Congenitally missing permanent canines in a sample of Chinese population: a retrospective study

BACKGROUND

Congenitally missing permanent canines (CMPC) have a significant impact on function and aesthetics. The prevalence is low, and the availability of rigorous studies on this issue in China is limited. This study was designed to investigate the prevalence and distribution of CMPC in patients and concomitant anomalies. Additionally, we aimed to compare the prevalence of CMPC between two age groups.

METHODS

A total of 10,447 patient's panoramic radiograph (PR) images from August 2021 to December 2023 were reviewed and data regarding the location and number of CMPCs were recorded. Age and gender were obtained from the clinical records. Additionally, concomitant anomalies such as persistent primary canines, congenitally missing other permanent teeth, supernumerary teeth and microdontia were also recorded in patients with CMPC. 10,447 patients were divided into two groups: group A (< 121 months of age) and group B (≥ 121 months of age) to record the number of patients with CMPC. The data were presented as counts (n) and percentages (%), and statistically analysed using the Chi-square test.

RESULTS

The average age of patients with CMPC was 9.2 years, with a prevalence of 0.69% (n = 72). The difference between genders was not statistically significant (p = 0.950). The prevalence of CMPC in group B (1.08%, 26/2400) was significantly greater than that in group A (0.57%, 46/8047) (p = 0.008). 89.42% (93/104) of the missing permanent canines had visible primary canines in patients. CMPC were more likely to occur in the maxilla (91.67%) than in the mandible (6.94%) (p<0.001). No significant difference was found between the left and right sides (p = 0.844). With respect to concomitant anomalies among those with CMPC, 22 patients had 58 congenitally other permanent teeth missing, 3 patients had 3 supernumerary teeth, and 12 maxillary lateral incisors from 7 patients presented with microdontia.

CONCLUSIONS

The prevalence of CMPC was 0.69%. CMPC were more likely to occur in the maxilla in the presence of persistent primary canines and were not influenced by gender or side. Early panoramic radiographs can improve the detection rate of CMPC, thereby facilitating prompt intervention and timely management.

Reverse Engineering Orthognathic Surgery and Orthodontics in Individuals with Cleft Lip and/or Palate: A Case Report

This case report presents a virtual treatment simulation of the orthodontic treatment and surgery-first orthognathic surgery employed to treat a patient with a repaired unilateral cleft lip and alveolus with Class III malocclusion and lower third facial asymmetry. The patient exhibited a negative overjet of 9 mm, a missing lower right second premolar, and a 5 mm gap between the upper right central and lateral incisors with midline discrepancy. The three-dimensional virtual planning began with virtual pre-surgical orthodontics, followed by the positioning of the facial bones and teeth in their ideal aesthetic and functional positions. The sequence of steps needed to achieve this outcome was then reverse-engineered and recorded using multiplatform Nemostudio software (Nemotec, Madrid, Spain), which facilitated both surgical and orthodontic planning. The treatment included a two-piece segmental maxillary osteotomy for dental space closure, a LeFort I maxillary advancement, and a mandibular setback with bilateral sagittal split osteotomy to correct the skeletal underbite and asymmetry. A novel approach was employed by pre-treating the patient for orthognathic surgeries at age 11, seven years prior to the surgery. This early phase of orthodontic treatment aligned the patient's teeth and established the dental arch form. The positions of the teeth were maintained with retainers, eliminating the need for pre-surgical orthodontics later. This early phase of treatment significantly reduced the treatment time. The use of software to predict all the necessary steps for surgery and post-surgical orthodontic tooth movements made this approach possible. Multi-step virtual planning can be a powerful tool for analyzing complex craniofacial problems that require multidisciplinary care, such as cleft lip and/or palate.

A Post-Implanto-Prosthetic Rehabilitation Study Regarding the Degree of Improvement in Patients' Quality of Life: A Before-After Study

BACKGROUND

Implant-prosthetic rehabilitation has the ability to improve the quality of life of patients, because, in addition to the role of restoring masticatory function, they also have many other benefits, such as restoring aesthetics or improving speech. This study aimed to analyze whether patients' quality of life was improved by implanto-prosthetic rehabilitation and which were the most important aspects.

MATERIALS AND METHODS

In this before-after study, we applied the Oral Health Impact Profile (OHIP-14) questionnaire to analyze the degree to which complex implanto-prosthetic rehabilitation led or not to an increase in patients' quality of life. The present study was carried out at the level of a private medical center in a city in the central region of Romania and included patients who visited this medical center between January and June 2022 and who benefited from a complex implanto-prosthetic rehabilitation, with the total number of patients eligible for inclusion in the study being 116.

RESULTS

Overall, an improvement in quality of life after implant-prosthetic rehabilitation was found. Patients' gender, age, or educational level did not significantly influence their responses. The network analysis offered an overview (intuitive visual representation) of the similarities but also the differences in the OHIP-14 item relationships in both situations: before and after oral rehabilitation.

CONCLUSIONS

A better understanding of how patients perceive implanto-prosthetic rehabilitation and the aspects that influence this perception can lead to an improvement in their quality of life, increasing the addressability of this type of medical procedure.

