Ramus Height Research Articles

Hanna's Modified Sagittal Split Osteotomy (HSSO): An Alternative to Inverted L Osteotomy-Merging Function and Aesthetics for Enhanced Stability, Attractiveness, and Nerve Protection.

Background: The current high standards in orthognathic surgery demand surgical solutions that are both ⁠ functionally ⁠ effective and aesthetically pleasing. Our approach offers one for enhanced stability, attractiveness, and nerve protection ⁠ with improved accessibility ⁠ in the majority of orthognathic scenarios ⁠ compared to an inverted L osteotomy. Methods: A case series is presented to illustrate the application and outcomes of HSSO, an optimised approach that combines the advantages of a transoral inverted L osteotomy with specific enhancements and increased versatility, ⁠ with accessibility and exposure similar to a BSSO. Results: HSSO as a completely transoral technique, demonstrate the ability to perform significant counterclockwise rotations of the mandible, eliminating the need for trocars or skin incisions. We experinced high postoperative stability when HSSO was performed in conjunction with a three-piece LeFort 1 osteotomy on a dynamic opposing arch. In comparison to an inverted L approach, we postulated that HSSO offers advantages in stability, due to the increased segmental overlap of the proximal and distal segments of the mandible. This approach is designed to enhance the safety of the inferior alveolar nerve compared to traditional sagittal split methods. Furthermore, HSSO represents an alternative to total joint replacement in select cases of idiopathic condylar resorption and is effective for correcting mandibular asymmetries while maintaining jawline aesthetics. This is achieved through the manipulation of the mandibular angle, ramus height, and inferior border without creating a step deformity in the soft tissue. Conclusions: The outcomes of HSSO highlight its capacity to deliver predictable, functional, and aesthetically pleasing results, offering a viable alternative to more traditional orthognathic techniques.

Prevalence of mandibular asymmetries in the pediatric population of Jazan: A radiographic analytical study

BackgroundFacial asymmetry results from variation in mandibular linear and angular dimensions on the right and left sides of the face. Mandibular asymmetry is of great significance to oral surgeons and orthodontists as it directly impacts the facial profile of an individual. AimThe present study aimed to measure the prevalence of mandibular asymmetry and its fluctuations during the mixed dentition growth phase in healthy children aged 6–8 years in the Jazan region of Saudi Arabia. MethodThis retrospective observational study was conducted by measuring linear asymmetrical measurements of mandible on orthopantomograms of 390 healthy children (182 boys and 208 girls, aged 6–8 years) with mixed dentition. Linear measurements from orthopantomograms were obtained using a standardized digitizer. Two sets of mandibular measurements were recorded, alongside subjective assessments of mandibular first molar development. An independent t-test was employed to assess the significance between measurements on both sides, while one-way ANOVA was used to demonstrate facial asymmetry significance among different age groups. ResultThe result of this study revealed a significant statistical difference (p-value≤ 0.05) for both sides of the mandible across two dimensions: condylar and ramus height (p value = 0.03) and mandibular length (p value = 0.04). The asymmetry index resulted in no asymmetry among most of the included subjects. However, compared to the other three linear measurements, many seven-year-old participants possess mandibular asymmetry on condylar height (54.5 %). ConclusionWithin the limitation it could be concluded that children in growing age have a significant mandibular asymmetry (mainly 7 years), which, however, is only seldom clinically significant. Hence, treatment plan should be cautiously planned.

Analysis of the effect on costochondral graft for TMJ ankylosis with jaw deformities in pediatrics.

