Use of long implants with distal anchorage in the skull base for treatment of extreme maxillary atrophy : the remote bone anchorage concept

The objectives of this study are to present a new concept of the bone anchorage using long implants in remote bone sites and to discuss four cases treated with this method. Our patients were treated with long implants with a distant anchorage in the skull bone. The planning procedure, the construction of the drill guide, and the surgical protocol are described. In the clinical cases described, all four patients were rehabilitated with the remote bone anchorage concept using long implants anchored in the skull base. Patients were followed for 5 - 12 years and the implants remained present and stable in these time periods. The skull base implant is a new concept of bone anchorage using long implants. It can be a solution for complicated clinical situations (often failed bone reconstructions and implant placements) or an alternative for bone grafting and maxillary augmentation procedures. There is effective implant retention in the skull base, an anatomical area that is often overlooked for implant placement

Effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults: a retrospective cephalometric assessment

Background. This study aimed to assess the effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults by cephalometric assessment. Methods. This retrospective study was conducted on 142 cephalograms of patients who underwent orthodontic treatment with premolar extraction in four groups of (I) 40 class I patients with bimaxillary protrusion and maximum anchorage, (II) 40 class I patients with moderate crowding and anchorage, (III) 40 class II patients with maximum anchorage, and (IV) 22 skeletal class III patients with maximum anchorage. The dimensions of the nasopharynx, velopharynx, oropharynx, and hypopharynx, and hyoid bone position were assessed on pre- and postoperative lateral cephalograms using AudaxCeph v6.1.4.3951 software. Data were analyzed by the Chi-square test, paired t-test, and Pearson's correlation test (alpha D 0.05). Results. A significant reduction in oropharyngeal, velopharyngeal, and hypopharyngeal airway dimensions was noted in groups I, III, and IV (P <0:001), which was correlated with the magnitude of retraction of upper and lower incisors (r =0:6-0:8). In group II, a significant increase was observed in oropharyngeal and velopharyngeal dimensions (P < 0:001). A significant increase in nasopharyngeal dimensions occurred in all groups (P < 0:001). Also, in groups I and III, the position of hyoid bone changed downwards and backwards, which was correlated with reduction in airway dimensions (r =0:4-0:6). Conclusion. According to the present results, extraction orthodontic treatment affects upper airway dimensions and hyoid bone position. Maximum anchorage decreases airway dimensions while moderate anchorage increases airway dimensions

Comparative anchorage maintenance between the intercanine coil, lip bumper, and mandibular cervical traction during cuspid retraction

Thesis (M.Sc.D.)--Boston University School of Graduate Dentistry, 1972 (Orthodontics)Bibliography included.The present study was undertaken to compare the efficiency of three different biomechanical mechanisms in preserving mandibular molar anchorage. Thirty-five patients were treated with intercanine coil, lip bumper, 9r mandibular cervical traction through the end of cuspid retraction. Midtreatment cephalograms were then taken. Superimposition of these midtreatment cepbalograms with the pretreatment cephalograms provided the author with the net mesial or distal movement of the mandibular first molar in each case. The data obtained from each case was accordingly placed in the appropriate biomechanical group. Each group was then statistically related to one another by means of the Mann-Whitney U Test. It was found that a stastically significant difference existed between lower cervical traction and the intercanine coil. The confidence level obtained (P < .02) indicated that less than two cases out of a hundred had a chance of coming from the same population. This data also showed a mean increase in mandibular anchorage with lower cervical traction ( +.062 mm. gained) indicating that there may be very good possibilities for this system to be used in orthodontic cases when anchorage is of a critical nature

Palatal skeletal anchorage: multiple applications with a single appliance

Using a single bone-borne maxillary appliance with twofold mechanics, that is, rapid palatal expander and nonfrictional distalizing appliance (Pendulum) is a valuable option to treat young-adult patients with poor compliance. In this particular case, the same appliance was used to disinclude 2.3, eliminating reaction forces on the arch. Therefore, the first expansive phase was followed by the distalizing phase. After enough space was obtained for the recovery of tooth 2.3, a triple-looped titanium-molybdenum alloy (TMA) spring was used to perform canine orthodontic traction. The core concept is that digital planning and optimal positioning of two palatal mini-screws can ensure a bicortical anchorage which, in turn, enabled to tolerate the different orthodontic phases. As a matter of fact, a tooth-bone-borne anchorage was followed by a pure bone-borne anchorage with no lost of stability

