Tooth position in relation to the denture base foundation

Esthetic orthodontic treatment with a double J retractor and temporary anchorage devices

The aim of this report is to describe a significantly deficient case of alveolar bone that was managed by alveolar bone augmentation using a technique of distraction osteogensis and onlay bone grafting prior to dental implant placement. Injury to the teeth and alveolar ridge of the maxillary anterior region can cause a severe alveolar ridge deficiency resulting in ridge atrophy and maxillary retrognathism. The loss of these teeth and alveolar bone together with fibrotic scar formation can result in adverse changes of the interarch space, occlusal plane, arch relationship, and arch form which complicates rehabilitation and can compromise the esthetic outcome. While implant dentistry has become a new paradigm in oral reconstruction and replacement of missing teeth, ideal implant positioning can be compromised by inadequate alveolar bone in terms of bone height, width, and quality of the bone itself. Correction of osseous deficiencies with ridge augmentation allows ideal implant placement and creates a more natural soft tissue profile which influences crown anatomy and esthetics. A 20-year-old female presented with a complaint of poor esthetics resulting from oral injuries incurred in a traffic accident six years previously. In addition to a mandibular parasymphyseal fracture, five maxillary anterior teeth and the most of the alveolar ridge were lost. Clinical examination revealed severe loss of bone in the maxillary anterior region, an absence of a labial sulcus, loss of upper lip support, and a slight over eruption of the mandibular anterior teeth. In preparation for dental implants a distraction osteogenesis surgical procedure was done to lengthen the height of the alveolar ridge. After a three-month healing period, the width of the residual ridge was found to be insufficient for implant placement. To correct this deficiency, a bone graft of a cortiocancellous block was harvested from the chin and fixed to the labial aspect of the ridge. To facilitate revascularization, small perforations were made in the cortical bone of the alveolar ridge at the recipient site before cancellous bone retrieved from the donor site was gently placed between the bone block and the ridge. The patient was then appropriately medicated and healing was uneventful. After three months, the width of the residual ridge was assessed to be adequate for endosseous implants. The clinical result reported here has shown several procedures may be necessary for the rehabilitation of a trauma patient. Distraction osteogenesis per se may not always satisfactorily improve the anatomical alveolar anatomy but it has advantages over other methods of augmentation. It can improve the height and also expand the soft tissue for further bone grafting. Augmentation of the alveolar bone with an onlay bone graft often provides the desired gain of bone, allows for the ideal placement of dental implants, and improves any discrepancy between the upper and lower arches.

Periodontal biotype is a key element influencing esthetic treatment outcomes in clinical practice. However, while the soft and hard tissue thicknesses of maxillary anterior teeth have been widely studied, information regarding mandibular anterior teeth is scarce. Therefore, the aim of this study was to determine whether there is a relationship in terms of hard and soft tissue thickness between maxillary and mandibular anterior teeth. The present study included 90 maxillary and 90 mandibular anterior teeth in 15 healthy patients. Clinical and cone beam computed tomography measurements were taken to determine gingival and buccal bone thickness, respectively, and a correlation was made between maxillary and mandibular anterior teeth. No statistically significant differences were found when comparing gingival and buccal bone thickness at the crestal third and midpoint of maxillary and mandibular teeth (P > .05). However, some differences were observed at the apical third between the two groups. The results suggest that soft and hard tissue dimensions of maxillary and mandibular anterior teeth are comparable, especially in the coronal third. However, more studies are necessary to confirm that maxillary anterior teeth can be used as a reference when dealing with mandibular incisors and canines.

