ORIGINAL ARTICLE
Year : 2023 | Volume
: 13 | Issue : 1 | Page : 23--29
Distribution of alveolar bone defects associated with periodontitis: A demographic study
Shivani V Sachdeva1, Amit Mani2, Mangesh B Phadnaik1, Harish Saluja3,
1 Department of Periodontology, Pravara Institute of Medical Sciences, RDC, Loni, Maharashtra, India
2 Department of Periodontics, GDC'H, Nagpur, Maharashtra, India
3 Department of Oral and Maxillofacial Surgery, Pravara Institute of Medical Sciences, RDC, Loni, Maharashtra, India
Correspondence Address:
Dr. Shivani V Sachdeva
Department of Periodontology, Pravara Institute of Medical Sciences, RDC, Loni, Maharashtra
India
Abstract
Introduction: Periodontal disease is one of the most widespread diseases of humankind. It is a chronic destructive infectious disease that involves the resorption of bone supporting the teeth. The purpose of this study was to analyse the prevalence and distribution of different forms of bone defects amongst different demographics in the Indian population. Materials and Methods: The study population comprised 44 patients of different age groups with moderate and severe periodontitis chronic periodontitis. A total sample of 1041 teeth were explored surgically and classified into suprabony, infrabony, inter-radicular and other bone defects. This study focuses on the differences in the distribution of various bone defects between different groups of age and gender. Results: Amongst 1041 teeth, the prevalence of bone defects was 97%. Craters and intrabony defects were almost equal for the age groups of 31–40 years and 41–50 years. However, in the age group of 51–60 years, craters comprised 33.3%, and intrabony defects comprised 66.7%. Males had two times more 3-wall defects than females. Conclusion: The present study reveals that there is a need for applying epidemiological principles to periodontal bone defects in order to better understand the natural history of periodontal disease and eradicate the factors responsible for their commencement and progression. The following research article has been presented at the 2nd international congress of the World Academy of Growth Factors and Stem Cells in Dentistry 25–27 October 2018.
How to cite this article:
Sachdeva SV, Mani A, Phadnaik MB, Saluja H. Distribution of alveolar bone defects associated with periodontitis: A demographic study.Adv Hum Biol 2023;13:23-29
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How to cite this URL:
Sachdeva SV, Mani A, Phadnaik MB, Saluja H. Distribution of alveolar bone defects associated with periodontitis: A demographic study. Adv Hum Biol [serial online] 2023 [cited 2023 Mar 31 ];13:23-29
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Full Text
Introduction
Lord Kelvin said, 'Until you can count it, weigh it, or express it in a quantitative fashion, you have scarcely begun to think about the problem in a scientific fashion'. Differences in the localisation of bone defects do exist, and that might be related to the associated loss of tooth support, to the site specificity of periodontal destruction, and to the possibility that ecological niches (deep pockets and furcation involvement) associated with some osseous lesions may represent site-specific risk factors or indicators for disease progression.[1],[2],[3]
Different studies depict that there are discrepancies in the distribution of defects between different groups for age, sex and socioeconomic status. An increasing frequency of periodontal intrabony defects with age has been observed in many studies.[4] There were also variations between the occurrences of bone defects in males and females.
The present study is a descriptive cross-sectional epidemiological study that aims to pertain the epidemiological principles to evaluate the distribution of alveolar bone defects, explored surgically under direct illumination within the age range of 30–60 years, amongst both genders. The question of exploring the secrets behind the peculiar behaviour of the alveolar bone carries special significance to the dental profession, as periodontal disease is a major public dental health problem and knowledge of the osseous defects is useful to arrive at a diagnosis, to assess prognosis and to plan the treatment.
