Dental anomalies in craniofacial microsomia and condylo-mandibular dysplasia: A retrospective study of 103 patients.

INTRODUCTION: Craniofacial microsomia (CFM) and camel-hump condylo-mandibular dysplasia (CMD) are developmental disorders affecting the mandible that share common clinical features. This study aimed to investigate and compare the dental anomalies (DA) between the two entities for differential diagnosis and to propose appropriate treatment. METHODS: This retrospective cross-sectional study was based on panoramic radiographs of patients diagnosed with CFM or CMD. DA were evaluated using the classification reported by Bilge. Delayed tooth eruption on the affected side was noted based on a comparison with the contralateral side. Nolla's stages of tooth calcification were used to assess dental development. RESULTS: A total of 103 patients were included, 80 subjects (77.7 %) in CFM group and 23 patients (22.3 %) in CMD group. The prevalence of DA among CFM and CMD-affected patients were 80.0 % and 95.7 %, respectively. Tooth ectopia, tooth impaction, dental development delay, and delayed tooth eruption on the affected side exhibited a significant association with the two craniofacial malformations. The overall affected teeth (molars, premolars, canines) differed between the two craniofacial malformations. Dental abnormalities such as oligodontia, hyperdontia, dentin dysplasia, and anomalies of shape were seen only in subjects affected by CFM. CONCLUSION: DA were widely observed in patients with CFM and CMD. The global distribution of affected teeth differed between the two conditions and some DA were detected only in CFM patients. When clinical diagnosis remains uncertain, some specific radiological characteristics of DA can be used to differentiate CFM from CMD.

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

OBJECTIVES: 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. MATERIALS AND METHODS: 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. RESULTS: On the 38 condyles studied in 21 included patients (mean age 23.7 ± 3.9 years), a condylar height (CH) loss of 0.66 mm (p < 0,03) was observed, with no correlation with the degree of ramus lengthening (mean 13.3 ± 0.76 mm). Only one patient presented an occlusal relapse of Class II, but a 3.4 mm (28%) condylar diameter loss and a 33% condylar volume reduction with loss of 1 mm and 3.4 mm in CH and condyle diameter, respectively. A mean 3.56 mm (p < 0.001) decrease in ramus height was noted, mainly due to bone resorption in the mandibular angles. CONCLUSION: This study confirms the overall stability obtained with IORVLO for the correction of PVI. CLINICAL RELEVANCE: This study aims to precise indication of IORVLO, and to validate the clinical and anatomical stability of results.

Stability of Le Fort 1 osteotomy in patients with bilateral cleft lip and palate: A retrospective study of 71 patients.

The aim of this study was to evaluate the sagittal and vertical relapses after Le Fort 1 osteotomy in bilateral cleft lip and palate (BCLP) patients. Lateral cephalograms before surgery, immediately after the procedure, at one year, and at least two years (when available) after surgery were superimposed. The positions of five landmarks were studied in a coordinate system. Uni- and multivariate analyses investigated the effect of various factors on the relapse. Of the 71 patients included for a BCLP, 54 presented complete data at one year, and 30 patients were included for the long follow-up study (mean of 55 months). The mean maxillary advancement was 6.2 mm on the sub-spinal point (A). Sagittal relapse occurred at one year (mean of 1.1 mm on point A, 0.7 mm on point prosthion (P); p < 0.0001) and progressed by 0.5 mm and 1.0 mm, respectively, on the same points at the last follow-up. The mean vertical relapse was 0.5 mm on point A (p = 0.044), 0.6 mm on point P (p = 0.16) and 0.5 mm on incisor (I) (p = 0.056). The vertical relapse was correlated to the degree of vertical movement. Three factors were associated to the recurrence including a prior pharyngeal flap, an associated mandibular osteotomy and smoking habits.

Alveolar bone changes in the mandibular incisors after genioplasty, a three-dimensional study.

