Change in condylar and mandibular morphology in juvenile idiopathic arthritis: Cone Beam volumetric imaging

AIM: The aim of this study was to show the importance of Cone Beam Computerized Tomography (CBCT) to volumetrically quantify temporomandibular joint (TMJ) damage in patients with juvenile idiopathic arthritis (JIA), measuring condylar and mandibular real volumes. Methods. Thirty-four children with temporomandibular involvement by JIA were observed by CBCT. Four were excluded because of several imaging noises. The mandible was isolated from others craniofacial structures; the whole mandibular volume and its components' volumes (condyle, ramus, emibody, emisymphysis on right side and on left side) has been calculated by a 3D volume rendering technique. Results. The results show a highly significant statistical difference between affected side volumetric values versus normal side volumetric values, above all on condyle region (P<0.01), while there was no statistical difference between right versus left side. Conclusion. The CBCT represents a huge improvement in understanding of the condyle and mandibular morphological changes, even in the early stages of the JIA. In children the JIA can lead to TMJ damage with facial development and growth alterations.     

Pathological changes in the TMJ and the length of the ramus in patients with confirmed juvenile idiopathic arthritis

IntroductionJuvenile idiopathic arthritis (JIA) is characterized by a progressive destruction of the joints. The temporomandibular joints (TMJ) are especially likely to be affected. The often undetected arthritis in the TMJ in particular can cause significant destruction and craniofacial developmental abnormalities. The aim of this study was to analyze the destructive impact of JIA on TMJ and mandibular development.Material and methodsWe analyzed a total of 92 joints and mandibular rami using digital cone-beam tomography (CBT) and compared 23 consecutively treated JIA patients with 23 healthy controls, matched for age and gender. We evaluated ramus length, vertical depth of the articular fossa, anterior–posterior dimensions of the mandibular head and condylar process. The statistical analysis was performed using non-parametric Wilcoxon and Kruskal–Wallis Rank Sum tests.ResultsThe JIA patients exhibited significantly more pronounced asymmetries. However, we were unable to detect significant differences in the metric measuring distances. The different JIA subtypes exerted no statistically significant influence.ConclusionsThe possible destruction arising as a result of JIA concerns the TMJ and the length of the mandibular ramus. These craniofacial anomalies demonstrate the central importance of sufficiently early detection and timely treatment in the prevention of such growth disturbances.     

Three-dimensional analysis of mandibular functional units in adult patients with unilateral posterior crossbite: A cone beam study with the use of mirroring and surface-to-surface matching techniques

Objectives:To use three-dimensional (3D) mirroring and surface-to-surface techniques to determine any differences in mandibular functional unit shape and morphology between the crossbite side and non-crossbite side in adult patients with posterior unilateral crossbite who had not received any corrective treatment for malocclusion.Materials and Methods:Cone-beam computed tomography (CBCT) records from 24 consecutive adult white patients (mean age, 27.5 years; range 22.6–39.7 years; 14 women and 10 men) seeking treatment for maxillary transverse deficiency were assessed in this study. The control group comprised CBCT scans from age- and sex-matched patients. Segmentation masks were generated to obtain 3D surface mesh models of the mandibles and analyze the six skeletal functional units, which were further analyzed with reverse engineering software.Results:Statistically significant differences in the mean surface distance when comparing the study sample and the control sample were found at the condylar process, mandibular ramus, angular process (P ≤ .0001), and alveolar process (P ≤ .01); no statistically significant differences were found for the coronoid process, the chin, and the mandibular body (P ≥ .5).Conclusions:The condylar, angular, and alveolar processes plus the mandibular ramus appear to play a more dominant role than did the body, the coronoid, and the chin units in the asymmetry of the mandible in patients with unilateral crossbite.     

