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A forward functional shift of the mandible is a significant problem that can cause both functional and aesthetic complications for many patients. This shift usually occurs in growing patients, and it is unusual to see in adult patients. This case report shows an adult patient with a forwarding functional shift that caused both anterior and posterior crossbites with a pseudo class III dental and skeletal relationship. The patient also showed severe upper arch crowding with blocked-out canines and mild crowding in the lower arch. The treatment of this patient involved extraction of the upper right and left first premolars and the lower right first premolar, followed by opening of the bite to relieve the neuromuscular reflex of the forward protrusion of the mandible during centric occlusion and to correct both the anterior and posterior crossbites. Extraction spaces were closed using class III elastics and elastomeric chains. At the end of the treatment, good functional and aesthetic results were obtained after the elimination of the forward functional shift.

Aim: To assess the occlusion in primary dentition among Saudi preschool children with Down syndrome (DS). Methods: This cross-sectional study was conducted over 10 months on 124 Saudi preschool children with DS aged 3-6 years with a complete set of primary dentition. The children were randomly selected from DS centers in Riyadh, Saudi Arabia. The primary molar relationship, canine relationship, overbite, overjet, posterior crossbite and scissors bite were recorded in centric occlusion. Results: The mesial step was the most observed (60.5%) molar relationship among the participants (P=0.001). Moreover, the Class III canine relationship represented 62.9% of the sample (P=0.001). More than one-third of the sample (39.5%) had an edge-to-edge overbite followed by an anterior open bite in 28.2% of the sample (P=0.027). The majority of the children examined (48.4%) had an edge-to-edge overjet followed by reversed overjet (anterior crossbite) in 27.4% of the sample (P=0.001). One-third (33.8%) of the children had a posterior crossbite. Conclusion: The results of this study are considered to be of importance to pediatric dentists making treatment decisions for preschool children with DS.

Purpose: Additional grafting procedures for the treatment of extremely atrophic jaws may be demanding, expensive, and sometimes require long time and multiple surgical sessions, which may reduce patient's acceptance and quality of life. This study evaluated the outcomes of 10 patients with extensive alveolar bone defects in the posterior jaws, treated in a single surgical session with grafting and implants. Materials and Methods: Ten consecutive patients were treated within 3 months of extraction. After ridge exposure, implants were positioned in 4-wall defects without contact with pristine bone, and mineralized particulate allograft packed around to stabilize them. Sites were covered with resorbable membranes and soft tissues were sutured tension-free. Five months later, implants were restored in centric occlusion. Results: At uncovering, newly formed bone filled all defects and all implants resisted at 30 Ncm of reverse torque. No complication was recorded throughout the study; survival rate was 100% for both implants and grafts. After 24 months of follow-up, mean periimplant bone level change was 0.15 ± 0.53 mm and mean bone gain at the defect site was 11.62 ± 1.04 mm. Conclusion: Rehabilitation of wide postextraction defects may achieve successful outcomes using allograft and a special implant design, even in the absence of optimal primary stability.

Objectives: The Frankel manoeuvre is a procedure by which the mandible of Class II individuals is postured forward in dental Class I relationship. The evaluation of the resulting facial profile provides information concerning the components determining the sagittal discrepancy. Data concerning the reproducibility of its assessment are not available. This study aimed to evaluate the intra-observer and inter-observer reproducibility of the assessment of the manoeuvre and to assess whether the amount of clinical experience affects its reproducibility. Methods: Two lateral photographs, one in centric occlusion, and the other with the mandible postured forward (Frankel manoeuvre) of 100 Angle Class II individuals aged between 9 and 13 years were evaluated by six orthodontists (T0). Each examiner was asked whether the facial profile worsen or not with the manoeuvre after being trained by an expert orthodontist. The test was repeated after 2 weeks interval (T1). Intra-observer and inter-observer agreement were evaluated by computing the Cohen’s K . Results: The agreement ( K values) between observations (T0 versus T1) for each examiner ranged from 0.49 to 0.72. The overall agreement was 0.65 [95% confidence interval (CI) = 0.54–0.75]. The agreement in the group with less clinical experience was 0.61 (95% CI = 0.46–0.76), while it was 0.68 (95% CI = 0.53–0.83) in the more experienced group. The amount of clinical experience did not affect intra-observer agreement ( P = 0.50). The overall agreement between the examiners and the trainer was 0.74 (95% CI = 0.65–0.83) and 0.73 (95% CI = 0.64–0.83) at T0 and T1 respectively. Conclusion: The assessment of the Frankel manoeuvre is reproducible and it is not influenced by the amount of clinical experience.

Background. The aetiology of temporomandibular joint disorders (TMD) is multifactorial, whereas occlusal disharmony is one of the predisposing factors. Researchers still discuss the relation between occlusion and TMD. Objective. The study aims to investigate the relation between static occlusal parameters and TMD clinical symptoms using T-Scan II analysis system. Material and methods. The sample consisted of 44 persons divided into the treatment group of 20 TMD patients and the control group of 24 subjects without TMD. The main task of T-Scan II computerized occlusal analysis system was to record every patient’s occlusion and estimate static occlusal parameters: centre of occlusal force, asymmetry index of maximum occlusal force and occlusion time. These results were compared between groups, data related to patients’ complaints and clinical symptoms. The analysis was carried out using Mann-Whitney U, Kruskal-Wallis and Chi-square tests. Results. Averages of the centre of occlusal force in TMD subjects were 6.55 ± 0.99 mm, in the control group – 5.88 ± 0.69 mm; the asymmetry index of maximum occlusal force averages: 15.90 ± 2.71 and 12.93 ± 1.88; occlusion time: 0.281 ± 0.036 s and 0.236 ± 0.022 s, respectively. There were no statistically significant differences between two groups but they were found in the centre of occlusal force and the asymmetry index in the two groups (p < 0.05). Conclusions. There exists a relation between complaints of patients with TMD and static occlusion parameters. Values of the centre of the occlusal force distance and the asymmetry index of occlusal force in TMD patients with pain in the temporomandibular joint (TMJ) were significantly higher than in the control group.