INTRODUCTION: Functional genioplasty aims to achieve lip competence at rest and reduces lip pressure against the mandibular incisors. The purpose of this study was to describe the radiographic changes in alveolar bone of the mandibular incisors after functional genioplasty. MATERIALS AND METHODS: Cone beam CT images from 36 patients were compared between immediate (T0) and delayed postoperative period (T1). The mean time to complete the second imaging was 10.9 ± 4.7 months. Dental and bone parameters were assessed: the vestibular bone height (BH), the bone thickness (BT) with regard to the apex of the central incisor (BT2) and at equidistance between the cementoenamel junction and the dental apex (BT1). The existence of fenestrations, the apical-root resorption and the incisor-mandibular plane angle (IMPA) were also collected. RESULTS: No significant change occurred in the BH. BT was improved of a mean 47.9% and 53.6% at the BT1 level on #31 and #41, respectively (p1=0.01 and p2=0.02, respectively); and of 53.0% at the level of the apex of both mandibular central incisors (p1=0.003 on #31 and p2=0.009 on #41). No difference in the number of fenestrations was observed between T0 and T1. A significant decrease in the root length on both mandibular incisors was observed on the delayed CBCT (from 21.96 ± 1.35 to 21.68 ± 1.32 mm for #31, p=0.0007; from 22.26 ± 1.66 to 21.96 ± 1.48 mm for #41, p=0.002). Finally, the IMPA remained stable between the two examinations with a mean 106.1 ± 7.38° vs 105.8 ± 6.51° (p=0.38). CONCLUSION: Functional genioplasty favours the alveolar bone formation of the mandibular central incisors, probably by direct bone grafting, but also by the relaxation of the perioral and chin musculature.

Long-term vertical stability of horseshoe osteotomy for the correction of large vertical excess of the maxilla, a retrospective assessment in 15 patients.

INTRODUCTION: Vertical stability after a Le Fort I (LF1) osteotomy with substantial upward movement can be compromised by the position and the volume of the inferior turbinate. A horseshoe (HS) osteotomy represents then an alternative as it preserves the hard palate and the intranasal volume. The aim of this study was to assess the vertical stability of the maxilla after HS osteotomy. MATERIALS AND METHODS: Patients who underwent a HS osteotomy for the correction of long-face syndrome were retrospectively analyzed. The vertical stability was assessed on lateral cephalograms performed preoperatively (T0), immediately postoperatively (T1), and at the last follow-up (T2) by studying points C (the distal cusp of the first maxillary molar), point P (the prosthion, the lowest edge of the maxillary alveolus of the central incisor), and point I (the upper central incisor edge) in a coordinate system. Postoperative complications and aesthetics of the smile were also investigated. RESULTS: Fifteen patients were included (7 females, 8 males, mean age 25.5 ± 9.8 yeras). The mean impaction ranged from 5 mm on point P to 6.1 mm on point C, with a maximal movement of 9.5 mm. A non-significant relapse of 0.8 ± 1.7, 0.6 ± 0.8, and 0.5 ± 1.8 mm was observed after a mean 20.7 months on point C, P, and I respectively. Smile parameters were significantly improved by the procedure, mainly regarding the correction of the gum smile. CONCLUSION: HS osteotomy represents a good alternative to total LF1 osteotomy for substantial maxillary upward movement in long face syndrome deformities.

Surgical Repositioning of the Premaxilla: Incidence, Indications and Growth Study About a 189 Bilateral Cleft Lip ± Palate Population.

OBJECTIVE: We aimed to evaluate the rate of patient requiring Surgical Repositioning of the Premaxilla in a population carrying BCL ± P, retrieve age and operative indication. Our secondary objective was to present further facial growth characteristics. SETTINGS: This was a retrospective, single-center cohort study conducted in Nantes University Hospital, Oral and Maxillofacial Surgery department, tertiary cleft center. PATIENTS: Patients with BCL ± P born between 1980 and 2019 treated at Nantes University Hospital were included. MAIN OUTCOME MEASURE: Our primary outcome measure was the rate of patient requiring SRP. RESULTS: Over the whole period, 189 patients with BCL ± P were identified. Three patients (1,58%) underwent SRP. Patients who underwent SRP all had BCLP. SRP was performed during their primary dentition period. The indication for surgical repositioning was always premaxilla vertical overgrowth with an overbite over 10 mm. Facial growth features in the three patients were mostly comparable with a population carrying BCLP who had no premaxillary surgery. CONCLUSION: Our results showed a low incidence of SRP. No SRP was necessary during early infancy (ie, before lip repair) or during adulthood. Surgical repositioning of the premaxilla is beneficial for patient with orthodontically uncorrectable vertical premaxillary excess, even more since facial development compared with other patients with BCLP appears comparable.