Use of an occlusal splint and intraoperative imaging with an intraoral approach in the management of mandibular subcondylar fractures

IntroductionTo evaluate the feasibility of safely managing subcondylar fractures using an original surgical procedure combining an intraoral approach, the use of a custom-made occlusal overlay splint, and intraoperative imaging.Materials and methodsCondylar fragment was freed from surrounding soft tissues, was laterally exposed to the ramus, and a miniplate was fixed in place for osteosynthesis. An overlay splint maintaining the dental occlusion was used to facilitate reduction and stabilization during fixation. Intraoperative monitoring by cone-beam computed tomography (CBCT) was performed before completing the fixation.ResultsBetween November 2018 and June 2019, 10 patients were treated using this procedure. The median length of the proximal condylar fragment was 29 mm (range 24–39 min). Five patients had an associated mandibular fracture. The median duration of the condylar fracture surgery was 54.5 min (range 38–79 min). All patients had satisfactory reduction and osteosynthesis with no complications.ConclusionIt is feasible to safely manage subcondylar fractures with this surgical procedure that could facilitate open reduction using intraoral approaches. Occlusal splints maintain downward pressure on the rami bilaterally and symmetrically, helping to anatomically reposition condylar process fractures. Intraoperative imaging is used to monitor this step.     

Unilateral superior condylar neck fracture with dislocation in a child treated with an acrylic splint in the upper arch for functional repositioning of the mandible

Background: To present the outcomes for a case of unilateral mandibular subcondylar fracture with dislocation in an 11-year-old female treated with an acrylic splint for functional repositioning of the mandible.

Clinical presentation: A splint was placed in the upper arch to restore the functional repositioning of the mandible. The splint’s height was increased up to 5.5 mm on the side of the fracture to stimulate growth on the deficient side. To correct the mandibular asymmetry, a construction bite was made by 4 mm advancing. The total treatment time was 16 months. Long-term five-year follow up showed complete healing. A portion of the ramus appeared lateral with respect to the condylar head, whereas the mandibular deviation to the right side was fully corrected.

Conclusion: Conservative treatment may be an appropriate method for children in select cases, as they have an increased potential for spontaneous regeneration.     

三维超声下颌定位技术在(牙合)垫治疗颞颌关节绞锁中的应用

目的应用三维超声下颌定位技术,观察颞颌关节绞锁应用于（牙合）垫治疗前后髁突运动轨迹的变化。方法对21例单侧颞颌关节绞锁患者使用下颌稳定性（牙合）垫治疗。运用三维超声下颌定位技术观察绞锁性颞颌关节在（牙合）垫治疗前后健患侧髁突运动轨迹在最大开口运动、最大前伸运动和侧方运动中运动范围的变化。结果通过三维超声下颌定位技术可观察到患者髁突运动轨迹表现为双侧的不对称性。患侧关节在（牙合）垫治疗前后运动范围的比较发现,在最大开口运动的矢状位、冠状位、轴位的髁突运动范围增大（P〈0．05）;前伸和侧方运动的矢状位、冠状位的髁突运动范围增大（P〈0．05）。结论（牙合）垫治疗后绞锁性颞颌关节健患侧髁突的运动轨迹更加对称,患侧关节运动轨迹的范围增大。三维超声下颌定位技术可作为（牙合）垫治疗颞颌关节绞锁髁突运动轨迹改变有效的观测与评价手段。     

Evaluating the remodeling of condyles reconstructed by transport distraction osteogenesis in the treatment of temporomandibular joint ankylosis

PurposeThis study aimed to evaluate the remodeling of condyles reconstructed by transport distraction osteogenesis (DO) in patients with temporomandibular joint (TMJ) ankylosis.Patients and methodsTwenty-one patients with 26 affected joints were followed up for 34.1 ± 13.3 months. Patients who had undergone gap arthroplasty and TMJ reconstruction by DO were included. Maximal mouth opening (MMO) and occlusion were recorded. Computed tomography images were obtained preoperatively (T0), upon completing distraction (T1), upon removal of the distraction device (T2), and >2 years postoperatively (T3). The following were measured: mandibular ramus height, distance between gonion and Frankfurt plane (Go–FN), condylar width, and condyle–ramus angulation.ResultsOf the 21 patients, one showed re-ankylosis, while five exhibited anterior open bite. From T1 to T3, the total amount of resorption of ramus height reached up to 8.2 ± 4.6 mm (p < 0.001), in comparison with a total distraction length of 13.8 ± 4.1 mm; the mean resorption rate was 59.4%. Similarly, Go–FN decreased by 6.2 ± 4.0 mm (p < 0.001).ConclusionOur findings indicated that DO combined with gap arthroplasty was an effective method for the treatment of TMJ ankylosis to improve MMO. The reconstructed condyle exhibited a high frequency of resorption in height.     