To evaluate the effects of costochondral grafting (CCG) used for temporomandibular joint ankylosis (TMJA) in growing patients. Pediatric patients with TMJA treated by CCG from 2010.5 to 2021.7 were included in the study. CT scans were performed before and after operations with at least 1 year follow-up. The height of the mandibular ramus, menton deviation or retraction, osteotomy gap, etc. were measured by ProPlan CMF1.4 software. CCG growth, resorption, and relapse were evaluated and analyzed with influencing factors such as age, ostectomy gap, etc. by generalized estimating equation. There were 24 patients (29 joints) with an average age of 6.30 ± 3.13 years in the study. After operation, the mandibular ramus was elongated by 5.97 ± 3.53mm. Mandibular deviation or retrusion was corrected by 4.82 ± 2.84mm and 3.76 ± 2.97mm respectively. After a mean follow-up of 38.91 ± 29.20 months, 58.62% CCG grew (4.18 ± 7.70mm), 20.69% absorbed (2.23 ± 1.16mm), and 20.69% re-ankylosed. The re-ankylosis was negatively correlated with the osteotomy gap (OR:0.348,0.172-0.702 95%CI, critical value = 6.10mm). CCG resorption was positively correlated with the distance of CCG ramus elongation (OR:3.353,1.173-9.586 95%CI, critical value = 7.40mm). An adequate osteotomy gap and CCG ramus elongation distance are the key factors for successful treatment of TMJA with jaw deformities in growing patients. TMJA affects mouth opening and jaw development in pediatric patients. The most common autogenous bone graft for pediatric patients is CCG due to its growth potential, convenient access and easy contouring. Also, it can simultaneously reconstruct the TMJ and improve jaw deformity by lengthening the mandibular ramus. But the growth of CCG is unpredictable. In this study, we explored several factors that may affect the absorption and re-ankylosis of CCG, expecting to provide several suggestions to improve future CCG treatment.

Retrospective Evaluation of Condyle and Ramus Asymmetry with Ortopantomography in Dentate and Total Edentulous Patients

Objectives: A symmetrical facial appearance affects people's social relationships. Mandibular asymmetry directly effects the facial appearance and may have many morphological and functional causes. Clinically healthy individuals may experience complete edentulousness in advancing ages, which may lead to asymmetry in the condyles and facial appearance. Our aim in this study is to evaluate whether fully-toothed and total edentulous conditions cause changes in the vertical height of the condyle and ramus and also asymmetry. Material and Methods: A total of 200 patients (104 female, 96 male) with 100 fully-toothed and 100 edentulous were included in the study. Right and left condylar ramus were measured and recorded according to the asymmetry measurement index of Habets et al., with using tracing paper under the reflector light on the patients' orthopantomographic images. Statistical analysis was done using SPSS:22 package program. T-tests, Mann-Whitney U and chi-square tests were used for comparisons. P <0.05 were considered significant. Results: In previous studies, the difference between the genders was found to be statistically insignificant, therefore we evaluated men and women together. In our research, the mean of the condyle and ramus height asymmetry index in edentulous patients was 4.76 mm and 2.12 mm respectively, and the mean of the condyle and ramus height asymmetry index in fully-toothed patients was 4.88 mm and 2.34 mm, respectively. According to the t-test, the mean of the condyle height and ramus height asymmetry index was found to be higher in fully-toothed patients but this difference was not statistically significant (p>0.05). Conclusion: Although condylar asymmetry was more common than ramus asymmetry in this study, this difference was not statistically significant when total edentulous and fully-toothed patients were compared. Keywords: Habets technique; condylar asymmetry; ramus asymmetry

Mandibular and dental measurements for sex determination using machine learning

The present study tested the combination of mandibular and dental dimensions for sex determination using machine learning. Lateral cephalograms and dental casts were used to obtain mandibular and mesio-distal permanent teeth dimensions, respectively. Univariate statistics was used for variables selection for the supervised machine learning model (alpha = 0.05). The following algorithms were trained: logistic regression, gradient boosting classifier, k-nearest neighbors, support vector machine, multilayer perceptron classifier, decision tree, and random forest classifier. A threefold cross-validation approach was adopted to validate each model. The areas under the curve (AUC) were computed, and ROC curves were constructed. Three mandibular-related measurements and eight dental size-related dimensions were used to train the machine learning models using data from 108 individuals. The mandibular ramus height and the lower first molar mesio-distal size exhibited the greatest predictive capability in most of the evaluated models. The accuracy of the models varied from 0.64 to 0.74 in the cross-validation stage, and from 0.58 to 0.79 when testing the data. The logistic regression model exhibited the highest performance (AUC = 0.84). Despite the limitations of this study, the results seem to show that the integration of mandibular and dental dimensions for sex prediction would be a promising approach, emphasizing the potential of machine learning techniques as valuable tools for this purpose.

Correlations between Dental Age, Skeletal Age, and Mandibular Morphologic Index Changes in Turkish Children in Eastern Anatolia and Their Chronological Age during the Pubertal Growth Spurt Period: A Cross-Sectional Study.

