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

Characterization of the anterior maxillary region for immediate implant placement: A radiographic cross-sectional study

STATEMENT OF PROBLEM

Information regarding the influence of local phenotypical features in the context of immediate implant placement (IIP) in the anterior maxillary region is sparse.

PURPOSE

The purpose of this clinical study was to characterize key phenotypical and anatomical characteristics of the anterior maxilla related to the feasibility of virtual IIP.

MATERIAL AND METHODS

Cone beam computed tomography (CBCT) scans acquired from adult participants were used for virtual implant placement and to measure periodontal phenotypical dimensions (buccal and palatal gingival (GT) and bone thickness (BT)), the buccal gap (BG) at different apico-coronal levels, and anatomical variables nasopalatine canal and ramifications, nasal cavity, maxillary sinus). The study sample was comprised of 330 maxillary anterior teeth. Two different immediate implant modalities were examined: cingulum emergence plan (CEP) and incisal edge emergence plan (IEP).

RESULTS

A total of 660 implants were virtually placed. The mean periodontal phenotypical dimensions showed variability between and within individuals depending on the apico-coronal level, tooth type, and implant placement modality. Immediate implant feasibility was 90.1% and 93.6% for the CEP and IEP groups, respectively, and was influenced by tooth type and anatomical variables. BG distance was generally greater at the coronal aspect and in the CEP. Thick bone and gingiva (≥1 mm) were observed in 15.2% and 89.3% of the sites, respectively. A minimum of 2 mm of apical bone availability to achieve primary stability was observed in 88.8% and 91.2% of the sites in the CEP and IEP groups, respectively.

CONCLUSIONS

This study highlights the variability in periodontal phenotypical and local anatomical features at anterior maxillary sites. These observations underscore the importance of recognizing such variations that should be identified and considered during the planning and execution of therapy.

Analysis of the Sagittal Root Position of the Maxillary and Mandibular Anterior Teeth in the Alveolar Bone Using Cone-Beam Computed Tomography

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.

Letter to the editor in response to "Microbial colonization in the partially exposed nonabsorbable membrane during alveolar ridge preservation" (Braz et al., clinical oral Investigations, https://doi.org/10.1007/s00784-024-05763-7.)

OBJECTIVE

This letter addresses the recent study by Braz et al. published in Clinical Oral Investigations in 2024 ( https://doi.org/10.1007/s00784-024-05763-7 ), which reported that intentionally exposed d-PTFE membranes modulate microbial colonization in alveolar ridge preservation (ARP) sites, creating a more homogeneous and anaerobic community on both the inner and outer surfaces of the membrane.

MATERIALS AND METHODS

We argue that the study's methodology may have skewed the results, particularly the inclusion of both intact and damaged extraction sockets (with loss of the buccal wall) and the absence of bone grafting.

RESULTS

The absence of bone graft might have contributed to membrane dislodgement and increased microbial contamination rather than the membrane's inherent properties.

CONCLUSION

This critique is significant because it challenges the conclusion that the d-PTFE membrane itself is responsible for microbial colonization, highlighting the need to consider extrinsic factors and study design limitations.

CLINICAL RELEVANCE

Our discussion aims to enhance the understanding of microbial dynamics in ARP procedures and emphasizes the need for caution when interpreting the study's findings, given the context of established clinical practices and existing evidence.

Relationship between soft tissue dimensions and tomographic radial root position classification system for immediate implant installation

The aim of this study was to evaluate the relationship between soft tissue dimensions and radial root position (RRP) classification for immediate implant placement on maxillary anterior teeth. Maxillary anterior teeth (n = 420) were analyzed in the radial plane of cone beam computed tomography (CBCT) scans. Each tooth was classified according to its RRP: class I, (IA, IB); class II (IIA, IIB) class III; class IV, and class V. Soft tissue thickness at different landmarks, supracrestal soft tissue height, and crestal bone thickness were measured in CBCT. Keratinized tissue width was clinically measured. Gingival phenotype (thick or thin) was evaluated by transparency of the periodontal probe and at the landmark 2 mm from the gingival margin in CBCT. Class I tooth position accounted for 31.7%, class II for 45%, class III for 13.3%, class IV for 0.5%, and class V for 9.5%. The gingival phenotype was associated with RRP (χ2 test, p < 0.05). Soft tissue dimensions were significantly different over RRP classes (ANOVA and Tukey tests, p < 0.05). Types IA and IIA presented both thick soft and hard tissues. When planning immediate implants in the anterior maxilla, soft tissue dimensions evaluation should be incorporated into RRP classification to increase the accuracy and predictability of treatment outcomes.