To measure passive tactile threshold of implant-supported single crowns (ISSC) in six orthogonal orientations, to analyze impact factors, and to guide the occlusal adjustment in a personalized manner. The passive tactile thresholds of 24 implant-supported single crowns (5 maxillary anterior teeth, 7 maxillary posterior teeth and 12 mandibular posterior teeth) from 19 ISSC patients (8 men and 11 women, from 25 years old to 56 years old) were measured in six orthogonal orientations (four horizontal orientations of labial or buccal, lingual, mesial and distal, and two axial orientations of apical and coronal) using a digital test system for tactile function of teeth.SPSS 19.0 for windows was used to analyze impact factors, using double-sided test, with a significance level of 0.05. Paired-samples t test was used to test the difference between implant-supported single crowns and the controlled natural teeth, and between different time points. One-way ANOVA was used to test the difference between different orientations, maxilla-mandibular anterior-posterior, and men-women. The passive tactile thresholds of ISSC and control teeth were (1282 ± 709) and (40 ± 40) mN respectively. The difference was of statistical significance (P < 0.001). The passive tactile thresholds of buccal-lingual, mesial-distal and axial of ISSC were (1334 ± 696), (1102 ± 605) and (1412 ± 791) mN respectively, of which, the difference between mesial-distal and axial was of statistical significance (P < 0.05). The passive tactile thresholds of ISSC of maxillary anterior teeth, posterior teeth and mandibular posterior teeth were (1003 ± 616), (1302 ± 620) and (1386 ± 769) mN respectively, of which, the difference between maxillary anterior teeth and posterior teeth was of statistical significance (P < 0.05). The passive tactile thresholds of ISSC of men and women were (1751 ± 784) and (946 ± 393) mN respectively, the difference was of statistical significance (P < 0.001). The passive tactile thresholds of ISSC of one-week and one-month after wearing the teeth were (1421 ± 826) and (1411 ± 814) mN respectively, the difference was of no statistical significance (P > 0.05). The passive tactile threshold of ISSC was more than 65 times as much as that of the natural teeth. There was statistical significance between different orientations, between maxillary anterior and posterior teeth, and between men and women. No statistical significance was found between maxillary and madibular posterior teeth and between one-week and one-month after wearing the teeth.

To compare the root length of maxillary and mandibular anterior teeth between open bite patients and normal overbite patients via cone-beam computed tomography (CBCT) as well as the root length of anterior teeth in different degree of open bite patients, and to analyze the correlation between the degree of open bite and root length. A total of 106 untreated patients were enrolled retrospectively (53 anterior open bite patients and 53 normal overbite patients).Three-dimensional position of the CBCT image for the patient's teeth was performed using Dolphin software. The median sagittal plane of the tooth was used as the measurement plane, and the line connecting the apical point and the midpoint between the labial and lingual cementoenamel junctions was defined as the root length. Independent t-test was used to compare the difference of anterior root length between the open bite group and normal overbite group, mild open bite group and moderate-severe open bite group. Pearson correlation analysis was used to explore the correlation between the degree of open bite and the root length of anterior teeth. Significant differences were found in the root length of maxillary and mandibular anterior teeth between the open bite group and the normal overbite group (P<0.001), and there was significant difference in root length of mandibular central incisor between mild open bite group and moderate-severe open bite group (P=0.039). Pearson correlation analysis showed that maxillary anterior teeth were correlated with root length of anterior teeth (all P<0.05). The root length of maxillary and mandibular anterior teeth in the open bite patients is shorter than that in the normal overbite patients, and the severer the degree of open bite, the shorter the root length of the mandibular central incisor tends to be. There is a certain relationship between maxillary anterior teeth and the root length of anterior teeth.

OBJECTIVE To measure the distance from cemento-enamel junction (CEJ) to alveolar crest (AC) of labial side of anterior teeth on skeletal Angle class III patients under direct vision during periodontal bone augmentation surgery and to make relevant analysis to find the relevant factors. METHODS In the study, 46 skeletal Angle class III patients (10 males and 36 females) received periodontal bone augmentation surgery of anterior teeth were included, with 67 jaws (27 maxillae and 40 mandibles) and 400 anterior teeth (161 maxillary anterior teeth and 239 mandibular anterior teeth). The mean age was 23.65 years. Maxillary anterior teeth consisted of 54 central incisors, 53 lateral incisors and 54 canines. Mandibular anterior teeth consisted of 79 central incisors, 80 lateral incisors and 80 canines. CEJ-AC was measured in three sites (mesial sites, central sites and distal sites) by Williams periodontal probes during periodontal bone augmentation surgery under direct vision by the same researcher. RESULTS The average CEJ-AC of 400 anterior teeth was (2.21±1.48) mm. The average CEJ-AC of maxillary anterior teeth was (1.72±1.13) mm, more than (2.54±1.60) mm of mandibular anterior teeth (P<0.05). The average CEJ-AC of canines was (2.42±1.78) mm, more than (2.06±1.27) mm of central incisors or (2.16±1.32) mm of lateral incisors (P<0.05). The average CEJ-AC of central sites was (3.04±2.01) mm, more than (1.79±0.86) mm of mesial sites or (1.81±0.89) mm of distal sites (P<0.05). CEJ-AC of 233 anterior teeth was more than 2 mm, accounting for 58.25%, and 117 anterior teeth with dehiscence were found, accounting for 29.25%. Multilevel and multivariate Logistic regression showed age, jaw, tooth and site were the relevant factors to the position of alveolar crest. CONCLUSION The position of alveolar crest of skeletal Angle class III patients who received periodontal bone augmentation surgery was lower than that of the general population, causing periodontal risks during decompensation orthodontics therapy before orthognathic surgery. The position of alveolar crest was lower in older patients than in younger patients, in mandibular teeth than in maxillary teeth, in canines than in central incisors or lateral incisors, and in central sites than in mesial sites or distal sites of labial side, which showed much higher risk.

