Occlusal Position Research Articles

Use of self-organizing maps for analyzing the behavior of canines displaced towards midline under interceptive treatment.

BackgroundDisplaced maxillary permanent canine is one of the more frequent findings in canine eruption process and it’s easy to be outlined and early diagnosed by means of x-ray images. Late diagnosis frequently needs surgery to rescue the impacted permanent canine. In many cases, interceptive treatment to redirect canine eruption is needed. However, some patients treated by interceptive means end up requiring fenestration to orthodontically guide the canine to its normal occlusal position. It would be interesting, therefore, to discover the dental characteristics of patients who will need additional surgical treatment to interceptive treatment.Material and MethodsTo study the dental characteristics associated with canine impaction, conventional statistics have traditionally been used. This approach, although serving to illustrate many features of this problem, has not provided a satisfactory response or not provided an overall idea of the characteristics of these types of patients, each one of them with their own particular set of variables. Faced with this situation, and in order to analyze the problem of impaction despite interceptive treatment, we have used an alternative method for representing the variables that have an influence on this syndrome. This method is known as Self-Organizing Maps (SOM), a method used for analyzing problems with multiple variables.ResultsWe analyzed 78 patients with a PMC angulation higher than 100º. All of them were subject to interceptive treatment and in 21 cases it was necessary to undertake the above-mentioned fenestration to achieve the final eruption of the canine.ConclusionsIn this study, we describe the process of debugging variables and selecting the appropriate number of cells in SOM so as to adequately visualize the problem posed and the dental characteristics of patients with regard to a greater or lesser probability of the need for fenestration. Key words:Interceptive orthodontic treatment, altered eruption, impacted canines, neuronal networks, self-organizing maps.

Can different occlusal positions instantaneously impact spine and body posture? : A pilot study using rasterstereography for a three-dimensional evaluation.

Orthodontists influence dental occlusion directly. To suggest any link between dental occlusion and body posture is highly contentious, as evidenced by the literature. Rasterstereography, an optical technique that enables three-dimensional (3D) body measurements to be collected, has not yet been used to impartially examine whether different occlusal positions could instantaneously alter spine and body posture. We therefore set out to use this technique to nonsubjectively evaluate this question under static conditions. Optical body scans were collected for 44 subjects, using the Diers formetric 4D system, for seven different mandible positions. In total, ten spinal and body posture parameters were assessed (trunk inclination, trunk imbalance, pelvic tilt, pelvic torsion, fleche cervicale, fleche lombaire, kyphotic angle, lordotic angle, surface rotation, and lateral deviation) for each mandible position and compared with scans performed with habitual intercuspation (HIC). Significant body posture deviations were found for the fleche cervicale (positionof the mandible: right eccentrically), fleche lombaire (positionsof the mandible: physiologic rest position, cotton rolls on both sides, bite elevation 1mm), and the kyphotic angle (positionsof the mandible: cotton rolls on both sides, right eccentrically). No other significant differences were detected. Data for the parameters that varied with different dental occlusions generated high standard deviations. Therefore, within the limitations of this pilot study, we could not conclusively associate dental occlusion to an instantaneous impact on the tested parameters. The posture changes that we detected could also have arisen from individual neuromuscular compensation; a possibility that must now be ruled-in, or out, by further research studies with a higher number of subjects.

Digital workflow for a dental prosthesis that considers lateral mandibular relation

Most digital prosthesis designs consider only the maximal intercuspal position (MIP) and not the lateral movement. During the computer-aided design and computer-aided manufacture (CAD-CAM) prosthesis delivery process, the clinician has to adjust the prosthesis to avoid occlusal interference during lateral excursion. The novel digital workflow described in this report can be divided into 2 steps. After obtaining interocclusal records for the MIP and the lateral excursion position, the crown CAD data were designed using a general digital workflow considering only the MIP. The previous crown CAD data were then adjusted in the lateral excursion state before manufacturing the prosthesis. This process using information for 2 occlusal positions means that the definitive prosthesis design reflects not only static occlusion but also lateral mandibular relation.