In age determination, different methods aiming to obtain the closest result to chronological age have been investigated so far. The most commonly used one among these is the radiological method, which is usually used to evaluate the developmental stages of wrist bones or teeth. In our study, we assessed bone age estimations using the Gilsanz-Ratib atlas (GRA), which has recently become commonly used for children aged 9 to 15 years; evaluated the dental age, determined with Cameriere's European method; conducted morphometric measurements of the mandibular bone; and then examined their relationships with chronological age. The results of our study reveal that, in children during the puberty growth spurt, Cameriere's EU formula might have higher accuracy in estimating chronological age in younger age groups, while the GRA might be more accurate for older ages. Additionally, we conclude that of the mandibular morphometric measurements, condylar height and tangential ramus height show strong positive correlations with age. As a result, we conclude that the morphometric measurements evaluated in the present study can be used as auxiliary methods in forensic anthropology and forensic dentistry.

Effects of modified twin block appliance in growing Class II high angle cases: A cephalometric study

Background Class II malocclusions represent anteroposterior dysplasia usually resulting from mandibular retrusion. Along with a retropositioned mandible, it can be associated with either upward or backward jaw rotation. High angle cases are often associated with a short ramal height, steeper mandibular plane, and large gonial angle. Twin block is a commonly used myofunctional appliance that incorporates bite planes that direct the occlusal forces in a more favorable direction for correction of the retrognathic mandible. We aimed to evaluate skeletal, dental, and soft tissue changes following modified twin block appliance therapy in high-angle cases. Methods A cephalometric study was performed on 15 growing (10-14 years) high angle (Frankfort mandibular angle 28-35°) Class II Division I malocclusion patients undergoing twin block therapy. Skeletal, dental, and soft tissue changes were evaluated by cephalometric analysis using Dolphin software. Results Pre- and post-treatment changes in cephalograms were assessed by analysis of variance and paired t-test. Significant changes in the position of the mandible (angle between Sella-Nasion-Point B [SNB] increased by 3.9 degrees, P=0.02), Wits appraisal (decreased by 1.54 mm, P=0.04), maxillo-mandibular relationship (angle between Point A-Nasion-Point B [ANB] decreased by 3.74 degrees, P=0.02) were observed. Soft tissue changes like the nasolabial angle were also significant, increasing by 3.8 degrees (P=0.04) and lower lip relation to E-line (reduction in lower lip protrusion) by 2 mm (P=0.04). Vertical parameters showed non-significant changes, like the Frankfort mandibular angle (FMA) increased by 0.07 degrees, (P=0.67), the angle between Sella-Nasion and Gonion-Gnathion (SN-Go-Gn) increased by 0.33 degrees, (P=0.67), Y-axis increased by 0.2 degrees, (P=0.32). The upper incisor inclination decreased non-significantly from 115.27±1.33 to 113.42±1.65 degrees, (P=0.12) and lower incisor increased non-significantly from 100.13±2.23 to 101.80 ±1.37 degrees, (P=0.08). Conclusions Modified twin block appliance can be used to successfully treat Class II Division I high angle cases with good vertical control.

Comparison of mandibular morphometric parameters in digital panoramic radiography in gender determination using machine learning.

This study aimed to evaluate the usability of morphometric features obtained from mandibular panoramic radiographs in gender determination using machine learning algorithms. High-resolution radiographs of 200 patients aged 20-77 (41.0 ± 12.7) were included in the study. Twelve different morphometric measurements were extracted from each digital panoramic radiography included in the study. These measurements were used as features in the machine learning phase in which six different machine learning algorithms were used (k-nearest neighbor, decision trees, support vector machines, naive Bayes, linear discrimination analysis, and neural networks). To evaluate the reliability, we have performed tenfold cross-validation and we repeated this 10 times for every classification process. This process enhances the reliability of the results for other datasets. When all 12 features are used together, the accuracy rate is found to be 82.6 ± 0.5%. The classification accuracies are also compared using each feature alone. Three features that give the highest accuracy are coronoid height (80.9 ± 0.9%), condyle height (78.2 ± 0.5%), and ramus height (77.2 ± 0.4%), respectively. When compared to the classification algorithms, the highest accuracy was obtained with the naive Bayes algorithm with a rate of 84.0 ± 0.4%. Machine learning techniques can accurately determine gender by analyzing mandibular morphometric structures from digital panoramic radiographs. The most precise results are achieved by evaluating the structures in combination, using attributes obtained from applying the MRMR algorithm to all features.

