Sigmoid Notch Research Articles

A novel method for measuring the direction and angle of Central ray and predicting rotation center via panorama phantom.

The aim of this study is to propose and evaluate a novel method for measuring the central ray direction and detecting the rotation center of panoramic radiography using the panorama phantom. To determine the central ray direction, two points passing through the same x-coordinate in a panoramic radiograph were identified and connected. The angles formed by the central ray with the midline and the angle to the arch form were measured using mathematical calculations. Further, by analyzing the continuous changes in the central ray obtained in this manner, the movement of the rotation center was detected and visualized. The angle between the central ray and the midline exhibited a progressive decrease from the anterior to the posterior direction. With regards to the arch form, the angle of the central ray exhibited an increasing pattern as it moved from the anterior to the posterior direction, culminating in its peak value at the lower second premolar cusp region, followed by a consistent decrease. The rotation center approximately started from the distolateral aspect of the coronoid process and then anteromedially moved to the midline in a curved line passing between the mandibular notch and coronoid process. By using the panorama phantom, we successfully obtained the central ray direction and detected the rotation center of the panoramic radiography.

The Transverse Sigmoid Notch Morphology Unravelled.

Background: Several studies have described pathology in relation to transverse sigmoid notch morphology, using the Tolat transverse sigmoid notch classification. It is believed that the entire shape of a sigmoid notch can be described using Tolat sigmoid types. We hypothesised that the determination of the sigmoid notch shape (SNS) depends on the level of the transverse CT plane on the axial axis of the distal radius. The aim of this study was to determine and compare the transverse SNS on different axial CT levels in the same wrist. Methods: The transverse SNS of 53 participants were independently qualitatively classified by two researchers in accordance with the four morphologies described by Tolat et al. The SNS was determined at two levels on the axial axis of the distal radius; at the level of the most prominent part of Lister tubercle, determined on the sagittal plane and at the level of the 'smallest distance between the ulnar head and sigmoid notch' (SDUS). Results: Forty-seven percent of the wrists demonstrated different SNS types according to Tolat classification, depending on the axial level of the CT scan. Interobserver agreement on the transverse sigmoid shape was 87% at Lister tubercle and 85% at SDUS, which can both be interpreted as 'excellent'. Conclusions: Despite an excellent interobserver agreement, 47% of the study population had different transverse sigmoid notch types within the same wrist. We, therefore, conclude that Tolat transverse sigmoid classification may not be useful for the description of potential pathology in relation to the sigmoid notch morphology.

Ultrasonographic assessment of the lateral pterygoid muscle for BoNT-A injection.

The upper head of the lateral pterygoid muscle (LPM) is known to insert into the capsule of the temporomandibular joint and articular disc, and therefore its relationship with temporomandibular disorders (TMD) has been consistently suggested. The aim of the study was to determine the anatomical features of the LPM using ultrasonographic (US) imaging. Around 120 hemifaces from 60 healthy Korean volunteers were included in this study. US images were taken with the subject's mouth 2 cm open. The transducer was placed at a position where the infratemporal fossa could be observed through the mandibular notch, and its position was recorded. The locations of the coronoid process (CorP), lateral margin of the condylar process (ConP), and midpoint of CorP and ConP (MP) were measured with reference to the ala-tragus line. The thicknesses of the skin and subcutaneous tissue, the masseter muscle, the temporalis muscle, and the depth of the LPM were measured at the MP. The masseter muscle, temporalis muscle, and LPM were observed in all cases and located in order from superficial to deep. The MP was located 39.6 ± 3.3 mm anterior and 7.8 ± 1.6 mm inferior to the tragus. The thicknesses of the skin and subcutaneous tissue, the masseter muscle, the temporalis muscle, and the depth of the LPM at the MP were 9.7 ± 1.0, 10.3 ± 1.3, 10.9 ± 1.6, and 30.9 ± 1.9 mm, respectively. The information reported in this study may be useful for determining the location of the LPM and adjacent anatomical structures in TMD patients and provide accurate and safe injection guidelines.