Investigation of the Mesiodistal Angulations of Maxillary Canines and Central Incisors for Missing Bilateral Maxillary Lateral Incisor

(1) Background: A missing bilateral maxillary lateral incisor (MBMLI) causes aesthetic and functional problems and a multidisciplinary approach is required for treatment. This study aimed to compare the changes in the mesiodistal axial angulations of the maxillary canines and central incisors with orthodontic treatment of MBMLI. (2) Methods: A total of 56 patients with MBMLI were included in the study, and three groups were formed: the control group (Group 1, n = 20) with untreated ideal occlusion and the space opening (Group 2, n = 20) and space closure (Group 3, n = 16) groups as treated study groups. The mesiodistal angulations between the long axes of the maxillary right canine (tooth no 13), right central incisor (tooth no 11), left central incisor (tooth no 21) and maxillary left canine (tooth no 23), and the bicondylar plane, were measured on the panoramic radiographs taken pre (T0) and post treatment (T1). p < 0.05 was accepted for statistical significance. (3) Results: At T0, while there was no significant difference between the mesiodistal angulations of the right-left maxillary canines and central incisors in all groups (p > 0.05), the mesiodistal angulations of the canines in the Group 1 were significantly higher than the study groups (p < 0.05). With treatment, while the mesiodistal angulation of the canines increased in Group 2, it decreased in Group 3 (p < 0.05). On the other hand, the mesiodistal angulation of the central incisors decreased in Group 2 and did not change in Group 3 (p > 0.05). At T1, the mesiodistal angulation of the canines was found to be lower in Group 3 than in Groups 1 and 2, while the angulation of the central incisors was found to be lower in Group 2 compared to Group 1 (p < 0.05). (4) Conclusions: In the orthodontic treatment of MBMLIs, changes in the mesiodistal angulations of the maxillary canine and central incisors should be taken into account for satisfactory outcomes. It was concluded that there should be a tendency to select the space closure method in which normal mesiodistal angulations are obtained in maxillary central incisors for aesthetics and planned incisor position, and also at a low cost.

"Examining the link between tooth agenesis and papillary thyroid cancer: is there a risk factor?" Observational study

BACKGROUND

Mutations in one or multiple genes can lead to hypodontia and its characteristic features. Numerous studies have shown a strong genetic influence on the occurrence of hypodontia, and identified several genes, including AXIN2, EDA, FGF3, FGFR2, FGFR10, WNT10A, MSX1, and PAX9, that are directly associated with dental agenesis and carcinogenesis. The objective of this study was to investigate the occurrence and pattern of tooth agenesis, microdontia, and palatally displaced canine (PDC) in women diagnosed with papillary thyroid cancer (PTC), compared to a control group of women without any malignancy or thyroid disease.

MATERIALS AND METHODS

This case-control study was carried at the Department of Orthodontics, School of Dental Medicine University of Zagreb, and Department of Oncology and Nuclear Medicine Sestre Milosrdnice University Hospital Centre. The study involved a clinical examination and evaluation of dental status, panoramic X-ray analysis, and assessment of medical and family history of 116 female patients aged 20-40 with PTC, as well as 424 females in the control group who were of similar age.

RESULTS

The prevalence of hypodontia, microdontia, and PDC was statistically higher in women with PTC than in the control group. The prevalence rate of hypodontia was 11.3% in the experimental group and 3.5% in the control group. The experimental group showed a higher occurrence of missing upper lateral incisors, lower left central incisors, and all the third molars (except the upper left) compared to the control group. Women with PTC showed the prevalence of PDC significantly higher than the control group (3.5%, 0.7%, p = 0.002). The probability of hypodontia as a clinical finding increases 2.6 times, and microdontia occurs 7.7 times more frequently in women with PTC.

CONCLUSION

Our study suggests a possible link between odontogenesis and PTC. The absence of permanent teeth may increase the likelihood of PTC in women. Leveraging the age-7 orthopantomogram to identify women at high risk for PTC within a critical early detection window could significantly improve oral health outcomes and PTC prognosis through proactive interventions.

Association between Hypodontia and Angle’s Malocclusions among Orthodontic Patients in Kathmandu, Nepal

Background. Disturbances during the early tooth development stages may result in the congenital absence of teeth. The purpose of this study was to assess the relationship between hypodontia and Angle’s malocclusions. Materials and Methods. The sample comprised 601 orthodontic patients’ pretreatment records (242 men and 259 women), selected from the achieved orthodontic records. Developmental anomalies of teeth affecting the number were examined on dental panoramic radiographs. Based on Angle’s classification, pretreatment dental casts were assessed and classified into different classes of malocclusion. The relationship between hypodontia and different classes of malocclusion was evaluated using the chi-square test. Results. The prevalence of tooth agenesis was 7.48%, that is, 45 out of 601 samples. There were a total of 72 (0.42%) missing teeth, excluding the third molars. The most frequent missing tooth was the maxillary lateral incisor (35, 48.61%), followed by the mandibular lateral incisor (14, 19.44%), the mandibular central incisor (6, 8.33%), the mandibular second premolar (5, 6.294%), and the maxillary second premolar (4, 5.55%). Hypodontia was more common in the upper jaw. Although hypodontia was mostly seen in Class I malocclusion patients (7.87%), followed by Class II malocclusion patients (6.99%) and least in Class III malocclusion patients. However, there was no significant difference in hypodontia among different classes of malocclusions (p = 0.352). Conclusion. The most frequently missing tooth was the maxillary lateral incisor, followed by lateral and central mandibular incisors and mandibular second premolars, while excluding the third molars. The present study did not find any association between various types of malocclusions and hypodontia.

