Osteogenesis imperfecta (OI) is a rare genetic disorder characterized by a defect in collagen type I, resulting in bone fragility and connective tissue disjunction ^[1][2][1,2]. The severity of clinical presentation can vary from mild to severe phenotype, depending on the subtype of the disease. In 1979, Sillence et al. classified OI into subtypes I–IV, ranging from mild to lethal based on clinical and radiological features ^[2][3][2,3]. With advances in genetic sequencing, the classification has been updated, and now a total of 20 subtypes (Sillence types I–XX) are known [4]. In general, vascular alteration, hearing loss, and blue sclerae are clinical signs that occur in patients with OI. The combination of poor bone density and quality can lead to skeletal deformities, spontaneous bone fractures, and impaired bone repair [5]. Therefore, bisphosphonate therapy is the treatment of choice for patients with OI [6]. In addition, interdisciplinary dental treatment may be required to correct jaw and dental abnormalities ^[7][8][7,8]. Orofacial manifestations associated with OI include dentinogenesis imperfecta, dental and skeletal malocclusion, and tooth anomalies ^{[7][8][9][10]}[7,8,9,10].

Since tooth agenesis is commonly diagnosed in patients with OI (ranging from 10 to 22% in the literature ^{[11][12][13][14]}[11,12,13,14]), dental implants may be a reliable treatment option to replace absent teeth. While dental implants are a safe therapy with high survival rates in healthy patients [15], the treatment outcome in patients with OI is questionable due to the complications associated with the disease and its treatment. Not only bone fragility but also bisphosphonate therapy may influence implant treatment [8]. Case reports in the literature suggest that dental implant therapy may be a reliable option for patients with OI ^{[7][8][9][16][17][18][19][20][21][22][23][24]}[7,8,9,16,17,18,19,20,21,22,23,24]. Oral rehabilitation treatments, ranging from single crowns to implant-supported prostheses, showed an acceptable outcome at short-term follow-up.

2. Dental Implants in People with Osteogenesis Imperfecta

Common dental aberrations in patients with OI include malocclusion, with a class III occlusion being the most common ^{[10][12][25][26]}[10,12,29,30]; a high prevalence of tooth agenesis ^{[11][12][13][14]}[11,12,13,14]; dentinogenesis imperfecta; denticles; and obliteration within the pulp cavity ^[27][31]. Those clinical findings can result in reduced OHRQoL ^[28][29][30][32,33,34]. Due to the increased prevalence of missing teeth, which may be further exacerbated by the involvement of dentinogenesis imperfecta, implants may provide an option to replace the lost teeth, with a survival rate of 94.0% (Table 1).

	No. of Subjects	No. of Implants	No. of Failed Implants	Survival Rate
Subtype
I	10	42	1 *	97.%
III	4	14	2	85.7%
IV	6	33	33	97.0%
NA	3	17	3 *	88.9%
Bone Augmentation
Ridge Augmentation
Autogenous bone used	5	22	1	95.5%
Allograft used	1	8	0	100%
No augmentation	2	26	2	92.3%
NA	15	60	4 **	93.4%
Sinus Floor Elevation
Sinus floor elevation performed	4	19	1	94.7%
Not performed	9	55	6 **	89.1%
NA (or information missing on some implants)	10	42	0	100%
Surgical Procedure
Immediately loaded	4	14	0	100%
Two-stage procedure	18	100	7 **	93.0%
NA	2	2	0	100%
Abutment
Crown	10	24	1*	95.8%
Bridge	7	31	2*	93.5%
Crown + Overdenture	3	17	0	100%
Locator + Overdenture	1	2	0	100%
Ridge + Overdenture	4	32	0	100%
NA	1	7	1	85.7%
Failed before loading	2	3	3

	No. of Subjects	No. of Implants	No. of Failed Implants	Survival Rate
Subtype
I	10	42	1 *	97.%
III	4	14	2	85.7%
IV	6	33	1	97.0%
NA	3	17	3 *	88.9%
Bone Augmentation
Ridge Augmentation
Autogenous bone used	5	22	1	95.5%
Allograft used	1	8	0	100%
No augmentation	2	26	2	92.3%
NA	15	60	4 **	93.4%
Sinus Floor Elevation
Sinus floor elevation performed	4	19	1	94.7%
Not performed	9	55	6 **	89.1%
NA (or information missing on some implants)	10	42	0	100%
Surgical Procedure
Immediately loaded	4	14	0	100%
Two-stage procedure	18	100	7 **	93.0%
NA	2	2	0	100%
Abutment
Crown	10	24	1 *	95.8%
Bridge	7	31	2 *	93.5%
Crown + Overdenture	3	17	0	100%
Locator + Overdenture	1	2	0	100%
Ridge + Overdenture	4	32	0	100%
NA	1	7	1	85.7%
Failed before loading	2	3	3

NA—not answered; *—each “*” indicates one implant lost due to mechanical complications.