Evaluation of effects of activator treatment on mandibular growth by analyzing components of condylar growth and mandibular rotation

PurposeThe objective of this study is to clarify the effects of activator treatment on mandibular growth in relation to condylar growth and total rotation of the mandible, and to investigate the relationships between the treatment responses and pretreatment facial morphology.Materials and methodsThirty Japanese girls with Class II division 1 malocclusion treated with activator were examined. Mean age at the start of treatment was 9.6 ± 1.6 years. Mean treatment duration was 19 ± 4 months. Lateral cephalograms obtained before and after treatment were used to analyze skeletal changes during treatment. Regional superimposition analysis was performed to evaluate activator effects by decomposing the mandibular growth into condylar growth and mandibular total rotation.ResultsThe changes in intermaxillary relationships were significantly correlated with vertical condylar growth and mandibular total rotation (P < 0.05 and P < 0.01). The changes in the forward displacement of the mandible were significantly correlated with sagittal condylar growth and mandibular total rotation (P < 0.05 and P < 0.01). Vertical condylar growth and mandibular total rotation were significantly correlated with pretreatment mandibular morphology (P < 0.05 and P < 0.01).ConclusionBoth the sagittal condylar growth and counterclockwise mandibular total rotation attributed to activator treatment contribute to forward displacement of the mandible. The activator effects are expected greater in patients with flat mandibular plane, small gonial angle, backwardly inclined mandibular ramus and long posterior facial height.     

A CBCT study on positional change in mandibular condyle according to metallic anchorage methods in skeletal class III patients after orthognatic surgery

PurposeThis study was to evaluate the postoperative stability of the mandibular condyle according to the number of screws in the proximal segment using cone beam computed tomography (CBCT).Patients and methodsThirty patients diagnosed with skeletal class III malocclusion and underwent sagittal split ramus osteotomy (SSRO) were enrolled in this study. In Group A, 4 screws and a 4-hole miniplate were used for the internal fixation of an osteotomy and 3 screws, only 1 screw in the proximal segment, and a 4-hole miniplate were used in Group B. We digitally measured anteroposterior, supero-inferior, and mediolateral positions and angles of the long axis of the mediolateral poles in CBCT scans pre-operatively, within 1 week postoperatively and 3, 6 months after surgery.ResultsThe condylar head angle in the axial plane showed consistent and significant changes. The condylar head angle in the coronal plane decreased in both groups, which shows that condylar heads bent inward. In the axial plane, Group A showed statistically significant differences while Group B did not in early stage (T0–T1–T2). The change in distance between condylar heads shows that these have moved outward in both groups.ConclusionThe results show that a fixation method using 3 screws with a 4-hole miniplate did seemed preferable and may give some flexibility for condylar heads to be positioned in physiologic position during postoperative phase.     

A longitudinal three-dimensional evaluation of the growth pattern in hemifacial microsomia treated by mandibular distraction osteogenesis: a preliminary report