Laser Decontamination and LED Photobiomodulation Promote Bone Regeneration and Wound Healing by Secondary Intention, in Alveolar Ridge Preservation-Clinical and Radiographic Evaluation: A Pilot Experience

Background: Tooth loss reduces crestal bone with important resorption of alveolar dimensions, reducing the possibility of placing implants after wounds healing. Objective: The goal of this pilot experience was to consider, in alveolar ridge preservation, the regenerative and decontaminating potential of oxygen high-level laser therapy (OHLLT), a high-frequency and high-power diode laser combined with hydrogen peroxide 10 volumes 3%, and to evaluate wound closure during the 14-21 days after surgery. Methods: For this study we selected 15 patients (age range from 30 to 70 years old) who underwent alveolar ridge preservation (three patients were treated in the anterior maxilla, 12 in the mandibular jaw, with molars and premolars involved). A clinical and radiographic examination was performed at baseline. In this pilot experience, after the extractions, the sockets were treated with photodynamic therapy without dye (OHLLT/SiOxyL+ protocol) to decontaminate the area that was treated, combined with allografts, Osteobiol, granulometry 25, Platelet-Rich Fibrin and collagen membranes, Biogide/Geistlich. Photobiomodulation (PBM) sessions with ATP38 were made for the first 4 months every 2 weeks. Clinical evaluations were performed at 14, 21, 90, and 240 days. Radiographic evaluations with cone beam computed tomography (CBCT) were performed at 240 days, before the second surgery. Two hundred seventy days after the first surgery, a new surgical treatment was made with the same concepts adopted in the first surgery, to place implants. Results: All alveolar ridge preservation surgeries were successful, with minimal bone resorption after 9 months. Closure of gingival tissue healed by secondary intention was achieved after 14 days for all patients, except one, who showed wound closure after 21 days. Conclusions: This pilot experience showed that this technique allowed to obtain new bone and wound healing by secondary intention in treated sites and to place implants in all patients, without other bone augmentation techniques, thanks to extracellular matrix induced by photodynamic laser therapy on grafts materials and to PBM made each 2 weeks for the first 4 months postsurgery. The study was conducted according to the guidelines of the Ethics Committee of the School of Medicine and Surgery at the Milano Bicocca University (protocol n. 11/17), and derived from the approval of Italian National Institute of Health (ISS), protocol 30 July 2007-0040488.

Implant treatment after traumatic tooth loss: A systematic review

BACKGROUND/AIMS

Treatment after traumatic tooth loss is challenging and is currently guided by expert opinion and the individual patient situation. The aim of this study was to provide an overview on the outcome of dental implant treatment in the anterior maxilla after traumatic tooth loss, based on a systematic review of the existing evidence.

MATERIALS AND METHODS

A systematic search of the literature was performed on PubMed, Cochran Library and Web of Science following the PRISMA guidelines based on a structured research question (PICO). All clinical studies of five patients or more with follow-up of at least 1 year after implant loading were included. Patients were at least 18 years of age. Cohen's Kappa-coefficient was calculated. The Newcastle-Ottawa Scale was applied to assess the quality of the included studies. Descriptive statistical methods were applied.

RESULTS

Nine hundred and ninety-nine articles were identified through the systematic search. Finally, six articles were eligible for inclusion. The studies comprised prospective and retrospective cohort studies and case series. From these, 96 patients with 120 implants were included. The age ranged from 18 to 59 years. The survival rates of implants and superstructures were 97% and 95%, respectively, after a mean follow-up of 3.5 years. Mean marginal bone resorption was 0.56 mm (range 0.21-1.30 mm). Complication rates were 7% and 11% on implant and superstructure level, respectively. Patient-reported outcome measures and objective evaluations showed a high level of satisfaction with the aesthetic outcome. Bone augmentation was performed in 60 implant sites. Three patients underwent pre-surgical orthodontic treatment. The maxillary central incisor was the most frequently replaced tooth (70%).

CONCLUSIONS

This systematic review revealed a low level of evidence on the outcome of dental implant treatment after traumatic tooth loss. Systematic reporting of treatment outcomes of tooth replacements after dental trauma is highly encouraged to further guide dentists for the benefit of these challenging patients.

Bidimensional system for space closure treatment of missing lateral incisors: 10 years follow-up

INTRODUCTION:

Missing lateral incisors represent a common condition that normally requires specific anchorage conditions to be treated with space closure mechanics to protract upper teeth creating a proper occlusal relationship.

CASE PRESENTATION:

Two cases showing Class II malocclusion with missing lateral incisors in developing age are presented, both treated with the same approach of maximum anterior anchorage applied using the Bidimensional Technique system. Long-term follow-up of 10 years is shown.

MANAGEMENT AND OUTCOME:

Bidimensional technique is a modified edgewise technique that uses sliding mechanics for protraction of the posterior segments by placing vertically slotted brackets of different sizes on the anterior (.018” x 0.025”) and posterior teeth (.022” x 0.028”). When a .018” x .022” wire is inserted in the .018” x .025” brackets slot on the incisors, third-order control is created in the incisor segment while the wire is undersized in the rest of the arch. Lateral brackets have been positioned on the canines, while the canine brackets have been positioned on the first premolars respecting a differential bonding height able to produce canine extrusion and first premolars intrusion and proper torque expression. Full Class II molar relationship and Class I substituted canine relationship has been reached in both cases and kept stable in the long-term follow-up (10 years).

DISCUSSION:

The described approach provided anterior anchorage with more simple mechanics expressing the anterior torque with a full engagement concept and adding few auxiliaries (uprighting springs) which do not require compliance.

Analysis of the sagittal root angle and its correlation with hard and soft tissue indices in anterior teeth for immediate implant evaluation: a retrospective study

BACKGROUND

To assess the root angle characteristics of maxillary incisors, and to analyze the relationship between the root angle and other implant-related anatomical indices to use the sagittal root angle as an index for immediate implant evaluation and design.