Materials and Methods
Source data
The prospective descriptive cross-sectional study was carried out in the Department of Periodontology at Pravara Institute of Medical Sciences after taking ethical approval from the Institutional Ethical Committee with the registration number of a research proposal as PIMS/DR/RDC/2020/341. The patient's enrolment and scrutinization process involved inclusion criteria with patients having a minimum of 10 natural teeth, a patient having infrabony and inter-radicular defects with moderate and severe chronic periodontitis and those having clinical attachment loss ≥3 mm and probing pocket depth of ≥5 mm.[5] The patients with any systemic disease and who had undergone any type of periodontal surgery were excluded. Patients with aggressive periodontitis and smokers were also not included in the study.[6],[7]
The sample size was calculated by the formula: n = Z2P (1 − P) d2, where n is the sample size, Z is the statistic corresponding to the level of confidence, P is expected prevalence which was obtained from the same studies in literature and d is precision (corresponding to effect size). The level of confidence aimed for the present study was 95%. The prevalence of severe periodontitis patients ranged from 15% to 19% in the literature, and accordingly, a sample size of 1960 patients was calculated. All the 2000 patients were examined for periodontitis, and out of those, 44 subjects required the need of periodontal surgery. The evaluation of prevalence and distribution of bone defects amongst these 44 patients within the age range of 30–60 years comprised 21 males and 23 females.
Method of collecting data
A given sample of 1041 teeth was explored. The patients were examined, and diagnosis of moderate and severe chronic periodontitis was made after the detailed clinical and standardised radiological examination. Informed consent was obtained from all patients.
Method of segregation of study sample
After taking a detailed case history, the study sample was segregated into different groups according to age and gender, which are depicted below:
Age
31–40 years41–50 years51–60 years.
Gender
MaleFemale.
Procedure
The non-surgical treatment consisting of plaque control instructions, scaling and root planing under local anaesthesia was carried out. Re-evaluation of the initial therapy was performed 6–8 weeks later, and then, patients were considered for periodontal surgical treatment. Periodontal surgery was performed, and the osseous defects were explored under good illumination.
Classification and description of periodontal bone defects
The periodontal bone defects were classified according to the newer morphological classification system by Sachdeva et al. wherein the periodontal bone defects were classified as:[8],[9],[10]
Suprabony (SB) defectsInfrabony (IB) defects: these defects included craters and intrabony defects. The intrabony defects included 1-, 2-, 3-, 4-wall and combination defectsOther bone (OB) defects: The OB defects included bulbous bony contour (BB), ledge (LD), reversed architecture (RA), fenestration (FN), dehiscence (DH), trench (TR) and ramp (RM)Inter-radicular (IR) defects: The IR defects include Grade I, Grade II, Grade III and Grade IV.[6]
Collection, comparison and statistical analysis
All the raw data were assembled in the master chart by counting the SB, IB, OB and IR defects for the study population. The data from the master chart were tabulated and segregated into groups of age and gender. The graphical representation for prevalence and distribution of bone defects was carried out for different demographics. Comparison of data by proportions and percentages was carried out under subheadings (Parts A and B).
Tests for statistical significance
Data was analyzed using statistical software SPSS windows version 23.0(SPSS, Inc., Chicago. IL, USA) was used for the analysis of data. The sampling technique was simple stratified random sampling. The percentage and distribution of different defects were evaluated for significance using the Chi-square test and Fisher's exact test.
It constituted evaluation of prevalence and distribution of SB, IB, OB and IR defects amongst three different groups for age (31–40, 41–50 and 50–60 years). In order to find the prevalence of different defects within the same age group, it was presumed that every group for age had 100% of defects. This enabled us in making a comparison of percentage of defects within the same age group (absolute intragroup comparison). It not only explored the occurrences of dominant and minor defects but also helped in evaluating the pattern of variation amongst different groups (relative intergroup comparison). Although, it did not allow us to perform absolute intergroup comparison as there was sample size variability. Henceforth, the percentages of SB, IB and OB defects was calculated and compared with each other, considering SB + IB + OB = 100%, in each group for age.
On similar grounds and following the same principles, percentages were calculated for both genders.
Percentage of defects
The prevalence and distribution of SB, IB (CR and IT), OB and IR were evaluated in each group for age and gender.