Objective: To evaluate the factors associated with the gingival papilla deficiencies of different degrees between maxillary anterior teeth showing alveolar ridge absorption. Methods: A total of 64 gingival papillae between maxillary anterior teeth of 14 patients with periodontitis, who received periodontal treatment and regular review in the Department of Periodontology, Peking University School and Hospital of Stomatology from June 2019 to December 2019, were observed in the present study. Indices were measured by using standardized clinical photographs and cone-beam CT images. The correlations between the gingival papilla deficiencies of different degrees and the distance from contact point to bone crest (CP-BC), the distance from proximal cemento-enamel junction to bone crest (pCEJ-BC), interproximal distance between roots (RD), the width of bone crest (BCW) and the height of gingival papilla (PH) were evaluated. Statistical analyses such as t-test, ANOVA, Pearson correlation coefficient and so on were conducted. Results: The rate of maxillary anterior gingival papilla completely filled the adjacent spaces between anterior teeth was 28% (18/64) and the rate of gingival papilla with deficiencies was 72% (46/64). The mild, moderate and severe deficiencies were 36% (23/64), 27% (17/64) and 9% (6/64) respectively. When CP-BC≥7.0 mm or pCEJ-BC≥4.5 mm, only moderate or severe deficiencies appeared. However, when CP-BC<5.0 mm or pCEJ-BC<1.5 mm, only completely filled adjacent tooth space or mild deficiency appeared. There was a strong positive correlation between CP-BC and pCEJ-BC. The Pearson correlation coefficient was 0.812 (P<0.01), and the linear fitting coefficient was 0.93 (R2=0.659) (64 gingival papillae). There was no significant difference of RD for gingival papilla deficiencies of different degrees between maxillary anterior teeth (P>0.05). BCW at the crest level increased slightly with the increase of the degree of gingival papilla deficiency, and the difference was statistically significant between completely filled adjacent tooth space and moderate or severe deficiency (P<0.05). However, PH at the crest level decreased slightly with the increase of the degree of gingival papilla deficiency, and the difference was statistically significant between completely filled adjacent tooth space and moderate or severe deficiency (P<0.05). Conclusions: When the alveolar ridge is absorbed, the rate of deficiency is significantly higher than the completely filled adjacent tooth space. The gingival papilla deficiencies of different degrees between maxillary anterior teeth are mainly associated with the absorption of bone crest.

Background/Objectives: The purpose of this study was to measure the bone thickness and angulation of the maxillary and mandibular anterior teeth on the buccal and palatal/lingual sides and also to analyze the sagittal root position (SRP) in the alveolar bone in relation to age and gender using cone-beam computed tomography (CBCT) in an Iraqi subpopulation. Methods: CBCT images of 1200 maxillary and mandibular central and lateral incisors and canines from 100 patients (48 males and 52 females) were retrospectively analyzed. These patients were categorized by age into group I ≤ 25, group II 26-40, and group III ≥ 41 years old. The SRP in the alveolar bone was classified as class I, class II, class III, and class IV, and the buccal type was further classified into subtypes I, II, and III. In addition, the buccolingual inclination of the tooth and buccal/palatal/lingual bone thickness at the coronal, middle, and apical thirds were evaluated and then compared based on age and gender. The data were analyzed using the Pearson chi-square test. Descriptive statistics, Kruskal-Wallis and Mann-Whitney U test were used to compare the thickness and angulation according to the SRP classes. Results: The mean frequency distribution of SRP of maxillary anterior teeth indicated that most of them were located buccally and were classified as (Class I) and subtype (III). Moreover, for mandibular anterior teeth, the majority were classified as (Class IV) and subtype (II). The mean sagittal angulation of maxillary anterior teeth approximately ranged from 5.9 for tooth 12# to 8.2 for teeth 13# and 23#, while for mandibular anterior teeth it ranged from 7.4 for tooth 33# to 10.3 for tooth 41#. The thickness of bone in the apical third of the buccal side of all maxillary and mandibular teeth was significantly related to age (p < 0.05). In the middle third, the thickness of bone in the buccal and palatal side of all maxillary anterior teeth and in the apical third of most mandibular teeth in the lingual side was significantly higher in males (p < 0.05). Conclusions: A majority of the maxillary anterior tooth roots were positioned close to the buccal cortical plate, while most of the mandibular anterior teeth were engaging both the buccal and lingual cortical plates. Males had more alveolar bone thickness for both maxillary and mandibular anterior teeth, and only the apical portion significantly changed with age. CBCT of the buccal and palatal/lingual bone and SRP is recommended for the selection of the appropriate treatment approach and implant placement.

