An open-source, three-dimensional growth model of the mandible.

The available reference data for the mandible and mandibular growth consists primarily of two-dimensional linear or angular measurements. The aim of this study was to create the first open-source, three-dimensional statistical shape model of the mandible that spans the complete growth period. Computed tomography scans of 678 mandibles from children and young adults between 0 and 22 years old were included in the model. The mandibles were segmented using a semi-automatic or automatic (artificial intelligence-based) segmentation method. Point correspondence among the samples was achieved by rigid registration, followed by non-rigid registration of a symmetrical template onto each sample. The registration process was validated with adequate results. Principal component analysis was used to gain insight in the variation within the dataset and to investigate age-related changes and sexual dimorphism. The presented growth model is accessible globally and free-of-charge for scientists, physicians and forensic investigators for any kind of purpose deemed suitable. The versatility of the model opens up new possibilities in the fields of oral and maxillofacial surgery, forensic sciences or biological anthropology. In clinical settings, the model may aid diagnostic decision-making, treatment planning and treatment evaluation.

Temporomandibular Joint Prosthesis in a Patient with Congenital Infiltrating Lipomatosis of the Face with Bony Ankylosis of the Temporomandibular Joint: A Case Report.

Hemifacial hyperplasia (HFH) is a rare congenital disorder characterized by marked unilateral overgrowth of the facial tissues. A subtype of HFH is congenital infiltrating lipomatosis of the face (CIL-F). This disease is characterized by unilateral diffuse infiltration of mature adipose cells in the facial soft tissue and is associated with skeletal hypertrophy. This work aims to report a case of a CIL-F patient with right facial asymmetry and progressive growth at adolescent age, causing mandibular asymmetry due to signs of concomitant unilateral condylar hyperplasia. At the age of seventeen, a condylectomy was performed to stop the progression of asymmetric mandibular growth. Five years later, the patient developed CIL-F-associated temporomandibular joint ankylosis, manifesting as progressive restricted mouth opening along with temporal facial pain. In this CIL-F patient, a TMJ reconstruction with an alloplastic total joint prosthesis was successfully performed with optimal maximal mouth opening, complete alleviation of temporal facial pain, and stable dental occlusion one year postoperatively. A TMJ reconstruction with a complete alloplastic total joint prosthesis proved to be a predictable, stable, and safe treatment option in a patient with CIL-F-associated TMJ ankylosis who was previously treated with condylectomy due to progressive mandibular asymmetry.

The Dutch Version of the Orthognathic Quality of Life Questionnaire (OQLQ-NL): Validation for Cleft Patients.

OBJECTIVE: The aim of this study is to validate the Dutch version of the Orthognathic Quality of Life Questionnaire (OQLQ-NL) for cleft patients who received orthognathic surgery. METHODS: To compare the OQLQ-NL with the CLEFT-Q, we used a convenience sample of thirty-two cleft patients. Using the Cronbach's alpha coefficient for multiple item scales, internal reliabilities of the OQLQ-NL were evaluated. The OQLQ-NL was repeated at a two-week interval and the intraclass correlation coefficient was calculated, to establish of the test-retest reliability. The construct validity of the OQLQ-NL was evaluated by using Spearman's correlation to test its correlation with the CLEFT-Q. RESULTS: Thirty-two patients filled in the OQLQ-NL and CLEFT-Q. The OQLQ-NL had excellent results in internal reliability and test-retest reliability. The vast majority of the correlations between the domains and scales of the questionnaires were as expected. Data from this study and previous studies confirm the construct validity of the OQLQ-NL. CONCLUSION: Our results suggest the OQLQ-NL is a valid and reliable instrument for measuring quality of life in cleft patients who have received orthognathic surgery in the Netherlands.

Interrater Reliability for Classifying Craniofacial Microsomia Severity: A Call for Objective Evaluation.