This study analyzed in three dimensions the longitudinal growth pattern of young patients with hemifacial microsomia (HFM) before and after mandibular distraction osteogenesis (DO). Six individuals with HFM (five boys and one girl; age at distraction, 12.5 +/- 2.4 years) were treated with similar procedures (surgery, type and direction of distraction, no functional orthodontic treatment before and after DO). Two individuals who did not undergo DO until late in their growth were used to compare growth patterns. In addition, one individual besides the six previously chosen sample in whom no DO was performed was also used to compare longitudinal growth patterns. Lateral and posteroanterior (PA) cephalograms were utilized preoperatively, spanning a period of 9 years. Computerized three-dimensional models were constructed from the lateral and PA cephalograms using a vector intercept algorithm. In the comparison group, for a period of 8 years on the affected side, the ramus height, body length, and total mandibular length increased at an average rate of 1.3, 1.9, and 3.0 mm per year respectively. On the unaffected side, the ramus height increased by 2.1 mm per year, 1.9 mm in the body, and 2.9 mm per year in total mandibular length. On average, the gonial angle on the affected side was increased by 1 deg per year, yet decreased by 1 deg per year on the unaffected side. The proportions between the affected to the unaffected side were maintained. In the six individuals 18 months after DO, it was found that the ramus height was reduced by 1.0 mm, whereas the body was found to resume its growth with a faster rate on the distracted side, maintaining its proportion. Angular changes demonstrated closing of the gonial angle on both the unaffected (0.5 deg) and distracted (3.5 deg) sides. Observed in three dimensions were the following: (1) On average, unoperated patients with isolated HFM tend to maintain their asymmetrical facial proportions and do not worsen substantially with time. (2) Different treatment effects were seen on the ramus, body, and total length of the mandible: changes in body length > ramus height > total length. (3) Eighteen months after DO, the correction was stable but with some degree of settling back from the initial overcorrection (< 5%). (4) Eighteen months after DO the mandibular body was found to have greater growth than the ramus. (5) Evaluating changes in three dimensions provides an improved understanding of the growth pattern and distraction effects on the mandible and its structural components. (6) Additional studies on the effect of mandibular distraction on other conditions involving mandibular deformities are required. In addition, the effect of various distractor devices should also be evaluated. Three-dimensional evaluation is recommended for improved accuracy.     

替牙期单侧完全性唇腭裂患者下颌骨体积的测量分析

目的　比较替牙期单侧完全性唇腭裂（unilateral complete cleft lip and palate,UCLP）患者裂隙侧与非裂隙侧下颌骨体积的差异,并将两者分别与非唇腭裂（non cleft lip and palate,NCLP）儿童单侧下颌骨体积比较,以研究唇腭裂对下颌骨生长发育的影响。方法　选取2012—2016年于青岛大学附属医院口腔正畸科就诊的替牙期UCLP患者25例作为UCLP组,另选同期就诊的替牙期NCLP儿童25名作为NCLP组。对所有研究对象的头颅部进行锥形束CT（cone-beam CT,CBCT）扫描,获取影像数据,利用Mimics 17.0软件对下颌骨进行三维重建。比较两组双侧的下颌升支、体部及半侧下颌骨体积,并将UCLP组裂隙侧和非裂隙侧的上述测量指标分别与NCLP组进行比较。结果　（1）UCLP组裂隙侧下颌升支体积大于非裂隙侧,差异有统计学意义（t = 2.192,P < 0.05）;而下颌体部及半侧下颌骨的体积比较,差异无统计学意义（均P > 0.05）;NCLP组两侧的下颌升支、体部及半侧下颌骨体积差异均无统计学意义（均P > 0.05）。（2）UCLP组裂隙侧与非裂隙侧的下颌升支体积均小于NCLP组,UCLP组非裂隙侧半侧下颌骨体积小于NCLP组,差异均有统计学意义（t值分别为-2.938、-3.325、-2.023,P < 0.05）。结论　替牙期UCLP患者两侧下颌骨体积存在差异,裂隙侧下颌升支体积大于非裂隙侧,且替牙期UCLP患者下颌骨的生长发育较NCLP儿童差。     

Maxillary-driven simultaneous maxillo-mandibular distraction for hemifacial microsomia

