Classification of Skeletal Phenotypes of Adult Patients With Cleft Skeletal Class III Malocclusion Using Principal Component Analysis and Cluster Analysis.

The purpose of this study was to classify the skeletal phenotypes of adult patients with skeletal class III (C-III) malocclusion and unilateral or bilateral cleft lip and palate using principal component analysis and cluster analysis. The samples consisted of 81 adult C-III patients with cleft lip and palate (CLP) who underwent orthognathic surgery (OGS) or distraction osteogenesis (59 males and 22 females; 50 unilateral cleft lip and palate and 31 bilateral cleft lip and palate; mean age when lateral cephalograms were taken, 22.2±4.6 y). Thirteen angular and one ratio cephalometric variables were measured. Using 4 representative variables obtained from principal component analysis (SNA, SNB, Gonial angle, and Bjork sum), K-means cluster analysis was performed to classify the phenotypes. Then, statistical analysis was conducted to characterize the differences in the variables among the clusters. Five clusters were obtained from 3 groups: severely retrusive maxilla and moderately retrusive mandible group: cluster-1 (23.5%, severely hyperdivergent pattern), cluster-4 (27.2%, moderately hyperdivergent pattern), and cluster-5 (11.1%, normodivergent pattern); moderately retrusive maxilla and normal mandible group: cluster-2 (30.9%, normodivergent pattern); normal maxilla and moderately protrusive mandible group: cluster-3 (7.4%, normodivergent pattern). Although skeletal phenotypes were diverse, distribution of sex and cleft type did not differ among 5 clusters ( P >0.05). Sixty-two percent of cleft patients showed a severely retrusive maxilla and moderately retrusive mandible (cluster-1, cluster-4, and cluster-5), which indicated that these are the main cause of skeletal C-III malocclusion in CLP patients who were treated with OGS. Therefore, it is necessary to consider presurgical orthodontic treatment and surgical planning based on the skeletal phenotypes of CLP patients.

Posterior airways and orthognathic surgery: What really matters for successful long-term results?

INTRODUCTION: Although it is well known that orthognathic surgery modifies the upper airways, it is still unclear which are the determining factors to achieve adequate and predictable results in all the patients regardless of the initial malocclusion type and satisfying all the traditional orthognathic treatment objectives. This study aimed to correlate airway changes with surgical movements and other variables and the planning modalities to better understand how to control airway dimensions with treatment. METHODS: This study involved 61 patients requiring bimaxillary surgery to correct various dentoskeletal deformities without a history of obstructive sleep apnea syndrome. In all the subjects, the orthosurgical treatment was planned according to the same treatment principles and regardless of the initial airway dimension. The 3-dimensional volume and minimal axial area values generated by cone-beam computed tomography at the preoperative, 3-week, and 1-year postoperative controls were evaluated and correlated with surgical movements and other variables. RESULTS: Although the planning did not consider the initial size of the airways, a significant increase was found for volume and minimal axial area in both the short term (volume, 29.0%; area, 51.2%) and long term (volume, 18.2%; area, 39.8%) with no regard to the type of malocclusion. Only 3 of the variables examined were found to significantly affect the airway: the preoperative dimensions, gender, and the extent of mandibular advancement. These 3 explanatory variables combined can predict the 1-year postoperative volume and minimal area with an accuracy of 71% and 44%, respectively. CONCLUSIONS: According to this study, orthosurgical treatment can protect airways from unexpected unfavorable changes and satisfy the other treatment goals regardless of the initial malocclusion as long as the facial deformities are properly addressed for each patient. Furthermore, these results identified 3 main variables that influence postoperative airways dimensions the most. Keeping in mind that the relationship between airway dimensions and obstructive sleep apnea syndrome is not clearly explained, these considerations may prove to be a useful tool to help in preventing and managing this disease. Studies involving larger samples of patients and evaluating more variables are mandatory to better understand the correlation between airways and sleep function.

Evaluation of stylohyoid complex in subjects with different types of malocclusions using cone-beam computed tomography: a retrospective study in a Turkish subpopulation.