Histopathology of Idiopathic Condylar Resorption Differs from TMJ-only Juvenile Idiopathic Arthritis

BackgroundIdiopathic condylar resorption (ICR) is a rare condition of unknown etiology characterized by progressive decrease in volume and pathologic remodeling of a previously normal mandibular condyle. Juvenile Idiopathic Arthritis (JIA) affecting only the temporomandibular joint (TMJ-only JIA) is characterized by synovitis and destruction of TMJ tissues without involvement of other joints. It is often difficult to differentiate the two conditions because they exhibit similar phenotypes. PurposeTo compare histology of resected condylar specimens from patients with ICR and TMJ-only JIA. Specific aims were: 1) To correlate longitudinal clinical data with histopathology of resected condyle specimens, 2) To compare resorption patterns between the two disease processes. Study design, setting, sampleThis was a retrospective cohort study of patients treated at Massachusetts General Hospital (MGH) from 1999 through 2023. Predictor/exposure/independent variablePrimary predictor variable was the diagnosis (ICR or JIA). Secondary predictor variables included age, gender, race, putative contributing factors, and laboratory studies. Main outcome variable(s)Primary outcome variable was presence or absence of inflammatory infiltrates in bone and synovial specimens. Secondary outcome variables were structural integrity and morphologic characteristics of the condylar cartilage and bone. AnalysesSpearman correlation was used to assess the relationship between histological scores and age, gender, and possible associated contributing factors. A p-value < 0.05 was considered statistically significant. ResultsThirty-five subjects (67 specimens) were included in Group 1 (ICR). Eight subjects (15 specimens) were included in Group 2 (TMJ-only JIA). The histopathologic findings in ICR consisted of severe and irregular cartilage surface disruption, fibrocartilage degeneration, and subchondral bone with no inflammatory infiltrate. Degeneration was observed to begin at the anterior pole of the condyle and progress eventually to total resorption to the sigmoid notch. TMJ-only JIA was notable for more severe condylar degeneration and inflammation in the bone and synovia. There was no specific pattern of degeneration. For both groups, the subject’s age, gender, or putative contributing factors did not correlate with the histopathologic scores. Conclusions and RelevanceThese results support the hypothesis that “ICR” and TMJ-only JIA are distinct clinical entities and can be distinguished by histopathologic findings in the mandibular condyles and synovia.

Prevalence of anatomic variations of temporomandibular joint on orthopantomogram and cone-beam computed tomography: A retrospective study

Maxillofacial radiography by means of orthopantamogram is used as a routine screening tool in the diagnosis and treatment planning in various fields of dentistry and is found to be less expensive when compared to other advanced imaging modalities like computed tomography, magnetic resonance imaging and cone-beam computed tomography. Morphological variations in the shape of mandibular condyle, coronoid process and sigmoid notch have been documented in the literature as indispensable aids in anthropological and forensic studies. 100 OPG and CBCT scans of same participants, comprising of 200 temporo-mandibular joints were evaluated for anatomical variations in shapes of mandibular condyle, coronoid process and sigmoid notch. The prevalence of various morphological variations were correlated with age and gender and subjected to statistical analysis. The most common shape of condyle, coronoid process and sigmoid notch on OPG was round, whereas on CBCT the most common shape of condyle, coronoid process and sigmoid notch were flat, triangular and wide respectively. Variations in the morphology of shape of mandibular condyle, coronoid process and sigmoid notch using panoramic radiographs can be tentatively used as a screening tool in human identification, owing to its ready availability and low cost.