Influence of dental occlusion on postural control and plantar pressure distribution

Objective: The number of studies investigating correlations between the temporomandibular system and body posture, postural control or plantar pressure distribution is continuously increasing. If a connection can be found, it is often of minor influence or for only a single parameter. However, small subject groups are critical. This study was conducted to define correlations between dental parameters, postural control and plantar pressure distribution in healthy males.Methods: In this study, 87 male subjects with an average age of 25.23 ± 3.5 years (ranging from 18 to 35 years) were examined. Dental casts of the subjects were analyzed. Postural control and plantar pressure distribution were recorded by a force platform. Possible orthodontic and orthopedic factors of influence were determined by either an anamnesis or a questionnaire. All tests performed were randomized and repeated three times each for intercuspal position (ICP) and blocked occlusion (BO). For a statistical analysis of the results, non-parametric tests (Wilcoxon-Matched-Pairs-Test, Kruskall-Wallis-Test) were used. A revision of the results via Bonferroni-Holm correction was considered.Results: ICP increases body sway in the frontal (p ≤ 0.01) and sagittal planes (p ≤ 0.03) compared to BO, whereas all other 29 correlations were independent of the occlusion position. For both of the ICP or BO cases, Angle-class, midline-displacement, crossbite, or orthodontic therapy were found to have no influence on postural control or plantar pressure distribution (p > 0.05). However, the contact time of the left foot decreased (p ≤ 0.001) while detecting the plantar pressure distribution in each position.Conclusions: Persistent dental parameters have no effect on postural sway. In addition, postural control and plantar pressure distribution have been found to be independent postural criteria.

The Diagnosis of Neuromuscular in Orthodontics Effects of TENS on The Antero-Posterior Maxilla-Mandibular Relationship

Objective:This study was conducted in order to assess the changes in the occlusal position of the mandible after ULF (Ultra Low Frequency)- TENS relaxing procedure in subjects in pubertal growth phase with diagnosed Angle Class II division I and mandibular dentoalveolar retrusion. Materials and methods: This study was performed on 70 patients (48 females,22 males) with an Angle Class II division I, aged between 10 and 15 years old (mean age 12.26, SD 1.32) characterized by mandible dentoalveolar retrusion and optimal vertical facial dimension, diagnosed by clinicaland cephalometric evaluation. Diagnostic neuromuscular registrations were made for all subjects. The casts were mounted on articulator in habitual intercuspal position with a tooth-guided wax bite registration. Reference points were chosen at molar level. Subsequently the same casts were mounted in myocentric position and compared to the habitual intercuspal position, assessing the antero-posterior shift after TENS procedure. Statistics: Mean and standard deviation were calculated on the amount of shifting at the left molar reference point after TENS procedure. Analysis of variance was carried out in order to evaluate the influence of sex and age on the amount of molar shift.Results: Nine subjects showed, in the antero-posterior plane, a forward mandibular shift in neuromuscular myocentric position compared to habitual intercuspal position. Six subjects showed no differences between habitual and myocentric position in the antero-posterio plane. Four individuals showed a backward mandible shift after TENS indicating worsening of the II molar in the antero-posterior plane. Conclusion: This study suggests that TENS recorded occlusion in subjects with Class II division I with mandible dentoalveolar retrusion allows to visualize an unusual trend of growth.The advancement of the mandible were not taken into account. These results could offer new diagnosis and prognosis methods for Class II malocclusions.

All-on-4 occlusion study: using T-Scan Ⅲ occlusal analysis system

To investigate the occlusal force distribution and the characteristics of the occlusion time of patients with All-on-4 rehabilitation at different occlusion position using T-Scan Ⅲ occlusal analysis system. Thirteen volunteers with All-on-4 rehabilitation were included in this study. T-Scan Ⅲ occlusal analysis system was used to measure the occlusal force distribution and the time character of the patients at intercuspal position, protrusive position, and lateral excursive position. Maximum intercuspation: the left and right premolars took most of the occlusal force, namely (17.3±3.1)%, (15.8 ± 4.6)%, (15.5 ± 2.2)% and (15.2 ± 5.5)% (24, 25, 14, 15), the implants areas including the premolar and anterior teeth took (64.0±6.7)%, (19.2±8.0)% of occlusal force. The left and right sides took the respective percentages of (50.5±6.1)%, (49.5±6.1)%, and there was no difference. Protrusion position: the region (11, 12, 21, 22) commitment to take the percentage of (90.4±27.7)%. Occlusion time: 0.18(0.11, 0.26) s, disclusion time: 0.52 (0.35, 1.14) s . At the left and right lateral position, 8 patients were single teeth-supported occlusion, 5 patients were group fuctional occlusion, the average occlusion time was 0.20(0.13, 0.34) s, and DT was 1.07 (0.58, 1.46) s. At maximum intercuspation: the implants areas including the premolar and anterior teeth were the occlusal force centers; the force concentrated in the area (11, 12, 21, 22) at the protrusion position. The lateral occlusal pattern shows multiformity.