Studies have explored occlusal marking interpretation, repeatability and accuracy. But, when an occlusion detection product is interposed between teeth, direct tooth-tooth occlusal contact relationships are replaced by tooth-material-tooth structures. Thus, the marks cannot reflect the original contacts. This has been shown for single tooth pair contacts. The purpose of this laboratory study was to similarly examine full dentitions. A dentiform was set into Class I centric occlusion with the mandible supported by a load cell. The maxillary arch was guided by precision slides. As the weighted (~52 N) upper assembly was lowered onto and raised off the mandibular arch, the loads on the mandible were measured. With and without (control) occlusal marking material, the steps were as follows: (cleaning - control 1 - material 1) … (cleaning - control 6 - material 6). The six materials were as follows: Accufilm I and II, Rudischhauser Thick and Thin, Hanel Articulating Silk and T-Scan. Then, the six sets of (cleaning - control - material) measurements were repeated with the mandibular assembly shifted, in turn, by 0·1 mm in the Anterior, Posterior, Right and Left directions. The five (Centric and four 0·1 mm shifted) occlusal relationships produced grossly different tooth-tooth (control) load profiles. And, in general, these controls were affected, in different ways, by the marking products. Among the five conventional products, the Rudischhausers fared the worst and the electronic T-Scan was an extreme outlier. Thus, in general, popular occlusal detection products alter the occlusal contact forces, and therefore, their markings cannot characterise the actual occlusion.

El presente estudio se realizó con el fin de conocer la prevalencia de trastornos témporomandibulares en niños de 8 a 12 años de la Escuela “Diego Abad de Cepeda” de la ciudad de Quito. La investigación se realizó en 228 niños que se distribuyeron en 128 mujeres y 100 hombres y bajo el método de observación se determinaron signos de trastornos témporomandibulares. Los trastornos que se evaluaron fueron dolor, limitación en apertura, deflexión, ruidos articulares y discrepancia entre relación céntrica y oclusión céntrica. El 49% de la población mostró al menos uno de los trastornos, siendo más prevalente en el sexo femenino con el 64%. Los trastornos más prevalentes en la población examinada fueron dolor con el 32% y ruidos articulares con el 25%. Los trastornos se encontraron con más frecuencia en aquellos niños que tuvieron uno o más hábitos perniciosos, apiñamiento y maloclusiones como mordida profunda, mordida abierta y mordida cruzada. Los resultados que se obtuvieron en el presente estudio nos ayudan a confirmar que los trastornos témporomandibulares pueden afectar también a los niños y nos impulsa a los odontólogos a aprender más sobre la articulación témporomandibular para saber tratarla adecuadamente.

The study and documentation of occlusal-articulation relationships has a high diagnostic significance in patients with bruxism and bruxomania. The study aims on the basis of registration of occlusal contacts via articulating paper and the T-Scan system to evaluate the advantages and disadvantages of both methods in occlusal diagnosis of patients with bruxism and bruxomania. Material and Methods: 40 patients with bruxism and / or bruxomania (29 women and 11 men) aged between 21 and 77 years from October 2010 to February 2014 was conducted computerized occlusal analysis using the systems T-Scan II (in 12 patients), T-Scan III (in 28 patients) and the software T-Scan III. All patients were subjected to registration of occlusal relationships in centric occlusion (CO) with articulating paper Bausch PROGRESS 100 µ and Bausch® Arti-Fol® 8 µ. Results and Discussion: In 90.0% of patients it is established unevenly distributed, irregular in size and intensity occlusal contacts. Essential factor for preventing the spontaneous bilateral closure with balanced forces is the presence of interceptive contacts and sliding occurring in the first frame of the occlusion time until the maximum intercuspation - MIP. Conclusion: Registration with articulating paper visualizes cumulative picture of the contacts in CO and interceptive contacts without being able to distinguish them in size and time of onset. Computerized occlusal analysis objectively and quantitatively determines interceptive contacts and distinguishes them from contacts in MIP and gives real meaning to the terms "strong" and "light contacts".

Background To ascertain the prevalence of malocclusion and orthodontic treatment need in schoolchildren dependent on armed forces personnel. To review the overall oral health using DMFT index and to evaluate any relation between increased DMFT index to existing orthodontic problems. Method Five schools were randomly selected among Army/KV/AF schools and a random sample of 1200 children aged 10–15 years old attending these schools dependant on armed forces personnel were selected. A survey form was filled up after the examination of children by the principal worker and need for orthodontic treatment was assessed using index for orthodontic treatment need (IOTN) and overall oral health status by DMFT index and totaled. Frontal intra oral photograph in centric occlusion were taken. Dental Health Component (DHC) of IOTN for all the patients was marked by one set of orthodontists. The most severe occlusal trait was identified by the examiner for any particular patient and the patient was then categorized according to this most severe trait. AC of the IOTN was assessed by second orthodontist, individual and a layperson. Results It was observed that prevalence of malocclusion in the sample was 53.7%. 32.8% (239 males & 154 females) of samples are in need of orthodontic treatment. 55.1% of samples shown no caries risk, 38.1% had moderate caries risk and 6.8% had high caries risk. Conclusion Significant percentage of the samples are in need for orthodontic treatment. There is significant relation between higher DMFT index and orthodontic treatment need. It was found that IOTN is a reliable and user-friendly index, which can be used for orthodontic surveys.

