprahyoid muscles on mouth opening with and without lateral pterygoid muscle: 3D inverse dynamic model analysis.

Objective: To evaluate the contribution of suprahyoid muscles to mouth opening in different hyoid bone positions.Methods: The jaw-opening and closing movements were imposed on the 3D inverse dynamic jaw model with and without the lateral pterygoid muscle (LPM). The activation of the muscles was evaluated for eight different positions of the hyoid bone.Results: The muscles with 100% activation provided maximum mouth opening (MMO). When the hyoid bone was replaced, the muscles could achieve MMO at the 135º, 180º, and 225º points with the LPM. Mouth opening was estimated to be 36.8 mm in the absence of the LPM. A jaw opening greater than 36.8 mm was seen when the hyoid bone was repositioned at the 90º, 180º, and 135º points.Discussion: The contribution of suprahyoid muscles to mouth opening varies in different hyoid bone positions, with the inferior and anterior positions having a positive impact.

Effects of alendronate on rate of distraction in rabbit mandibles.

PURPOSE: Bisphosphonates are used for inhibiting bone resorption in several diseases. In this experimental study, the effects of alendronate on the mandibular distraction gap in rabbits at 2 different rates were evaluated. MATERIALS AND METHODS: The study was performed using 15 New Zealand white rabbits. Group 1 consisted of animals with distraction at the rate of 1 mm/day. Group 2 consisted of animals with distraction at the rate of 2 mm/day. These experimental groups had a postoperative alendronate injection during the first 3 days of their distraction phase. Group 3 consisted of animals with distraction at the rate of 1 mm/day, without alendronate injections. Distraction was performed on only the left sides of all animals until a gap of 10 mm was achieved. On postoperative day 45, the animals were sacrificed, and the mandibles of all animals were evaluated radiographically and histologically, and with dual-energy x-ray absorptiometry (DEXA). Radiographic images were also evaluated using transmission densitometry (TD). RESULTS: Histologically, bone healing was found to be significantly accelerated in groups 1 and 2 compared with group 3 (P < .05). Bone healing was superior in group 2, but the difference was not statistically significant compared with group 1. The TD results revealed no statistical difference between experimental groups, whereas the results for group 2 showed significantly denser osteogenic formation in the distraction gap compared with group 3. There was a significant increase in mean bone mineral density in the experimental groups compared with the control group. CONCLUSION: Histologic, TD, and DEXA results showed that alendronate injections during the distraction phase may be effective in accelerating new bone formation in the distraction gap in rabbit mandibles. The TD results also support the concept that an administration of alendronate may allow a 2 mm/day elongation instead of 1 mm/day in the rabbit mandible.

Histomorphometric evaluation of the effects of zoledronic acid on mandibular distraction osteogenesis in rabbits.

PURPOSE: To assess the effect of systemic administration of zoledronic acid (ZA) on mineralization of newly formed bone and to determine strain-related osteoporosis on surrounding bone during lengthening of immature rabbit mandible. MATERIALS AND METHODS: Eighteen New Zealand white rabbits were divided randomly into 2 groups, and bone lengthening was carried out in the left portion of the mandible through distraction osteogenesis with a rate of 0.5 mm every 12 hours for 5 days. The experimental group was administered 0.1 mg/kg ZA intravenously. The control group was given saline infusion only during operation. All animals were sacrificed at the end of the 28-day consolidation period. The mandibles of all animals were removed and regenerate was evaluated. Osteoblasts, osteoclasts, collagen fibers, and fibroblasts were marked within 0.1-mm(2) area and newly formed bone area was measured within 0.5-mm(2) area. All data were analyzed using Mann-Whitney U test. RESULTS: Although irregular bone destruction spots were seen in the control group, the experimental group showed regular ossification areas and significant difference between osteoblast and osteoclast numbers (P < .05). In the regenerate zone, there was considerable difference between the 2 groups in terms of osteoblast, osteoclast, and collagen amounts (P < .05). Additionally, newly formed bone areas and fibroblast count were higher in experimental group. CONCLUSIONS: The results of this study showed that ZA had positive effects on the new bone formation, which may potentially shorten the consolidation period.