Decompression corrective osteotomy of the distal radius for treatment of the DRUJ-incongruency and impingement syndrome with focus on posttraumatic cases

IntroductionPosttraumatic or congenital ulna-minus variance with altered shape of the sigmoid notch and increased tension of the distal oblique band of the interosseous membrane (DIOM) can lead to painful impingement in the distal radioulnar joint (DRUJ) during rotation and loading of the forearm. As an operative treatment concept, a new method was described in 2016. Its goal is to restore the osseous congruency, which is required for normal painless function. The hypothesis is based on remodelling of the joint surface and the decompression of the DRUJ by releasing the DIOM. The purpose of this study is to analyze the results of performed operations with detailed focus on posttraumatic cases. Materials and Methods: The indication for the operation is the impingement and incongruency in the DRUJ with ulna-minus variance. The surgical procedure is based on shortening and closed-wedge osteotomy of the distal radius with an ulnar translation of the radial shaft. Fifty-nine operations were performed between 2011 – 2022 on 52 patients (13 men, 39 women). Twenty-four patients were operated on the right side, 21 on the left side and 7 bilaterally. In 45 cases the operation was indicated because of congenital, in 12 cases due to posttraumatic incongruency and in 2 cases because of iatrogenic impingement after previously performed excessive ulnar shortening osteotomy. Modified Mayo-Wrist-Score, patient questioning, VAS and ROM were used to evaluate the results. ResultsSignificant reduction of pain on VAS from 7.22 to 1.98 (p < .001) was achieved. The pre- and postoperative range of motion did not show any significant changes (mean total arc of motion 301,94° vs. 295,20°, p = .300). Specific complications we observed included a too distally performed osteotomy, DRUJ instability, de Quervain´s tenosynovitis, persistent pain and conversion into an ulna-plus variance. ConclusionUnder consideration of the indication criteria and correct execution of the osteotomy, in about 90 % of the cases this operation leads to good-to-excellent results with pain reduction and improvement of weight-bearing and power. The preoperative examination, verification of the DRUJ stability and the radiological diagnostics are crucial for a good outcome.

Positions of the Mandibular Foramen and Canal in Different Skeletal Classes and Implications for Bilateral Sagittal Split Osteotomy.

To evaluate the positions of the mandibular foramen (MF) and mandibular canal (MC) between different skeletal classes to highlight the implications for bilateral sagittal split osteotomy (BSSO). A cross-sectional study was performed using cone-beam computed tomography on 90 patients classified into classes I, II and III. Linear measurements were performed on multiplanar reconstructions as follows: from the MF to the edge of the mandibular ramus (1), to the mandibular notch (2), to the ramus width (3) and to the occlusal plane (4); and from the MC to the alveolar crest (A), to the lower border of the mandible (B) and to the mandibular buccal cortical bone (C). Mandibular thickness (D), width (E) and height (F) of the MC were measured. Intra-class correlation coefficient (ICC) checked the reliability. Two-way ANOVA and Tukey's test were used to compare measurements and classes. Linear measurements 2 presented a statistically significant difference between classes I and II. There was no statistically significant difference between the classes and measurements B, C, D, E and F. Linear measurements A were shorter in class III than in class II. Although most measurements suggest that the BSSO technique does not need to be modified for each skeletal class, measurements from the MF to the mandibular notch in class II and from the MC to the alveolar crest on distal of the second molars in class III could help surgeons to recognize critical regions.

Does the distal radioulnar joint orientation influence the outcome of ulnar shortening osteotomy: a retrospective study.

The aim of this retrospective study was to evaluate the long-term outcome of ulnar shortening osteotomy. A total of 66 patients treated with an ulnar shortening osteotomy for a primary or post-traumatic ulnar impaction syndrome were included, with a median follow-up time of 75 months.There was a positive correlation between the sigmoid notch angle and the final QuickDASH score, but no correlation with final range of motion, grip strength or pain level. Radiological signs of osteoarthritis of the distal radioulnar joint were seen in 20% of patients, yet there was no correlation between the development of distal radioulnar joint osteoarthritis and the sigmoid notch angle. No symptomatic distal radioulnar joint osteoarthritis was observed.Ulnar shortening osteotomy is a good option to treat patients with ulnar impaction syndrome regardless of the distal radioulnar joint angle.Level of evidence: IV.