ANALYSIS OF THE RESULTS OF LABORATORY STUDIES OF ORAL FLUID AND BLOOD SERUM OF PATIENTS IN THE RETENTION PERIOD OF ORTHODONTIC TREATMENT

In the course of complex treatment of patients with dentomaxillofacial abnormalities, two periods are distinguished: the period of active apparatus treatment and the retention period (consolidation of the results of orthodontic treatment). Ensuring the stability of the treatment results in patients with abnormalities of occlusion and irregular position of the teeth depends on the correct diagnosis and treatment plan. There are special methods, confirming the effectiveness of orthodontic treatment (anthropometric, radiological, photometric). Analysis of the results of laboratory studies of oral fluid and blood serum of patients who are in the retention period allows evaluation of the effectiveness of treatment and the stability of results. Aim - studying of the results of laboratory indicators of oral fluid and blood serum of patients in the retention period of orthodontic treatment. Material and methods. The total number of examined orthodontic patients was 156. At the first stage of the study, 96 patients were examined and divided into 3 groups. At the second stage, 60 people were examined (4th group). We performed the diagnostics of gingival crevicular fluid as the most promising material in terms of diagnostic capabilities, noninvasiveness and the ease of obtaining samples, and the possibility of retaking of biomaterial. All the patients underwent the study of biochemical and immunological parameters of blood serum, oral and gingival fluid. Results. At the end of treatment, biochemical indices are aligned, and osteoblastic activity decreases, which indicates the completion of the active adjustment and normalization of bony tissue.

A controversy with respect to occlusion.

SummaryThere are very little controversies on occlusion in healthy individuals, where centric relation is regarded as the criterion for assessing the present occlusion and also for establishing a new occlusal relationship between the upper and the lower jaws. On the other hand, the occlusal position in patients with deformed condyles still remains to be clarified. In this review, the effectiveness and limits of centric relation in these patients are discussed. In addition, the muscle induced occlusal positions, such as the muscular position and the terminal positions of habitual closing movements, are suggested as a substitution for centric relation. Finally, the importance of a stable intercuspal position, where the habitual closing movements terminate without any premature tooth contact, is emphasized.

Optimization of the occlusion strategy in visual tracking

Interference and anti-interference are two opposite and important issues in visual tracking. Occlusion interference can disguise the features of a target and can also be used as an effective benchmark to determine whether a tracking algorithm is reliable. In this paper, we proposed an inner Particle Swarm Optimization (PSO) algorithm to locate the optimal occlusion strategy under different tracking conditions and to identify the most effective occlusion positions and direction of movement to allow a target to evade tracking. This algorithm improved the standard PSO process in three ways. First, it introduced a death process, which greatly reduced the time cost of optimization. Second, it used statistical data to determine the fitness value of the particles so that the fitness more accurately described the tracking. Third, the algorithm could avoid being trapped in local optima, as the fitness changes with time. Experimental results showed that this algorithm was able to identify a global optimal occlusion strategy that can disturb the tracking machine with 86.8% probability over more than 10000 tracking processes. In addition, it reduced the time cost by approximately 80%, compared with conventional PSO algorithms.

The relationship between the incisor position and lingual surface morphology in normal occlusion.

This study aimed to investigate the relationship between the morphological characteristics of maxillary incisors and the anterior occlusion. The study materials comprised dental casts and lateral cephalograms of 26 modern Mongolian females with Angle Class I normal occlusion (mean age, 21years 5months). Computed tomography (CT) images of the dental casts were taken with an X-ray micro-CT system (SMX-100CT, Shimadzu, Kyoto Japan). The thickness of the marginal ridges and incisal edges, and the overjet and overbite, was measured on the three-dimensional images of the dental casts. On the lateral cephalogram, maxillary incisor to sella-nasion plane angle (U1 to SN angle), maxillary incisor to nasion-point A plane distance (U1 to NA distance), mandibular incisor to nasion-point B plane distance (L1 to NB distance), incisor mandibular plane angle, and interincisal angle were measured by tracing the left incisors of the maxilla and mandible. Spearman's single rank correlation coefficients were used to investigate any correlation between measurement items for each maxillary incisor. The thickness of the marginal ridges and incisal edges was positively correlated with the overbite. The thickness of the incisal edges was positively correlated with the irregularity index of the maxilla. There were significant negative correlations between overbite and U1 to SN angle, U1 to NA distance, and L1 to NB distance. Significant positive correlations were noted between the overbite and the overjet. In conclusion, there was no strong relationship between the morphological characteristics of maxillary incisors and the anterior occlusion.

