Clinical Assessment of the Bone Width Following Lateral Ridge Expansion in Augmentation of Narrow Alveolar Ridges for Placing Immediate Dental Implants.

Background: Less residual alveolar bone at extraction site at esthetic and functional tooth position is the main limitation in placing a dental implant, especially at long-span edentulous ridges. This needs ridge augmentation. Aims: To assess bone width gain and implant stability following narrow ridge augmentation using the vertical ridge split technique. Materials and
Methods: In 22 subjects within the age group of 20-60 years and the mean age of 38.46 years. The vertical ridge split technique was done in all subjects for horizontal ridge augmentation. Paraesthesia, pain/discomfort, mobility, and radiographic crestal bone width were assessed 6 months postoperatively. The data were described as mean and standard deviation along with number and percentage. Paired t-test was also used keeping the level of significance at P < 0.05.
Results: Implant stability was seen in 86.36% (n = 19) study subjects and were not stable in 13.63% (n = 3) subjects. Bone width preoperatively was in the range of 3.1-4.4 mm with the mean value of 3.64 ± 0.41. Postoperatively, the bone width increased and was in the range of 5.2-6.3 mm with the mean value of 5.62 ± 0.45 mm. This increase postoperatively was statistically significant with a P value of <0.001.
Conclusion: The present study concludes that acceptable success results are seen using the ridge split technique with simultaneous dental implants placement in both atrophic maxilla and mandible. Copyright:

INTRODUCTION

Dental implants are favored over other fixed prostheses to replace missing teeth. Implants have many advantages over other teeth replacement options including remaining alveolar bone preservation, better hygiene, longevity, and no effect on adjacent teeth. However, there are few limitations in placing dental implants including less remaining alveolar bone and unfavorable ridge dimensions (transverse, sagittal, and or vertical).[1]

After tooth extraction, rapid remodeling occurs to fill the socket. The bone from the crest region is resorbed and is deposited in the apical area. This remodeling is rapid in the initial 2 weeks and continues for 6 months.[2] This results in marked morphologic alterations in soft tissues and bone around the extraction site leading to the hypermobile ridge crest. The alveolar bone is not only reduced in height but also causes 3D changes. More bone resorption in the buccal/lingual area results in knife-edge ridges. However, resorption is governed by various systemic factors, hormones, chewing patterns, and inflammations.[3]

The less residual alveolar bone at extraction site at esthetic and functional tooth position is the main limitation in placing a dental implant, especially at long-span edentulous ridges. More horizontal bone loss occurs compared to vertical loss with 5% crestal width loss within 1 year of extraction. These atrophic ridges limit endosseous implant placement and lead to problems after placement.[4]

Various techniques exist to augment these narrow ridges to get at least 1 mm of bone around placed implants. These techniques to widen ridges are bone block grafting, alveolar distraction osteogenesis, onlay grafting procedure, and lateral augmentation with/without bone regeneration. Each technique has its limitations including postoperative morbidity and surgical risks. Ridge widening techniques are bone spreading, osteotome technique, bone spreading, and ridge splitting.[5]

One such widely accepted technique is ridge split, which utilizes ridge expansion for implant placement or interpositional bone graft insertion. Ridge split is used for thin ridges before placing dental implants, which uses a mallet for splitting with minimal discomfort. Ridge split leads to cortical plates repositioning around dental implants resulting in bone regeneration. Bone regeneration occurs between the cortical plates that are expanded. Ridge split has advantages of the decreased cost, no surgical morbidity, less treatment duration, and the single surgical site.[6] Limited data in the literature exist concerning the use of the ridge split technique of narrow ridge augmentation in immediate dental implant placement. Hence, the present study was conducted to assess bone width gain and implant stability following narrow ridge augmentation using the vertical ridge split technique.

MATERIALS AND METHODS

The present prospective clinical study was conducted after obtaining clearance from the concerned Ethical committee. The study included 22 subjects from both genders within the age group of 20–60 years and the mean age of 38.46 years. The study subjects were recruited from the patients visiting the Oral and Maxillofacial surgery department for replacement of missing teeth.