[INLINE:1]
Results
The prevalence of defects in 1041 teeth was 97%. These 1010 defects were the absolute defects which comprised SB, IB and OB defects. Out of these 1010 defects, 184 defects were associated with one tooth, while 826 defects were associated with more than one tooth. Defects associated with one tooth were IT, RA, DH and TR defects. Moreover, the defects associated with more than one tooth were SB, CR, BB and LD and RM. Amongst the absolute bone defects, FN was not observed.
In the present study, IR defects were counted separately because they depict the stage in the progress of disease and its severity. Therefore, they have been classified as relative defects in the present study. Total, 404 multirooted teeth were explored, and out of that, 254 IR defects were observed comprising Grade I, II and III furcation involvement. Grade IV furcation involvement was not observed amongst the relative IR defects. The prevalence of IR defects amongst 404 multirooted teeth examined was 62.8%. Amongst these 404 teeth, 250 multirooted teeth did not have IR defects, while 154 teeth were associated with IR defects. Hence, the prevalence of teeth with relative defects was 38.1%.
Age
The prevalence and distribution of absolute defects (SB, IB and OB defects) were evaluated for three different groups of age, as depicted in [Table 1].{Table 1}
The statistical evaluation for the prevalence of SB, IB and OB defects in 3 different groups for age was found to be statistically significant, using Chi-square test at 95% confidence interval. Although the differences in percentages of SB, IB and OB defects for the age groups of 31–40 and 41–50 years were minimal, the statistical evaluation was done to compare the prevalence in these two groups for age, and the results were found to be statistically not significant (χ2 = 0.6914; P = 0.7077, which is >0.05).
[Table 2] depicts the prevalence of defects in the age group of 31–40 years, CR is 49.6% and IT formed 50.4% defects. The statistical evaluation for the prevalence of two IB defects, i.e., CR and IT, showed P > 0.05. Hence, the difference in the results amongst three different groups for age was found to be statistically not significant.{Table 2}
The prevalence and distribution of various IT defects, i.e., 1-, 2-, 3-, 4-wall and CB defect in different age groups, showed P < 0.05. Hence, the differences in results in three different age groups for various IT defects were found to be statistically significant, as depicted in [Graph 1].[INLINE:2]
The prevalence and distribution of OB defects are depicted in [Graph 2] and showed P > 0.05. Hence, the differences in the results in three different groups for age were statistically not significant.[INLINE:3]
The statistical evaluation for the prevalence of IR defects showed P ≤ 0.001. Hence, the differences in the results in three different groups for age were found to be statistically highly significant, as tabulated in [Table 3].{Table 3}
Gender
The prevalence and distribution of absolute defects (SB, IB and OB defects) were evaluated for different sexes. In males, the total defects explored were 451. In females, the total defects explored were 559. The distribution is depicted in [Graph 3].[INLINE:4]
The statistical evaluation for the prevalence of SB, IB and OB defects showed P > 0.05. Hence, the differences in groups for sex were found to be statistically not significant, using the Chi-square test at a 95% confidence interval.
The prevalence and distribution of IB defects were evaluated for sex. In males, 58 defects (41.7%) were CR, while 81 defects (58.2%) were IT defects. In females, 89 defects (50.9%) were CR, while 86 defects (49.1%) were IT defects. The statistical evaluation for the prevalence of two IB defects, i.e., CR and IT, showed P > 0.05. Hence, the differences in groups for sex were found to be statistically not significant, using Fisher's exact test at a 95% confidence interval.
The prevalence and distribution of IT defect in different groups for sex were calculated and are shown in graphical representation [Graph 4]. Although the differences were found to be statistically not significant, they were significant clinically.[INLINE:5]
The prevalence and distribution of OB defects according to sex were calculated. In males, OB defects, i.e., BB, LD, RA, FN, DH, TR and RM, were evaluated to be 8 (33.3%), 12 (50%), 2 (8.3%), 0, 0, 1 (4.2%) and 1 (4.2%), respectively, while in females, defects evaluated were 6 (20.7%), 10 (34.5%), 1 (3.5%), 0, 4 (13.8%), 5 (17.2%) and 3 (10.3%) for BB, LD, RA, FN, DH, TR and RM, respectively.