OBJECTIVE: The severity of craniofacial microsomia (CFM) is generally classified using the Orbit, Mandible, Ear, Soft tissue, Nerve (OMENS) classification score. The global assessment of the Phenotypic Assessment Tool for Craniofacial Microsomia (PAT-CFM), is a pictorial modification of the OMENS classification. The aim of this study was to assess the interrater reliability of the PAT-CFM global assessment score. DESIGN: In this prospective cohort study, three clinicians completed the global assessment form of the PAT-CFM. The mandible was classified based on orthopantomogram- and/or computed tomography images. PARTICIPANTS: Consecutive patients with CFM or microtia.Interrater agreement was calculated using the weighted Krippendorff alpha (α), with 95% confidence intervals (CI). RESULTS: In total, 53 patients were included (106 hemifaces). The reliabilities of the main classification components ranged from high for the mandible (α = 0.904 [95% CI 0.860-0.948]) and ear (α = 0.958 [95% CI 0.934-0.983]) subscales, to tentative for the orbital summary score (α = 0.682 [0.542-0.821]), and nerve summary score (α = 0.782 [0.666-0.900]) subscales. CONCLUSIONS: The reliability of the ear and radiographic mandible scales of the PAT-CFM global classification were high, while the orbit, facial nerve and soft tissue subscales may have limited reliability. Research focusing on radiographic severity scores for hypoplasia of the orbits and soft tissues, as well as objective measures for overall facial hypoplasia using non-ionizing forms of imaging for early classification, are warranted.

Normal variation of mandibular asymmetry in children.

OBJECTIVE: To explore the normal variation of asymmetry in mandibles of children in the age group of 1 to 12 years. MATERIALS AND METHODS: The study group consisted of 92 cadaveric mandibles of children with a dental age of 1 to 12 years old in possession of ACTA (Academic Centre for Dentistry Amsterdam), Faculty of Dentistry, the Netherlands. 3D models of the mandibles were obtained from CT-scans and hemimandibular volumes of all mandibles were calculated. The condylar height, ramus height, mandibular body length and the gonial angle were bilaterally determined using a novel landmark-based method, and the degree of asymmetry was calculated. RESULTS: No relationship was found between dental age and asymmetry of the studied parameters (P < .05). The highest degree of asymmetry was found in the ramus height, whereas the gonial angle presented the lowest degree of asymmetry. A positive correlation was found between the asymmetry of the hemimandibular volume vs the height of the ramus (P < .05) and the length of the mandibular body (P < .05). An inverse correlation was found between the asymmetry of the ramus height vs the condylar height (P < .05), mandibular body length (P < .05) and gonial angle (P < .05). CONCLUSIONS: Mandibular asymmetries in children did occur (9.8% of the included mandibles presented with a relevant overall asymmetry of ≥3%) and were unrelated to age. The different segments of the mandible seem to compensate for each other, in order to maintain a functional equilibrium.

Quality of Life After Orthognathic Surgery in Patients with Cleft: An Overview of Available Patient-Reported Outcome Measures.

Measuring the impact of orthognathic surgery on quality of life is of significant importance in patients with cleft deformities. Standardized tools such as patient-reported outcome measures (PROMs) are needed to fully comprehend patients' needs and perceptions. Therefore, the availability of reliable, valid, and comprehensive questionnaires for patients is essential. The aim of this study is to identify PROMs measuring the impact of orthognathic surgery on quality of life in patients with cleft deformities and to evaluate the identified PROMs.A systematic search of the literature was performed according to the preferred reporting items for systematic reviews and meta-analysis guidelines. All validated PROMs, regarding the impact of orthognathic surgery on quality of life in patients with cleft deformities, were identified and assessed according to the quality criteria proposed for measurement properties of health status questionnaires.An electronic search yielded 577 articles. After a full-text review of 87 articles, 4 articles met the inclusion criteria, comprising 58 PROMs. Of these 58 PROMs, 1 PROM (the CLEFT-Q) has been validated to measure the impact of orthognathic surgery on patients with a facial cleft. Evaluation of methodological quality of the included articles and assessment of the measurement properties of the CLEFT-Q show that the CLEFT-Q scores relatively good for all available measurement properties, making it suitable for immediate use.The CLEFT-Q was found to be the only valid instrument so far to measure the impact of orthognathic surgery on the quality of life in patients with cleft deformities.