Three-Dimensional Quantitative Study and Functional Outcome Analysis of Coronoid Fracture in Different Elbow Injury Patterns

BackgroundCoronoid fractures are often part of a complex fracture-dislocation of the elbow. For an optimum prognosis, it is important to understand the characteristics of coronoid fractures in different elbow injury patterns. Significant differences in these characteristics have been observed in various studies, but these previous studies have suffered from limitations, such as insufficient quantification and unknown prognostic differences among different injury patterns. Therefore, we aimed to quantitatively analyze coronoid fracture characteristics and functional outcomes in different elbow injury patterns using 3D-CT. MethodsAll patients with coronoid fractures surgically treated at our hospital between January and December 2017 were categorized into three groups according to elbow injury pattern: PLRI, VPMRI and OFD. 3D models were reconstructed using Mimics 17.0, and the total volume (TV) and number of coronoid fragments (NCF) were measured. The coronoid process edge was classified into different anatomical regions, and each region was assigned a number to quantify the distribution of fracture lines. At the last follow-up, the ROM, VAS, MEPS, complications and reoperations were recorded. ResultsThe ninety-two patients enrolled had an average age of 42±15 years and a male-to-female ratio of 66:26. The median TV in PLRI patients was less than that in VPMRI patients [431 (132, 818)mm3 vs. 1125 (746,1421)mm3,adjusted P<0.001] and OFD patients [431 (132, 818) mm3 vs. 2565 (381, 4076)mm3, adjusted P =0.001]. The median NCF in PLRI patients was also less than that in VPMRI patients [1 (1, 2) vs. 2 (1, 3), adjusted P=0.043]. Most of the PCFL-Rs (79%) were located around the volar edge of the lesser sigmoid notch. Compared with that of PLRI, the PCFL-Us of the VPMRI and OFD tended to be located on the more ulnodorsal side of the coronoid process edge. The median ROM [110 (90, 133), P=0.001] and the median MEPS [85 (68, 95), P=0.038] of patients with OFD were significantly less than those of patients with the other two patterns. The incidence of elbow stiffness (56%, 5/9, P=0.001) and implant-related irritation (44%, 4/9, P<0.001) in the OFD group was significantly higher than that in the other two groups. ConclusionCoronoid fractures differ significantly in fragment volume, comminution severity and fracture line distribution among different elbow injury patterns. OFD has the worst functional outcomes among complex elbow injury patterns.

Role of Vickers Ligament in the Pathogenesis of Madelung Deformity.

The Vickers ligament is thought to hinder the growth of palmar ulnar radius by tethering the lunate to the radius, leading to Madelung deformity. The purpose of this study was to clarify the nature of the Vickers ligament and investigate its pathogenesis in Madelung deformities based on our observation of the Vickers ligament. All 22 patients (33 wrists) with Madelung deformities treated surgically between 2018 and 2022 were included. The diagnosis was confirmed radiographically in all patients. The three-dimensional computed tomography (3D-CT) data of 16 patients (19 wrists) were available. Magnetic resonance imaging (MRI) data were available for 9 patients (14 wrists). Wrist arthroscopy was used in 4 patients. The Vickers ligament was resected and submitted for histopathological examination in 8 patients. Radiographic outcomes, 3D-CT, MRI, arthroscopy, surgical findings, and histopathology of the Vickers ligament were evaluated. The 3D-CT revealed that the Vickers ligament originated in the metaphysis and formed a metaphyseal defect at the palmar ulnar radius. In the sequential MR coronal images, the Vickers ligament could be divided into 3 branches, extending to the lunate, triquetrum and ulnar styloid. Arthroscopy and surgical findings revealed that the nature of the Vickers ligament was the stretched palmar ligament of the wrist. The histopathology results revealed ligamentous tissue and fibrocartilaginous metaplasia with a structure similar to that of the triangular fibrocartilage complex (TFCC). The Vickers ligament is not a separate aberrant ligament. The nature of the Vickers ligament is a combination of the stretched TFCC ligament (palmar radioulnar ligament, ulnotriquetral ligament and ulnolunate ligament) and radiolunate ligament. The possible pathogenesis of Madelung deformity might be focal early epiphyseal closure at the middle part of the sigmoid notch, which leads to focal growth retardation of the radius and pulls palmar ligaments proximally to form the Vickers ligament.