Background: The aims of orthodontic treatment are to achieve the best interdigitation in centric occlusion in relation with good facial aesthetic and to get a pleasant dento-facial looked with good function as well. Nowadays, people who are seeking orthodontic treatment to fulfill those need come to orthodontist, mostly for aesthetic reason, for good teeth arrangement that will be more aesthetically favorable. However, not all people with malocclusion seek the orthodontic treatment due to the fact, they do not realize that they have orthodontic problem. On the other hand, some other feel they need orthodontic treatment but they can not afford it. Purpose: To determine the knowledge of malocclusion and demand for orthodontic treatment in related to Aesthetic Component (AC) IOTN. Methods: The samples were 107 college students of Faculty of Dentistry Airlangga University divided into two as 1st and 7th semester group. Both of the groups were given questionnaire about their knowledge of malocclusion and demand of orthodontic treatment. Then, they were asked to examine themselves using AC IOTN, then researcher and orthodontist examine them. Results: There was a significant difference on knowledge of malocclusion between both groups, no significant difference on demand of orthodontic treatment between both groups, and no correlation between demand and AC IOTN in both groups. There was a significant difference in AC IOTN score examined by respondent, researcher and orthodontist. Conclusion: Knowledge of malocclusion was not the only factor that determines demand of orthodontic treatment.Latar belakang: Tujuan perawatan ortodonti adalah untuk mendapatkan hubungan interdigitasi yang baik berhubungan dengan penampilan estetik wajah untuk mendapatkan fungsi dan penampilan dento-fasial yang baik. Saat ini, banyak orang mencari perawatan ortodonti untuk memenuhi kebutuhan fungsi dan penampilan. Tujuannya adalah susunan gigi yang rata yang lebih dapat diterima secara estetik. Namun, tidak semua orang dengan maloklusi mencari perawatan ortodonti, karena sebagian dari mereka tidak menyadari bahwa mereka memiliki masalah ortodonti, sedangkan sebagian lainnya merasa mereka membutuhkan perawatan ortodonti tetapi tidak bisa membiayainya. Tujuan: Mengetahui hubungan pengetahuan maloklusi dan demand perawatan ortodonti dengan Aesthetic Component (AC) IOTN. Metode: Sampel adalah 107 mahasiswa Fakultas Kedokteran Gigi Universitas Airlangga yang dibagi ke dalam 2 kelompok, semester 1 dan semester 7. Kedua kelompok kemudian diberi kuesioner tentang pengetahuan maloklusi dan demand perawatan ortodonti. Kemudian responden diminta untuk menilai diri mereka sendiri menggunakan AC IOTN, setelah itu responden dinilai peneliti dan ortodontis. Hasil: Terdapat perbedaan pengetahuan maloklusi yang signifikan antara kedua kelompok, tidak ada perbedaan demand perawatan ortodonti yang signifikan pada kedua kelompok, tidak ada hubungan antara demand dan AC IOTN pada kedua kelompok. Ada perbedaan yang signifikan pada skor AC IOTN yang diperiksa oleh responden, peneliti dan ortodontis. Simpulan: Pengetahuan maloklusi bukan satu-satunya faktor yang mempengaruhi demand perawatan ortodonti.

Correct occlusal relationships are part of the successful prosthetic treatment for edentulous patients. Fabrication of complete dentures comprises of clinical and laboratory procedures that should be executed accurately for achieving success with fabricated dentures. Errors occurring during the clinical and laboratory procedures of a denture may subsequently lead to the occlusal errors in the final prosthesis. These occlusal errors can be corrected in two ways: i) in patient's mouth ii) by recording new centric relation and remounting dentures on an articulator. The latter method is more feasible because the mobility of denture base on the mucosa in oral cavity does not permit the identification of premature contacts in centric occlusion and tooth guided eccentric excursions. This article describes a modest and effective clinical chair-side remount procedure using customized mounting platforms.

Background: The concept of scalloped implants to maintain the natural contour of the alveolar ridge has been a source of controversy for many years. Purpose: This study examined the long-term clinical performance of the scalloped NobelPerfect implant in a one-stage procedure (immediate loading in the esthetic zone). Materials and Methods: In 20 patients, immediate prosthetic restorations were placed on 31 NobelPerfect implants in a private practice and followed for up to 78 months. Twenty-one implants were placed immediately after extraction, seven implants were placed after osseous consolidation of the extraction sockets, and three implants were placed secondary to extended alveolar ridge augmentation procedures. All implants were provisionalized on the day of implant placement and adjusted to clear all contacts in centric occlusion and during eccentric movements. Outcome variables were success rates, marginal bone levels, and pink esthetic score (PES) assessed per implant. Results: One implant failed after 1.4 months. Five patients with six implants in total were scored in the 5-year follow-up as dropouts. Mean follow-up period of remaining 24 implants was 65 months (range, 55–78 months). Cumulative success rates according to the criteria specified by Smith and Zarb were 96.8%. Marginal bone levels averaged 1.1 mm above the first thread. Mean PES ratings were 10.5 (range, 3–13). Conclusions: Survival rates, marginal bone levels, and esthetic results suggest proof of principle for the preservation of the interproximal bony lamella with a scalloped implant design in long-term data.

Objective : To provide information on the state of occlusion and the spaces available after complete eruption of the primary dentition and to compare the characteristic features of the primary dentition in Chennai and Hyderabad, two of the metropolitan cities in South India. Materials and Methods : Children in the age range between 3 and 5 years were selected from different schools of both Chennai and Hyderabad, with a complete set of primary dentition. Study casts were obtained and assessment of spacing in the primary dentition and the primary molar relationship were recorded in centric occlusion. The data obtained was subjected to statistical analysis. Results : The mean values and standard deviations for the primary molar relationship and spacing in primary dentition are given in the tables. Conclusion : Bilateral flush terminal plane relationship of the second primary molars and spaced dentition was most frequent in primary dentition of the children in both Chennai and Hyderabad groups. Significant differences were not found among both groups and genders.