We treat hemifacial microsomia with a combination of surgery and orthodontic treatment during the growth period, resulting in early improvement in facial asymmetry and the induction of normal growth. We previously used gradual distraction of the mandibular ramus for Pruzansky’s type II classification (Pruzansky, 1969).In type II cases, the maxilla should also be treated actively as, using this technique, improvement of the occlusal plane is difficult to achieve, resulting in a cross bite and difficulties in post-operative orthodontic treatment—especially in older patients. Morphologically, the mandibular angle region of the operative side is flat, and the angle of the mouth remains elevated.We performed mandibular-driven simultaneous maxillo-mandibular distraction while the occlusion was maintained using intermaxillary anchorage. However, mandibular-driven distraction tended to elongate the face because the mandible only elongated downwards and the mandibular ramus did not reach the glenoid. Furthermore, external distraction devices produce significant distress for patients until removal of the device and cause scars on the face.We developed a new internal distraction device with a variable angle and performed maxillary-driven simultaneous maxillo-mandibular distraction using this device. The result was morphologically satisfactory and solved the above problems. Because the patient was in the growth period, careful follow-up and induction to normal growth were important while the inferior growth of the affected side was monitored.     

One-year assessment of surgical outcomes in Class III patients using cone beam computed tomography

The purpose of this study was to apply a novel method to evaluate surgical outcomes at 1 year after orthognathic surgery for Class III patients undergoing two different surgical protocols. Fifty patients divided equally into two groups (maxillary advancement only and combined with mandibular setback) had cone beam computed tomography (CBCT) scans taken pre-surgery, at splint removal, and at 1-year post-surgery. An automatic cranial base superimposition method was used to register, and shape correspondence was applied to assess, the overall changes between pre-surgery and splint removal (surgical changes) and between splint removal and 1-year post-surgery at the end of orthodontic treatment (post-surgical adaptations). Post-surgical maxillary adaptations were exactly the same for both groups, with 52% of the patients having changes >2 mm. Approximately half of the post-surgical changes in the maxilla for both groups were vertical. The two-jaw group showed significantly greater surgical and post-surgical changes in the ramus, chin, and most of the condylar surfaces (P < 0.05). Post-surgical adaptation on the anterior part of the chin was also more significant in the two-jaw group (P < 0.05). Regardless of the type of surgery, marked post-surgical adaptations were observed in the regions evaluated, which explain the adequate maxillary–mandibular relationship at 1-year post-surgery on average, with individual variability.     

Correction of Mandibular Asymmetry with the Ligated Anterior Repositioning Splint

Mandibular asymmetry may be the result of unequal ramus height, unequal corpus length, or a combination of both problems. The diagnosis of asymmetry is essential in treatment planning, since a number of therapeutic options must be considered in the treatment to a seated condylar position in the glenoid fossa. When asymmetry exists, it may be necessary to: accept finished treatment with the mandibular midline to the right or left of the maxillary midline, finish the molars and canines in an end-to-end relationship on the short side, treat with asymmetric extractions, intervene surgically, or use functional appliances to enhance greater growth or remodeling of the mandible on the short side. The purpose of this study was to assess the effect of the ligated anterior repositioning splint, or LARS, in the correction of mandibular asymmetry in Class II patients.     

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??Objective    To evaluate the mandibular and dentoalveolar asymmetry in a group of patients with class??subdivision malocclusion??and to investigate its mechanism in order to provide evidence for clinical treatment. Methods     Seventeen patients with class?? subdivision malocclusion and sixteen patients with normal occlusion underwent cone-beam CT evaluation. Mandibular and dentoalveolar asymmetry measurements were performed on these images using Mimics10.01 software. The independent samples t-test and paired t-test were used in statistical analysis. Results          No statistically significant differences existed in the right and left sides of class??subdivision malocclusion group except for condylar height. There were significant differences between the class??side of class??subdivision malocclusion group and normal occlusion group in ramal length?? mandibular body length??condylar height and the height of the highest point of condyle. Significant differences were found between the class ??side of class?? subdivision malocclusion group and normal occlusion group in ramal length??mandibular body length??the width of gonion and incisura mandibulae??condylar width??and the width and height of the highest point of condyle. Significant differences existed between the right and left sides of class??subdivision malocclusion group in the position of maxillary and mandibular first molar. Conclusion    Except for condylar height??class??subdivision malocclusion patients have symmetrical mandibular. The length of mandibular body and ramus is shorter when compared to normal occlusion samples. The ramus in class??side of class?? subdivision malocclusion has the trend of rotating inward. The maxillary first molar is in the mesial position and the mandibular first molar is in the distal position in class??side of class?? subdivision malocclusion.     