Deep masseteric triangular area to define masseter neurovascular bundle: A cadaveric study

IntroductionFacial reanimation procedures are used in the treatment of the disorder that impairs mimetic function and jeopardizes physical and psychological health, and one of the most important instruments of these techniques is the masseteric neurovascular bundle (NVB) and proper identification at the mandibular notch level. In the current study, a triangular area (deep masseteric triangle, DMT) on the lateral surface of the masseter muscle that was identified to help reliable determination of the masseteric NVB at the mandibular notch level. Material and methods40 parotideomasseteric region dissections were performed in 10 female and 10 male donated cadavers. Structures lateral to the masseter muscle were removed. The edge length of the masseter muscle on the zygomatic arch side was measured. After the edges of the DMT were measured, the masseteric NVB was found by dissection and its distance (depth) from the skin line was measured. ResultsThe mean lengths of the superior, posterior, and anterior margins were 17.3 (±4.5) mm, 25.9 (±6.2) mm, and 26.3 (±6.5) mm, respectively. The total length of the upper edge of the masseteric muscle attached to the zygomatic arch averaged 52.7 (±5.2) mm. The masseteric neurovascular bundle was detected at a depth of approximately 17 mm from the skin of the parotideamasseteric region. DiscussionThe visualization of the DMT can be used as an important landmark for access to branch-free part of the masseteric nerve. Moreover, an specific approach for masseteric NVB localization can be established by drawing a line between the mandibular angle and the midpoint of the upper edge of the DMT. This technique can greatly improve the accuracy of both masseteric nerve harvesting and masseteric nerve block procedures.

New quantitative analyses of the Nacholapithecus kerioi proximal ulna confirm morphological affinities with Equatorius and large papionins.

The elbow of Nacholapithecus has been extensively described qualitatively, however its ulnar morphology has never been the focus of an in-depth quantitative analysis before. Hence, our main aim is quantifying the proximal ulnar morphology in Nacholapithecus and exploring whether it is similar to those of Equatorius and Griphopithecus as previously reported. We compared Nacholapithecus proximal ulnar morphology with a sample of extant and extinct anthropoids through principal component analysis and agglomerative hierarchical cluster analysis. Moreover, we calculated the Cophenetic Correlation Coefficient and checked for taxonomical group mean differences through MANOVA and pairwise post-hoc comparisons, as well as the phylogenetic signal in the variables used. The Nacholapithecus ulna displays a moderately long and relatively narrow olecranon, a relatively wide trochlear surface-radial notch width, and a relatively thin sigmoid notch depth. These features resemble those of large papionins and chimpanzees, and some extinct taxa, mainly Equatorius. Results presented here reinforce previous inferences on the functional morphology of the Nacholapithecus elbow, showing adaptations for general quadrupedal behaviors. However, other derived features (e.g., a relatively wide trochlear surface) might be associated with the ape-like traits described for its distal humerus (e.g., wide trochlear groove), thus displaying a combination of primitive and derived features in the proximal ulna. Finally, affinities with large papionins could suggest the presence of some terrestrial habits in Nacholapithecus. However, the lack of evidence in the rest of the skeleton prevents us from suggesting terrestrial affinities in this taxon in a conclusive manner.