METHODS

A random sample consisting of 400 cone-beam computed tomography (CBCT) images and 65 maxillary plaster models were selected for the present study. CBCT and stereolithography (STL) scan images were imported as DICOM files into coDiagnostiX software for matching the hard and soft tissue. The angle between the long axis of the anterior tooth and the corresponding alveolar bone and implant-related hard and soft tissue indices were measured in the sagittal section. Descriptive statistics, frequency analysis, multi-level comparisons, and correlation analyses were performed.

RESULTS

The average sagittal root angles were 15° at the central incisor and 19° at the lateral incisor. The root angle in males was significantly larger than that in females, and increased with age. The largest angle, 22.35°, was found in the lateral incisors of the oldest (> 50 years old) male group. The root angle was found to correlate with coronal buccal bone thickness, coronal palatal bone thickness, apical buccal bone thickness, palatal bone thickness, and the below apex bone thickness.

CONCLUSIONS

The sagittal root angle could reflect the distribution of other implant-related anatomical indices, which may provide additional reference for the evaluation of immediate implant placement.

Relationship between dental calcification of mandibular teeth and cervical vertebrae maturity in patients with unilateral complete cleft lip and palate

OBJECTIVE

The purpose of this study was to investigate the relationship between the dental calcification stage (DCS) of the mandibular teeth and the cervical vertebral maturation stage (CVMS) in patients with unilateral complete cleft lip and palate (UCLP).

METHODS

One hundred sixty-two UCLP patients (100 males and 62 females) between 8-16 years old were included in this study. The DCS was estimated by the Demirjian method and was converted to the dental age (DA). The CVMS was evaluated by the Baccetti method. The DA of mandibular teeth on two sides of the cleft were analyzed using a t-test. Spearman correlation was used to study the association between CVMS and DCS. The correlation coefficient between the two sides of the cleft was then compared.

RESULTS

The total DA was significantly smaller on the cleft side than on the noncleft side in males (p = 0.022). The Spearman rank correlation coefficient revealed a significant correlation between the DCS of each examined tooth and the CVMS (r = 0.627-0.793 in males and r = 0.806-0.899 in females). Additionally, the correlation of the two sides was not significantly different (p > 0.05). The DCS of the first premolar showed the strongest correlation with the CVMS.

CONCLUSION

The results confirm the utility of the DCS on both sides of the mandible in male UCLP patients as a simple first-level diagnostic test to evaluate growth and development. The findings also indicate that both the DCS and the CVMS should be assessed if the maturity stage of a growing UCLP patient is relevant to clinical practice.

Anterior loop of the mental nerve in Saudi sample in Riyadh, KSA. A cone beam computerized tomography study

Background

The portion of inferior alveolar nerve (IAN) existent anterior to the mental foramen, before parting the canal, is referred to as the anterior loop (AL) of the IAN. The presence of AL is important when placing the implant interforaminal area of the mandible. These anatomical discrepancies can be assessed by cone-beam CT (CBCT), for evaluating its position and exact location. The AL is classified into Types I, II and III. In Type I, Y-shaped anatomy; in Type II, anatomy is T-shaped; and in Type III, Y-shaped anatomy is seen, and the incisive branch is thicker as compared to the main branch.

Aim

In this study, we aim to analyse the prevalence of different types of AL of the IAN in Saudi sample population.

Materials and Methods

The present study is a retrospective analysis of 149 (86 female & 63 male) CBCT images of patients records from 2018 June to 2018 September in the department of implant dentistry, KSMC, Riyadh. The age range of the patients who participated in the study was 30–60 years. The mean age of female participants is 42.5 ± 5.8, for the male participants is 48.6 ± 11.4 years respectively.

Results

The most frequent type of AL of mental nerve noticed on the right side was of type I (59.1%), followed by type II (27.5%) and type III (13.4%). The most frequent type of AL of mental nerve noticed on the left side was type I (61.7%), followed by type II (26.8%) and type III (11.4%).

Conclusion

The results of the study encourage the usage of CBCT for planning implant treatment. We also suggest that it is obligatory for professionals to categorise the presence of AL and to measure them appropriately when planning for the procedures in the interforaminal region.

Oral Rehabilitation of Hypodontia Patients Using an Endosseous Dental Implant: Functional and Aesthetic Results

Hypodontia often leads to limited bone availability of the alveolar ridges. Oral rehabilitation of severe hypodontia patients is challenging. In this retrospective study, we evaluated the functional and aesthetic results after dental implants in hypodontia patients, corroborated by Albrektsson implant success criteria. Over a period of 15 years (2000–2015), a total of 43 patients were diagnosed with hypodontia and 165 dental implants were inserted. Six patients who received 10 implants were lost in the follow-up. We examined 155 implants in 37 patients between December 2015 and May 2017. Besides family history, patients evaluated the general satisfaction, functionality, and aesthetics of the implants. Study subjects were between 17 and 44 years old (mean ± SD: 21.4 ± 5.6). Hypodontia patients were missing one to five teeth (n = 28), whereas patients diagnosed with oligodontia (≥6 missing teeth, n = 9). In this study, 24 patients (64.9%) with hypodontia had a positive family history; the remaining 13 patients had no family member with hypodontia. The final follow-up time ranged between 5 and 189 months after implant placement. Orthodontic treatment was performed in 32 patients (86%) before implant placement. Rehabilitation resulted in 62% of the cases being treated with 1–2 implants and 38% treated with 3–15 implants. However, out of 155 inserted dental implants, 18 implants failed to meet Albrektsson criteria, under which two implants were removed. Only autografts were used for bone augmentation with 97 implants. More than two-thirds of the patients showed high general satisfaction and masticatory function (69.4%) as well as phonetic ability (80.6%). The aesthetic outcome was rated as excellent by 17 patients (47.2%). The findings emphasize the importance of interdisciplinary treatment of hypodontia, leading to a satisfactory, functional, and long-term fixed prosthodontics using dental implants.