The relationship between tomographic sagittal root position of maxillary anterior teeth and the bone housing

Objects : The purpose of this case report is to restore healthy tooth function with compromised tooth replacement so that patients are more confident and chew food well, a good choice of denture selection methods are good for patients with loss of one anterior maxillary tooth with adhesive bridge denture treatment and choice of removable partial denture metal frames as an alternative solution to the replacement of mandibular posterior teeth. Methods : A 65 years old female patient came to Dental Hospital Hasanuddin University with complaints of a loose maxillary partial denture complaining and difficulty chewing food because her posterior teeth had been removed +/- 7 years ago and her anterior teeth were removed about +/- 5 years ago. Want to replace the old removable partial denture with fixed denture for maxillary anterior teeth and also want to make a partial denture metal frames for mandibular teeth. Results : The case of loss of one maxillary anterior tooth was successful with the treatment of adhesive bridge dentures and the use of a removable partial denture metal frames a more stable and retentive mandibular posterior tooth loss that showed a better prognosis. Conclusion : Use of adhesive bridge dentures for maxillary anterior teeth and partial dentures metal frames for posterior mandibular teeth provides satisfaction for patients because it can overcome aesthetic problems and improve good phonetic and masticatory functions.

The bucco-palatal sinus width (SW) appears as relevant factor for graft consolidation after maxillary sinus (MS) floor augmentation. The present study aimed to assess (a) SW at different height levels of posterior teeth, (b) possible factors influencing SW, and (c) whether a simple/meaningful sinus classification based on SW is possible. The following parameters were recorded on computed tomographies of 76 edentulous and 86 partially edentulous maxillary quadrants displaying 383 tooth sites in total: (a) alveolar ridge height, (b) -area, (c) -width 2mm apical to the alveolar crest, (d) -width at the sinus floor, and (e) SW and sinus area at a level 2, 4, 6, 8, and 10mm above the sinus floor. The possible influence of gender, tooth position [i.e., premolar (PM); molar (M)], tooth-gap extent, and residual alveolar ridge dimensions on SW was assessed. Further, based on percentiles of average values or on the frequency distribution of SW <10, 10-15, or >15mm, it was attempted to classify the sinus at each given site into narrow, average, or wide. Gender and tooth-gap extent presented no relevant impact on MS dimensions; however, significant differences were observed among the various tooth positions regarding all evaluated parameters. The lower the residual alveolar ridge, the wider the MS at 4-10mm height, while the wider the residual alveolar ridge, the wider the MS. Large variation in SW classes among the different height levels within the same tooth position and among tooth positions within the same person was observed, irrespective of the threshold applied. Further, at a MS height of 10mm at PM1, PM2, M1, and M2, SW was <10mm in 68%, 33%, 0%, and 7% of the cases, respectively, while in 3%, 21%, 65%, and 57%, respectively, SW was >15mm. There is a large variation in SW depending on the height level within the sinus and on tooth position, which does not permit a simple/meaningful classification of each sinus as "narrow," "average," or "wide." Nevertheless, narrow sinuses (<10mm) are rather prevalent in the premolar region, while wide sinuses (>15mm) in the molar region; further, a wider and shorter residual alveolar ridge is associated with a wider SW.

With the rapid development of computer technology, the application of digital technology to the display and processing of medical images has become a common concern. In recent years, oral digital imaging technology has received more and more attention. This paper mainly aims at the ODIS-1 oral digital imaging system to analyze and study the image quality and image aims at the ODIS-1 oral digital imaging system to analyze and study the image quality and processing technology, of which X-ray imaging is indispensable. In this paper, the ODIS-1 digital scanning technology is used to detect different types of dental tissues, and its application in diagnosing oral diseases is evaluated. This paper takes 320 inpatients as the research object and uses Kodak dental film to compare the image quality of different positions. It is found that there is no significant difference in image quality between the maxillary anterior teeth and mandibular anterior teeth and the maxillary posterior teeth and mandibular posterior teeth (P>0.05); the image quality of maxillary anterior teeth, mandibular anterior teeth, and maxillary posterior teeth and mandibular teeth are significantly different (P<0.05); among the various positions of the ODIS-1 oral digital imaging system, the image quality of the anterior teeth area is the best, while the image quality of the maxillary posterior teeth area is the worst. However, the system has a variety of image post-processing functions, which can adjust the brightness and contrast of the image arbitrarily, select the area of interest in the image according to the detection requirements, and perform local amplification, edge enhancement, and other technologies to make the image achieve the best effect. In the case of poor image quality, the clarity of the image can be further improved through image post-processing and analysis.