Treatment of Congenital Ulnar Impingement Syndrome by Corrective Osteotomy of the Distal Radius - Clinical Results

In 2016, a new method was described to treat the painful impingement syndrome of the DRUJ: decompression corrective osteotomy of the distal radius. Clinical symptoms are based on a positive compression test; pain occurs with weight-bearing on the forearm. This phenomenon is seen in conjunction with a deformed sigmoid notch together with ulna minus-variance, which leads to increased tension in the distal oblique bundle of the interosseous membrane. The etiology of the condition can be either congenital, post-traumatic, or iatrogenic. Through the proposed osteotomy, decompression in the DRUJ is achieved. This study summarises the results of these surgical procedures performed in our hand centre exclusively in cases of congenital origin. Remodelling of the DRUJ is achieved through the shortening of the distal radius together with closed wedge osteotomy. Relief of the interosseous membrane is accomplished by ulnar translation of the radial shaft. This study only included patients with congenital incongruency in the DRUJ. The results were evaluated using a visual analogue scale (VAS) and the Krimmer Wrist Score and by measuring the preoperative and postoperative range of motion as well as grip strength. Within 11 years, 45 procedures were performed with our method on 38 patients, of which 17 were treated on the right side, 14 on the left side, and 7 bilaterally. In cases of bilateral incongruency, only the symptomatic side was treated. The statistical evaluation showed a significant reduction of pain on the VAS from 7.2 to 2 (p<0.001). No significant changes were seen in the range of motion (p=0.812). The Krimmer Wrist Score showed good to excellent results in almost 90% of cases. If the indication criteria are met, contraindications are avoided and the osteotomy is correctly performed, this technique leads to an improvement of patients' functionality and quality of life. From a preventive viewpoint, the influence on the progression of the degenerative changes is yet to be demonstrated in further studies. At any rate, this is a safe procedure, which leaves the path open for other possible options.

Mandibular Contouring in Subjects With Class II or Class III Dentofacial Deformities and Treatment Needs

Facial contouring relates to hard and soft structures that make up the face. Skeletal class II and III subjects present bone structure and position changes, significantly impacting the soft tissues. This study aims to analyze the morphology of the mandible at mandibular ramus and angle level in subjects with skeletal facial deformity class II and III who are candidates for orthognathic surgery and to define implications in facial contour. A cross-sectional study used cone beam computed tomography to compare the mandibular contour (mandibular angle and ramus region) in orthognathic surgery candidates. One hundred sixty orthognathic surgery candidates were analyzed, ranging in age from 18 to 58 years (31.29 ± 11.97). Regarding the skeletal class, 95 (59.37%) were skeletal class II, and 65 (40.62%) were skeletal class III. Class II subjects had a larger antegonial notch than class III subjects. Concerning the mandibular contour, class II subjects presented less vertical distance than class III subjects, but both presented similar gonial angles. Concerning the ideas to assess the need for mandibular contouring surgery, the 2 proposals to determine the need for mandibular contouring surgery in class II and III subjects present a similar distribution. The mandibular notch is an objective element and is commonly present in subjects with a class II facial pattern; this element can be used in contour analysis to define expected facial characteristics, including the patient’s facial sex, in the decision of surgical techniques for lower facial contour augmentation or reduction.

A new anatomical variation in ramus: the sigmoid canal

During the radiological examination with CBCT of the patient who complained of joint pain, a structure with a length of 8.1 mm and a diameter of 0.6 mm was detected, starting from the sigmoid notch and descending down the ramus. The patient was unaware of the existence of this structure, and moreover, the patient did not show any symptoms. There was doubt as to whether the observed structure was an anatomical variation or a pathological phenomenon, and MRI was used to determine its content. It was realized that the structure imaged by MRI carried a branch of the maxillary artery. This structure was called the sigmoid canal. It was noteworthy that this anatomical structure was likely to cause complications in surgical interventions.