The prevalence and distribution of different IR defects were calculated for different groups of sex. In males, the prevalence and distribution were 64 (49.6%), 51 (39.5%) and 14 (10.9%), while in females, they were 75 (60%), 43 (34.4%) and 7 (5.6%) for Grade I, II and III IR defects, respectively. It was also found that the prevalence and distribution for Grade II and III IR defects increased for males than females, while in females, Grade I IR defects increased. Hence, the severity of IR defects was found more for males than females. The differences were clinically significant but statistically not significant.
Discussion
The greatest of American epidemiologists stated that 'Epidemiology is something more than the total of its established facts. It includes their orderly arrangement into chains of inference which extends more or less beyond the bounds of direct observation. Such of these chains are well and truly laid and guide in the investigation to the facts of the future. Those that are ill laid, fetter progress.'[11]
Hence, in the present study, different variables such as age, sex, socioeconomic status, arch and segments were assessed for differences in the prevalence and distribution defects. The paper in the assessment of arch and segments has already been published, while SES is not included in this current article. It was found that the statistically significant differences in defects were associated with age, while between differences were statistically not significant for gender.
In the present study, both clinical and radiographical analyses helped in the diagnosis of moderate and severe chronic periodontitis patients. In order to overcome the limitations of other methods, the surgical inspection was done in the present study, which is considered to be the gold standard for the evaluation of periodontal bone defects.[4],[12]
In the present study, defects were explored, classified[8] and their distribution was assessed. We have classified the defect into SB defects, IB defects, OB defects and inter-radicular defects (IR). It was carried out on 44 subjects in the age range of 30–60 years, and the average age of patients was 36.8 years. The total number of 1041 teeth was surgically explored from 21 males and 23 females for evaluating the prevalence and distribution of bone defects in patients having moderate and severe chronic periodontitis.
The data were qualitative and not ordinal; hence, Chi-square and Fisher's exact test were applicable in the present study. These tests were also enhanced to test whether the distribution of attributes in different groups was due to sampling variation or not.
Age
Destructive periodontal disease has been so consistently associated with ageing that many authors in the past came to see it as an inevitable consequence of growing older. In the present study, patients were segregated into different age groups: 31–40, 41–50 and 50–60 years. This was done to evaluate the prevalence and distribution of defects amongst different stages in life. It was also done to assess the variations in patterns of defects for different age groups.
In the age group of 31–40 years, 773 absolute defects were found within 803 teeth, while in 41–50 years, 103 absolute defects were associated with 104 teeth, and in the age group of 50–60 years, 134 absolute defects were found in 134 teeth examined. In the present study, it was observed that absolute defects increased with ageing, and the differences were statistically significant amongst three different age groups.
These were similar to the findings of Saari et al.[13] that there was the tendency of the defects to increase with age.
It was seen, both clinically and statistically, that the prevalence of SB defects for the age groups of 31–40 and 41–50 years were similar, but it decreased in the age group of 50–60 years, while IB defects were similar for the age groups of 31–40 and 41–50 years, but they increased for the age group of 50–60 years. Furthermore, OB defects consistently increased with ageing.
It can be seen that in the age groups of 31–40 and 41–50 years, the CR and IT defects were found to be almost equal, while in the age group of 50–60 years, IT defects were found to be more than CR. It was also observed that CR decreased with ageing, while IT defects increased with age. Hence, the differences were clinically significant but statistically not significant.
IT defects increased with ageing. This finding of the present study was in agreement with the finding of Nielsen et al. (1980).[14] They found that the difference in the prevalence of defects amongst the different age groups was statistically significant, and intrabony defects occurred more frequently in the older age group (45–55 and >60 years). They also observed that 37% of individuals older than 60 years had at least one IT defect, whereas this was found in only 18% of patients in the age group of 30–44 years, which depicts a drastic increase in IT defects.