Experimental evaluation of the effects of zoledronic acid on regenerate bone formation and osteoporosis in mandibular distraction osteogenesis.

PURPOSE: The aim of this study was to evaluate the effects of systemically administered zoledronic acid (ZA) on the bone mineral density (BMD) and bone mineral content (BMC) at mandibular distraction sites in rabbits. MATERIALS AND METHODS: Eighteen New Zealand white rabbits were randomly divided into 2 groups. Bone lengthening was performed in the left portion of the mandible through distraction osteogenesis at a rate of 0.5 mm every 12 hours for 5 days. While the experimental group rabbits were administered intravenous 0.1 mg/kg ZA, control group rabbits were given only saline infusion during operation. All animals were sacrificed at the end of the consolidation period of 28 days. The mandibles of all animals were removed and both the anterior and posterior pin regions of the regenerate and regenerate region were evaluated by dual energy x-ray absorptiometry (DEXA). BMD and BMC data were statistically analyzed. RESULTS: Except for 1 rabbit from the experimental group that had an infection at the external pin region, all animals showed complete clinical healing. When the values in the group receiving ZA were compared with those of the control group, it was observed that the BMD values of the anterior pin region of regenerate, regenerate region, and posterior pin region increased by 23%, 20%, and 31%, respectively; and BMC values increased by 22%, 24%, and 32%, respectively. When data of these regions were compared, both BMD and BMC were found statistically different in all regions (P < .05). CONCLUSION: Results of this study showed that ZA had positive effects on new bone formation at and around the distraction gaps of the lengthened rabbit mandibles by distraction osteogenesis.

Histomorphometric evaluation of short-term changes in masseter muscle after lengthening the rabbit mandible by distraction osteogenesis.

PURPOSE: Structural changes in muscles may affect the process during and after distraction osteogenesis (DO) of the mandible. However, the response of the masticatory muscles is still not well defined after gradual lengthening of the mandible. In this experimental study, short-term structural changes in masseter muscles of the rabbits are evaluated after mandibular DO. MATERIALS AND METHODS: Left mandibles of 10 New Zealand rabbits were lengthened by DO for 7 days in the rate of 1 mm/day. Mandibles of all animals were removed at the end of the consolidation period. Muscle biopsy samples of distracted and contralateral sides were histopathologically investigated, and histomorphometric results were statistically analyzed. RESULTS: Atrophy, hypertrophy, regeneration, and concomitant mild interstitial edema and fibrosis were found more evident in experimental side biopsy samples 30 days after distraction. Histomorphometric analysis revealed a statistically significant decrease in the mean regions of masseter muscle fibers of the distracted sides compared with the control sides (P <.05). CONCLUSION: This experimental study showed that the structure of masseter muscle is influenced during and shortly after mandibular distraction osteogenesis. Atrophic changes of the ipsilateral masseter muscles may be regarded as regenerative response that occurs during and shortly after distraction period.

Dentoalveolar distraction osteogenesis for rapid orthodontic canine retraction.

PURPOSE: We present a technique to reduce the overall orthodontic treatment time by means of dentoalveolar distraction osteogenesis. PATIENTS AND METHODS: Eleven patients who were planned to undergo orthodontic treatment with bilateral first premolar extractions and subsequent bilateral canine tooth distalization underwent osteotomy around the canine tooth. The first premolar was extracted, and the buccal bone was carefully removed. After wound closure, a special orthopedic device was mounted and cemented to the first molar and canine teeth. Distraction was started the same day at the rate of 0.4 mm twice a day and continued until adequate movement of the canine teeth was achieved. The device was then removed, and orthodontic therapy was continued with fixed appliances. RESULTS: The distraction rate and the device were well tolerated by all of patients. No anchorage loss in the second premolar and first molar teeth, root resorption, dental ankylosis, discoloration, or loss of vitality was detected. CONCLUSION: The concept of distraction osteogenesis for rapid orthodontic tooth movement is promising and feasible for clinical practice.