Alveolar bone changes after tooth-borne surgically assisted rapid maxillary expansion: A three-dimensional study.

INTRODUCTION: Surgically assisted rapid maxillary expansion (SARME) with a dental-anchorage appliance can induce dental and skeletal complications adjacent to the teeth supporting the device. The purpose of this study was to quantify the dentoskeletal changes observed after SARME using a tooth-borne device. MATERIALS AND METHODS: Cone beam CT images from 39 patients were compared between the preoperative (T1) and the postoperative period (T2). The mean time to complete the second imaging was 13.8 ± 6.9 months after the SARME. Dental and bone parameters were assessed: the vestibular bone height (BH), the bone thickness (BT), the existence of fenestrations, and the root resorption at the level of first upper premolar (P1) and the first upper molar (M1). The maxillary expansion parameters were also collected. RESULTS: Both vertical and horizontal vestibular bone loss were observed mainly in the first upper molar sectors: The BT decreased from 0.93 ± 0.50 mm to 0.53 ± 0.51 mm (p < 0.0001) and the BH decreased from 1.84 ± 1.05 mm to 0.93 ± 1.02 mm (p < 0.0001) for tooth #16. The bone loss also affected the first upper premolars but in a more limited manner. Significant fenestrations were observed at the apex of the mesio-vestibular root of teeth #16 and #26. We noted significant root resorption affecting the mesio-, disto-vestibular and palatal roots of tooth #16 (mean reductions of 0.32, 0.35, and 0.55 mm, respectively; p < 0.05), and the palatal root of tooth # 26 (loss of 0.58 mm; p = 0.004). The mean bone expansion was 3.76 mm and 1.41 mm at the premolar and molar levels, respectively (p < 0.0001), while a mean 6.24 mm and 4.23 mm inter-cuspid expansion was noted at the P1 and M1 levels (p < 0.0001). CONCLUSION: Our results document the vestibular bone changes and low root resorption, mostly in the molar sectors, associated with SARME using dental-anchorage devices.

Impact of Orthodontic Gap Closure versus Prosthetic Replacement of Missing Maxillary Lateral Incisor on Dental Arch Relationships and Symmetry in 212 Patients with Cleft Palate: Retrospective Study.

BACKGROUND: Maxillary lateral incisors are frequently missing in patients with cleft lip and/or palate. The aim of this study was to assess how orthodontic gap closure or prosthetic rehabilitation of the missing maxillary lateral incisor affected dental arch relationships and symmetry at the end of treatment. The authors also aimed to determine the effect of the level of oral hygiene on the decision made to manage the missing maxillary lateral incisor gap. METHODS: A descriptive, retrospective cohort study including all patients with cleft lip and/or palate born between 1980 and 1999 and treated at Nantes Cleft Center was performed. Patients presenting unilateral or bilateral missing maxillary lateral incisors were reviewed. Data on management of the missing incisor gap, dental arch relationships, symmetry, and level of oral hygiene were collected. RESULTS: A total of 486 patients with cleft lip and/or palate were reviewed, including 212 patients with unilateral or bilateral missing maxillary lateral incisors. When compared with orthodontic gap closure, prosthetic replacement of the gap was associated with better final dental arch relationships (59.8 percent versus 10.3 percent; p < 0.01) and better dental arch symmetry (88.1 percent versus 44.0 percent; p < 0.01) for patients with unilateral missing incisors but not for patients with bilateral missing incisors. A higher level of oral hygiene was associated with more cases of prosthetic replacement for patients with unilateral missing incisors ( p = 0.03) but had no effect for patients with bilateral missing incisors. CONCLUSION: Prosthetic replacement of the missing maxillary lateral incisor gap provided better functional and aesthetic results for patients with cleft lip and/or palate presenting with unilateral missing maxillary lateral incisor.

Outcomes of functional treatment of condylar mandibular fractures with an articular impact: a retrospective study of 108 children.