PURPOSE: According to the functional matrix theory, the development of maxillomandibular complex may be affected by the surrounding tissues. The aim of this study was to evaluate the length and angulation of the styloid process in different types of malocclusions using cone-beam computed tomography (CBCT). METHODS: Angulations and length of the styloid process were evaluated in CBCT images of 97 individuals retrospectively. The patients were classified as class I, II, and III groups according to sagittal skeletal classes. The mean length, anterior angulation, and medial angulation of the styloid process were analyzed. Statistical significance was evaluated at p < 0.05. RESULTS: The mean styloid process length in group class III was found to be significantly longer than class I (p: 0.035). Anterior angle was significantly higher in class III group than in other groups (p < 0.05). No statistically significant difference was found in medial angle between the groups (p: 0.506). CONCLUSION: According to present findings, class III malocclusion is associated with the stylohyoid complex morphology due to longer styloid process lengths and higher anterior angle values.

Cleft Palates and Occlusal Outcomes in Pierre Robin Sequence.

OBJECTIVE: To assess the dental class occlusion and lateral cephalometry of children with conservatively treated Pierre Robin sequence (PRS) and to identify associations between these findings and prepalatoplasty cleft palate measurements. STUDY DESIGN: Retrospective cohort study. SUBJECTS AND METHODS: Among 22 patients with PRS, the following data were prospectively collected: demographics and preoperative cleft palate measurements. After patients reached age 6 years, an orthodontist assessed dental occlusion class and performed a lateral cephalometric analysis. PRS cephalometric data were compared with reference population values. Bivariate logistic regression was used to test the association with malocclusion class. Results are presented as odds ratios with 95% profile likelihood confidence intervals. The association between cleft measurements and cephalometric parameters was tested with Spearman's correlation ( rs). RESULTS: All 22 patients had bimaxillary hypoplasia and were prone to hyperdivergency, with a 41% rate of dental class III malocclusion. An increased anterior growth of the still retrusive mandible mostly accounts for the occurrence of the class III malocclusion in PRS (class II SNB = 74.3° vs class III SNB = 77.6°, P = .04). A larger cleft at the time of the cleft repair (mean, 11 months) was associated with increased mandibular retrusion (smaller SNB angle, rs = -0.5, P = .02). CONCLUSIONS: The 41% rate of class III malocclusion among these conservatively treated patients needs to be considered in the choice of the initial airway approach. The future impact of early mandibular advancement will have to be determined.

Orthognathic surgery in "older" adults with Hemi-Mandibular Elongation: Long-term occlusion outcomes.

PURPOSE: The purpose of this study was to describe a consecutive series of subjects with HME who underwent orthognathic correction after 26 years of age. The investigators hypothesized that for this group of HME subjects, bimaxillary orthognathic correction would result in a favorable initial and long-term occlusion. MATERIALS AND METHODS: A retrospective cohort study was implemented. The sample included a consecutive series of HME subjects >26 years of age undergoing bimaxillary osteotomies. The outcome variables were the achievement and maintenance of a corrected occlusion after surgery. We compared the occlusion at intervals before surgery (T1), 5 weeks postoperatively (T2), >2 years after surgery (T3). Descriptive and bivariate statistics were calculated. P < 0.05 was considered significant. RESULTS: 13 subjects met inclusion criteria with a mean age of 36 years. All subjects underwent maxillary advancement. All subjects underwent mandibular surgery with 92% receiving advancement. Sixty-nine percent of subjects had a maxillary occlusal cant. In 12 of 13 subjects, a favorable occlusion was maintained long-term (T3) after surgery. CONCLUSION: We confirmed that bimaxillary orthognathic surgery in HME subjects >26 years of age results in a favorable initial occlusion which is maintained long-term. These findings are similar to that previously reported in HME subjects <26 years of age.

Camouflage treatment of skeletal Class III malocclusion in an adult cleft-palate patient using passive self-ligating system.