Furthermore, skulls of the age 60 years tended to have, on average more intrabony defects than skulls of the younger age group. These findings of Larato[15] were in accordance with our study. However, the present study has contrasting findings from a study by Papapanou et al.[16] where angular bone defects increased till 50 years and thereafter dropped was seen. While in the present study, no drop in IT defects was appreciated in the age group of 50–60 years, rather they increased after 50 years. The possible explanation could be the difference in the study design as this study was carried out by examining intraoral X-rays, where we are bound to find the decreased incidence of intrabony defects due to overlapping of facial and lingual/palatal cortical plate, while in the present study, there was a direct surgical exploration of defects.[14],[15],[16],[17]
The possible explanation of increased IT defects in the age group of 50–60 years can be explained, as the individual mean bone level, i.e., the distance between the CEJ and the coronal border of the alveolar bone, increased with increasing age.[17],[18],[19],[20] Furthermore, as the reduction in alveolar bone height with age occurred, there was an increase in the thickness of alveolar bone, which could have led to the formation of more intrabony defects.
It was inferred that in the age groups of 31–40 years and 50–60 years, 2-wall and 3-wall were the dominant defects, while in 41–50 years, 1-wall and 4-wall were the dominant defects. The least prevalent defect was the CB defect for all the age groups. The differences were clinically as well as statistically significant.
The prevalence and distribution of OB defects showed that LD increased with ageing, while DH and RM decreased with ageing. For BB, RA and TR, no such trend could be determined. The differences were clinically significant but statistically not significant. There was an observed decrease in DH with age. This finding was consistent with the trend reported by Rupprecht et al.[21] This observation may be due to increased tooth loss with age that results in fewer teeth being at risk. FN was not found in the present study, which might be related to the possible conversion of FN from young subjects to DH in older subjects.
In the present study, it was observed that the severity of IR defects increased with age. Amongst the IR defects for age groups 31–40 years and 41–50 years, Grade I > II > III, while in the age group of 50–60 years, Grade II > III > I. The differences were clinically as well as statistically highly significant. This corresponded with studies by Larato[22] and Svärdström and Wennström.[23] The possible explanation for this finding could be that with increasing age, the oral hygiene deteriorates[20] and more severe bone loss occurs in the inter-radicular bone between two roots of multirooted teeth.[18] Hence, it can be inferred that as age increases, the severity of IR defects increases, i.e., Grade II and III IR defect increases.
Gender
The differences in occurrences of defects were assessed for both males and females in order to evaluate the variations, if present, in patterns of bone defects amongst two different sexes. In males, the absolute defects found were 451. In a sample of 454 teeth, this formed 99.4% of occurrences, while in females, absolute defects found were 559, in a sample of 587 teeth explored, accounting for 95.2% of occurrences. This showed that males had a higher prevalence of absolute defects than females.
The differences in SB, IB and OB defects amongst two genders were neither clinically nor statistically significant. The findings of Nielsen et al.[14] were similar to the findings in the present study that there was no statistically significant difference between the prevalence and distribution of defects in males and females. However, the slight difference in occurrences could be explained by the long-known difference in periodontal status between men and women, which is usually attributed to women's better oral hygiene practices (Burt 1994).[24],[25]
It was ascertained that in males, the prevalence of IT defects was more than craters, while in females, craters and IT defects occurred equally. The present study accords with the findings of Wouters et al. that interproximal intrabony defects occurred more frequently in men than women, but they found differences to be statistically significant.
It was also inferred that 2-wall and 3-wall defects were found to be more for males, while 1-wall and 2-wall defects were found to be more for females. The CB defect was least prevalent both for males and females. Males had two times more 3-wall defects than females. Although the differences were found to be statistically not significant, they were significant clinically.