Evaluating International Diagnostic, Screening, and Monitoring Practices for Craniofacial Microsomia and Microtia: A Survey Study.

To (1) appraise current international classification and clinical management strategies for craniofacial microsomia (CFM) and microtia, and (2) to assess agreement with the European Reference Network "European Guideline Craniofacial Microsomia" recommendations on screening and monitoring.This was a cross-sectional online survey study. The survey consisted of 44 questions on demographics, diagnostics and classification, obstructive sleep apnea, feeding difficulties, speech and language development, hearing, ocular abnormalities, visual development, orthodontic screening, genetic counselling, psychological wellbeing, and extracraniofacial anomalies.Respondents were participants of 3 international cleft and craniofacial conferences, members of the American Cleft Palate and Craniofacial Association and members of the International Society for Auricular Reconstruction. Respondents were requested to complete 1 questionnaire per multidisciplinary team.Fifty-seven responses were received from 30 countries (response rate ∼3%).The International Consortium for Health Outcomes Measurement diagnostic criteria were used by 86% of respondents, though 65% considered isolated microtia a mild form of CFM. The Orbit, Mandible, Ear, Facial Nerve and Soft Tissue classification system was used by 74% of respondents. Agreement with standardized screening and monitoring recommendations was between 61% and 97%. A majority of respondents agreed with screening for extracraniofacial anomalies (63%-68%) and with genetic counselling (81%).This survey did not reveal consistent agreement on the diagnostic criteria for CFM. Respondents mostly supported management recommendations, but frequently disagreed with the standardization of care. Future studies could focus on working towards international consensus on diagnostic criteria, and exploring internationally feasible management strategies.

Management of Asymmetry.

Orthognathic surgery in asymmetric cases is challenging because of diversity and individuality. Clinical observations are of paramount importance and need to be systemically thorough. Three-dimensional diagnosis and virtual planning have been proven extremely helpful in facilitating treatment toward symmetry in difficult cases with increasing precision. Compared with orthognathic surgery in symmetric situations, asymmetries produce numerous pitfalls and provide opportunities for out-of-the-box procedures.

Advantages and disadvantages of mandibular distraction in Robin sequence.

Robin sequence (RS) is diagnosed in infants born with micrognathia, glossoptosis and varying degrees of upper airway obstruction (UAO). Due to the variable levels of hypoxia, severe breathing and feeding problems can occur. Treatment is determined by clinical severity, ranging from conservative interventions for mild cases to surgical interventions for severe cases. Mandibular distraction osteogenesis (MDO) is a surgical technique that gradually lengthens the mandible after an osteotomy by using an internal or external distraction device, directly correcting the micrognathia. This review will focus on advantages and disadvantages of mandibular distraction in infants with RS.

The Orthognathic Quality of Life Questionnaire: Translation and Validation into Dutch.

OBJECTIVE: The aim of this study is to translate and validate the Orthognathic Quality of Life Questionnaire (OQLQ) in the Dutch language (OQLQ-NL). METHODS: The translation of the OQLQ into the Dutch language was performed following the guidelines for the Process of Cross-Cultural Adaption of Self-Report Measures. Sixty-two patients who received orthognathic surgery in the past 10 years were included for participation. Internal reliabilities of the OQLQ-NL were evaluated for multiple item scales with the use of the Cronbach alpha coefficient. For the establishment of the test-retest reliability, the OQLQ-NL was repeated with a 2-week interval and the intraclass correlation coefficient was calculated. Spearman correlation was used to test the correlation with the OHIP-49NL and the FACE-Q, to be able to evaluate the construct validity of the OQLQ-NL. RESULTS: Thirty-five patients filled in the OQLQ-NL, OHIP49NL, and FACE-Q upon arrival and 22 patients returned the OQLQ-NL after 2 weeks (response rate of 56.6% and 62.9%, respectively). The OQLQ-NL showed excellent results in internal reliability and test-retest reliability. The vast majority of the correlations between the domains of the questionnaires were as expected. Data from this study and previous studies confirm the construct validity of the OQLQ-NL. CONCLUSION: The OQLQ-NL appears to be a valid and reliable instrument to measure quality of life for patients receiving orthognathic surgery in the Netherlands.