The inclusion criteria for the study were sufficient residual alveolar ridge height between 3 and 5 mm within the age of 20–60 years. The subjects were excluded if they had an insufficient alveolar ridge of <3 mm, were medically compromised, had infections/pathologies at the implant site, had poor oral hygiene, and were smokers or did not give consent.

After final inclusion, detailed history and intraoral examination were done, followed by surgical site assessment with OPG, CBCT, and intraoral radiographs. The vertical ridge split technique was then done in all subjects for horizontal augmentation of the alveolar ridge under strict aseptic conditions using cylindro-conical screws [Figure 1]. Following ridge split, sandblasted, and acid-etched two pieces, titanium dental implants were placed immediately at the site. The length of implants placed in 22 subjects was between 8 and 13 mm having a diameter of 3.2–5 mm. Postsurgery oral hygiene instructions, mouthwash, analgesics, and antibiotics were prescribed for 5 days, and suture removal was done on the seventh postoperative day. At 3 months postoperative, healing abutment was placed, and 15 days after that abutment was placed. A follow-up was then done at 6 months postoperative.

Figure 1

(a) Ridge split using expansion screws. (b) Implant Insertion. (c) Surgical site Closure. (d) Preoperative CBCT (Coronal view). (e) Postoperative CBCT

The parameters assessed clinically were paraesthesia, pain/discomfort on percussion and force application, mobility, and radiographic crestal bone width with CBCT at 6 months postoperative [Figure 1]. CBCT was done only at 6 months and preoperatively. Functional implant loading was done at 6 months.

Paraesthesia was assessed using a neurosensory test and pain using Visual Analogue Scores (VASs). The collected data were subjected to the statistical evaluation for results formulation using SPSS software v. 23.0. The data were described as mean and standard deviation along with number and percentage. Paired t-test was also used keeping the level of significance at P < 0.05.

RESULTS

The present study was conducted to assess bone width gain and implant stability following narrow ridge augmentation using the vertical ridge split technique. The study included 22 subjects from both genders within the age group of 20–60 years and the mean age of 38.46 years. The demographic characteristics of the study subjects are described in Table 1.

Table 1

Demographic characteristics of the study subjects

Characteristics	%	n
Age
Mean±S.D	38.46±3.8
	20-60
Age range (years)
21-30	13.63	3
31-40	18.18	4
41-50	31.81	7
51-60	36.36	8
Gender
Females	59.09	13
Males	40.90	9
Implant placement site
Mandible	54.54	12
Maxilla	45.45	10

It was seen that there were 13.63% (n = 3) subjects were in the age range of 21–30 years, 18.18% (n = 4) subjects were in the age range of 31–40 years, 31.91% (n = 7) subjects were from 41 to 50 years group, and 36.36% (n = 8) subjects were from 51 to 60 years age group. The study had 59.09% (n = 13) females and 40.90% (n = 9) males. Concerning implant site placement, 54.54% (n = 12) implants were placed in the mandible, whereas 45.45% (n = 10) implants were placed in the maxilla [Table 1].

The study also assessed paraesthesia and pain [Table 2]. It was seen that paraesthesia was present in 9.09% (n = 2) subjects and was absent in 90.90% (n = 20) study subjects after implant placement. VAS scores were 0 in 59.09% (n = 13) subjects, 1 in 31.81% (n = 7) subjects, 2 in 1 subject, and 4.54% (n = 1) subjects had VAS value more than 2.

Table 2

Pain and paraesthesia after implant placement in the study subjects

Parameter	Subgroup	Percentage (%)	Number (n)
Paraesthesia	Absent	90.90	20
	Present	9.09	2
	Total	22	100
VAS scores	0	59.09	13
	1	31.81	7
	2	4.54	1
	More than 2	4.54	1
	Total	22	100

On assessing the implant stability and bone width postoperatively at 6 months recall, it was seen that implant stability was seen in 86.36% (n = 19) of study subjects and was not stable in 13.63% (n = 3) subjects. Bone width preoperatively was in the range of 3.1 n 4.4 mm with the mean value of 3.64 ± 0.41. Postoperatively, the bone width increased and was in the range of 5.2 n 6.3 mm with the mean value of 5.62 ± 0.45 mm. This increase postoperatively was statistically significant with a P value of <0.001 [Table 3].