BB, LD and RA were found more in males than females, while DH, TR and RM were found more in females than males. In the OB defects, males had 50% of LD and 33% of BB, while females had 34% of LD and 20% of BB. Although the differences were statistically not significant, they were clinically significant. This finding was similar to the findings of Horning et al. (2001), where buccal alveolar bone enlargements were common in males than females. DH occurred exclusively in females and was not evident in males; the present finding accords with the finding of Rupprecht et al.[21],[26],[27]
The order of prevalence of IR defects in descending order was Grade I > II > III, both for males and females. It was also found that prevalence and distribution for Grade II and III IR defects increased for males than females, while in females, Grade I IR defects increased. Hence, the severity of IR defects was more for males than females.[28],[29] The differences were clinically significant but statistically not significant. This finding was in accordance with the study by Svärdström and Wennström.[23] They also had no significant sex difference in inter-radicular bone defects, but the severity of advanced furcation involvement was more for men.
Conclusion
The present study concludes the need for applying epidemiological principles to periodontal bone defects in order to better understand the natural history of periodontal disease and eradicate the factors responsible for their commencement and progression.[28],[29] It was concluded that in the age groups of 31–40 years and 50–60 years, the 2-wall and 3-wall defects were the dominant defects, while in the age group of 41–50 years, the 1-wall and 4-wall were the dominant defects. The least prevalent defect was the CB defect for all the age groups. IT defects increased with ageing. Males had two times more 3-wall defects than females. BB, LD and RA were found more in males than females, while DH, TR and RM were found more in females than males. The order of prevalence of IR defects in descending order was Grade I > II > III, both for males and females.
Limitations
The limitations of the present study were sample size variability for the parameters of age groups. Furthermore, the study holds true for moderate and severe chronic periodontitis patients when probing pocket depth was ≤4 mm, because patients with pocket depth ≤4 mm were not included, irrespective of the presence of defects, and subjectivity might have been there as a single examiner has classified bone defects, and there might be variability in the designation of defects.
Future perspective
Furthermore, future research relating the periodontal bone defects with ageing can be better studied under longitudinal study. For today's periodontists and patients, regeneration of the periodontium lost by periodontitis is an ultimate goal. The high prevalence, as well as great variation and complexity of bone defects, supports the view that treatment procedures with predictable success rates are of great significance in periodontal therapy.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
| 1 | Vrotsos JA, Parashis AO, Theofanatos GD, Smulow JB. Prevalence and distribution of bone defects in moderate and advanced adult periodontitis. J Clin Periodontol 1999;26:44-8. |
| 2 | Sachdeva S, Phadnaik MB, Mani A, Saluja H, Singh M. Prevalence and distribution of bone defects associated with moderate and severe periodontitis patients. Clin Epidemiol Global Health 2020;8:712-7. |
| 3 | Papapanou PN, Tonetti MS. Diagnosis and epidemiology of periodontal osseous lesions. Periodontol 2000 2000;22:8-21. |
| 4 | Persson RE, Hollender LG, Laurell L, Persson GR. Horizontal alveolar bone loss and vertical bone defects in an adult patient population. J Periodontol 1998;69:348-56. |
| 5 | Carranza FA, Takei H. The surgical phase of therapy. In: Newman MG, Takei HH, Carranza FA, editors. Carranza's Clinical Periodontology. 9th ed. Missouri: Saunder's; 2003. p. 719-24. |
| 6 | Helmi MF, Huang H, Goodson JM, Hasturk H, Tavares M, Natto ZS. Prevalence of periodontitis and alveolar bone loss in a patient population at Harvard School of Dental Medicine. BMC Oral Health 2019;19:254. |