This case report describes the successful camouflage treatment to correct a moderate skeletal Class III malocclusion in a 19-year-old male cleft-palate patient. Early closure of the palate produced palatal scar tissue that inhibited midfacial growth, causing maxillary arch deficiency, severe maxillary crowding, and anterior and posterior crossbites. Combined surgical-orthodontic therapy would have been the preferred treatment of choice; however, the patient declined this option because of surgical risks and costs. Therefore, nonextraction camouflage treatment using a passive self-ligating bracket system was used. Treatment aims including expansion of the maxillary arch and correction of the anterior and posterior crossbites were achieved without the use of an additional maxillary arch expander or other auxiliary appliances. This treatment resulted in satisfying facial esthetics and a normal dental occlusion.

Achondroplasia: Orocraniofacial Features and Orthodontic-Surgical Management Guidelines Proposal.

In this study, the authors aimed to describe orocraniofacial features and to suggest orthodontic-surgical managements in achondroplasia, based on a literature review. The authors focused on skeletal and dentoalveolar malocclusion in order to highlight the place of orthognathic surgery, based on our experience of 3 patients. Maxillary hypoplasia in achondroplasia typically results in an Angle class III malocclusion with an anterior open bite. The other orocraniofacial features include enlarged calvarium, prominent forehead and frontal bossing, midface hypoplasia, elongated lower face and saddle-shaped nose due to lack of development of the nasomaxillary complex.All our patients had a typical facial appearance but each of them had their own particularities regarding medical history and severity of the dentoskeletal dysmorphosis. Two of them were successfully treated by orthognathic surgery; the other declined surgical treatment and underwent orthopedic treatment only (anchorage plates). The treatment failure of this 3rd patient raises the question of the efficiency of anchorage plates in achondroplasia. In the light of the literature and our results, the authors conclude the need for personalized management based on age, medical history, severity of the dentoskeletal dysmorphosis, functional and/or esthetic disorders, and the patient's needs and requests. In any patient, orthodontic management should be initiated at an early age, and orthognathic surgery modalities should be personalized and adapted to each situation.

[Mandibular asymmetry: determination of a reliable skin measurement technique]. / Latéromandibulie : détermination d'une mesure cutanée fiable.

INTRODUCTION: Clinical measurements in the frontal view underevaluate chin deviation in mandibular asymmetry. The aim of this descriptive study is to search for a reliable method of measuring deviant chins using a facial X-ray as reference. MATERIAL AND METHOD: Seventy patients with mandibular asymmetry who had consulted a maxillofacial surgeon were systematically included. Age, sex, cephalometric characteristics, reasons for patient consultation and type of surgery were collected. Two cephalometric methods were tested with respect to the medial sagittal plane (PSM) to compare the assessment of mandibular asymmetry on soft tissue and by cephalometry. RESULTS: On average, the patients selected were young (26 years +/- 9), women (75% of cases), presented open bite (average FMA: 28° +/- 8°), a skeletal class III tendency, a left-side shift of the chin (63% of cases). They consulted for both aesthetic and functional reasons (51% of cases) and required bimaxillary surgery (66% of cases). Comparison between the photographic angle (formed by the PSM and the line passing through the nasion and reaching the chin point) and the radiographic angle (formed by the PSM and the line passing through the Crista Galli process and the bony chin point angle) showed no significant difference (p = 0.937) and is thus reliable.

Gender differences in morphological and functional outcomes after mandibular setback surgery.

PURPOSE: The aim of this study was to examine and compare morphological and functional outcomes after either isolated mandibular setback or bimaxillary surgery in males and females. MATERIALS AND METHODS: A retrospective study was done on 52 patients, in whom surgical correction for mandibular prognathism was performed either by isolated mandibular setback (30 cases) or by bimaxillary surgery (22 cases). Morphological changes were studied using cephalograms and functional changes studied using impulse oscillometry (IOS) taken before surgery (T0), 3 months (T1) and 1 year after surgery (T2). Also 3% oxygen desaturation index (ODI) was measured at T0 and T2. RESULT: Posterior airway space decreased significantly in both groups and both sexes but more so in males after mandibular setback surgery and in females after bimaxillary surgery. Changes in supine R20 (central airway resistance at 20 Hz) and supine R5 (total airway resistance at 5 Hz) in IOS statistically significantly increased in the period T0-T1 in males compared with females after mandibular setback surgery (p < 0.05). CONCLUSION: Gender dimorphism is present according to morphological and functional outcomes, with males at a higher risk for obstructive sleep apnea (OSA) after mandibular setback surgery and females after bimaxillary surgery; however, compensatory changes act as a barrier against this.