Multidisciplinary Approach for Treating Malocclusion of Patient With Basal Cell Nevus Syndrome: A Case Report

Basal cell nevus syndrome (BCNS) is a rare genetic disorder that can be caused by mutation of multiple genes, including PTCH1, PTCH2, and SUFU, in an autosomal dominant manner. The symptoms include some craniofacial features such as keratocystic odontogenic tumors (KCOTs), macrocephaly, and cleft lip and/or palate. Although comprehensive orthodontic treatment is frequently required for some of these craniofacial deformities, there are few reports that show the outcomes of comprehensive orthodontic treatment. Here, we report a case of BCNS with multiple KCOTs, macrocephaly, skeletal class III malocclusion, asymmetric dental arch, and mandibular crowding, which was successfully treated with comprehensive orthodontic treatment.

Considerations Regarding Anodontia in Dental Medical Practice

Aim: This article is set on presenting various types of anodontia, the most frequent types found in a dental office and to bring awareness to parents and also the dentists on the signs of agenesis and its consequences in time. Material and method: for a year (1st September 2017 – 31th August 2018) various patients with different types and locations of anodontia were diagnosed correctly by an oral and radiological exam in a dental office. Results. Anodontia is found almost equally in both sexes without major differences between males and females. Real agenesis is most frequently found in the second premolars – study reports show that this is because of phylogenetic evolution. False agenesis is more frequent in the 3rd molars because they are most likely extracted. Third molars are usually extracted because they don’t have space to emerge on the maxilla or mandible or they emerge in a vicious position. Canine agenesis has a very low frequency. Conclusions: It is very important to do a thorough check-up and a correct case history followed by radiological investigations each time a suspicion of a possible anodontia exists. It can only be certainly diagnosed by having a full oral and radiological exam. Also a difference must be made between the real, false and pseudoanaodontia.

[Dental-craniofacial manifestation and treatment of rare diseases in China]

Rare diseases are genetic, chronic, and incurable disorders with relatively low prevalence. Thus, diagnosis and management strategies for such diseases are currently limited. This situation is exacerbated by insufficient medical sources for these diseases. The National Health and Health Committee of China recently first provided a clear definition of 121 rare diseases in the Chinese population. In this study, we summarize several dental-craniofacial manifestations associated with some rare diseases to provide a reference for dentists and oral maxillofacial surgeons aiming at fast-tracking diagnosis for the management of these rare diseases.

Ultraviolet Functionalization Improved Bone Integration on Titanium Surfaces by Fluorescent Analysis in Rabbit Calvarium

This study evaluated the effect of ultraviolet functionalization (UV) on bone integration ability in rabbit model, using epifluorescence microscopy. Each of 12 rabbits (n = 6) received randomly four titanium domes prepared with or without ultraviolet for 48 hours (UVC, λ = 250 ± 20 nm; Philips, Tokyo, Japan): (1) turned surface (T), (2) turned surface with UV (T-UV), (3) sandblasted (120 μm aluminum oxide) and etched by 18% hydrochloric acid and 49% sulphuric acid at 60°C for 30 min (SLA) and (4) SLA surface with UV (SLA-UV). Fluorochrome bone labels were marked by oxytetracycline at 25 mg/kg on 13th days and 14th days and calcein at 5 mg/kg on 3th days and 4th days before euthanization. The study samples were sacrified at 2 weeks and 4 weeks. The undecalcified specimens were prepared. The newly formed total bone of cross-sectional area (TB, %), the mineralized trabecular bone of cross-sectional area (MB, %), and the new bone and dome contact (BDC, %) were measured and analyzed by fluorescence microscope and Image Pro Express 6.0. The data of MB and TB showed new bone regeneration was increased in all groups, but no signs of difference were found. However, the means BDC of UV treatment on turned surface at 4 weeks, the UV treated on SLA surface at 2 weeks and 4 weeks were statistically significantly higher than the control group (P &lt; .05). Within the limitations of the study, it can be concluded that ultraviolet functionalization on the titanium surface could enhance the new bone tissues and titanium surface integration.

Dental-craniofacial manifestation and treatment of rare diseases

Rare diseases are usually genetic, chronic and incurable disorders with a relatively low incidence. Developments in the diagnosis and management of rare diseases have been relatively slow due to a lack of sufficient profit motivation and market to attract research by companies. However, due to the attention of government and society as well as economic development, rare diseases have been gradually become an increasing concern. As several dental-craniofacial manifestations are associated with rare diseases, we summarize them in this study to help dentists and oral maxillofacial surgeons provide an early diagnosis and subsequent management for patients with these rare diseases.

Agenesis of the upper lateral incisors: Study of an orthodontic population and clinical illustration

In his daily practice, the orthodontist is regularly asked to treat patients with one or more missing teeth. Considering their functional and esthetic specificities, and the relatively high frequency of agenesia, our interest was to focus on the permanent lateral upper incisors. Our study, based on an orthodontic population including 1000 patients, shows that about 7.8% of these patients present agenesis of at least one permanent tooth (out of which 3.6% are agenesis of the upper lateral incisor). Treatment options for these cases are multiple with several decisional factors to consider: the solutions often lead to compromises, and require a multidisciplinary coordination. Therefore, the purpose of this article, was to describe the prevalence of these agenesia based on a retrospective study, and to present two clinical cases: the first case is a bilateral agenesis of the maxillary lateral incisors treated with space opening in order to place two implant-supported restorations. The second case is an agenesis of tooth 12 treated with space reopening and the placement of a cantilever bridge. These clinical cases are presented to illustrate the multidisciplinary approach involving orthodontics, prosthodontics, and periodontology, in order to achieve the most esthetic and functional results possible.