Minimal Access Retromandibular Approach to Fractures of Vertical Segment of the Mandible: A Versatile Technique

Abstract Introduction Fractures of the condylar region of the mandible, although fairly common, also generate the most debate regarding management—both closed and open treatment options have been recommended and shown to yield good results. We present our experience with a minimal access retromandibular approach to fractures of the vertical mandible. Materials and Methods This is a retrospective study of all patients who underwent open reduction and internal fixation for fractures of the vertical mandible (condyle, subcondylar region, ramus) using a retromandibular approach at a tertiary care hospital in a metropolitan city in India between January 2022 and July 2023. All fractures were approached using a standard technique through a retromandibular incision and a transparotid route. The proximal segment was mobilized, reduced, and fixed to the ramus with two 2-mm miniplates—one along the posterior border and the other along the sigmoid notch border. Postoperative guiding elastics were placed for 2 weeks without any rigid maxillomandibular fixation. Patients were followed at weekly intervals for 1 month followed by monthly visits for 6 months. At each visit, mouth opening, occlusion, and facial nerve function were assessed. Scar quality was assessed by both examiner and patient using the Patient and Observer Scar Assessment Scale (POSAS) scoring system. Results A total of 25 subcondylar fractures in 20 patients were fixed using the retromandibular approach. Nineteen were male and 1 was female. The etiology of trauma was road accident (8), fall from train (2), fall from height (5) and assault (5). Fifteen patients had unilateral fractures while 5 had bilateral fractures. All patients had concomitant fractures of the mandibular arch which were also fixed. The interval between trauma and surgery ranged from 5 to 28 days. All patients had premature molar contact on the side of fracture with anterior open bite. Mouth opening ranged from 1.5 to 2.5 cm. All the fractures could be fixed using the retromandibular approach. None of the patients developed any facial nerve dysfunction or salivary leak. The occlusion was restored to pretrauma status in all patients and was stable at 6 months' follow-up. Mouth opening ranged from 3.5 to 4 cm. The POSAS observer score ranged from 09 to 19 with a mean score of 12.7. The POSAS patient score ranged from 17 to 28 with a mean score of 20.3 revealing that all patients were extremely happy with the scar. Conclusion The minimal access retromandibular approach to the vertical mandible is a versatile technique enabling accurate reduction and fixation of fractures of the vertical segment of the mandible with good long-term functional and cosmetic results.

Distinctive Anatomical Patterns of the Mandibular Coronoid Process, Condyle, and Sigmoid Notch: Cone Beam Computed Tomography (CBCT) Imaging for Advanced Personal Identification.

The human mandible plays a significant role in personal identification due to its unique morphological characteristics. The coronoid process, condyle, and sigmoid notch exhibit variations that can be utilized for forensic and anthropological purposes. This study aims to analyze the morphological diversities of these mandibular features in our ethnic group using cone beam computed tomography (CBCT) imaging. A retrospective analysis was conducted using 100 CBCT images obtained from the archives of the Department of Oral Medicine and Radiology. The images were captured using Carestream 9600 machines (Carestream Dental LLC, Atlanta, GA) with standard exposure parameters. Curved slicing screenshots were utilized for tracing the morphological variations of the coronoid process, condyle, and sigmoid notch. Out of 100 CBCT images analyzed (corresponding to 200 sides), the shape-wise distribution of the coronoid process revealed that a triangular shape was most commonly observed in 59% (118) of cases. The condyle exhibited a predominantly round shape in 38.7% (77) of cases based on shape parameter-wise distribution. Similarly, the sigmoid notch displayed a round shape in 40.5% (81) of cases based on shape-wise distribution. Personal identification using radiographs has gained significance in the current scenario due to its feasibility. Cone beam computed tomography imaging has become a reliable and accurate method for revealing hidden details in forensic odontology, especially when antemortem records are available. This research sheds light on the morphological variations of the mandibular coronoid process, condyle, and sigmoid notch within our ethnic cohort, enhancing personal identification practices. Further research encompassing larger sample sizes and diverse populations would enhance the applicability of these findings in forensic and anthropological contexts.

A modified partial wedge-shaped metaphyseal ulnar osteotomy for the treatment of ulnar impaction syndrome with reverse oblique sigmoid notch.