Dental anomalies in different growth and skeletal malocclusion patterns.

OBJECTIVES: To evaluate prevalence, distribution, and sexual dimorphism of dental anomalies (DA) among different skeletal malocclusions (SM) and growth patterns (GP) under the hypothesis that specific clinical patterns exist and may indicate common etiological roots. MATERIALS AND METHODS: A total of 1047 orthodontic records of patients older than 8 years were evaluated. The SN-GoGn angle was used to classify GP (hypodivergent, normal, and hyperdivergent), and the ANB angle was used to verify SM (Angle Classes I, II, and III). These assessments were done from lateral cephalometric radiographs. DA were diagnosed using panoramic radiographs by one calibrated investigator. Odds ratios, chi-square, and Student's t-tests were used. RESULTS: Of the subjects, 56.7% were female, with mean age of 16.41 (±10.61) years. The prevalence of DA was 15.7%. Impaction and tooth agenesis were the most prevalent DA, with relative frequencies of 14.4% and 9.7%, respectively. DA were most prevalent in Class III SM (80.8%) and in hypodivergent GP (82.5%), although this was not statistically significant. Tooth agenesis ( P < .01) and microdontia ( P = .025) were significantly more common among hypodivergent GP and Class III SM, respectively. CONCLUSIONS: The results of this study support the idea that DA are preferentially associated with certain patterns of malocclusion.

Relationship Between Occlusal Features and Enzyme Replacement Therapy in Patients With Mucopolysaccharidoses.

PURPOSE: The aim of this study was to describe the relation between occlusal features and enzyme replacement therapy in patients with mucopolysaccharidoses. MATERIALS AND METHODS: A cross-sectional study was conducted. The sample consisted of 20 patients with mucopolysaccharidoses, 10 of whom were undergoing treatment at a hospital in northeast Brazil. Occlusal features were evaluated by clinical examination and panoramic radiography. A structured questionnaire was administered to evaluate the dental care of each patient. Pearson χ2, Fisher exact, and Mann-Whitney tests were used for data analysis, with a level of significance of 5%. RESULTS: Marked overjet (75%) and anterior open bite (70%) were the most frequent occlusal alterations, and 15% had Class III disorders. Radiography visualized the presence of impacted teeth (75%) and prolonged retention of deciduous teeth (65%). Patients with enzyme replacement therapy had a lower average maximum protrusion (P = .033). A total of 75% of mothers said they had not been advised to take their children to the dentist and 10% of children had never been to the dentist. CONCLUSION: Patients with mucopolysaccharidoses exhibited notable occlusal alterations, especially marked overjet and anterior open bite. Enzyme replacement therapy seems to influence the maximum protrusion of patients.

Effect of Long-Term Use of Facemask With Miniplate on Maxillary Protraction in Patients With Cleft Lip and Palate.

The purpose of this retrospective study was to investigate the effect of a long-term use of facemask with miniplate (FM-MP) on maxillary protraction in cleft lip and palate (CLP) patients. The subjects were 21 CLP patients (16 unilateral CLP and 5 bilateral CLP patients), who were treated with identical lip and palate surgical method and FM-MP therapy performed by single surgeon and single orthodontist. Lateral cephalogram was taken before (T1; mean age, 11.1 years) and after maxillary protraction (T2; mean age, 16.9 years). The mean duration of FM-MP was 68.0 months. After 17 cephalometric variables were measured, statistical analysis was performed. During T1-T2, the maxilla showed significant forward movement (ΔA-vertical reference plane, 4.8 mm, P < 0.001; ΔSNA, 1.9 degree, P < 0.001; ΔA-N perp, 1.9 mm, P < 0.05), although the mandible exhibited a forward growth (ΔSNB, 1.2 degree, P < 0.05). Despite downward movement of the posterior maxilla with counterclockwise rotation (Δpalatal plane angle, -1.5 degree, P < 0.05), the mandible did not exhibit clockwise rotation but counterclockwise rotation (ΔSN to mandibular plane angle, -1.4 degree, ΔBjork sum, -1.4 degree, Δocclusal plane to SN plane angle, -1.5 degree, ΔFMA, -1.0 degree, all P < 0.05) and showed decrease in Gonial angle (-1.2 degree, P < 0.01). Although there was labioversion of the maxillary incisor (ΔU1 to SN, 4.1 degree, P < 0.05), the mandibular incisor did not exhibit significant linguoversion (ΔIMPA, -1.3 degree, P > 0.05). Long-term use of FM-MP is effective on maxillary protraction in adolescent CLP patients without clockwise rotation of the mandible, the main drawback of conventional facemask with tooth-borne anchorage.