Analyzing Mandibular Characteristics for Age and Gender Variation Through Digital Radiographic Techniques: A Retrospective Study.

Background Forensic odontology has emerged as a crucial method for identifying skeletal or dental remains. Due to the restricted accuracy of current techniques for estimating age at death, researchers have endeavored to illustrate age-related alterations in dental hard tissues. Bone remodeling constitutes an ongoing and intricate process throughout our lifespan. It is believed that morphological changes in the mandible during an individual's lifetime are influenced by both dental condition and the individual's age. Objectives This study aims to evaluate the efficacy of mandibular parameters such as projective ramus height (PRH), maximum ramus breadth (MaRB), bigonial width (BGW), antegonial depth (Ant.D), and antegonial angle (Ant.A), as a gender-determining tool and compare and analyze the mandibular parameter measurements using digital orthopantomography. Methodology In this study, the total number of samples used was 500 out of which 250 were males and 250 were females. Planmeca software (Version 6.0, Planmeca Romexis, Charlotte, NC) was used and the accuracy test, analysis of variance (ANOVA), multiple regression, and discriminant analysis for gender were performed using SPSS for Windows, Version 16.0(SPSS Inc., Chicago, IL). Results For age estimation, the least standard error of 0.008 was observed for BGW. A maximum standard error of 0.230 was observed for Ant.D. For sex determination, the coefficient function was positive for PRH, BGW, and Ant.A, with values of 0.202, 0.805, and 0.052, respectively. Ant.D and MaRB both exhibited negative values of -0.204 and -0.379, respectively. Conclusions Out of all the parameters assessed, BGW is the most preferred parameter for age estimation and Ant.A can be preferred for sex estimation. Age and gender can be estimated using the two parameters in the Indian population.

The Relationship Between Hand Preference and Mandibular Asymmetry: A Preliminary Study

Objective: The objective of this study was to evaluate the relationship between functional laterality (hand preference) and mandibular asymmetry in skeletal Class I, normodivergent patients.
 Methods: 21 left-handed and 40 right-handed Class I normodivergent patients were included in the study. The hand preferences of the participants were determined by using the Oldfied hand preference questionnaire. Mandibular condylar height (CH), ramal height (RH), and total height (CH+RH) were measured on pretreatment panoramic radiographic images of the patients, and asymmetry values were obtained according to the formula of asymmetry indices. Data were analyzed with the Student’s t-test and Pearson chi-square.
 Results: Right and left CH values were greater in left-handed patients than in right-handed patients. Right and left RH and CH+RH values were greater in right-handed patients than in left-handed. However, there was no difference between the measurements (p > .05). There was no significant relationship between the functional values and hand-use preference (p > .05).
 Conclusions: Hand use preference was not associated with condylar, ramal, and total mandibular asymmetry.

Cranial Base Measurements in Skeletal Malocclusion among Orthodontic Patients.

Facial growth and development is necessary for proper orthodontic diagnosis and treatment planning. Growth of cranial base is linked to the overall growth of facial bones, especially the maxilla and mandible. Any change in the amount and direction of growth of the cranial base can have direct or indirect effects on the developing maxilla and mandible. Thus the aim of this study was to determine the linear and angular cranial base measurements in different skeletal malocclusion in Nepalese population. Pretreatment lateral cephalograms of 225 patients aged between 17-30 years were collected. Linear measurements Sella-Nasion (S-N), Sella-Articulare (S-Ar), Articulare-Gonion (Ar-Go), Gonion-Gnathion (Go-Gn) and angular measurements Saddle angle (N-S-Ar), Articular angle (S-Ar-Go) and Gonial angle (Ar-Go-Gn) were measured. In angular measurements statistically significant differences were found in the saddle and gonial angles between class I, II, and III skeletal pattern. In linear measurements, anterior and posterior cranial base lengths were not significantly different among groups however, ramal height and mandibular body length were significantly different among groups with a P value < 0.05. Skeletal class III has a larger gonial angle, ramal height and mandibular length. Males have larger linear measurements and females have larger angular measurements.

Exploring Age and Gender Identification Through Mandibular Parameters Using Orthopantomography: An Observational Study.

