Treatment of a patient with a crowded Class I malocclusion and a congenitally missing mandibular incisor

This case report describes the management of maxillary and mandibular crowding in a patient with facial esthetic concerns and a tooth-size discrepancy due to a missing mandibular central incisor. The treatment included extracting the remaining mandibular central incisor and the 2 maxillary first premolars. The mandibular canines were repositioned to substitute for lateral incisors, and the mandibular premolars were used as canines.     

Prosthodontic rehabilitation of a patient with partial anodontia: a clinical report

This clinical report describes the prosthodontic rehabilitation of a 22-year-old female patient diagnosed with partial anodontia. A combined dental therapy approach was used and included endodontic therapy and a post-and-core buildup on the mandibular left canine, fabrication of a mandibular removable denture, and fabrication of maxillary fixed restorations. Canine-protected occlusion was developed in the final restorations to decrease lateral forces on the posterior dentition. Protrusive guidance was evenly distributed across the maxillary and mandibular incisors. Functional and esthetic results were achieved.     

两种拔牙模式矫治后相关平面的变化研究

目的研究拔除4颗第一前磨牙（上四下四）和拔除双侧上颌第一前磨牙和下颌第二前磨牙（上四下五）2种拔牙模式矫治前后腭平面、平面及下颌平面的变化。方法固定正畸矫治患者166例,拔除上四下四62例,拔除上四下五7 6例,不拔牙2 8例,测量矫治前后的腭平面角、咬合平面角和下颌平面角等项目。结果 2种拔牙模式患者腭平面和平面的变化差异无统计学意义;拔除上四下四矫治的均角型患者矫治后下颌平面角轻微增加（t=2.97,P〈0.05）;其余患者的改变差异没有统计学意义。结论拔除上四下四和拔除上四下五2种拔牙模式不会导致腭平面、平面的改变,拔除上四下四矫治的均角型患者下颌平面角轻微增加。     

Skeletal stability following bioresorbable versus titanium fixation in orthognathic surgery: a systematic review and meta-analysis

Despite developments in bioresorbable fixation over recent decades, controversy remains regarding skeletal stability following the use of this material in orthognathic surgery. This systematic review and meta-analysis investigated evidence from the international literature from studies comparing skeletal stability between bioresorbable and titanium fixation in orthognathic surgery. Key words were searched in MEDLINE, Embase, and Cochrane Library, and relevant journals and reference lists were searched for additional material, up to January 2017. Study quality was assessed with the Newcastle–Ottawa scale. The meta-analysis was performed using RevMan software. Ten cohort studies were included. The meta-analysis showed no statistically significant difference between bioresorbable and titanium fixation (SMD (95% CI)) for maxillary horizontal relapse (maxillary advancement 0.09 (?0.16 to 0.33); maxillary setback ?0.04 (?0.64 to 0.56)), maxillary vertical relapse (maxillary elongation 0.15 (?0.31 to 0.61); maxillary impaction ?0.30 (?1.10 to 0.50)), mandibular horizontal relapse (mandibular advancement 0.16 (?0.72 to 1.03); short-term mandibular setback ?0.33 (?0.82 to 0.15)), and mandibular angular relapse (mandibular clockwise rotation ?0.39 (?0.79 to 0.00); mandibular counter-clockwise rotation 0.14 (?0.37 to 0.66)). However, after mandibular setback, titanium fixation showed significantly less relapse in the long-term (0.97 (0.47 to 1.47)). With regard to skeletal stability, bioresorbable fixation is comparable to titanium fixation when used in maxillary setback and mandibular clockwise rotation; however titanium fixation may be preferable in mandibular setback. Further high-quality studies are needed to draw more definitive conclusions.     