A Three-Dimensional Study of Midfacial Changes Following Le Fort II Distraction With Zygomatic Repositioning in Syndromic Patients.

Le Fort II distraction with zygomatic repositioning introduced the ability to restore central midfacial height and convexity independent of changes in orbital morphology. This study analyzes midfacial and orbital morphology before and after Le Fort II distraction with zygomatic repositioning.All patients who underwent Le Fort II Distraction with zygomatic repositioning between 2013 and 2015 were included. Two- and 3-dimensional measurements were made using 3dMD Vultus software to assess canthal tilt, nasolabial angle, ratio of midfacial to lower facial height, and absolute change in nasal length. Presence of an open bite and Angle classification were assessed before and after surgery.Four patients underwent segmental midface advancement using Le Fort II distraction with zygomatic repositioning. Associated diagnoses included Apert syndrome, Goldenhar syndrome, and achondroplasia. Changes in facial dimensions included: 3.19° improvement in canthal tilt (range -4.7° to 8.4°), 9° change in nasolabial angle (range -1.0° to 19°), and 0.69 cm increase in absolute nasal length (range 0.2-0.94 cm). Mean ratio of midfacial to lower facial height was 0.79 preoperatively and 0.89 postoperatively. Preoperatively, all patients demonstrated Angle class III with 3 of 4 patients demonstrating anterior open bite. All achieved closure of open bite and demonstrated class I or II occlusion. No complications were observed.Le Fort II distraction with zygomatic repositioning resulted in normalization of midfacial soft tissue landmarks. This form of advancement demonstrates the ability to selectively improve midfacial height and canthal tilt while restoring normal occlusion.

Condylar resorptions and orthodontic-surgical treatment: State of the art.

Resorption of the mandibular condyle [RMC] is a disease of the temporomandibular joints, with multifactorial origins. The clinical manifestations take the form essentially of joint pain and occlusal disorders, depending on the rate at which the condyle is affected. X-ray imaging shows that the condyle is reduced in volume, flattened and displaced backwards, with loss of cortical substance in advanced forms. The aim of this article is to recall some pathophysiological features and then to review all the diagnostic and etiological factors and discuss possible modes of management.

Long-Term Incisal Relationships After Palatoplasty in Patients With Isolated Cleft Palate.

PURPOSE: Various palatoplasty techniques have limited incisions in the hard palate due to concerns that these incisions may limit maxillary growth. There is little convincing long-term evidence to support this. Our purpose is to determine incisal relationships, an indicator for future orthognathic procedure, in patients after repair of an isolated cleft of the secondary palate. METHODS: Our craniofacial database was used to identify patients aged 10 years or greater with an isolated cleft of the secondary palate who underwent palatoplasty between 1985 and 2002. Data collected included age at palatoplasty and follow-up, cleft type, associated syndrome, Robin sequence, surgeon, repair technique, number of operations, and occlusion. Incisal relationship was determined through clinical observation by a pediatric dentist and orthodontist. RESULTS: Seventy eligible patients operated on by 9 surgeons were identified. Class III incisal relationship was seen in 5 patients (7.1%). Palatoplasty techniques over the hard palate (63 of 70 patients) included 2-flap palatoplasty, VY-pushback, and Von Langenbeck repair. There was an association between class III incisal relationship and syndromic diagnosis (P <0.001). Other study variables were not associated with class III incisal relationships. CONCLUSION: In patients with an isolated cleft of the secondary palate, there was no association between class III incisal relationship and surgeon, age at repair, cleft type, palatoplasty technique, or number of operations. Increased likelihood of class III incisal relationship was associated primarily with syndromic diagnosis.