INTRODUCTION: The treatment of fractures of the mandibular condylar process remains controversial, especially in children. The aim of this study was to assess the long-term clinical and radiographic outcomes of functional treatments for mandibular condylar fractures with an articular impact. MATERIALS AND METHODS: Young patients (< 15 years of age) presenting with either a unilateral or a bilateral mandibular fracture of the condylar process were included in this retrospective study. The clinical analysis focused on investigation of joint amplitudes at 1, 2, 6, 12, and 24 months after the beginning of the treatment, and at the end of their physical growth for the long-term study. Other clinical parameters included temporomandibular joint (TMJ) disorders and facial asymmetry. Photographs of patients and panoramic X-rays were assessed to identify any growth disorders at the end of the follow-up. RESULTS: One hundred and eight patients were included in this study, and 33 patients who were no longer undergoing mandibular growth at the time of the last follow-up were included in the long-term study. The mean age at the time of the trauma was 9.33 years, and the mean follow-up was 82.2 months. A significant improvement was observed in the maximal mouth opening (MMO), diduction, and propulsion in the first months after the trauma, reaching 44.31 mm (p < 0.0001), 10.50 mm (p = 0.0001), and 6.33 mm (p = 0.01), respectively, at 6 months. Three patients experienced a clinical posterior vertical insufficiency, one of which required a surgical procedure, while four patients exhibited a ramus asymmetry of up to 10 mm, albeit with no clinical consequences. One case of TMJ ankylosis was noted. CONCLUSION: Our study suggests that functional treatment is appropriate for fractures of the mandibular condyle with an articular impact in children, as it promotes mandibular growth and good functional recovery. Children have to be followed up, however, until completion of growth.

Evaluation of vertical ramus osteotomy for the surgical correction of unilateral mandibular posterior vertical insufficiency: Long-term follow-up results.

PURPOSE: Unilateral posterior vertical insufficiency (PVI) is a growth defect of the mandibular condyle that results in a facial asymmetry. Various surgical procedures can be used to elongate the hypoplastic ramus. The aim of this study was to evaluate long-term aesthetic and architectural outcomes of vertical ramus osteotomy (VRO) in patients with unilateral PVI. MATERIALS AND METHODS: Patients operated on with unilateral VRO were included in this retrospective study. Aesthetic and architectural parameters were evaluated on frontal photographs as well as on frontal and lateral cephalograms preoperatively, postoperatively, at 1-year and at the end of the follow-up. RESULTS: A total of 48 patients were analyzed. The aesthetic assessment revealed significant correction of the chin deviation (CD) and of the lip commissural line tilt after VRO (p1 = 0.0038 and p2 = 0.0067, respectively) with stable results. The architectural analysis revealed significant improvement in the maxillary and mandibular occlusal planes, as well as the chin deviation (p < 0.0001). A tendency to relapse was noted for the mandibular canting and the CD during the follow-up. VRO allowed for a mean mandibular lengthening of 8.39 mm (ranging from 2.5 to 14 mm). CONCLUSION: VRO allows for immediate restoration of the symmetry of the lower third of the face in patients with unilateral PVI. A revisional procedure may be needed due to a tendency for the chin deviation to relapse.

Structural comparison of hemifacial microsomia mandible in different age groups by three-dimensional skeletal unit analysis.

PURPOSE: The goal of this study was to understand the three-dimensional (3D) structural characteristics of hemifacial microsomia (HFM) mandible in terms of skeletal units, especially to locate the underdeveloped skeletal regions for treatment. Another goal was to compare the HFM structure of different age groups to understand growth potential relevant to treatment scheduling. MATERIALS AND METHODS: We reconstructed 3D mandibles from computed tomographic images of French and Korean patients with HFM (N = 28; group II) and normal subjects (N = 27; group I). Each mandible was classified by Pruzansky's HFM types I, II and III, and by age group (child, adolescent, and adult). The mandible was divided into skeletal units, and geometrical representation by skeletal unit line was performed, including the condylar, body, coronoid, and angular units. Their length and angulations were measured and statistically analyzed. RESULTS: The results showed that the affected condylar unit in type II HFM and the condylar/coronoid unit in type III were smaller in young age groups than were other units. The angulation between the skeletal units in type II, though not type III, tended toward normalcy with age, but not to the normal degree of angulations in group I. CONCLUSION: Our study shows the major involvement of condylar unit and minor involvement of body unit for HFM, improving with age in type II. The mandibular skeletal unit analysis seems to be a useful tool for individualized diagnosis, allowing identification of the major etiopathogenic area and treatment planning, including a simulation to set up a regimen for successful reconstruction of HFM.

Familial autosomal dominant severe ankyloglossia with tooth abnormalities.