Orthodontic treatment for an adolescent with a history of acute lymphoblastic leukemia

This case report describes the treatment of a Class I malocclusion that involved ectopic position of the maxillary permanent left canine and the mandibular permanent right second molar. The patient was an adolescent who presented with a medical history that was remarkable for diagnosis and treatment of acute lymphoblastic leukemia (ALL). Dental history was remarkable for significant, generalized shortened roots that were more severe in the mandibular arch. The treatment included fixed appliance therapy in the maxillary arch only and surgical luxation of the mandibular second molar. Successful integration of the maxillary permanent left canine was accomplished without excessive flaring of the maxillary permanent incisors or disruption of the buccal segment occlusion. The risk of external root resorption on teeth with abnormal root morphology, as a result of fixed appliance therapy, should be weighed against the relative benefits that are expected from treatment.     

Maxillary and mandibular width changes studied using metallic implants.

The purpose of this implant study was to evaluate the transverse stability of the basal maxillary and mandibular structures. The sample included 25 subjects between 12 and 18 years of age who were followed for approximately 2.6 years. Metallic implants were placed bilaterally into the maxillary and mandibular corpora before treatment. Once implant stability had been confirmed, treatment (4 first premolar extractions followed by fixed appliance therapy) was initiated. Changes in the transverse maxillary and mandibular implants were evaluated cephalometrically and two groups (GROW+ and GROW++; selection based on growth changes in facial height and mandibular length) were compared. The GROW++ group showed significant width increases of the posterior maxillary implants (P <.001) and the mandibular implants (P =.009); there was no significant change for the anterior maxillary implants. The GROW+ group showed no significant width changes between the maxillary and mandibular implants. We conclude that (1) there are significant width increases during late adolescence of the basal mandibular and maxillary skeletal structures and (2) the width changes are related with growth potential.     

Evaluation of dental arch width and form changes after orthodontic treatment and retention with a new computerized method.

The purpose of this study was to evaluate longitudinal arch width and form changes and to define arch form types with a new computerized method. Maxillary and mandibular models of 21 Class II Division 1 patients were examined before treatment (T(0)), after treatment (T(1)), and an average of 3 years after retention (T(2)). Arch width measurements were made directly on scanned images of maxillary and mandibular models. Arch form changes at T(0)-T(1) and T(1)-T(2) were evaluated by superimposing the computer-generated Bezier arch curves with a computer program. Types of dental arch forms were defined by superimposing them with the pentamorphic arch system, which included 5 different types of arch forms: normal, ovoid, tapered, narrow ovoid, and narrow tapered. Maxillary arch widths were increased during orthodontic treatment. Mandibular posterior arch widths were also increased. The expansion of the mandibular arch forms was less than in the maxillary arch forms. Arch width changes were generally stable, except for reduction in maxillary and mandibular interlateral, inter-first premolar, and mandibular intercanine widths. Pretreatment maxillary arch forms were mostly tapered; mandibular arch forms were tapered and narrow tapered. In maxillary arch forms, 76% of the treatment changes were maintained. Mandibular arch form was maintained in 67% of the sample, both during treatment and after retention. In mandibular arches, 71% of orthodontically induced arch form changes were maintained.     

Prosthetic rehabilitation of a mandibular gunshot defect with an implant-supported fixed partial denture: a clinical report

This report describes the clinical evaluation of a patient with a mandibular gunshot defect and the prosthodontic treatment with an implant-supported screw-retained fixed partial denture. Treatment included cemented crowns for 2 maxillary implants and an implant-supported screw-retained fixed partial denture supported by 8 mandibular implants. Despite the implant malposition limitations, the esthetic and functional demands of the patient were fullfilled.     

Incidence of patent furcal accessory canals in permanent molars of a Turkish population