Coxalgia and temporomandibular disorders: a case report

Background: Although the occlusal equilibration in bite plate-induced occlusal position has been reported to be effective in resolving temporomandibular disorder (TMD)-related symptoms, it still remains unclear whether coxalgia is included in those TMD-related symptoms. Method and Findings: Occlusal equilibration was performed for a TMD patient with coxalgia. First, painful symptoms were relieved by appliance therapy. Subsequently, occlusal analysis was performed on the patient by mounting dental models mounted on an articulator and identifying a deviation of the occlusal position from the bite plate-induced occlusal position (BPOP). Occlusal equilibration to the BPOP was performed for the patient by selective tooth grinding. On treatment completion, the occlusal position was shifted 1 mm forward on the left side and 1 mm backward on the right side from the previous habitual occlusal position. The TMD-related symptoms (temporomandibular joint clicking and pain) were resolved, and left coxalgia disappeared. Conclusion: Coxalgia is thought to be included in TMD-related symptoms.

パーシャルデンチャーによる咬頭嵌合位と中心咬合位の一致

咬合支持を喪失した部分歯列欠損症例を対象とした，パーシャルデンチャー応用による補綴歯科治療を成功に導くためには，「中心咬合位」を的確に採得することが大前提となる．そして，咬合器上に再現した「中心咬合位」と「パーシャルデンチャーによる咬頭嵌合位」とを一致させるとともに，「パーシャルデンチャーによる咬頭嵌合位」の咬合接触状態がコンプリートデンチャーにおける咬合接触状態と可及的に同一となるように設計すべきである，と私は考えている．咬合採得における術式の要点と，パーシャルデンチャーによる補綴歯科治療の在り方を再考してみる．

Search of Biomarker in the Oral Rehabilitation

Are there any ways to analyze objectively if any good changes happen to the bodies for the patients with acquired edentulous by getting a treatment to recover occlusion? In this study, we focused on interleukin 6 (IL-6) as inflammatory cytokine, cortisol known as a stress related substance and secretory immune globulin A (SIgA) related to immune reaction, and chose 14 patients who had occlusion reconstructed by the immediately loaded dental implants because occlusion contact with maxillary and mandibular dentition was lost caused by edentulous jaws or maxillary and mandibular teeth crossing each other and their jaw position and central occlusion position could not settle, and verified the relationship with changes of patients’ physical and mental states during the 6 months of the treatment and the effect of the immediately loaded implants treatment by using saliva which was non-invasive and easy to sample in biomarkers in saliva. Moreover for female subjects, the changes of facial color tones were measured by using Robo Skin Analyz-er?, a digital image analyzer, to measure the condition of their skin. In conclusion, the positive correlation between the amount of IL-6 and cortisol was not admitted. However, it was admitted that IL-6 tended to increase when a systemic change which interrupted curing such as the interruption of fusion of the implant and the bone was observed even though the patient did not notice any particular symptoms and cortisol tended to increase when the patient noticed discomfort and mentioned any events under stress on his or her medical record. Moreover with the skin color analysis by Robo Skin Analyzer?, the possibility that the occlusion treatment by the immediate implant had an effect on physical and psychological health promotion through the acquisition of the masticatory function and the aesthetic recovery was indicated.

Percutaneous left atrial appendage occlusion - treatment outcomes and 6 months of follow-up - a single-center experience.