Ankyloglossia is a congenital oral anomaly characterized by the presence of a hypertrophic and short lingual frenulum. Mutations in the gene encoding the transcription factor TBX22 have been involved in isolated ankyloglossia and X-linked cleft palate. The knockout of Lgr5 in mice results in ankyloglossia. Here, we report a five-generation family including patients with severe ankyloglossia and missing lower central incisors. Two members of this family also exhibited congenital anorectal malformations. In this report, male-to-male transmission was in favor of an autosomal dominant inheritance, which allowed us to exclude the X-linked TBX22 gene. Linkage analysis using short tandem repeat markers located in the vicinity of LGR5 excluded this gene as a potential candidate. These results indicate genetic heterogeneity for ankyloglossia. Further investigations with additional families are required in order to identify novel candidate genes.

Progressive Atrial Conduction Defects Associated With Bone Malformation Caused by a Connexin-45 Mutation.

BACKGROUND: Inherited cardiac conduction disease is a rare bradyarrhythmia associated with mutations in various genes that affect action potential propagation. It is often characterized by isolated conduction disturbance of the His-Purkinje system, but it is rarely described as a syndromic form. OBJECTIVES: The authors sought to identify the genetic defect in families with a novel bradyarrhythmia syndrome associated with bone malformation. METHODS: The authors genetically screened 15 European cases with genotype-negative de novo atrioventricular (AV) block and their parents by trio whole-exome sequencing, plus 31 Japanese cases with genotype-negative familial AV block or sick sinus syndrome by targeted exon sequencing of 457 susceptibility genes. Functional consequences of the mutation were evaluated using an in vitro cell expression system and in vivo knockout mice. RESULTS: The authors identified a connexin-45 (Cx45) mutation (p.R75H) in 2 unrelated families (a de novo French case and a 3-generation Japanese family) who presented with progressive AV block, which resulted in atrial standstill without ventricular conduction abnormalities. Affected individuals shared a common extracardiac phenotype: a brachyfacial pattern, finger deformity, and dental dysplasia. Mutant Cx45 expressed in Neuro-2a cells showed normal hemichannel assembly and plaque formation. However, Lucifer yellow dye transfer and gap junction conductance between cell pairs were severely impaired, which suggested that mutant Cx45 impedes gap junction communication in a dominant-negative manner. Tamoxifen-induced, cardiac-specific Cx45 knockout mice showed sinus node dysfunction and atrial arrhythmia, recapitulating the intra-atrial disturbance. CONCLUSIONS: Altogether, the authors showed that Cx45 mutant p.R75H is responsible for a novel disease entity of progressive atrial conduction system defects associated with craniofacial and dentodigital malformation.

Efficacy of proportional condylectomy in a treatment protocol for unilateral condylar hyperplasia: A review of 73 cases.

INTRODUCTION: Unilateral condylar hyperplasia (UCH) is characterized by an excessive growth of a mandibular condyle, resulting in facial, and occlusal deformities. Scintigraphic hyperactivity usually triggers the need of condylectomy. Delaire has presented a protocol for the treatment of active or non-active UCH using systematically a proportional condylectomy, which could solve both aetiology and adaptive deformities. The aim of this study was to evaluate this protocol by clinical and radiographical analysis. MATERIALS AND METHODS: Seventy-three patients with UCH were included in this retrospective study, and divided by clinical and cephalometric analysis in vertical, or transversal forms of UCH according to Delaire's classification. All patients were treated with 'proportional condylectomy', any indicated orthognathic procedures, along with maxilla-mandibular elastic therapy, and rehabilitation. Architectural, aesthetical, occlusal, and functional features were evaluated using clinical, cephalometric, and photographic measurements both preoperatively, and at the end of the follow-up. RESULTS: A female predominance was observed (65.8%). Vertical forms were more represented than transversal forms (61.6% versus 38.4%). There was a significant improvement of the occlusal plane, the posterior vertical excess, the chin deviation and the soft-tissue features (p < 0.0001), regardless of the preoperative scintigraphic activity status (p < 0.0001). The occlusion, and temporo-mandibular joint (TMJ) functions was considered as normal in respectively 72.7%, and 93% of the patients. CONCLUSION: The results of this study have demonstrated that a protocol using a 'proportional condylectomy', any indicated orthognathic techniques, maxilla-mandibular elastic therapy, and rehabilitation, is a reliable option for treating UCH, regardless the activity status of the pathology.