 

For the treatment of OI, bisphosphonates are often prescribed to increase bone mineral density in children and adults ^[6][31][32][6,37,38]. The various influences that bisphosphonates can have on dentistry are not yet fully understood. It is known that bisphosphonates can prevent bone resorption through their direct effect on osteoclasts ^[33][39]. However, this desired effect in OI may have further implications. Studies have shown that orthodontic tooth movement was slower in patients treated with bisphosphonates ^[34][35][40,41]. Despite this, affected patients were able to undergo both treatment with orthodontics and orthognathic surgery and achieved stable results. It should be taken into account that patients receiving bisphosphonate therapy have longer orthodontic treatment times and require greater forces ^[36][42]. This is especially important for preprosthetic restoration in order to prepare patients for definitive prosthetic treatment.

Most case reports did not indicate whether the patient was taking bisphosphonates. This information is essential to draw conclusions about the effects of bisphosphonates on implant survival or the occurrence of bisphosphonate-related osteonecrosis of the jaw (BRONJ). However, a recent study has shown that patients with a history of bisphosphonates are at no higher risk of implant failure than patients without a history of bisphosphonates ^[37][43]. Whether this is also the case in patients with OI and a history of bisphosphonates requires further investigation.

Another study by Contaldo et al. ^[38][44] showed that BRONJ does not occur in the pediatric OI population after dental procedures, but it is still unclear whether BRONJ can occur later in life when comorbidities develop.

Although sinus floor elevation and ridge augmentation are now standardized procedures when insufficient bone is available prior to implant placement, studies provided little information on these procedures in an OI population ^{[39][40][41][42]}[45,46,47,48]. Sinus elevation was performed in 19 implants prior to implant placement and ridge augmentation was reported for 30 implants. Onely of the nineteenne implants (5.3%) placed after failed in patient 23, in whom a sinus floor elevationlift was performed failed during the follow-up period with autogenous bone from the iliac crest in combination with allograft. No implant loss was reported in all other implants placed in which either a sinus floor elevation or ridge augmentation was performed prior to the placement.

There is still no standardized protocol for the preoperative use of antibiotics to prevent implant failure. While Park et al. ^[43][49] concluded that practitioners should not routinely use antibiotics in healthy patients, a recent study from Kim et al. ^[44][50] described a 53% reduced risk of implant failure in patients who received antibiotics preoperatively. When antibiotics are prescribed prior to dental implant placement, oral amoxicillin is used in most cases, according to a recent study in the United Kingdom ^[45][51].

Other antibiotics used were amoxicillin, cefuroxime, cefalexin, and cefazolin, all of which have been reported in the literature for preoperative treatment of dental implants ^[46][52].

Preoperative antibiotic use may reduce the risk of early implant failure.

In order to rehabilitate patients with missing teeth as quickly as possible, immediate loading with predictable results is increasingly performed, both in partially edentulous and completely edentulous patients ^[47][48][49][53,54,55]. In the included study by Prabhu et al. [21], the patient was prosthetically rehabilitated with a total of 10 immediately loaded maxillary implants. The follow-up period for the first implant placed in this study was 48 months, with probing depths ranging from 2 to 4 mm.

Although data were still insufficient to provide predictive results, the included case reports showed that implant treatment with immediate loading protocol may also be a viable option for treating patients with OI.

3. Conclusions

Prosthetic rehabilitation of patients with osteogenesis imperfecta with dental implants has a high implant survival rate. Therefore, dental implants should be a method of choice when restoring affected patients. More cases with longer follow-up periods are needed to further evaluate implant survival. It is important that future studies provide complete patient data so that conclusions can be drawn about possible adverse effects or alternative causes of implant failure.