AimTo present the results of treatment and evaluate 6 months of follow-up in a group of patients with non-valvular atrial fibrillation, who underwent the procedure of percutaneous left atrial appendage occlusion (PLAAO).Material and methodsPercutaneous left atrial appendage occlusion was performed in 34 patients with non-valvular atrial fibrillation and contraindications for oral anticoagulation therapy. The risk of thromboembolic and bleeding complications was determined based on the CHA2DS2VASc and HAS-BLED scales. The Amplatzer Amulet system from St. Jude Medical was used. On the first postoperative day, all patients were started on double antiplatelet therapy with 75 mg/day of acetylsalicylic acid (ASA) and 75 mg/day of clopidogrel (CLO). On the 30th postoperative day, the efficacy of the antiplatelet therapy was assessed with impedance aggregometry using a Multiplate analyzer (Roche). Echocardiographic examinations were performed intraoperatively and on the first postoperative day; subsequently, follow-up examinations were conducted 1 and 6 months after the implantation.ResultsIn all patients, proper occluder position was observed throughout the follow-up. No leakage or thrombi around the implants were found. No strokes or bleeding complications associated with the antiplatelet therapy were observed. Multiplate assessment of platelet activity was conducted in 20 out of 34 patients. The efficacy of ASA treatment was demonstrated in all patients; no response to clopidogrel treatment was observed in 5 out of 20 patients. One patient suffered from cardiac tamponade, which required the performance of full sternotomy. Local complications (hematomas of the inguinal region) were observed in 3 patients. One of the patients died for reasons unrelated to the procedure.ConclusionsPercutaneous left atrial appendage occlusion is an effective procedure in patients with non-valvular atrial fibrillation and contraindications for chronic anticoagulation therapy. Further observation is necessary to evaluate the longterm results.

Dental Clenching: A Way to Improve Body Stability In Subjects Suffering From Whiplash Injury. Part 1: Patients With Physiological Occlusion

Aim: Aim of this study is analyze the effects of dental occlusion on postural stability in patients with previous whiplash and normal occlusion.. Materials and Methods: 36 adult patients with previous whiplash and normal occlusion (good alignment, 1st class or mild 2nd class deep bite for mandibular retrusion) were selected. The patients were suffering from masticatory muscles pain caused by clenching during sleep. Exclusion criteria: Use of Psych drugs: To simulate the conditions of sleep (with a reduction of proprioand esteroceptive inputs for postural management performed by CNS), we used postural Romberg analysis (feet together, closed eyes) on stabilometric platform changing occlusal parameters only, under the following conditions: 1) in occlusal rest position, 2) in centric occlusion, 3) in clenching, 4) with occlusal disengage with cotton rolls and 5) in clenching on cotton rolls. Time of each test: 15 seconds. It was performed a statistical analysis with T-test comparing between them the mean of all tests. Results: Stabilometry data (postural ball and ellipse) show better postural performances in centric occlusion and clenching in centric occlusion, and a worsening in all tests with occlusal disengage (with statistically significant difference p<0.05). Conclusion: Postural instability caused by whiplash increases muscles tone and dental clenching as compensatory effects, with onset of facial pain. An occlusal disengage (like an occlusal splint to reduce clenching) induces a postural worsening in patients with normal occlusion, while centric occlusion increases the stability. These results suggest that stomatognathic organ has a new physiological function: the posture stabilization.

Influence of the Lower Jaw Position on the Running Pattern.

IntroductionThe effects of manipulated dental occlusion on body posture has been investigated quite often and discussed controversially in the literature. Far less attention has been paid to the influence of dental occlusion position on human movement. If human movement was analysed, it was mostly while walking and not while running. This study was therefore designed to identify the effect of lower jaw positions on running behaviour according to different dental occlusion positions.MethodsTwenty healthy young recreational runners (mean age = 33.9±5.8 years) participated in this study. Kinematic data were collected using an eight-camera Vicon motion capture system (VICON Motion Systems, Oxford, UK). Subjects were consecutively prepared with four different dental occlusion conditions in random order and performed five running trials per test condition on a level walkway with their preferred running shoes. Vector based pattern recognition methods, in particular cluster analysis and support vector machines (SVM) were used for movement pattern identification.ResultsSubjects exhibited unique movement patterns leading to 18 clusters for the 20 subjects. No overall classification of the splint condition could be observed. Within individual subjects different running patterns could be identified for the four splint conditions. The splint conditions lead to a more symmetrical running pattern than the control condition.DiscussionThe influence of an occlusal splint on running pattern can be confirmed in this study. Wearing a splint increases the symmetry of the running pattern. A more symmetrical running pattern might help to reduce the risk of injuries or help in performance. The change of the movement pattern between the neutral condition and any of the three splint conditions was significant within subjects but not across subjects. Therefore the dental splint has a measureable influence on the running pattern of subjects, however subjects individuality has to be considered when choosing the optimal splint condition for a specific subject.

The Influence of Monocular Spatial Cues on Vergence Eye Movements in Monocular and Binocular Viewing of 3-D and 2-D Stimuli.