Aim This study aimsto examine five mandibular parameters: coronoid ramus height, condylar ramus height, projective ramus height, minimum ramus breadth, and gonial angle, using orthopantomography (OPG). Introduction The mandible, a crucial part of the human skull, demonstrates sexual dimorphism, which makes it an important tool for determining sex in forensic and anthropological investigations.Its form and structure are relatively resistant to significant changes after death. Among all skeletal components, the mandible stands out as a primary indicator of sexual differences. In forensic investigations, establishing the age and sex of an individual is considered a crucial initial step. This process can be particularly challenging in scenarios involving mass casualties, natural calamities, or extensively fragmented remains. Due to its responsiveness to growth patterns, the mandible is adept at accurately determining both age and sex. Materials and methods This study employed a sample size of 500 individuals, split equally between males and females, with 250 participants each. The age bracket chosen for this cohort ranged from 20 to 30 years, considering that bone growth characteristics within this range can assist in sex determination. The height of the mandibular ramus was assessed using Planmeca software, and subsequent data analysis was conducted using SPSS. Results When estimating age, the condylar ramus height exhibited the smallest standard error (0.010), whereas the maximum standard error for the gonial angle was 0.028. Positive t values were observed for the gonial angle (1.182), minimum ramus breadth (0.114), and coronoid ramus height (0.733). In terms of determining sex, the gonial angle, coronoid ramus height, and projective ramus height demonstrated positive coefficient functions, specifically 0.676, 0.090, and 0.286, respectively. Conversely, both the minimum ramus breadth and the condylar ramus height displayed negative values of -0.385 and -0.126, respectively. Conclusion Among the parameters evaluated, condylar ramus height emerges as the most suitable choice for estimating age, while gonial angle, coronoid ramus height, and projective ramus height are preferable for determining sex.

Gender Determination by Measuring the Mandibular Ramus and Body of the Mandible: A Retrospective Radiographic Study

Aims:1) To measure the height and width of the mandibular ramus and height of the body of the mandible on digital orthopantomograms. 2) To compare the measurements on the mandibular ramus &amp; body of the mandible and use them in gender determination. Setting and Design: Retrospective study on 120 retrieved digital ortho pantomograms of individuals of Indian origin. Materials and Methods: A study was conducted on 120 retrieved digital orthopantomograms which were categorized into three age groups of age between 21-50 years. 40 digital orthopantomograms were selected under each age group which included 20 male and 20 female radiographs. The Digital OPG images that were obtained using the PLANMECA PROLINE XC machine were measured using PLANMECA ROMEXIS 2.3.1.R software.

A single-centre retrospective 10-year experience of the rhombic 3D condylar fracture plate for open reduction and internal fixation of condylar neck and base fractures

Fractures of the mandibular condyle account for a significant proportion of mandibular fractures. The specific functional loads require particular specifications for the implant design used for open reduction and internal fixation of such fractures. The clinical and radiographic outcomes in patients treated using a single rhombic 3D condylar fracture plate for open reduction and internal fixation at a single institution, and who fulfilled the inclusion and exclusion criteria, are presented.The primary outcome variables were: occlusion, maximum interincisal distance and mandibular excursion at 1, 3, and 6 months postoperatively, and radiographic measurements for mandibular height and gonion angle.In total, 263 patients were included, of whom 173 (65.8%) were male and 90 (34.2%) female. The mean age was 40.4 ± 18.9 years. There was satisfactory occlusion in 98.9% of patients at the 6-month follow-up, and a significant improvement in all parameters for mandibular excursion (p < 0.001), with a reduced ramus height and an increase in the gonion angle on the fractured side.Excellent clinical and radiographic results were achieved using the rhombic-shaped implant, deeming it appropriate for the osteosynthesis of mandibular condyle fractures.

Role of the Growth Hormone Receptor (GHR) Gene in Skeletal Class II Malocclusion and Its Significant Influence on the Skeletal Facial Profile in Both the Sagittal and Vertical Dimensions: A Systematic Review.