Background: One of the common types of oro-dental morphopathologic relationship is the Class II Division 1 malocclusion. Therefore, the study of tongue position in Class II Division 1 may reveal a role of the tongue in the etiology or diagnosis of malocclusion. Aims: Present study was done with the aim to evaluate the tongue position radiographically in centric occlusion and rest position in the subjects with Angle's Class 1 normal occlusion and subjects with Angle's Class II Division 1 malocclusion and to find out any differences in tongue position between Angle's Class 1 normal occlusion and Angle's Class II Division 1 malocclusion group. Materials and Methods: The present study was conducted on lateral cephalogram of 40 subjects between the age ranges of 16 to 22 years. The samples were divided into the Angle's Class 1 normal occlusion group (Group I) and the Angle's Class II Division 1 malocclusion group (Group II) with the 20 in each groups. The study involved the evaluation of tongue position at rest position and centric occlusion on the lateral head cephalogram. Results: This study for the evaluation of the tongue position from the rest position to the centric occlusion showed no statistically significant changes in both groups. However, there were greater changes in various parameters (From the rest position to the centric occlusion) in the subjects with Angle's Class II Division 1 malocclusion as compared to the subjects with the Angle's Class I normal occlusion group. Conclusion: From the present study following conclusion can be drawn: with the closure of mandible from the rest position to centric occlusion the tongue moved antero-superiorly in the tip region, superiorly in the dorsum region, and antero-superiorly in the posterior region in normal occlusion and postero-superiorly in Class II Division 1 malocclusion.

OBJECTIVE: To examine changes in gravity fluctuation caused by experimentally altering the area of occlusal contact. MATERIALS AND METHODS: Subjects consisted of 15 adult Japanese males with normal stomatognathic function, no missing teeth except for the third molars, and equivalent occlusal contact in the anterior and bilateral posterior regions. Silicon biteplates fabricated for each subject to evaluate gravity fluctuation in relation to changes in occlusal contact area were as follows: RP(−)–OC(+) (entire occlusal surface covered in centric occlusion); RP(+)–OC(+) (entire occlusal surface covered with bite slightly raised); Ant or Pos/RP(+)–OC(+) (anterior or posterior region selectively covered); and RP(+)–OC(−) (only retromolar pads covered, no occlusal coverage). RESULTS: No significant differences in gravity fluctuation were noted between subjects wearing biteplates covering the entire occlusal surface. Subjects wearing biteplates with no occlusal contact showed greater gravity fluctuation than those with occlusal contact. In addition, gravity fluctuation for the Ant/RP(+)–OC(+) group (no occlusal contact in the posterior region) was greater than for RP(+)–OC(+) and Pos/RP(+)–OC(+). However, groups with unilateral occlusal contact in the posterior region exhibited large right and left sway amplitude. CONCLUSIONS: These results suggest that occlusal contact, especially posterior occlusal contact, affects gravity fluctuation, and that appropriate occlusion attained by maintaining even occlusal contact in the posterior region is crucial for gravity fluctuation.

Introduction: The primary second molar relation is also called the terminal plane, which is the relation between the distal surface of the maxillary and mandibular second primary molars in a centric occlusion position. One of the most important characteristics of the ideal occlusion development on the primary dentition is if the primary second molar relation classified as the flush terminal plane. This relation plays a significant role in determining the relation in permanent molar because the eruption of the first permanent molars are guided by the distal surface of the maxillary and mandibular second primary molars. The purpose of this study was to found out the clinical description of the primary second molar relation among the preschool-aged children in four kindergartens in Banda Aceh. Methods: This study was a descriptive study with cross-sectional study approach. The subject selection method was performed with a purposive sampling method involving as much as 37 subjects, which were students of State Kindergarten of Pembina 1, State Kindergarten 2, State Kindergarten 3, and State Kindergarten of Adidarma 4, Banda Aceh. The examination was performed by using the intraoral mirror when the teeth were in the centric occlusion position. Decisions regarding the primary second molar relation were made by the bilateral occlusion (left and right). Results: The flush terminal plane was found in 45.9% of all respondents, the mesial step was 54.1%, and the distal step was 0.0%. Conclusion: The primary second molar relation among preschool-aged children generally had the mesial step.

Aim: This study evaluates relationships in humans between various occlusal contacts and the presence of deeper probing depths, reduced width of keratinized tissue, and less than favourable initial prognosis. Materials and Methods: The tooth level relationship between various occlusal contacts and pocket probing depths, width of keratinized gingiva, and prognosis at the time of initial examination was evaluated (multivariate model) in a group of patients (85 patients, 2219 teeth) with active periodontal disease. Results: The following were noted to be associated with significantly deeper pocket probing depths: premature contacts in centric relation (0.89 mm, p

SUMMARY The occlusal conditions of periodontitis patients were investigated by using a computerized monitoring device. Thirty-three mild to severe periodontitis patients were enrolled in the study and they were categorized into three groups by their periodontitis severity. Each subject answered a preliminary questionnaire, received routine dental examinations, and underwent MKG/EMG tests using the K6 Diagnostic System. Clinical manifestations of periodontitis were confirmed by the questionnaire and the routine clinical examinations. According to the MKG tests, the traces of maximum opening distance and vertical freeway space showed no significant statistical difference among the groups. However, the velocity of terminal tooth contact was significantly delayed in the severe periodontitis group. According to the EMG tests, there was no significant difference in the rest mode EMG activities, but the function mode EMG activities significantly weakened in the severe periodontitis group. These results showed that severe periodontitis patients had poor occlusal conditions that might have been triggered by the instability of centric occlusion due to attachment loss.

A patient who visited our department after job relocation was reexamined, and a marked discrepancy was found in mandibular position between centric occlusion and centric relation. Although the patient was originally scheduled to undergo orthodontic treatment only, the results of comprehensive tests indicated that surgery would be needed to resolve this discrepancy. Surgery was performed with the patient's consent, yielding favorable results. Although the entire orthodontic treatment lasted 3 years and 11 months, including treatment prior to transfer, it was clear that long-term use of intermaxillary elastics would not have corrected the discrepancy and that surgery was the right decision.