Healing at the Interface Between Autologous Block Bone Grafts and Recipient Sites Using n-Butyl-2-Cyanoacrylate Adhesive as Fixation: Histomorphometric Study in Rabbits

The aim of the present split-mouth (split-plot) study was to describe the sequential healing in the interface between autologous bone grafts and recipient parent bone, fixed using an n-butyl-2-cyanoacrylate adhesive with or without an additional titanium fixation screw. Bone grafts were collected from the calvaria and fixed to the lateral aspect of the mandible in 24 rabbits. The cortical layers of the recipient sites were perforated, and the grafts were randomly fixed using an n-butyl-2-cyanocrylate adhesive, either alone or in conjunction with a 1.5 mm × 6.0 mm titanium fixation screw. The animals were sacrificed after 3, 7, 20, and 40 days, and histomorphometric evaluations of the interface between graft and parent bone were performed. Only 2 of 6 grafts in each group were partially incorporated to the parent bone after 40 days of healing. The remaining grafts were separated from the parent bone by adhesive and connective tissue. It was concluded that the use of n-butyl-2-cyanoacrylate as fixation of an autologous bone graft to the lateral aspect of the mandible was able to maintain the fixation over time but did not incorporate the graft to the recipient sites. Use of fixation screws did not improve the healing.

Alveolar bone resorption after primary tooth loss has a negative impact on straightforward implant installation in patients with agenesis of the lower second premolar

OBJECTIVES

To compare the alveolar bone dimensions in patients with lower second premolar (P2) agenesis prior to and after primary molar loss on CT scans, and assess the possibility for straightforward implant placement.

METHODS

Alveolar bone dimensions were evaluated on 150 mandibular CT scans in three groups: (i) agenesis of P2, with the primary tooth in situ, and regularly erupted first premolar (P1) and molar (M1) (AW); (ii) agenesis of P2, without the primary tooth in situ for ≥3 m, but regularly erupted P1 and M1 (AWO); and (iii) P1, P2, and M1 regularly erupted (CTR). The possibility of straightforward placement of an implant 3.5 or 4.3 mm in Ø × 10 mm long was digitally simulated and compared to the actually performed treatment.

RESULTS

Buccolingual width (7.3 ± 2.0 mm) at the coronal aspect of the ridge in the AWO group was statistically significantly smaller comparing with both the AW (9.2 ± 1.4 mm) and the CTR (9.5 ± 1.1 mm) group; width reduction appeared to be mainly due to "collapse" of the buccal aspect of the ridge. Simulated straightforward placement of implants with a diameter of 3.5 or 4.3 mm was possible in 62% and 56% of the cases in the AWO vs. 86% and 84% in the AW group (p = .006 and .002, respectively). Straightforward implant placement was actually possible in all patients (22) in the AW group, while 28% (11 of 39) of the patients in the AWO group needed additional hard tissue augmentation.

CONCLUSIONS

Significant dimensional differences exist in the alveolar ridge, especially in the coronal part, at lower P2 agenesis sites missing the primary tooth for ≥3 m, when compared to P2 agenesis sites with the primary tooth in situ. It seems thus reasonable to advise that the primary second molar should be kept as long as possible, in order to facilitate straightforward implant installation and reduce the probability of additional bone augmentation procedures.

Three-Dimensional Evaluation of Alveolar Bone and Soft Tissue Dimensions of Maxillary Central Incisors for Immediate Implant Placement: A Cone-Beam Computed Tomography Assisted Analysis

INTRODUCTION

This study explored the relationship between the thickness of bone and soft tissue along the labial and palatal aspect of maxillary central incisors. The influence of overall socket width, labiopalatal positioning of the incisor on the bone, and soft tissue thickness were also investigated.

MATERIALS AND METHODS

This study used cone-beam computed tomography of 150 patients to determine labial, palatal soft and hard tissue thickness, labiopalatal (B-P) socket width and corelated the same to the labiopalatal positioning of maxillary central incisors.

RESULTS

Mean (SD) thicknesses of the labial soft tissue at cervical (C), midroot (M), and apical (A) locations and the corresponding bone thicknesses were 1.07 (0.28), 0.987 (0.27), 1.240 (0.41), and 0.928 (0.39), 0.894 (0.52), 1.57 (0.88), respectively. Similarly, palatal soft tissue and bone thicknesses at locations C, M, A were 1.807 (0.66), 1.557 (0.62), 1.639 (0.66), and 1.679 (0.62), 3.439 (1.28), 6.038 (1.63), respectively. Mean (SD) thicknesses of the B-P socket width at location C was 8.047 (0.963).

CONCLUSIONS

There is a positive correlation between the labial and palatal bone and corresponding soft tissue thickness, between thickness of the labial bone and the labiopalatal thickness of the alveolar socket. No correlation was observed between the thickness of the labial cortical bone and the labiopalatal positioning of the tooth.