This systematic review aims to determine the role of the growth hormone receptor (GHR) gene in skeletal malocclusion and its significant influence on the growth of the maxilla and the mandible in both sagittal and vertical dimensions. A search of the electronic databases of PubMed, Google Scholar, and Cochrane up to and including the year 2023 was made. In addition to this, a hand search of orthodontic and dentofacial orthopaedic journals was carried out. This search included randomized control trials. The Mesh terms used were "skeletal class II malocclusion", "mandibular retrognathism", "sagittal malocclusion", "genetic expression", "genetic factors", "genetic study", "genetic polymorphism", and "single nucleotide polymorphism". The inclusion criteria included studies such as clinical trials and orthopaedic appliances in the presurgical phase. The exclusion criteria for the study were studies not in the English language, case reports, case series, and studies with irrelevant data. It has been cited in various literature that polymorphic variations of the GHR gene could cause variations in mandibular morphogenesis affecting both the mandibular body length and ramal height. However, its effects are quite variable and are based on different population groups. Polymorphism of the GHR gene can be considered a reliable indicator predicting variations in affecting the growth of the mandible with greater significance in affecting the vertical ramal height compared to the body length of the mandible. Its effects on the maxillary skeletal base are rather limited comparatively.

Application of panoramic radiographs in the diagnosis of temporomandibular disorders.

To evaluate the feasibility of temporomandibular disorder (TMD) diagnosis with panoramic radiography, and provide standardized data for artificial intelligence-assisted diagnosis by measuring the differences in the condylar and mandibular ramus heights. A total of 500 panoramic radiographs (219 male and 281 female participants) of healthy individuals were examined. The panoramic machine compatible measurement software, SCANORA 5.2.6, was used to measure the bilateral condylar height and mandibular ramus height, and SPSS 27.0 was used to calculate the left- and right-side differences in condylar height and mandibular ramus height of healthy individuals. Magnetic resonance images of the temporomandibular joint region obtained from 46 outpatients in the Stomatology Department were selected along with their corresponding panoramic radiographs. The left- and right-sided differences were measured and compared with the magnetic resonance imaging results. The measurement data are expressed as mean ± standard deviation (mm). t Tests were used to analyze data from healthy male and healthy female groups. The findings revealed that while there was no significant difference (P > .05) in the height of the condyle between men and women, there was a significant difference (P < .05) in the height of the mandibular ramus. In healthy population, the difference in height between the left and right condyle was 1.09 ± 0.99 mm. The difference in height of mandibular ramus in men was 1.26 ± 0.85 mm and that in women was 1.19 ± 0.87 mm. For the diagnosis of TMD, the sensitivity of panoramic radiographs was 94.74% (36/38), specificity was 75.00% (6/8), and diagnostic accuracy was 91.30% (42/46). The height of the right and left lateral condyles was not identical in healthy individuals, resulting in a discernible height discrepancy. In addition, the height of the mandibular ramus varied. By considering the left-right lateral height differences identified in this study along with clinical examination, it is possible to employ this metric as a preliminary screening tool for patients with TMD. Further, the use of panoramic radiographs for initial TMD screening is both viable and significant.

Vertical mandibular asymmetry and hand measurements in patients in growth: cross-sectional study.

The aim of this study was to determine the relationship between the vertical mandibular ramus asymmetry and the hand measurements asymmetry in growing patients. Panoramic radiographs and comparative radiographs of the right and left hands of 40 patients (14 males and 26 females) between 6 and 16 years old (mean age of 11.35±1.99 years) were evaluated. The total height of the mandibular ramus was measured, and the asymmetry index was calculated. The lengths of the proximal, middle and distal phalanges and the metacarpals of the five digits of both hands were measured and the absolute differences R-L were calculated for each one. A statistically significant association between the presence of vertical mandibular ramus asymmetry and the presence of phalanges asymmetry FPII (p=0.016), FPIII (p=0.016), FPIV (p=0.033), FMIII (p=0.031) and FMIV (p=0.016) was observed. Mandibular asymmetry appears not to be isolated but also present in other body districts such as the phalanx bones. The total vertical asymmetry of the mandibular ramus showed an association with the asymmetry of the lengths of the FPIII, FMIII, FPIV, FMIV and FPII in growing individuals, with association between the side of mandibular asymmetry and the side of the phalanx's asymmetry. The asymmetry of this phalanges increases with increasing index of vertical mandibular ramus asymmetry.

3D analysis of condylar and mandibular remodeling one year after intra-oral ramus vertical lengthening osteotomy.