We describe a modified metaphyseal ulnar osteotomy to treat ulnar impaction syndrome with a reverse oblique sigmoid notch. Based on a computational analysis of radiographs, a modified wedge metaphyseal ulnar osteotomy was devised with its apex positioned at the ulnar styloid base to avoid impaction between the sigmoid notch and ulnar head. Subsequently, nine patients with ulnar impaction syndrome and a reverse oblique sigmoid notch underwent this operation, combined with arthroscopic exploration and transosseous triangular fibrocartilage complex repair. The mean follow-up was 14 months. All patients achieved bone union within 5 weeks, with no degenerative changes being observed during the follow-up assessments. The final follow-up assessments revealed decreases in ulnar variance and in the scores for Visual Analogue Scale, Quick Disabilities of the Arm, Shoulder and Hand questionnaire and the Patient-Rated Wrist Evaluation. All patients achieved excellent or good grades on the Modified Mayo Wrist Score. This technique is effective in treating the ulnar impaction syndrome with a reverse oblique sigmoid notch.Level of evidence: IV.

Medial sigmoid depression prevalence and association with a sigmoid notch: cone beam computed tomography and panoramic image study

This study aims to determine whether and how the data of the medial sigmoid depression (MSD) area via cone beam computed tomography (CBCT) differs from panoramic radiography. This study also aims to evaluate various sigmoid notch types and assess the relationship between sigmoid depression and notch morphology. A total of 129 individuals consisting of 258 sides were evaluated. Chi-Square/Fisher Exact tests were used to assess parameters on a categorical scale between two or more groups. McNemar’s test compared the findings detected on panoramic and CBCT images. MSD was more prevalent in females than males in both techniques, but this difference was not statistically significant. There was no association between the prevalence of MSD and the morphology of the sigmoid notch. The incidence of MSD shape was not significantly different between both imaging modalities. In both panoramic and CBCT, we found a high and similar prevalence of MSD. While the MSD prevalence was 66.7% for CBCT, it was 58.1% for panoramic. The shape or prevalence of MSDs in either approach did not correlate with sigmoid notch morphology. The two approaches' identical prevalence indicates that the panoramic image has adequately defines MSD. The high prevalence of MSD demonstrated how important it is for clinicians to characterize this anatomical variation accurately for the surgical treatment.

Anatomical Identification and Possibilities of Transfer of the Masseteric Nerve for Facial Reanimation

The masseteric nerve (MN) is often used as a donor nerve for facial reanimation. In addition to already established techniques, MN transfer is rapidly gaining importance, mainly due to the single-stage approach of the procedure and its reconstructive potential. This anatomical study and the associated questionnaire study aimed to evaluate the established methods for identification of the MN and its suitability for direct nerve transfer as well as to assess the importance of MN transfer in the daily clinical routine. Bilateral dissection of 25 fresh-frozen head specimens (n=50; 13 female, 12 male) was performed with accompanying measurement of the MN. In a questionnaire study conducted at established centres for facial surgery in German-speaking countries, clinical experience data of MN transfer was collected using the SurveyMonkey software. The data obtained was statistically analysed using Microsoft Excel and presented in numerical tables and boxplots. Using anatomical landmarks such as the zygomatic arch and the mandibular notch for orientation, the MN was found in 100% of cases. Its average length from the emerging point below the zygomatic arch towards its entry into the masseter muscle was measured to be 22 mm and was the length available for nerve transposition. Tension-free coaptation of the MN with the zygomatic branch was possible in 94% of cases. The questionnaire showed that the MN is considered an important donor nerve for motor nerve transfers and that MN transfer is now largely established as a standard procedure. In accordance with previously published studies, the MN was reliably found at the height of the mandibular notch and, in the vast majority of cases, was suitable for tension-free coaptation with the zygomatic branch. Differences to the existing literature, however, can be seen in the length of the nerve available for nerve transposition and the frequency of its division into several branches before entering the masseter muscle. In German-speaking countries, Cross-Face Nerve Grafting (CFNG) is still the preferred method for facial reanimation surgery. However, MN transfer is also well established by now, both as an alternative and a supplement to other techniques, possibly due to its low donor site morbidity and short time to regeneration.