| 7 | Natto ZS, Hameedaldain A. Methodological quality assessment of meta-analyses and systematic reviews of the relationship between periodontal and systemic diseases. J Evid Based Dent Pract 2019;19:131-9. |
| 8 | Sachdeva S, Phadnaik MB, Saluja H, Mani A. Newer morphologically classification system: In sight in periodontics. EC Dent Sci 2019;18:1197-206. |
| 9 | Caton J, Armitage G, Berglundh T, Chapple L, Jepsen S, Kornman K. A new classification scheme for periodontal and periimplant diseases and conditions-introduction and key changes from the 1999 classification. J Clin Periodontol 2018;45:1-8. |
| 10 | Papapanou PN, Sanz M, Buduneli N, Dietrich T, Feres M, Fine DH, et al. Periodontitis: Consensus report of workgroup 2 of the 2017 world workshop on the classification of periodontal and peri-implant diseases and conditions. J Clin Periodontol 2018;45:162-70. |
| 11 | John CG. Epidemiology and indexing of periodontal disease. J Periodontol 1959;30:133-9. |
| 12 | Eickholz P, Riess T, Lenhard M, Hassfeld S, Staehle HJ. Digital radiography of interproximal bone loss; validity of different filters. J Clin Periodontol 1999;26:294-300. |
| 13 | Saari JT, Hurt WC, Biggs NL. Periodontal bony defects on the dry skull. J Periodontol 1968;39:278-83. |
| 14 | Nielsen IM, Glavind L, Karring T. Interproximal periodontal intrabony defects. Prevalence, localization and etiological factors. J Clin Periodontol 1980;7:187-98. |
| 15 | Larato DC. Intrabony defects in the dry human skull. J Periodontol 1970;41:496-8. |
| 16 | Papapanou PN, Wennström JL, Gröndahl K. Periodontal status in relation to age and tooth type. A cross-sectional radiographic study. J Clin Periodontol 1988;15:469-78. |
| 17 | Hou GL, Hung CC, Yang YS, Shieh TY, Tsai CC. Radiographic alveolar bone loss in untreated Taiwan Chinese subjects with adult periodontitis measured by the digital scanning radiographic image analysis method. Dentomaxillofac Radiol 2003;32:104-8. |
| 18 | Müller HP, Ulbrich M. Alveolar bone levels in adults as assessed on panoramic radiographs. (I) Prevalence, extent, and severity of even and angular bone loss. Clin Oral Investig 2005;9:98-104. |
| 19 | Goldman HM, Stallard RE. Limitations of the radiograph in the diagnosis of osseous defects in periodontal disease. J Periodontol 1973;44:626-8. |
| 20 | Eickholz P, Kim TS, Benn DK, Staehle HJ. Validity of radiographic measurement of interproximal bone loss. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:99-106. |
| 21 | Rupprecht RD, Horning GM, Nicoll BK, Cohen ME. Prevalence of dehiscences and fenestrations in modern American skulls. J Periodontol 2001;72:722-9. |
| 22 | Larato DC. Furcation involvements: Incidence and distribution. J Periodontol 1970;41:499-501. |
| 23 | Svärdström G, Wennström JL. Prevalence of furcation involvements in patients referred for periodontal treatment. J Clin Periodontol 1996;23:1093-9. |
| 24 | Gupta OP. An epidemiological study of periodontal disease in Trivandrum, India. J Dent Res 1964;43:876. |
| 25 | Wouters FR, Salonen LE, Helldén LB, Frithiof L. Prevalence of interproximal periodontal intrabony defects in an adult population in Sweden. A radiographic study. J Clin Periodontol 1989;16:144-9. |
| 26 | Choi JY, Chaudhry K, Parks E, Ahn JH. Prevalence of posterior alveolar bony dehiscence and fenestration in adults with posterior crossbite: A CBCT study. Prog Orthod 2020;21:8. |
| 27 | Sun L, Yuan L, Wang B, Zhang L, Shen G, Fang B. Changes of alveolar bone dehiscence and fenestration after augmented corticotomy-assisted orthodontic treatment: A CBCT evaluation. Prog Orthod 2019;20:7. |
| 28 | Indurkar MS, Verma R. Evaluation of the prevalence and distribution of bone defects associated with chronic periodontitis using cone-beam computed tomography: A radiographic study. J Interdiscip Dent 2016;6:104-9. |
| 29 | Jain A, Bhavsar NV, Baweja A, Bhagat A, Ohri A, Grover V. Gender Associated Oral and Periodontal Health Based on Retrospective Panoramic Radiographic Analysis of Alveolar Bone Loss [Online First], IntechOpen; 30th September, 2020. [Doi: 10.5772/intechopen.93695]. Available from: https://www.intechopen.com/online-first/73398. |
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