Second premolar agenesis is associated with mandibular form: a geometric morphometric analysis of mandibular cross-sections

The aim of this study was to compare mandibular form (i.e., size and shape) between patients with agenesis of the lower second premolar (P2) and a control group with no agenesis. Three hypotheses were tested: (H1) agenesis causes a change in mandibular morphology because of inadequate alveolar ridge development in the area of the missing tooth (mandibular plasticity); (H2) agenesis is caused by spatial limitations within the mandible (dental plasticity); and (H3) common genetic/epigenetic factors cause agenesis and affect mandibular form (pleiotropy). A geometric morphometric analysis was applied to cross-sectional images of computed tomography (CT) scans of three matched groups (n=50 each): (1) regularly erupted P2; (2) agenesis of P2 and the primary second molar in situ; and (3) agenesis of P2 and the primary second molar missing for >3 months. Cross-sections of the three areas of interest (first premolar, P2, first molar) were digitized with 23 landmarks and superimposed by a generalized Procrustes analysis. On average, the mandibular cross-sections were narrower and shorter in patients with P2 agenesis compared with that in the control group. Both agenesis groups featured a pronounced submandibular fossa. These differences extended at least one tooth beyond the agenesis-affected region. Taken together with the large interindividual variation that resulted in massively overlapping group distributions, these findings support genetic and/or epigenetic pleiotropy (H3) as the most likely origin of the observed covariation between mandibular form and odontogenesis. Clinically, reduced dimensions and greater variability of mandibular form, as well as a pronounced submandibular fossa, should be expected during the treatment planning of patients with P2 agenesis.

Three-dimensional evaluation of root dimensions and alveolar ridge width of maxillary lateral incisors in patients with unilateral agenesis

Background

The objective of this retrospective case-control study was to measure the maxillary lateral incisor root dimensions and quantify the labial and palatal bone in patients with unilateral maxillary lateral incisor agenesis (MLIA) after orthodontic treatment and compare them to non-agenesis controls using cone beam computed tomography.

Methods

The labiopalatal and mesiodistal root dimensions, mesiodistal coronal dimensions, and labiopalatal bone and alveolar ridge widths of the maxillary lateral incisor were assessed on posttreatment cone beam computed tomography scans of 15 patients (mean age 16.5 ± 3.4 years, 9 females and 6 males) with maxillary lateral incisor agenesis and 15 gender-matched patients (mean age 16.08 ± 3.23 years) with no dental agenesis or anterior Bolton discrepancy. The Mann-Whitney test was used to distinguish any differences in root width, crown width, or changes in labial or palatal bone width between the two groups.

Results

The median labiopalatal root width was narrower in the MLIA group at the level of the cementoenamel junction (CEJ) to 8 mm apical of the CEJ compared to controls (p ≤ 0.009). The mesiodistal root width was significantly reduced in the MLIA group at the CEJ and at 4 mm apical to the CEJ. The labiopalatal alveolar ridge width was significantly decreased at 2 mm apical to the CEJ in MLIA group. The mesiodistal crown width was significantly smaller in the MLIA group at both the incisal edge and at the crown midpoint. The bone thickness was similar in both groups.

Conclusions

Coronal and root dimensions in patients with MLIA were reduced compared to controls. Alveolar ridge width was also reduced in patients with MLIA, although bone thickness was not different than controls.

Tooth replacements in young adults with severe hypodontia: Orthodontic space closure, dental implants, and tooth-supported fixed dental prostheses. A follow-up study

INTRODUCTION

Children with severe hypodontia have a substantial impairment of their dental health starting early in life. The purpose of this study was to describe types and locations of substitutes for missing teeth in patients with severe hypodontia and to compare the crown and soft tissue morphologies of orthodontic space closure, dental implants, and tooth-supported fixed dental prostheses for replacing teeth in the anterior region.

METHODS

Fifty patients missing 6 or more teeth and aged 18 years or older (mean age, 25.6 years) took part in a follow-up study. The patients were examined clinically with panoramic radiographs and clinical photographs. Crown and soft tissue variables (mucosal discoloration, crown morphology, color, and papilla index) were compared for orthodontic space closure, dental implant fixtures, and fixed dental prostheses.

RESULTS

Dental implants, orthodontic space closure, and retaining deciduous teeth were the most commonly prescribed treatments. Persisting deciduous teeth showed a good survival rate at the follow-up examination. Mucosal discoloration was seen only for implant fixtures and was evident for almost all fixtures in the anterior mandible and two thirds of those in the anterior maxilla. The papilla index scored poorer for both implant fixtures and fixed dental prostheses compared with orthodontic space closure.

CONCLUSIONS

Dental implants in the anterior region proved to be an inadequate treatment modality in patients with severe hypodontia because of pronounced mucosal discoloration.

Adjunctive Orthodontic Applications in Dental Implantology

Implant placement is often necessitated for replacement of teeth with pathologically damaged alveolar bone due to periodontitis or traumatic injury. Surgical augmentation of resorbed bone has many limitations, including lower efficacy of vertical augmentation than horizontal augmentation, as well as morbidity associated with grafting procedure. Orthodontic therapy has been proposed as a useful method for augmenting the resorbed alveolar bone and reforming aesthetically appealing gingival margin, prior to implant placement. This narrative review summarizes the available evidence for the application of orthodontic strategies that can be used as adjunct in selected cases to augment bone volume for the future implant site and maintain space for the prosthetic parts of the implant. These are (1) orthodontic extrusion of compromised teeth to generate vertical bone volume and enhance gingival architecture, (2) tooth preservation and postponing orthodontic space opening to maintain bone volume in future implant site, (3) orthodontic implant site switching to eliminate the deficient bone volume or risky implant sites, and (4) the provision of a rigid fixed-bonded retainer to maintain the implant site. Although there are no randomized controlled clinical trials to evaluate the efficacy of orthodontic therapy for implant site development, clinical case reports and experience document the efficacy of orthodontic therapy for this application.