Occlusal diagnosis plays an important role in the planning and subsequent delivery of predictable functional and aesthetic restorations and prostheses. Once an occlusal problem is identified there are a number of techniques and materials that can be utilised to record occlusal relationships, subsequently analyse them and incorporate information obtained into the delivery of tooth restoration or replacement. This paper discusses the clinical and technical aspects of occlusal examination and analysis outlining contemporary and traditional techniques in their utilisation. Aspects of occlusal examination will be revisited; the identification and recording of centric occlusion as well as subsequent articulation will be discussed. The requirement for occlusal splint provision will also be discussed and illustrated.

The purpose of this study was to evaluate the effect of changing mandibular position on body posture and reciprocally, body posture on mandibular position. Forty-five (45) asymptomatic subjects (24 males and 21 females, ages 21-53 years, mean age 30.7 years) were included in this study and randomly assigned to one of two groups, based on the table of random numbers. The only difference between group I and group II was the sequence of the testing. The MatScan (Tekscan, Inc., South Boston, MA) system was used to measure the result of changes in body posture (center of foot pressure: COP) while subjects maintained the following 5 mandibular positions: (1) rest position, (2) centric occlusion, (3) clinically midlined jaw position with the labial frena aligned, (4) a placebo wax appliance, worn around the labial surfaces of the teeth and (5) right eccentric mandibular position. The T-Scan II (Tekscan, Inc., South Boston, MA) system was used to analyze occlusal force distribution in two postural positions, with and without a heel lift under the right foot. Total trajectory length of COP in centric occlusion was shorter than in the rest position (p < 0.05). COP area in right eccentric mandibular position was larger than in centric occlusion (p < 0.05). When subjects used a heel lift under the right foot, occlusal forces shifted to the right side compared to no heel lift (p < 0.01). Based on these findings, it was concluded that changing mandibular position affected body posture. Conversely, changing body posture affected mandibular position.

Although it may appear, when examining the deciduous dentition, that similar malocclusions to those seen in the permanent dentition can be identified, it does not always follow that they will persist. Incipient crowding of the teeth is usually masked by spacing which should normally be present. Small discrepancies of occlusion can arise or be masked as a result of deviation of the mandible away from centric occlusion. Unilateral crossbites, anterior open bites and excessive overjets which are associated with a sucking habit, will usually prove transient and improve spontaneously. It is also possible that crossbites and buccal occlusion of individual premolars may develop as these teeth erupt; these are often caused by displacement due to crowding. If these factors are allowed for then a fairly accurate prediction of arch relationship can be made. Correlations of tooth size, arch size and spacing of teeth were not strong enough to be used individually for predicting the degree of crowding to be expected in the permanent dentition. However, observation of all these factors, especially if radiographs are available may be used to give a fairly accurate prognosis.

Introduction: The aim of this follow-up study was to evaluate the number of contacts in centric occlusion during a 1-year retention period in patients treated with 2 retention procedures and in a control sample. Methods: Twenty patients received modified wraparound Hawley retainers, and 20 received maxillary Jensen plates with mandibular fixed retainers. These retention patients were compared with a control group of 20 subjects with normal occlusions. Silicone-based impression bites were used to record occlusal contacts. Paired and independent-sample t tests were used to evaluate intragroup and intergroup differences. Results: Contacts increased in the total arch and the posterior combined (actual/near) during the retention period compared with the control group. In the Hawley retainer group, actual contacts on the second molars (P .05), near contacts on the premolars (P .05), and total contacts on the first molars (P .05) and premolars (P .01) had statistically significant increases. In the maxillary Jensen plate and mandibular fixed lingual retainer group, the number of actual contacts on the posterior segment increased. Actual contacts on the first molars (P .01), second molars (P .01), premolars (P .05), and canines (P .05), and total contacts on the first (P .05) and second (P .05) molars had statistically significant increases. During the observation period, some slight occlusal changes were seen in the control sample, presumably from growth and development. At the end of the study, during the 1-year follow-up period, no statistically significant occlusal contact differences were observed in the 3 groups. Conclusions: Retention procedures carried out in this study allowed relative vertical movement of the posterior teeth.

Purpose To develop an easy-to-use, dentition planning method which is based on three-dimensional (3D) computer planning technology to replace conventional plaster-cast occlusion planning techniques.

Oral appliances (OAs) have been widely used to treat snoring and sleep apnea, but their effects on craniofacial structures in patients after 5 years or more of wear have not yet been quantified.Seventy-one patients who had worn adjustable mandibular repositioners to treat snoring or sleep apnea were evaluated. Upright lateral cephalometric radiographs in centric occlusion taken before treatment and after a mean of 7.3 +/- 2.1 years of OA use were compared. Baseline sleep studies and patient demographic data were included in the analysis.Cephalometric analyses after long term OA use showed significant (P.01) changes in many variables, including increases in mandibular plane and ANB angles; decreases in overbite and overjet; retroclined maxillary incisors; proclined mandibular incisors; increased lower facial height; and distally tipped maxillary molars with mesially tipped and erupted mandibular molars. The initial deep overbite group had a significantly greater decrease in overbite. Duration of OA use correlated positively with variables such as decreased overbite and increased mandibular plane angle; changes in the dentition appeared to be progressive over time.After long-term use, OAs appear to cause changes in tooth positions that also might affect mandibular posture.