Characteristics of mandibular anterior alveolar bone in patients with different degrees of periodontitis: a retrospective study based on CBCT

OBJECTIVES

To investigate the alveolar bone characteristics of mandibular anterior teeth in patients with periodontitis.

MATERIALS AND METHODS

100 patients with periodontitis were selected and grouped according to the degrees of alveolar bone resorption, age, gender, and tooth type. The labial thickness of the alveolar bone, the degree of alveolar bone resorption, angulation between the long axis of teeth and alveolar process, alveolar bone height and density of the mandibular anterior teeth were measured.

RESULTS

There were significant differences in alveolar bone morphology between these three groups. Compared with the mild and moderate groups, the severe group showed that the alveolar bone in the half of the root crown was thickened, the alveolar bone height was decreased, the cancellous alveolar bone density was increased, and the cortical alveolar bone density was decreased. The resorption of alveolar bone was characterized by greater resorption of proximal bone than that of labial bone with increased bone loss. There were also differences in alveolar bone characteristics among patients of different ages, genders, and tooth types.

CONCLUSIONS

The morphology of the mandibular anterior alveolar bone changed accordingly with the degree of periodontitis. Labial alveolar bone thickness and cortical alveolar bone density were negatively correlated with the degree of periodontitis, while alveolar bone height and cancellous alveolar bone density were positively correlated with the degree of periodontitis.

CLINICAL RELEVANCE

These results allow clinicians to better understand the alveolar bone morphology of the mandibular anterior teeth in patients with periodontitis, facilitating better treatment design and avoiding complications.

Anatomical characteristics of the alveolar process and basal bone that have an effect on socket healing

Following tooth extraction, a sequence of events takes place in order to close the wound and restore tissue homeostasis, a process called socket healing. The outcome of socket healing includes a marked reduction of the ridge dimensions. The amount of tissue loss that occurs during healing is influenced by several local and systemic factors. Thus, the aim of the present review was to describe the effect of anatomical characteristics of the alveolar process and basal bone on the socket healing outcome. The studies included showed that the quantity (number) and quality (composition) of socket walls exhibited a significant influence on the ridge diminution. A damaged socket (3 walls or less), as well as a thin buccal bone wall, which quickly resorbs negatively affected the healing outcome. Periodontally compromised sockets appeared to promote more extensive dimensional changes. Angulation between tooth and basal bone in addition to basal bone dimensions may also have altered the wound environment and influenced socket healing. The findings from the present review suggest that some anatomical characteristics of the alveolar process and basal bone have an effect on socket healing.

Determining the periodontal phenotype-Probe transparency versus actual: A diagnostic study

AIMS

Assessment of the validity of the transparency of the periodontal probe as a tool for determining the periodontal phenotype.

MATERIALS AND METHODS

The periodontal phenotype was assessed at the six upper anterior teeth of 75 subjects using two methods. One is through assessing the transparency of the periodontal probe upon insertion into the gingival sulcus. The second method was through the assessment and clustering of the width of keratinized gingiva clinically and the gingival and buccal plate thickness on Cone Beam Computed Tomography scan.

RESULTS

The probe transparency approach correctly identified thick periodontal phenotype in most cases (41 out of 43 [95%]). However, this was not the case for thin periodontal phenotype; probe transparency approach identified 64% of the thin sites (261 out of 407) and misclassified nearly one third of the patients.

CONCLUSION

The probe transparency approach is a valid approach in identifying the phenotype in subjects with thick phenotype but not in subjects with thin phenotype.

CLINICAL SIGNIFICANCE

The definition of periodontal phenotype has recently changed. Accurate designation has been shown to affect treatment outcomes especially esthetic ones in different disciplines of dentistry. Probe transparency is commonly used by clinicians and researchers. Assessment of the validity of this method based on the most recent definition and compared to actual assessment of bone and gingival thickness is of great clinical value.