The Anatomical Basis for Plate Fixation in BSSO to Minimize Condylar Torquing: A Comparative CT Study of Mandibular Advancement and Setback

IntroductionCondylar displacement after bilateral sagittal-split osteotomy (BSSO) occur in the sagittal plane as clockwise/counter-clockwise rotation of the ramus, in the coronal plane as medial/lateral inclination, or in the axial plane as medial/lateral condylar torquing. The purpose of this prospective CT study was to evaluate the role of plate fixation in minimizing condylar torquing or rotational changes in the axial plane.Materials and MethodsThis prospective study was carried out on 26 patients, 13 of whom underwent advancement BSSO and 13 setback BSSO, without maxillary LeFort I osteotomies. All mandibular movements were symmetrical. Fixation of the osteotomized segments was achieved with a single 4-hole plate and monocortical screws. In case of mandibular setbacks, a straight plate was used, whereas an inset-bent plate was used for advancements. Computed tomography scans were obtained preoperatively and postoperatively to measure condylar rotation or torqueing in the axial plane. An increase in condylar angle on axial slices was considered as lateral condylar torquing, whereas a decrease was considered as medial condylar torquingResultsA mean medial condylar torquing of 0.2° was noted postoperatively in case of setbacks (p > 0.05 not significant). This suggested minimal condylar torquing, indicating that the proximal and distal segments maintained contact at the anterior vertical osteotomy fixed with a straight plate. In case of advancements, a mean lateral condylar torquing of 2.2° was noted postoperatively (p < 0.005, highly significant). This suggested that the proximal segment flare at the anterior vertical osteotomy site was maintained by inset-bent plate fixation.ConclusionThe gaps between the proximal and distal segments created by mandibular advancement and setback should be maintained. An attempt to close these gaps, especially in mandibular advancement, will result in an unfavourable axial condylar torque. Consequently, the areas of bony contact between the proximal and distal osteotomy sites created by mandibular advancement and setback should be maintained as well.     

安氏Ⅱ类亚类错牙合颅颌面结构三维形态分析

目的    从三维影像分析安氏Ⅱ类亚类错牙合畸形的颅颌面结构,阐明安氏Ⅱ类亚类错牙合畸形的发生机制,为制定临床矫治方案提供依据。方法    选取2011年7月至2013年10月佛山市第一人民医院正畸科收治的安氏Ⅱ类亚类错牙合畸形患者17例为研究组。同期选取在校大学生个别正常牙合志愿者16名为对照组。应用三维测量软件Mimics10.01对两组研究对象进行下颌骨、牙牙合相关项目测量。结果    （1）安氏Ⅱ类亚类错牙合下颌骨除髁突高度外,其余测量项目左右侧差异均无统计学意义（均P＞0.05）;（2）安氏Ⅱ类亚类错牙合中性关系侧与正常牙合相比在升支长度、体部长度、髁突高度、髁突顶点高度等方面差异有统计学意义（均P＜0.05）;（3）安氏Ⅱ类亚类错牙合远中关系侧与正常牙合相比在升支长度、体部长度、下颌角点宽度、乙状切迹点宽度、髁突内外径、髁突顶点高度、髁突顶点宽度等方面差异均有统计学意义（均P＜0.05）。（4）研究组两侧上、下颌第一磨牙的位置差异均有统计学意义（均P＜0.05）,表现为远中关系侧的上颌第一磨牙近中错位和下颌第一磨牙远中错位,且该侧磨牙位置与对照组比较差异均有统计学意义（均P＜0.05）。结论    安氏Ⅱ类亚类错牙合畸形除乙状切迹点位置外,下颌骨左右侧对称,其升支长度和体部长度较正常牙合偏短。远中关系侧的升支有向内旋转的趋势,牙牙合表现为该侧的上颌第一磨牙近中错位和下颌第一磨牙远中错位。     

Evaluation of post-surgical stability in skeletal class II patients with idiopathic condylar resorption treated with functional splint therapy