Statement of problem A variety of treatment philosophies persist concerning the need for coincidence of centric occlusion (CO) and maximum intercuspation (MI) in prosthodontic restoration; however, no consensus exists. Purpose The purpose of this study was to determine the philosophies of dental educators throughout the United States at both the predoctoral and postdoctoral levels and to compare their attitudes toward desirable maxillomandibular relationships in defined clinical situations. Material and methods A survey was constructed with 5 clinical scenarios presented describing patients with a difference between maximum intercuspation and centric occlusion. The survey was mailed to 171 dentists involved in either predoctoral or postdoctoral dental programs in the United States; including 56 dental schools; the Army, Navy, and Air Force postdoctoral programs; 8 Department of Veterans Affairs postdoctoral programs; and 7 hospital-based programs. Descriptive statistics of the responses were provided. Chi-squared (α=.05) and Fisher's exact test analyses (α=.05) comparing predoctoral and postdoctoral program responses for each question were performed. Results Forty-three predoctoral dental school program responses were received. Forty-one postdoctoral program directors, including the dental school–based programs, 3 armed service branches, 2 Veterans Administration programs, and 1 hospital-based program responded to the survey. Fifteen respondents indicated that they represented both predoctoral and postdoctoral programs, and these data were deleted from the sample. Summarized results for each question reflect on whether the clinicians philosophically believed patients were better off with the elimination of an existing occlusal interference between MI and CO or not. There was no statistically significant difference seen between the predoctoral and postdoctoral responses. Conclusion The controversy regarding the preferred mandibular position for treatment of dentulous and partially edentulous patients continues among dental educators at both the predoctoral and postdoctoral levels in the United States.

Background: Anterior open bites a vertical discrepancy where the upper incisors crowns fail to overlap the lower incisors crown when the mandible brought into the centric occlusion. The aims of this study were to determine the prevalence of anterior open bite in the permanent dentition in a sample of sample of Yemeni adults, 18-25 years old in Sana’a city. Materials and methods: The study was conducted in Sana’a at the faculties of dentistry (Sana’a, Al-Salam, and Science and Technology Universities) to ensure a mixed ethnic sample from all cities in Yemen for a sample of 1585 students (576 male and 1009 female). The overbite was recorded in the dental clinics for the dental students directly in the oral cavity by measuring with metallic rulers the degree of the vertical overlap of the upper incisors to the lower incisors during centric occlusion. The data was processed and analyzed using computer software program “SPSS” (Statistical Package for Social Sciences) version 17. A descriptive statistical analysis was used in this study. Results: The overall prevalence of the anterior open bite in the current study was 4.1%, more frequent among male (8%) than female (1.9%). The normal overbite account was 41.2%, increased overbite reported in 26.75% of the sample, reduced over bite in 22.15%, while edge to edge was recorded in 5.8% of the sample. Conclusion: The prevalence of anterior open bite in Yemeni adults was 4.1%. Males generally showed a higher percentage, 4 times more than female (7.99 in male and 1.88 in female).

To clarify the correlation between the changes in the status of the occlusion system and the systemic posture, an investigation of the states of denture wearing in edentulous and changes in their body sways associated with occlusal support was made, focusing on the postural reflex. Body sway was assessed under four conditions: during clenching, centric occlusion, the rest position wearing upper and lower dentures and during the rest position with no dentures. The following results were obtained:1. The standard deviation in the X component (right-left direction) of body sway was significantly larger during the rest position without dentures than during either of the rest position, centric occlusion, or clenching with dentures.2. The differences in the standard deviations in the Y component (anterior-posterior direction) were not significant among the above four conditions.3. The distance of body sway during the rest position with dentures was significantly larger than any distance during centric occlusion or clenching with dentures, or during the rest position without dentures.

Recording the maxillomandibular relationship is often a challenge. In situations where there is vertical support but no horizontal stability, and the space between posterior teeth of opposing jaws is not adequate for an interocclusal record, impression plaster can be used. Despite limited clinical use, impression plaster is known for its stability. With this technique, the interocclusal record is obtained by applying the material to the buccal surfaces of the posterior teeth, resulting in a precise and stable cast relationship.

Mandibular movement occurs during chewing, speech and swallowing functionally or during bruxism and clenching parafunctionally. Further, the occlusal facet is caused by functional mandibular movement and parafunctional mandibular movement. However, it is not defined to what extent the occlusal facet is within the range of functional mandibular movement. The purpose of this study was to examine the extent of functional tooth grinding in chewing mandibular movement. One hundred dental students were used in this study, and the portion of correspondence of path of chewing and lateral border movement was measured using Sirognathograph Analyzing System III. As a result, some subjects had a large corresponding portion of path of chewing mandibular movement and path of lateral border movement. The extent of functional tooth grinding in chewing movement has been considered to be small near the centric occlusion, however, the results suggested that a large portion of the grinding surface was used by functional mandibular movement.

The purpose of this experiment was to clarify the relation between masticatory path pattern and function, specifically the stability of movement, and to find the path pattern that is the most functionally effective. One hundred healthy subjects were asked to chew chewing gum on one side, and the fifth to the fourteen cycles were classified into eight patterns according to the method developed by Akiyama et al. Stability in terms of masticatory path and rhythm were quantitatively compared between the chewing patterns. As a result, it was found that there was an intimate relation between masticatory path pattern and stability and that the pattern which opened smoothly from the centric occlusion toward the working side and then closed toward the centric occlusion but showed a convex closing path in the vicinity of the centric occlusion was the most functionally effective. Furthermore, it was concluded that it was relatively easy to objectively evaluate masticatory function by merely observing the masticatory path pattern.

This study compared the initial and long-term skeletal and dental effects of Herbst and Bass appliance therapy for correction of Class II malocclusion. The sample comprised 18 pairs of boys matched for growth period at the time of therapy, with similar pre-treatment sagittal and vertical jaw base relationships. One boy in each pair was treated with the Herbst and the other with the Bass appliance. At follow-up, 15 boys of the Herbst group and 17 of the Bass group were available. Lateral cephalograms in centric occlusion taken before treatment, after 6 months of treatment and at the end of growth were analysed. After 6 months of treatment the Bass appliance seemed to have a greater effect on mandibular jaw base position. The correction of overjet and sagittal molar relationship was more complete in the Herbst patients due to dental changes. At follow-up varying effects both between and within pairs were observed. Overall, the skeletal and dental changes from start of treatment to end of growth were of the same magnitude. A restraining effect on the position of the maxilla was observed in both groups, somewhat more pronounced in the Bass sample. Both treatment methods are most useful in correction of severe Class II malocclusions. It was, however, difficult to find possible differences in treatment effects between the two methods due to great individual variations of growth.