Orthodontic palatal implants: clinical technique

The aim of this paper is to familiarize the readers with some of the clinical considerations necessary to ensure successful use of mid-palatal implants. Both surgical and technical aspects will be discussed along with a description of impression techniques used

The effect of miniscrew length and bone density on anchorage resistance: An in vitro study

Introduction > With conventional anchorage, it is usually hard to accomplish a satisfactory result with an absolute anchorage, and this limitation could be resolved by the usage of mini-screw. The successful rate of miniscrew usage depends on its stability, which was determined by its length, bone density, cortical bone thickness, the insertion technique, the insertion angle, and the applied loads. Objective > To observe the effect of miniscrew length and bone density on anchorage resistance. Material and methods > Thirty pieces of miniscrew with 1.6 mm in diameter were divided into three groups based on its length (n = 10): 10 mm (L), 8 mm (M), and 6 mm (S). Each group was further divided into 2 sub-groups: to be planted in optimal density bovine ribs (L1, M1, S1) and to be planted in low-density bovine ribs (L2, M2, S2). The density of bovine ribs was measured by CBCT. After the insertion of miniscrews based on respective groups, tensile test was done by means of Autograf Univerval Testing Machine to measure its stability. The data recorded was analysed using the Least Significant Difference (LSD) Fisher's test. Results > The results of this study showed that L1 provided the greatest stability than other groups. On the other hand, the least stability was found in S2. Conclusion > The length of miniscrew and the density of bone affect the stability of miniscrew. In bone with optimum density, 10 mm and 8 mm miniscrew equipped good anchorage resistance while in bone with low-density only 10 mm miniscrew provided favourable anchorage resistance

Er:YAG laser, piezosurgery, and surgical drill for bone decortication during orthodontic mini-implant insertion: primary stability analysis-an animal study

It is important to identify factors that affect primary stability of orthodontic mini-implants because it determines the success of treatment. We assessed mini-implant primary stability (initial mechanical engagement with the bone) placed in pig jaws. We also assessed mini-implant insertion failure rate (mini-implant fracture, mini-implants to root contact). A total of 80 taper-shaped mini-implants (Absoanchor® Model SH1312-6; Dentos Inc., Daegu, Korea) 6 mm long with a diameter of 1.1 mm were used. Bone decortication was made before mini-implant insertion by means of three different methods: Group G1: Er:YAG laser (LiteTouch®, Light Instruments, Yokneam, Israel) at energy of 300 mJ, frequency 25 Hz, fluence 38.2 J/cm2, cooling 14 ml/min, tip 1.0 × 17 mm, distance 1 mm, time of irradiation 6 s; Group G2: drill (Hager &amp; Meisinger GmbH, Hansemannstr, Germany); Group G3: piezosurgery (Piezotom Solo, Acteon, NJ, USA). In G4 group (control), mini-implants were driven by a self-drilling method. The primary stability of mini-implants was assessed by measuring damping characteristics between the implant and the tapping head of Periotest device (Gulden-Medizinteknik, Eschenweg, Modautal, Germany). The results in range between − 8 to + 9 allowed immediate loading. Significantly lower Periotest value was found in the control group (mean 0.59 ± 1.57, 95% CI 0.7, 2.4) as compared with Er:YAG laser (mean 4.44 ± 1.64, 95% CI 3.6, 5.3), piezosurgery (mean 17.92 ± 2.73, 95% CI 16.5, 19.3), and a drill (mean 5.91 ± 1.52, 95% CI 5.2, 6.6) (p &lt; 0.05). The highest failure rate (33.3%) during mini-implant insertion was noted for self-drilling method (G4) as compared with G1, G2, and G3 groups (p &lt; 0.05). The small diameter decortication by Er:YAG laser appeared to provide better primary stability as compared to drill and piezosurgery. Decortication of the cortical bone before mini-implant insertion resulted in reduced risk of implant fracture or injury of adjacent teeth. The high initial stability with a smaller diameter of the mini-implant resulted in increased risk of fracture, especially for a self-drilling metho