Impact of Bone Volume Upon Condylar Activity in Patients With Unilateral Condylar Hyperplasia.

PURPOSE: Unilateral condylar hyperplasia or hyperactivity (UCH) is a bone overgrowth disorder affecting the mandible. The purpose of this study was to determine the relations among age, condylar bone structure, condylar bone volume, and condylar bone activity on single-photon emission computed tomographic (SPECT) scans in patients with UCH. MATERIALS AND METHODS: This study included 20 patients with a clinical presentation of progressive mandibular asymmetry and a positive bone SPECT scan. A bone SPECT-derived standardized uptake value (bSUV) for the condylar region was determined. All patients underwent condylectomy to arrest further progression of the disease. The resected condyles were scanned with a micro-computed tomographic scanner (18-µm resolution). Bone architectural parameters were calculated with routine morphometric software. RESULTS: The mean bSUV of the condyle on the affected side was 15.32 (standard deviation [SD], 8.98) compared with 9.85 (SD, 4.40) on the nonaffected side (P = .0007). For trabecular bone structure, there was a nonsignificant correlation between the SUV of the affected condyle and the measured bone volume fraction (r = 0.13; P = .58) and trabecular thickness (r = 0.03; P = .90). CONCLUSION: No meaningful relation was found between condylar bone volume fraction and condylar activity on bone scan; therefore, the impact of bone volume fraction on the results of bone scans is limited. The measured condylar activity on SPECT scan seems to be primarily a reflection of the remodeling rate of bone.

Unilateral condylar hyperplasia: a 3-dimensional quantification of asymmetry.

PURPOSE: Objective quantifications of facial asymmetry in patients with Unilateral Condylar Hyperplasia (UCH) have not yet been described in literature. The aim of this study was to objectively quantify soft-tissue asymmetry in patients with UCH and to compare the findings with a control group using a new method. MATERIAL AND METHODS: Thirty 3D photographs of patients diagnosed with UCH were compared with 30 3D photographs of healthy controls. As UCH presents particularly in the mandible, a new method was used to isolate the lower part of the face to evaluate asymmetry of this part separately. The new method was validated by two observers using 3D photographs of five patients and five controls. RESULTS: A significant difference (0.79 mm) between patients and controls whole face asymmetry was found. Intra- and inter-observer differences of 0.011 mm (-0.034-0.011) and 0.017 mm (-0.007-0.042) respectively were found. These differences are irrelevant in clinical practice. CONCLUSION: After objective quantification, a significant difference was identified in soft-tissue asymmetry between patients with UCH and controls. The method used to isolate mandibular asymmetry was found to be valid and a suitable tool to evaluate facial asymmetry.

Interobserver variation of single-photon emission computed tomography bone scans in patients evaluated for unilateral condylar hyperactivity.

OBJECTIVE: This study assessed the quantitative evaluation of the region of interest (ROI) by mean and maximum pixel counts of single-photon emission computed tomography (SPECT) scans in patients with clinical suspicion of unilateral condylar hyperactivity (UCH); the interobserver reliability and the correlation of condylar activity with patient age was determined. METHODS: Two independent observers analyzed 67 bone SPECT scans. Maximum and mean activity values within an ROI on the mandibular condyle were analyzed; a cutoff value of 55% was used to determine the qualitative outcome. RESULTS: Excellent interobserver agreement was seen for both maximum (kappa 1.0) and mean activity analysis (kappa 0.94). Maximum and mean condylar activities were strongly correlated (r > 0.98). Maximum and mean condylar activity of the normal condyle decreased significantly with increasing age. CONCLUSIONS: Maximum and mean condylar activity levels were highly correlated in patients with mandibular asymmetry. An excellent interobserver agreement was found with either maximum or mean condylar activity.