PurposeTo assess postsurgical stability of mandibular advancement combined with orthodontic treatment, following functional splint therapy, in patients with idiopathic condylar resorption (ICR).Patients and methodsSixteen patients who were treated with functional splint therapy followed by orthognathic surgery combined with orthodontic treatment between 2010 and 2017 were included in this retrospective study. The primary outcome variable was skeletal stability, measured on the y-axis to point B (y-axis–B). Cephalometric analysis, including measurement of temporomandibular joint spaces, was carried out on serial magnetic resonance images (MRI) prior to orthognathic surgery (T0), immediately after surgery (T1), and after at least 1 year of follow-up (T2). The differences in the data between time points were compared using statistical analyses.ResultsAll patients obtained an esthetic facial profile after orthognathic surgery, with normal occlusion as well as normal protrusive and laterotrusive excursion after treatment. Mean advancement of the mandible immediately following surgery (y-axis–B, T1 − T0) was 7.28 ± 5.79 mm. This was the only skeletal measurement that showed a sagittal positional change of the mandible. Mean backward movement (T2 − T1) was −1.04 ± 2.35 mm (p₂ = 0.116). Thirteen out of 16 patients experienced no postsurgical relapse or less than 2 mm of mandibular backward movement (81.25%), while two out of 16 patients showed more than 2 mm of mandibular backward movement (12.5%).ConclusionsPatients who underwent mandibular advancement combined with orthodontic treatment, following functional splint therapy, exhibited a stable mandibular position at the 1-year follow-up. This study indicated that functional splint therapy prior to orthognathic surgery for mandibular advancement may be a good adjuvant treatment for ICR patients.     

Condylar response to functional therapy with Twin-Block as shown by cone-beam computed tomography

Objective:To evaluate the condylar changes through cone-beam computed tomography (CBCT) images in patients treated with Twin-Block functional appliance.Materials and Methods:In this retrospective study, CBCT images of 30 patients who were treated with the Twin-Block appliance were used. Mandible was segmented and pretreatment and posttreatment (T0 and T1) condylar volume was compared. The angle between sella-nasion-Point A (SNA), angle between sella-nasion-Point B (SNB), angle between Point A-nasion-Point B (ANB), midfacial length (Co-A), mandibular length (Co-Gn), and the distances from right condylion to left condylion (Co_R-Co_L) were also measured on three-dimensional images. Differences were analyzed with Wilcoxon signed rank tests, and Mann-Whitney U-tests were used to compare the scores of male and female participants. Significance was set at P < .05.Results:In this study, a decrease in SNA and ANB (P < .05 and P < .01, respectively) and an increase in SNB (P < .01) were found. Additionally, Co_R-Co_L, Co-Gn, and condylar volume increased at both the left and right sides (P < .01). However, increase at Co-A was not statistically significant (P > .05). Comparison of differences by sex was not statistically significant for all measurements (P > .05).Conclusion:Twin-Block appliance increases condylar volume, mandibular length, and intercondylar distance by stimulating growth of condyle in an upward and backward direction.     

A retrospective study of using removable occlusal splint in the treatment of condylar fracture in children

BackgroundAlthough the concept of conservative treatment for paediatric condylar fracture is well understood, there is still a lack of a recognized method for treating child patients with a condylar fracture. The purpose of this study was to investigate the effect of the removable occlusal splint in treating condylar fractures in children and adolescents.Materials and methodsForty children and adolescents with condylar fracture, aged 3–16, were included in this study. A removable occlusal splint with varying thickness was fabricated according to the age, developmental stage of the mandible, and degree of condylar dislocation. This was worn for 1–3 months, accompanied by functional exercises. Follow-up was carried out by clinical observation and panoramic X-ray.ResultsClinically satisfactory results with good occlusion were obtained in all the patients, along with unimpaired function and normal growth and development of the mandible. The panoramic image showed remodelling and reconstruction of the fractured condyles.ConclusionsOur results confirm that conservative treatment has a satisfactory clinical outcome in treating condylar fracture in children. The removable occlusal splint is a promising approach for treating condylar fracture in children and adolescents.