When making a complete denture, not only denture stability but also the restoration of function such as mastication and speech must be considered. The purpose of this study was to compare the pressure distribution in the supporting tissue under simulated upper and lower complete dentures using two different posterior occlusal schemes: fully balanced occlusion and lingualized occlusion.The results were as follows:1. In centric occlusion, the occlusal scheme of the artificial posterior teeth did not affect the pressure distribution under complete denture.2. In case of unilateral biting, the occlusal scheme affected the pressure distribution under complete denture with Livdent FB artificial posterior teeth, remarkably.3. In case of unilateral biting in eccentric occlusion, the occlusal scheme affected the pressure distribution. The pressure values increased on the nonworking side.It was concluded that the lingualized occlusion increases the denture stability and distributes the occlusal force to the supporting structures on the nonworking side.

BACKGROUND The management of subcondylar mandibular fractures has been a matter of controversy. Although closed reduction is the most useful method, it can be difficult to achieve anatomical reduction with this technique compared with open reduction and internal fixation (ORIF). Most surgeons prefer to treat subcondylar fractures by extraoral approaches rather than intraoral approaches because extraoral approaches provide good visualization of the operative field. The retromandibular, submandibular, and perilobular approaches are commonly performed in the treatment of displaced condylar or subcondylar fractures and that the functional results of these treatments are good. However, extraoral approaches have a high rate of surgical complications such as salivary fistula formation, visible scarring, and facial nerve injury, compared with intraoral approaches. Therefore, this clinical study evaluated the clinical results of ORIF for mandibular subcondylar fractures through a transoral approach using an angulated screwdriver system without endoscopic assistance. METHODS A study was conducted between March 2011 and October 2012. Eleven patients with subcondylar fractures of the mandible were treated through a transoral approach using an angulated screwdriver. There were 10 male patients and 1 female patient aged 21 to 72 years (mean, 38 years). Nine patients had a symphyseal or parasymphyseal fracture, and 2 patients had isolated subcondylar fractures of the mandible. RESULTS Eleven patients with subcondylar fractures of the mandible were treated with a transoral approach using an angulated screwdriver. The subcondylar fracture was on the left side in 6 patients and on the right in 5. All patients achieved satisfactory ranges of temporomandibular joint movement with an interincisal distance of more than 40 mm without deviation and stable individual centric occlusion. The maximum operation duration was 165 minutes, and the average duration of ORIF was 97 minutes. The association between the operation duration and the number of operations was statistically significant. CONCLUSIONS Our clinical study shows that subcondylar fractures of the mandible can be treated using an angulated screwdriver system through a transoral approach and that this technique provides reliable, satisfactory, and safe clinical outcomes.

Aim The purpose of this prospective study was to determine the number of contacts in centric occlusion during retention with modified and full-coverage thermoplastic Essix retainers. Methods This research was based on 36 patients who were randomly assigned to wear either modified (18 patients) or full-coverage (18 patients) Essix retainers. Silicone-based bite registrations were used to record occlusal contacts at the beginning (T1), end of full-time (6 months; T2), and end of night-time (3 months; T3) wear of retainers. The occlusal contacts determined in treated patients were compared with the values of 18 untreated "normal" Class I subjects. Bonferroni-adjusted Wilcoxon and Kruskal-Wallis tests were used to evaluate intra- and intergroup differences. Results Total posterior contacts increased significantly at T3 compared to T1 and T2 only in the modified Essix group. Non-ideal and total contacts on premolars, non- ideal and actual contacts on first molars, and actual contacts on second molars increased significantly at T3 in the modified Essix group. No significant increase was determined in the final total posterior contacts in the full-coverage Essix group. Actual contacts on premolars and first molars and total posterior actual contacts were significantly greater at T3 in the modified Essix group compared to the full-coverage Essix Group. Also the number of final posterior ideal contacts in the modified Essix group was greater than in the normal sample. Total anterior contacts decreased significantly in the modified Essix group, whereas they increased significantly in the full-coverage Essix group. Conclusions Increase in posterior contacts was achieved only during night-time wear of modified Essix retainers.

This study was conducted on the occlusal contacts during physical exercise.The experiment was carried out to examine the clenching strength on the occlusal contact area and occlusal force when one grips by using a Dental Prescale System. The subjects were 9 males.The results were as follows:1. Majority of subjects showed the maximum clenching strength on the occlusal contact area and occlusal force.2. Some who clenched eccentrically, as for jaw relation, and clenched unilaterally to the centric occlusion were observed.3. Some who clenched stronger than the maximum clenching strength and the rest who clenched weaker than maximum clenching strength were observed.

The purpose of this study was to determine the patterns of occlusal contacts and location in intercuspal position of natural teeth.A cross-sectional study was conducted with a sample size of around seventy patients within a span of seven months, complete mouth impressions were made of each patient with hydrocolloid material and the impressions were poured in dental stone. The contact areas of the teeth in the maximum intercuspation position were determined by wax. Three distinct types of indentations were noted on the wax interocclusal record. Then similarly the centric occlusion contacts of the teeth on the cast were determined by interposing a new piece of wax, approximating the casts in the maximum intercuspation position by hand, and applying pressure. The oral and cast wax recordings were then compared. The occlusal relation for each individual tooth was then classified and recorded in a Performa.Following wax interocclusal record of natural teeth in intercuspation an ideal occlusion was absent, a difference in morphology of anterior and posterior teeth was also evident that inevitably affects the nature of occlusal contacts.The ideal occlusion was not found in any of the patient’s investigation.