Bilateral agenesis of maxillary permanent canines: Review of the literature

Oligodontia, or agenesis of six or more teeth, excluding third molars, which involves canine agenesis is rare, and restorative management can be challenging. Bilateral agenesis of a permanent canine in the general population often indicates a several missing adult teeth. The most common sign of it is the primary canine retention beyond its exfoliation age. The multistage restorative management includes the early diagnosis, excluding associated medical problems as well as assessment of patient's malocclusion and facial skeletal pattern, life span of deciduous teeth, possibility of premolar substitution, minimum required number of prosthetic units, patient's preferences, and the cost of treatment. A 10-year-old boy with bilateral agenesis of maxillary permanent canines is described. Some thoughts on the multidisciplinary restorative management of this case are discussed.

A multidisciplinary treatment of congenitally missing maxillary lateral incisors: a 14-year follow-up case report

Absence of the maxillary lateral incisor creates an aesthetic problem which can be managed in various ways. The condition requires careful treatment planning and consideration of the options and outcomes following either space closure or prosthetic replacement. Recent developments in restorative dentistry have warranted a re-evaluation of the approach to this clinical situation. Factors relating both to the patient and the teeth, including the presentation of malocclusion and the effect on the occlusion must be considered. The objective of this study was to describe the etiology, prevalence and alternative treatment modalities for dental agenesis and to present a clinical case of agenesis of the maxillary lateral incisors treated by the closure of excessive spaces and canine re-anatomization. A clinical case is presented to illustrate the interdisciplinary approach between orthodontics and restorative dentistry for improved esthetic results. In this report, the treatment of a girl with a Class II malocclusion of molars and canines with missing maxillary lateral incisors and convex facial profile is shown. Treatment was successfully achieved and included the space closure of the areas corresponding to the missing upper lateral incisors, through movement of the canines and the posterior teeth to mesial by fixed appliances as well as the canines transformation in the maxillary lateral incisors. This is a 14-year follow-up case report involving orthodontics and restorative dentistry in which pretreatment, posttreatment, and long-term follow-up records for the patient are presented.

Is buccolingual angulation of maxillary anterior implants associated with the crestal labial soft tissue thickness?

We aimed to examine the relationship between crestal labial soft tissue thickness (CLSTT, measured with a digital calliper at the crestal level of casts) and implant buccolingual angulation (IBLA). The records of 22 females and 10 males treated with two bone-level implants (3.3-4.6mm) between the maxillary canines were evaluated. IBLA was recorded as cingulum, incisal, or labial based on the screw access hole position on provisional restorations. Postoperative implant labial bone thickness (ILBT) at the crestal (2mm from crest) and mid-implant levels were measured on sectional cone beam computed tomography scans. The mean (SD) ridge width at the crestal level was 6.81 (0.98) mm. Mean (SD) CLSTT for implants with cingulum, incisal, and labial angulations were 2.98 (0.84), 2.24 (0.51), and 1.71 (0.72) mm, respectively. Significant differences were detected between CLSTT of implants with cingulum and incisal, as well as cingulum and labial angulations (P<0.01). Of implants with cingulum, incisal, and labial angulations, 3.4%, 20%, and 53.3%, respectively, had a CLSTT<2mm. Overall, 74.2% of CLSTT variance could be predicted by IBLA and ILBT at the crestal and mid-implant levels. A significant association between CLSTT and IBLA was noted when ILBT (crestal level) was <2mm (P<0.01). Implants with labial angulations carry a higher risk of soft tissue complications when the crestal implant labial bone thickness is <2mm.

Partial craniofacial duplication: a review of the literature and case report

Diprosopus (Greek; di-, "two" + prosopon, "face"), or craniofacial duplication, is a rare craniofacial anomaly referring to the complete duplication of facial structures. Partial craniofacial duplication describes a broad spectrum of congenital anomalies, including duplications of the oral cavity. This paper describes a 15 month-old female with a duplicated oral cavity, mandible, and maxilla. A Tessier type 7 cleft, midline meningocele, and duplicated hypophysis were also present. The preoperative evaluation, surgical approach, postoperative results, and a review of the literature are presented. The surgical approach was designed to preserve facial nerve innervation to the reconstructed cheek and mouth. The duplicated mandible and maxilla were excised and the remaining left maxilla was bone grafted. Soft tissue repair included closure of the Tessier type VII cleft. Craniofacial duplication remains a rare entity that is more common in females. The pathophysiology remains incompletely characterized, but is postulated to be due to duplication of the notochord, as well as duplication of mandibular growth centres. While diprosopus is a severe deformity often associated with anencephaly, patients with partial duplication typically benefit from surgical treatment. Managing craniofacial duplication requires a detailed preoperative evaluation as well as a comprehensive, staged treatment plan. Long-term follow up is needed appropriately to address ongoing craniofacial deformity.

An Unusual Accessory Mandible and a Submucosal Cleft Palate—A Case Report and Review of the Literature

An accessory mandible is a rare congenital anomaly that requires multidisciplinary management. This case report describes a female patient with an unusual accessory mandible, a dysplastic overgrowth of bone, containing teeth that extended from the midsymphyseal region. A submucosal cleft palate and cleft of the lower lip were also present. Her treatment plan took a staged approach with initial surgical resection of the accessory bone and teeth. The second stage, still in the planning phase, will correct the secondary deformity of an anterior open bite and will restore the missing lower anterior teeth. The original deformity and subsequent growth are discussed with the relevant literature.