Aim To determine the incidence of patent furcal accessory canals in permanent molars of a Turkish population. Methodology Two‐hundred extracted teeth consisting of 50 maxillary first molars, 50 maxillary second molars, 50 mandibular first molars and 50 mandibular second molars from Turkish patients attending the Oral Surgery Department of the Faculty of Dentistry, ?stanbul University, ?stanbul, Turkey, were included in the study. After preparation of access cavities and removal of pulp tissue, the teeth were stored in 5.25% sodium hypochlorite for 1 h. Following double‐sealing of the access cavities, all tooth surfaces except the furcation regions were covered with nail varnish. The teeth were stored in 0.5% basic fuchsin for 1 week. The teeth were sectioned at the cemento‐enamel junction and the presence of patent furcal canals was established by examining the pulp chamber floor with a stereomicroscope (10×) to determine staining. Results Patent furcal accessory canals were detected in 24% of maxillary first molars, 16% of maxillary second molars, 24% of mandibular first molars, and 20% of mandibular second molars. No statistically significant differences were found between the tooth types. Conclusions In a Turkish population, the incidence of patent furcal accessory canals on the pulp chamber floor of maxillary and mandibular first and second molars ranged between 16 and 24%.     

Skeletal and dental contributions to posterior crossbites

The objective of this retrospective study was to compare skeletal and dental arch morphology of children with posterior crossbites with a control group of children without posterior crossbites. The study included 93 patients with a posterior crossbite (33 boys and 60 girls) and 97 patients without a posterior crossbite (50 boys and 47 girls). Skeletal and dental characteristics between the two groups were compared using measurements of dental casts, and lateral and posteroanterior cephalograms. Univariate analyses revealed that seven characteristics were significantly different between the crossbite and non-crossbite groups: mandibular plane angle, lower face height, skeletal maxillary to mandibular width ratio, maxillary intermolar width, mandibular intermolar width, maxillary to mandibular intermolar width ratio, and mandibular unit length. Using maxillary to madibular intermolar width ratio as the outcome measure, a stepwise variable selection technique, analyzed all 190 patients and found only two variables significantly associated with this measure: skeletal maxillary to mandibular width ratio and lower face height. The coefficient of multiple determination for this model was only 13%, indicating that these two variables accounted for only a small portion in the variation of the ratio between the maxillary and mandibular intermolar widths.     

Long-term outcome in a patient with Class I malocclusion with severe crowding treated without extractions.

The treatment of a patient with a Class I malocclusion with significant skeletal transverse maxillary discrepancy and severe crowding is presented. The maxilla was narrow compared with the mandible, and the posterior teeth were compensated, with the maxillary teeth inclined buccally and the mandibular teeth inclined lingually. Treatment included rapid palatal expansion to correct the transverse maxillary deficiency and to gain arch length. Long-term follow-up (20 years) with a stable result is reported.     

Critical assessment of a device to measure incisor crown inclination.

The aims of this study were to critically assess the use of a disposable device--the tooth inclination protractor (TIP)--to record incisor crown inclination and to compare its reliability and validity with that of traditional cephalometric radiographic analysis. The sample comprised 30 dental students with lateral cephalometric radiographs and dental casts. Four examiners were trained and calibrated to digitize radiographs and to use intraoral (on patients and dental casts) and extraoral (on dental casts) TIPs. The following angles were measured on the radiographs: maxillary incisor to maxillary plane, mandibular incisor to mandibular plane, maxillary incisor to occlusal plane, and mandibular incisor to occlusal plane. Measurements were also made with the TIP: maxillary incisor to occlusal plane and mandibular incisor to occlusal plane. All techniques were reliable between examiners. There were statistically significant systematic differences between the TIP and the radiographic assessments. The following differences were found. The TIP tended to record maxillary incisor crown inclination an average of 14 degrees less than maxillary incisor to maxillary plane. The TIP tended to record mandibular incisor crown inclination as similar to mandibular incisor to mandibular plane. The TIP recorded mandibular crown inclination 19 degrees less than mandibular incisor to occlusal plane. The disposable TIP was shown to be a simple, inexpensive, reliable, and valid method of assessing incisor inclination.     

Growth analysis of a patient with ectodermal dysplasia treated with endosseous implants: a case report.