The influence of monocular spatial cues on the vergence eye movements was studied in two series of experiments: (I) the subjects were viewing a 3-D video and also its 2-D version-binocularly and monocularly; and (II) in binocular and monocular viewing conditions, the subjects were presented with stationary 2-D stimuli containing or not containing some monocular indications of spatial arrangement. The results of the series (I) showed that, in binocular viewing conditions, the vergence eye movements were only present in the case of 3-D but not 2-D video, while in the course of monocular viewing of 2-D video, some regular vergence eye movements could be revealed, suggesting that the occluded eye position could be influenced by the spatial organization of the scene reconstructed on the basis of the monocular depth information provided by the viewing eye. The data obtained in series (II), in general, seem to support this hypothesis.

Freehand Condyle-Positioning During Orthognathic Surgery: Postoperative Cone-Beam Computed Tomography Shows Only Minor Morphometric Alterations of the Temporomandibular Joint Position.

Purpose of this study was to evaluate changes in the temporomandibular joint (TMJ) position after bilateral sagittal split osteotomy (BSSO) of the mandible by the help of pre- and postoperative cone-beam computed tomography (CBCT) images. A collective of n = 78 patients was investigated between 2009 and 2011 before and after BSSO of the mandible in mono- or bimaxillary orthognathic surgery procedures. No intraoperative fixation of the condyles was administered. CBCT scans were performed in all patients before and immediately after surgery with the KaVo 3DeXam device in the position of terminal occlusion. Subsequently, all scans were analyzed by help of the eXam Vision program and the ImageJ image processing software. Alterations of the TMJs were quantified by determining pre- to postoperative differences of the intercondylar distance, the mandibular angle on both sides, and the condylar angles in the transversal plane. The difference between pre- and postoperatively ascertained values was minimal (means: lateral condylar distance -0.17 mm; distance of condylar centers -0.32 mm; medial condylar distance -0.49 mm; left mandibular angle +1.06°; right mandibular angle +2.06°; condylar angles in relation to a reference line: left -2.93, right -0.75; angle of cutting +3.42). There is no apparent tendency toward a positional change in any of the 3 examined planes. Between bi- and monomaxillarily operated patients there was no difference either, except for the osteotomy plane. A 3-dimensional analysis of CBCT data of the TMJ seems to be appropriate to determine the condylar position pre- and postoperatively. Performed by an experienced orthognathic surgeon, BSSO of the mandible does not effectuate any relevant changes of the TMJ-position, thus making an intraoperative condyle-fixation unnecessary.

Effect of structural composition and position of occlusion on the legibility of occluded Chinese characters.

The study examined the effect of structural composition, position of occlusion, and education background on response time and accuracy rate of adult participants in recognition of occluded Chinese characters used in graphic design. Based on 18 Chinese characters selected from the top 4,000 most commonly used characters, a recognition experiment was conducted. Results indicated that, for the characters with two different composition structures, the right position was the best position of occlusion because the recognition of the radical or feature of a character would be least affected, leading to a shorter response time and more accurate reading comprehension. Educational background did not have a significant influence on response time and recognition accuracy.

New classification of lingual arch form in normal occlusion using three dimensional virtual models.

ObjectiveThe purposes of this study were 1) to classify lingual dental arch form types based on the lingual bracket points and 2) to provide a new lingual arch form template based on this classification for clinical application through the analysis of three-dimensional virtual models of normal occlusion sample.MethodsMaxillary and mandibular casts of 115 young adults with normal occlusion were scanned in their occluded positions and lingual bracket points were digitized on the virtual models by using Rapidform 2006 software. Sixty-eight cases (dataset 1) were used in K-means cluster analysis to classify arch forms with intercanine, interpremolar and intermolar widths and width/depth ratios as determinants. The best-fit curves of the mean arch forms were generated. The remaining cases (dataset 2) were mapped into the obtained clusters and a multivariate test was performed to assess the differences between the clusters.ResultsFour-cluster classification demonstrated maximum intercluster distance. Wide, narrow, tapering, and ovoid types were described according to the intercanine and intermolar widths and their best-fit curves were depicted. No significant differences in arch depths existed among the clusters. Strong to moderate correlations were found between maxillary and mandibular arch widths.ConclusionsLingual arch forms have been classified into 4 types based on their anterior and posterior dimensions. A template of the 4 arch forms has been depicted. Three-dimensional analysis of the lingual bracket points provides more accurate identification of arch form and, consequently, archwire selection.