Mandibular Body Resection and Setback for Severe Malocclusion in Lymphatic Malformations.

Extensive lymphangiomas of the facial skeleton result in deforming forces leading to ongoing masticatory, speech, oral hygiene, and airway problems. This paper presents a small series of patients with severe mandibular overgrowth secondary to lymphatic malformations. Following debulking of the malformations and tongue reductions, the authors describe the results of their treatment with bilateral mandibular body resections and setback. The authors' results suggest that severe functional impairment from deforming malformations can be addressed in childhood with orthognathic surgery. Improved occlusion, oral closure, and airway opening can be achieved using this procedure.

Effect of Secondary Alveolar Bone Grafting on the Maxillary Growth: Unilateral Versus Bilateral Cleft Lip and Palate Patients.

The purpose of this study was to investigate the effect of secondary alveolar bone grafting (SABG) on the maxillary growth in patients with unilateral (UCLP) and bilateral cleft lip and palate (BCLP). The samples consisted of 40 Korean boy cleft patients who had the similar initial skeletal characteristics and were treated with the identical treatment protocol. They were divided into UCLP group (N = 25; mean SABG age, 9.9 years; mean follow-up duration, 42.3 months) and BCLP group (N = 15; mean SABG age, 10.2 years; mean follow-up duration, 40.6 months). In the lateral cephalograms taken 1 month before (T1) and at least 2 years after SABG (T2), cephalometric variables were measured. At T1 stage, the 2 groups did not exhibit significant differences in the cephalometric variables except posterior maxillary height (P-HRP) (P < 0.05). At T2 stage, both groups exhibited the reduced sagittal growth (UCLP, ANB, P < 0.001; AB to facial plane angle (AB-FPA), P < 0.01; BCLP, A to N perpendicular, P < 0.05; ANB and AB-FPA, P < 0.001) and the undisturbed vertical growth (A-HRP and P-HRP, all P < 0.001) of the maxilla. During T1 to T2, BCLP group experienced more aggravation of Class III skeletal pattern than UCLP group (ΔAB-FPA, P < 0.05). There, however, were no differences in the amounts of changes in the maxillary vertical position and mandibular plane angulation between the 2 groups. Two-stage SABG procedure subgroup in patients with BCLP demonstrated a more retrusive maxilla compared with 1-stage SABG procedure subgroup (ΔSNA, P < 0.05). Patients with BCLP, especially who underwent 2-stage SABG procedure, might have a possibility of poor sagittal growth of the maxilla compared with patients having UCLP.

Influencia del patrón morfogenético en el crecimiento y desarrollo / Influence of morphogenetic pattern on growth and development

Se plantean dos situaciones clínicas de pacientes adultos, hermanos, que presentan la misma maloclusión (Clase III con desviación mandibular hacia la izquierda), distinto sexo y biotipos faciales diferentes. En ellos queda de manifiesto en qué manera el patrón facial de cada individuo es determinante en la génesis de una maloclusión, teniendo una influencia directa en el pronóstico y plan de tratamiento. Uno de los casos se resolvió ortodóncicamente, con un tratamiento de compensación y extracción asimétrica del elemento 44, al tiempo que en el otro se efectuó un tratamiento ortodóncico-quirúrgico.

Upper airway obstruction and resultant growth factors influencing malocclusions.

Upper airway obstruction is associated with many dental and skeletal malocclusions. Recognizing and removing the problems at an early age is encouraged. However, the malocclusions caused by upper airway obstruction can be addressed and corrected at different stages of dentitions using various types of appliances and orthodontic techniques. This article reports several cases, which were treated with the help of medical experts and otolaryngologists.