Congenital absence of multiple teeth and poorly developed alveolar ridges are associated with ectodermal dysplasia. Affected patients often require dental prosthetic treatment during their developmental years. Maxillofacial growth and development in a preadolescent female patient with ectodermal dysplasia following oral rehabilitation with maxillary and mandibular endosseous dental implants is reported. Four maxillary and 4 mandibular implants were successfully integrated and restored at 8 years of age. Growth analysis 12 years later revealed that the implants followed maxillary and mandibular growth displacement. Minor impaction of the maxillary implants was observed, and mandibular implants were affected by the mandibular growth rotation, which led to a change in implant inclination. The treatment outcome is compared to similar previously reported studies and cases.     

Skeletal components of class III malocclusions and compensation mechanisms

Summary  The aim of this retrospective study was to assess the skeletal characteristics of sagittal maxillary and mandibular discrepancies resulting in class III malocclusions and compensation mechanisms in one Caucasian European population (Croatian). The study sample included 107 patients (63 females and 44 males), aged between 11 and 18 years of age (mean age 14·6 ± 2·2), with a class III malocclusion. Forty-three angular and linear measurements were assessed from the pre-treatment lateral cephalographs of each subject. anova , Tukey post hoc and t -test were used for statistical analysis. The most common differential skeletal type was mandibular prognathism with a normal maxilla (43%), followed by maxillary retrognathism with a normal mandibular position (19·6%), while the combination of maxillary retrognathism and mandibular prognathism was found to be rare (<5%). Subjects with maxillary retrognathia, appeared to also have a vertical facial pattern, suggesting a tendency towards vertical growth as a possible compensation mechanism. Those with mandibular prognathia tended to exhibit a horizontal facial growth pattern and typically included more pronounced dento-alveolar compensation, that is, proclination of maxillary and retroclination of mandibular incisors. There were no differences observed in gender, overjet or soft tissue profiles between different sagittal skeletal types. Dominant protrusive mandible in Croatians can be related to European Caucasian ancestry, where this entity is historically described as 'Habsburg jaw'.     

The inter-relationship between mandibular autorotation and maxillary LeFort I impaction osteotomies

The purposes of the present investigation were to: 1)locate the instantaneous rotation center of mandible autorotation during maxillary surgical impaction; 2) identify the discrepancies between the resultant mandibular position following by maxillary surgical impaction and presurgical predictions, which use the radiographic condylar center as the rotation center for mandibular autorotation; and 3)find the interrelation between the magnitude of maxillary surgical impaction and the sagittal change of mandible. Ten patients underwent maxillary LeFort I impaction without concomitant major mandibular ramus split osteotomies were included. The preoperative (T0) and postoperative (T1) lateral cephalograms were used to evaluate the surgical changes and locate the center of rotation of mandibular autorotation with Reuleaux method. Prediction errors were measured by comparing the predicted (Tp) and postoperative (T1) cephalometric tracings. The magnitude of the maxillary surgical impaction was compared to the positional changes of mandible after mandibular autorotation with correlation and regression analysis. The results demonstrated that the centers of mandibular autorotation located 2.5 mm behind and 19.6 mm below the radiographic condylar center of the mandible in average with large individual variations. By using the radiographic condylar center of the mandible to predict the mandibular autorotation would overestimate the horizontal position of chin by 2 mm and underestimate the vertical position of chin by 1.3 mm following an average of 5 mm surgical maxillary impaction. The magnitude of maxillary impaction was highly and positively correlated to the horizontal displacement of chin position. The rotation centers of mandibular autorotation following by maxillary LeFort I impaction osteotomies might not usually locate at the radiographic condylar center of the mandible also with large individual variations in their positions. Surgeons and orthodontists should be aware of the horizontal and vertical discrepancies of chin positions while planning a two-jaw surgery by using the radiographic center of mandibular condyle as the rotation center in mandibular autorotation.     