In making a complete denture, the selection of the artificial posterior teeth is one of the important factors to obtain denture stability and to avoid high pressure applied to the supporting structure under a denture. The purpose of this study was to investigate the influence of the occlusal surface of the artificial posterior teeth on the pressure distribution under a complete denture.The results were as follows:1. In centric occlusion, the occlusal surface of different artificial teeth did not affect the pressure distribution under the complete denture.2. In one-side occlusion, the pressure values were changed remarkably in the buccal area on the working side and palate area as compared with the pressure distribution under the complete denture with two different artificial teeth.3. In one-side occlusion at an eccentric position, the occlusal surfaces of the artificial teeth affect the pressure distribution under the complete denture. The pressure values under the lower denture with Bio-Ace artificial posterior teeth increased on the nonworking side.

In order to clarify various aspects of bearing stress due to change of buccolingual arrangement at centric occlusion, distribution and mobility of bearing stress applied on the basal seat of the complete upper denture were comparatively studied.The results were as follows:1. Bearing stress distribution1) Bearing stress on bone was low compared with that of mucosa in all of C, B and P arrangements.2) Bearing stress on the ridge, border and buccal was increased in B compared with C, while it was decreased in P. The stress on the palate and postdam was decreased in B, while it was increased in P.2. Bearing stress mobility1) Duration of bearing stress on bone was shorter compared with that of mucosa in all arrangements. It was remarkably shorter on the palate and tuberosity in B as well as on the buccal and tuberosity in P.2) Duration of bearing stress on the ridge, border and buccal in B was approximately equal to that of C, while it was shorter on the border and buccal in P. The stress on the palate and postdam in B was reduced, while it was extended in P.3) Load reaching time was approximately equal in all arrangements.4) Duration of bearing stress was approximately equal to load reaching time in all arrangements. It was shorter on the palate, postdam and tuberosity of bone in B as well as on the border, buccal, postdam and tuberosity of bone in P.

This study was designed to identify differences in the masticatory muscles between patients with mandibular prognathism and normal subjects. Electromyograms during maximum centric occlusion and in the occlusion adjusted to 5 kg by the use of a jaw force meter (NIHON KOHDEN Co.) were recorded at the masticatory muscles (masseter, anterior and posterior temporal muscles) by means of surface electrodes. The occlusal force and total contact area during maximum occlusion were recorded and calculated using an Occlusal Prescale System (Fuji Film Co.). Thirteen patients with mandibular prognathism and 20 subjects without craniomandibular dysfunction were studied in terms of their electromyographic signals and occlusal force before and after orthognatic surgery. Histochemical analysis of the masseter muscles was carried out in 9 patients and 4 normal subjects.The results were as follows:1) The masseter muscles are the main muscles during masticatory movement in subjects without biting malfunction. The anterior temporal and posterior temporal muscles change their activity according to the working side and the balancing side.2) It was found that patients had higher electromyographic activity than subjects without malfunction in a closed-jaw position before surgery.The total-contact-area and occlusal force were significantly lower in patients compared with the normal group. There was no difference in average biting pressure.3) After orthognathic surgery, total-contact-area of centric occlusion and occlusal force were increased. There were no significant differences between patients and subjects without malfunction. There were also no significant differences in average biting pressure between the two groups both before and after surgery.4) There was a period of electric-overdischarge among the patients for 2 or 3 months after operation. Concurrently, a change in load ratio among the muscles was noted.5) A so-called “type 1 fiber predominance” masseter in which type 1 fibers accounted for over 55% of muscle fibers was found frequently in the patients. In some cases, electric-myographic volume was still high even after operation. This was found particularly among patients with a high-Type 1 fiber-ratio.

We studied the effects of complete occluded maxillary and mandibular dentures with regard to maintenance, stability and surrounding supportive tissues and measured the stress-bearing of maxillary denture mucosa and bones at the centric occlusion. The results were compared with the stress-bearing of a complete maxillary denture with a good fit between maxillary and basal mucosa.The results were as follows:1. Distribution of stress-bearingThe stress-bearing of the top of the residual ridge of anterior teeth, part of the basal margin and buccal region was remarkably higher than that of fit complete denture (FCD). The stress-bearing of incisive papilla, top of the molar residual ridge, top of the maxillary tuberosity, part of the buccal region, palate and post dam was lower than that of FCD2. Mobility of stress-bearing1) It was especially quick in the top of the maxillary tuberosity and palate. The onset of stress-bearing of the residual ridge, basal margin and buccal region was slower than that of FCD. It was quick for the palate and post dam.2) It was much quicker than the loading time of the maxillary bone of the top of the tuberosity, palate and post dam.3) The start of stress-bearing was slower than that of loading of the palate and maxillary tuberosity.

The purpose of the present study was to elucidate how the distribution of bearing stress and dynamics of basal seat under upper complete denture on during mastication give influence on the disorder of the under denture. First, evaluation was made on bearing stress of basal seat under upper complete denture at the centric occlusion on the alveolar bone.The results were as follows:1. Distribution of bearing stress Compared with the case of alveolar mucosa, the bearing stress on the alveolar bone was remarkably low.The bearing stress on the alveolar ridge was higher in both alveolar mucosa and alveolar bone than on the other measuring points. In paticular, the bearing stress was highest on the incisive papilla. Next to the alveolar ridge, it was high on the border. On the buccal region and palate, the bearing stress was lower compared with the alveolar ridge and border. The postdam region was the lowest.2. Dynamics of bearing stress1) The time of occurrence of the bearing stress on the alveolar bone was shorter than on the alveolar niucosa. Particularly, this was more remarkable on maxillary tuberosity and palate.2) Time of the bearing stress occurrence was approximately equal to the load reaching time, but it was remarkably shorter on maxillary tuberosity and a part of the palate.