Among the existing techniques for the correction of mandibular posterior vertical insufficiency (PVI), the intra-oral ramus vertical lengthening osteotomy (IORVLO) can be proposed as it allows simultaneous correction of mandibular height and retrusion. This study assessed the 3D morpho-anatomical changes of the ramus-condyle unit and occlusal stability after IORVLO. This retrospective analysis compared immediate and 1-year post-operative 3D CBCT reconstructions. The analysis focused on the condylar height (primary endpoint) and on the changes in condylar (condylar diameter, condylar axis angle) and mandibular (ramus height, Frankfort-mandibular plane angle, gonion position, intergonial distance, angular remodeling) parameters. Additionally, this analysis investigated the maxillary markers and occlusal stability. On the 38 condyles studied in 21 included patients (mean age 23.7 ± 3.9years), a condylar height (CH) loss of 0.66mm (p < 0,03) was observed, with no correlation with the degree of ramus lengthening (mean 13.3 ± 0.76mm). Only one patient presented an occlusal relapse of Class II, but a 3.4mm (28%) condylar diameter loss and a 33% condylar volume reduction with loss of 1mm and 3.4mm in CH and condyle diameter, respectively. A mean 3.56mm (p < 0.001) decrease in ramus height was noted, mainly due to bone resorption in the mandibular angles. This study confirms the overall stability obtained with IORVLO for the correction of PVI. This study aims to precise indication of IORVLO, and to validate the clinical and anatomical stability of results.

Efficacy of navigation system-assisted distraction osteogenesis for hemifacial microsomia based on artificial intelligence for 3 to 18 years old: study protocol for a randomized controlled single-blind trial

BackgroundMandibular distraction osteogenesis (MDO) is a major part of the treatment for hemifacial microsomia patients. Due to the narrow surgical field of the intraoral approach, osteotomy accuracy is highly dependent on the surgeons’ experience. Electromagnetic (EM) tracking systems can achieve satisfying accuracy to provide helpful real-time surgical navigation. Our research team developed an EM navigation system based on artificial intelligence, which has been justified in improving the accuracy of osteotomy in the MDO in animal experiments. This study aims to clarify the effect of the EM navigation system in improving the MDO accuracy for hemifacial microsomia patients.MethodsThis study is designed as a single-centered and randomized controlled trial. Altogether, 22 hemifacial microsomia patients are randomly assigned to the experiment and control groups. All patients receive three-dimensional CT scans and preoperative surgical plans. The EM navigation system will be set up for those in the experiment group, and the control group will undergo traditional surgery. The primary outcome is the surgical precision by comparing the osteotomy position of pre- and postoperative CT scan images through the Geomagic Control software. The secondary outcomes include mandibular symmetry (occlusal plane deviation angle, mandibular ramus height, and body length), pain scale, and complications. Other indications, such as the adverse events of the system and the satisfactory score from patients and their families, will be recorded.DiscussionThis small sample randomized controlled trial intends to explore the application of an EM navigation system in MDO for patients, which has been adopted in other surgeries such as orthognathic procedures. Because of the delicate structures of children and the narrow surgical view, accurate osteotomy and protection of nearby tissue from injury are essential for successful treatment. The EM navigation system based on artificial intelligence adopted in this trial is hypothesized to provide precise real-time navigation for surgeons and optimally improve patient outcomes, including function and aesthetic results. The results of this trial will extend the application of new navigation technology in pediatric plastic surgery.Trial registrationChinese Clinical Trial Registry ChiCTR2200061565. Registered on 29 June 2022.

Radiographic Estimation of Association between Condylar Morphology, Ramal Height, and Mandibular Plane Angle in Various Growth Patterns in District Solan Population in Himachal Pradesh

Introduction: In young adults, the mandibular condyle plays an essential role in the stability of long-term orthodontic and orthognathic treatments. Its morphology varies significantly between individuals and is associated with age, sex, facial type, occlusal force, functional load, malocclusion type, and right and left sides. Aim: The aim of the study was to estimate the association between morphology of condyle, ramus height, and mandibular plane (MP) angle in young adult patients with various vertical skeletal growth patterns. Materials and Methods: The present study was conducted on 90 pretreatment panoramic radiographs of subjects aged between 17 and 21 year of age; the patients were divided into three groups as hypodivergent, normodiveregent, and hyperdivergent with 30 subjects in each group on the basis of Sella-Nasion-MP angle. Various parameters were measured to record the condyle morphology, ramus height, and mandibular angle for all the groups. Results: The intergroup comparisons showed that hypodivergent group has statistically significantly greater values compared to those in the hyperdivergent group. A statistically significant difference was detected between the normodivergent and hypodivergent groups only in the condylar area measurements Conclusion: The condylar height was greater in patient with Class I malocclusion. The condylar height width and other perimeters were greater in males than females.