Apical root displacement is a critical risk factor for apical root resorption after orthodontic treatment

Objectives:To identify risk factors for apical root resorption (ARR) of maxillary and mandibular incisors using mathematical quantification of apical root displacement (ARD) and multiple linear mixed-effects modeling.Materials and Methods:Periapical radiographs of maxillary and mandibular incisors and lateral cephalograms of 135 adults were taken before and after orthodontic treatment. ARR was measured on the periapical radiographs, and movement of central incisors was evaluated on the superimposed pre- and posttreatment lateral cephalograms. ARD was mathematically calculated from pretreatment tooth length, inclination change, and movement of the incisal edge. Linear mixed-effects model analysis was performed to identify risk factors for ARR, and standardized coefficients (SCs) were calculated to investigate the relative contribution of the risk factors to ARR.Results:Vertical ARD showed the highest SCs for both maxillary and mandibular incisors. Horizontal ARD showed the second highest SC for mandibular incisors but was not significantly correlated with the ARR of maxillary incisors. When horizontal and vertical ARDs were included in the mixed-effects model, the use of self-ligating brackets was significantly correlated with increased ARR of mandibular incisors.Conclusions:ARD is a critical factor for ARR after orthodontic treatment. Careful monitoring of ARR is recommended for patients requiring significant ARD of incisors.     

Macrodontia in association with a contrasting character microdontia

The dental, genetic, radiological and dermatoglyphic findings of a 19-year-old girl showing macrodontia of maxillary permanent central incisors in association with a contrasting character, microdontia of maxillary permanent lateral and mandibular primary central incisors and bilateral absence of maxillary first premolars and missing of the right mandibular second premolar and peg-shaped mandibular primary lateral incisors and canines were presented.     

The prosthodontic rehabilitation of malpositioned implants in a patient with basal cell carcinoma: a clinical report

This clinical report describes the prosthodontic rehabilitation of a patient with a partially edentulous maxilla and compromised mandibular anatomy caused by resection of bone due to basal cell carcinoma. Placement of a fibula bone graft was followed by placement of 2 implants. The implants were malpositioned in the anteroposterior plane due to the altered form of the alveolar bone. Prosthodontic treatment included a maxillary removable partial denture and a mandibular partial overdenture supported by implants and remaining teeth.     

An occlusal and cephalometric analysis of maxillary first and second premolar extraction effects

The purpose of this study was to examine dimensional changes in the maxillary arch following the extractions of maxillary first or second premolars. Pre- and posttreatment records of 71 patients treated by one experienced orthodontist were randomly selected from completed premolar extraction cases. Forty-five patients involved the extraction of maxillary first premolars; of these, 15 also had extractions of mandibular first premolars and 30 had extractions of mandibular second premolars. Twenty-six patients involved the extraction of maxillary second premolars, and all of these also had extractions of mandibular second premolars. Pretreatment factors that seemed to suggest a basis for the extraction choice in this sample included incisal overjet, molar relationship, and maxillary incisor protrusion. Mean reductions with treatment in the anteroposterior arch dimension were similar within all premolar extraction groups. There was evidence of greater mean maxillary intermolar-width reduction following the extractions of maxillary second premolars than following extractions of maxillary first premolars. Greater mean maxillary incisor retraction was found in the maxillary first premolar extraction group than in the maxillary second premolar group. A wide range of individual variation in incisor and molar changes did, however, accompany treatment involving both maxillary premolar extraction sequences.     

Considerations in correction of mandibular protrusion by intra-oral vertical ramus osteotomy

This case report presents a case that underwent orthognathic treatment with intra-oral vertical ramus osteotomy (IVRO). The patient was a 19-year-old female with mandibular protrusion and severe maxillary anterior crowding. The overbite was +0.5 mm and the overjet −1.5 mm. She had orofacial pain and tenderness of the temporomandibular joints (TMJ) and surrounding muscles. The pre-surgical orthodontic treatment included the extraction of the maxillary right lateral incisor, maxillary right second premolar, maxillary left canine, mandibular left second molar and mandibular right second premolar. After 18 months of pre-surgical orthodontic treatment, the left and right sides of the mandible were set back 8 and 6 mm, respectively, via IVRO to improve mandibular protrusion. The total treatment period was 26 months. The patient showed the backward reaction of the mandible, which occurred after release of the maxillo-mandibular fixation. The usage of the Class II elastics during the post-surgical phase to maintain the overjet made the inclination of the maxillary incisors more lingual.