Background: The aesthetic and functional aspects of artificial tooth selection are pivotal for an individual's quality of life, a skill paramount to every prosthodontist. It gives a pleasing, expressive and confident life to the patient. Aim: This study aimed to juxtapose the dimensions of natural maxillary and mandibular anterior and posterior teeth with those of three commercially available denture teeth brands: Acryrock, Biorock, and Ivoclar Vivadent, taking into account gender variations Materials and Methods: Dentate casts from 23 males and 77 females were scrutinized for length and width of the natural anterior and posterior teeth dimensions. These measurements, collected by a single examiner employing a digital vernier calliper and flexible ruler, were subsequently compared to the specifications provided in the respective denture teeth mold charts. like Acryrock, Biorock, Ivoclar vivadent. The dimensions thus obtained are compared between the three systems of artificial teeth and natural teeth for selecting the best system of artificial teeth for complete denture prosthesis. Results : The study revealed that all three artificial teeth systems matched the width of natural maxillary anterior teeth. However, only the Ivoclar Vivadent teeth set closely resembled the dimensions of mandibular anterior and posterior teeth, as well as maxillary posterior teeth, across both genders. Conclusion: The findings confirm the feasibility of employing natural teeth dimensions to determine the size of anterior and posterior artificial teeth for complete denture prosthesis fabrication, providing a statistically and mathematically supported approach. keywords: artificial teeth, aesthetics, complete denture, dentulous subjects, mesiodistal width, prosthesis.

Purpose:The objective of this study was to use cone-beam computed tomography (CBCT) scans to measure and correlate the maxillary and mandibular tooth–ridge angulation (TRA) and labial bone perforation (LBP) in anterior teeth.Materials and Methods:A standardized technique was used to orientate Planmeca CBCT images in 140 patients. On the sagittal section, TRA was defined as the angle between the long axis of the tooth and the alveolar housing of the corresponding tooth. The maxillary and mandibular anterior teeth’s sagittal root locations were evaluated. Virtual implant software was used to analyze bone perforations using a predetermined taper implant system.Results:A total of 1680 teeth were scanned for this investigation, and 1338 teeth were selected for further analysis. In comparison to the mandible, the maxilla had a greater TRA. LBP was found to be 4.26% (57 teeth) more common in the mandibular arch (n = 39; 68.42 and) than in the maxillary arch (n = 18; 31.58%). When comparing both the sides, there was no significant difference in LBP. There was a significant relationship between TRA and LBP (P < 0.05). There was a significant association between all parameters. There was no statistically significant difference in TRA, sagittal root position (SRP), and LBP between the right and left teeth.Conclusions:The SRP type 1 is most typically present in the anterior teeth. The maxillary anterior teeth were placed at a 5°–10° angle, while the mandibular incisors were parallel to the alveolar ridge. The LBP was more characteristically present in the mandibular incisors. SRP and TRA were directly correlated with LBP. Clinically, bone perforations may be reduced using taper implants and abutments with a 5°–10° angle in maxillary anterior teeth, while straight implants are preferred in mandibular anterior teeth, which may be recommended.

OBJECTIVE:To comparatively evaluate the ability of three different customized lingual appliance systems in achieving predicted results with respect to the mesiodistal crown tip, labiolingual crown inclination, in–out position of Maxillary permanent anterior teeth, and Maxillary arch form.METHODS:Three commercial houses: Incognito, iLingual 3D, and Lingual matrix were analysed in this study. The final sample size consisted of 42 cases. Fourteen digital prediction and posttreatment models of the maxillary arch were provided by three orthodontic offices each using a different system. Discrepancies between the prediction and posttreatment model in mesiodistal tip, labiolingual inclination, in–out position of anterior teeth, and arch form were analyzed.RESULTS:Incognito displayed the highest accuracy in all parameters except for in–out positioning. Lingual Matrix showed greater precision in achieving planned mesiodistal positions than labiolingual inclination while it was just the opposite for iLingual 3D. All three systems proved to be clinically reliable in achieving the predicted in–out positions of permanent Maxillary anterior teeth.CONCLUSION:These systems were considerably accurate in achieving planned treatment goals with minute deviations from the predicted value.