Table 3

Clinical and radiographic outcomes at 6 months recall in the study subjects

Clinical outcomes	%		n
Stability of dental implant
Absent	13.63		3
Present	86.36		19
Total	22		100
	Range	Mean±S.D	P
Bone width alteration (mm)
Preoperatively	3.1-4.4	3.64±0.41	<0.001
Postoperatively	5.2-6.3	5.62±0.45

DISCUSSION

Dental implants have been widely adopted as a teeth replacement option. However, placing dental implants is difficult in areas with inadequate alveolar bone. An alveolar ridge expansion is an acceptable method for ridge augmentation and involves procedures like ridge expansion, bone spreading, and/or ridge splitting. The present study was conducted to assess bone width gain and implant stability following narrow ridge augmentation using the vertical ridge split technique. The study included 22 subjects from both genders (13 females and 9 males) within the age group of 20–60 years and the mean age of 38.46 years. Bone width preoperatively was in the range of 3.1–4.4 mm with the mean value of 3.64 ± 0.41.

It was seen that there were 13.63% (n = 3) subjects were in the age range of 21–30 years, 18.18% (n = 4) subjects were in the age range of 31–40 years, 31.91% (n = 7) subjects were from 41 to 50 years group, and 36.36% (n = 8) subjects were from 51 to 60 years age group. The study had 59.09% (n = 13) females and 40.90% (n = 9) males. Concerning implant site placement, 54.54% (n = 12) implants were placed in mandible, whereas 45.45% (n = 10) implants were placed in maxilla. These demographics were comparable to the demographic characteristics in the studies conducted by Ibrahim N et al.[7] in 2013 and Khoshal M et al.[8] in 2013 with the same study characteristics.

Concerning clinical parameters, implant stability, and bone width postoperatively at 6 months recall, it was seen that implant stability was seen in 86.36% (n = 19) study subjects and was not stable in 13.63% (n = 3) subjects. Bone width preoperatively was in the range of 3.1–4.4 mm with the mean value of 3.64 ± 0.41. Postoperatively, the bone width increased and was in the range of 5.2 n 6.3 mm with the mean value of 5.62 ± 0.45 mm. This increase postoperatively was statistically significant with a P value of <0.001. Bone width was assessed using CBCT. The study results shown were in agreement with the studies by Cortes AR et al.[9] in 2010 and Sethi A et al.[10] in 2012, where authors showed acceptable results on ridge expansion in both maxillary and mandibular atrophic ridges.

The study also assessed paraesthesia and pain after implant placement and ridge expansion. It was seen that paraesthesia was present in 9.09% (n = 2) subjects, and was absent in 90.90% (n = 20) study subjects after implant placement. VAS scores were 0 in 59.09% (n = 13) subjects, 1 in 31.81% (n = 7) subjects, 2 in 1 subject, and 4.54% (n = 1) subjects had VAS value more than 2. This shows that the ridge expansion procedure is painless.

The implant success was assessed by evaluating the implant stability. It was seen in 86.36% (n = 19) study subjects and were not stable in 13.63% (n = 3). These results were following the results of Dermarosi et al.[11] in 2009 and Arora V and Kumar D[12] in 2014, where success rates of more than 90% were shown following ridge split and simultaneous implant placement.

CONCLUSION

Within its limitations, the present study concludes that acceptable success results are seen using the ridge split technique with simultaneous dental implants placement in both atrophic maxilla and mandible. The ridge split technique provides a successful alternative to more invasive, time taking, and traumatic techniques of ridge augmentation. The ridge split technique has added advantages of being cost effective and less invasive. However, the study had few limitations including a smaller sample size, shorter monitoring period, geographical area biases, and not be done on very thin ridges. More longitudinal clinical studies are required with a long monitoring period and a larger sample size to reach a definitive conclusion.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.