Er:YAG laser, piezosurgery, and surgical drill for bone decortication during orthodontic mini-implant insertion: primary stability analysis-an animal study

It is important to identify factors that affect primary stability of orthodontic mini-implants because it determines the success of treatment. We assessed mini-implant primary stability (initial mechanical engagement with the bone) placed in pig jaws. We also assessed mini-implant insertion failure rate (mini-implant fracture, mini-implants to root contact). A total of 80 taper-shaped mini-implants (Absoanchor® Model SH1312-6; Dentos Inc., Daegu, Korea) 6 mm long with a diameter of 1.1 mm were used. Bone decortication was made before mini-implant insertion by means of three different methods: Group G1: Er:YAG laser (LiteTouch®, Light Instruments, Yokneam, Israel) at energy of 300 mJ, frequency 25 Hz, fluence 38.2 J/cm2, cooling 14 ml/min, tip 1.0 × 17 mm, distance 1 mm, time of irradiation 6 s; Group G2: drill (Hager &amp; Meisinger GmbH, Hansemannstr, Germany); Group G3: piezosurgery (Piezotom Solo, Acteon, NJ, USA). In G4 group (control), mini-implants were driven by a self-drilling method. The primary stability of mini-implants was assessed by measuring damping characteristics between the implant and the tapping head of Periotest device (Gulden-Medizinteknik, Eschenweg, Modautal, Germany). The results in range between − 8 to + 9 allowed immediate loading. Significantly lower Periotest value was found in the control group (mean 0.59 ± 1.57, 95% CI 0.7, 2.4) as compared with Er:YAG laser (mean 4.44 ± 1.64, 95% CI 3.6, 5.3), piezosurgery (mean 17.92 ± 2.73, 95% CI 16.5, 19.3), and a drill (mean 5.91 ± 1.52, 95% CI 5.2, 6.6) (p &lt; 0.05). The highest failure rate (33.3%) during mini-implant insertion was noted for self-drilling method (G4) as compared with G1, G2, and G3 groups (p &lt; 0.05). The small diameter decortication by Er:YAG laser appeared to provide better primary stability as compared to drill and piezosurgery. Decortication of the cortical bone before mini-implant insertion resulted in reduced risk of implant fracture or injury of adjacent teeth. The high initial stability with a smaller diameter of the mini-implant resulted in increased risk of fracture, especially for a self-drilling metho

Induced Ankylosis of a Primary Molar for Skeletal Anchorage in the Mandible as Alternative to Mini-Implants

Background Mesial protraction of mandibular posterior teeth requires increased anchorage to avoid undesired tooth movements. Orthodontic mini-implants have become a popular and successful way to increase skeletal anchorage in such cases. However, mini-implants may cause injury to adjacent teeth or anatomical structures and may lead to tissue inflammation. Induced ankylosed primary teeth have been used in the past as abutments for the protraction of the maxilla in cases of maxillary retrognathism. However, this technique has not been described in the literature for the protraction of mandibular molars. The aim of this paper is to present, through a case report, an alternative to mini-implant devices to maximize anchorage in the mandible by inducing ankylosis on a primary molar. Findings A 13-year-old female with class II right malocclusion, deep bite, and congenitally missing right second premolars was referred for orthodontic treatment. Treatment plan involved removal of the primary teeth and mesial protraction of the posterior. In the mandible, ankylosis was induced on the retained primary second molar by extraction, bisection, replantation of the mesial part after endodontic treatment, and bonding of a rigid splint. Ankylosis was diagnosed after 10 weeks and a closing T-loop sectional wire was inserted to move the permanent first molar mesially. At 6 months, the remaining space was closed using elastic chain on a rectangular stainless steel wire with tip-back bends, supported by class II elastics. Conclusions Induced ankylosis of primary teeth can be an alternative to orthodontic mini-implants in selected cases, with minimal risks and maximum biocompatibility