Reduced Arch Length as a Factor for 4-Implant Immediate Function in the Maxilla: A Technical Note and Report of 39 Patients Followed for 5 Years.

PURPOSE: To determine whether maxillary arch length deficiency treated with a V-4 implant placement method is adequate for immediate functional loading during a 5-year follow-up. MATERIALS AND METHODS: Thirty-nine patients were treated with maxillary immediate function from January 3, 2011 to February 28, 2011 and followed for a period of 5 years. Arch length after implant placement was measured retrospectively around the arch from the anterior sinus wall to the contralateral anterior sinus wall in a mid-alveolar arc on the occlusal view of the preoperative computed tomogram. Eight patients with an osseous arch length shorter than 45 mm were treated with a V-4 pattern. Thirty-one patients with an arch length longer than 45 mm were treated with an M-4 placement pattern. The aim was to determine whether immediate function with a shorter arch length could be obtained on the day of surgery using a V-4 placement and whether implant stability would persist during the 5-year follow-up. Any surgical events, including lost implants, were recorded in the charts. Late follow-up was performed by panoramic films. RESULTS: During the 2-month treatment period, 39 patients (8 with V-4 placement and and 31 with M-4 placement) received maxillary treatment. The 8 patients in the V-4 group had an arch length average of 36.0 mm available for osseointegration. The 31 patients in the M-4 group had an arch length average of 56.6 mm. There were 7 implant losses (and replacements) during the 5-year follow-up, 1 in the V-4 group and 6 in the M-4 group. CONCLUSION: When the arch length bone available for osseointegration is shorter than 45 mm, a V-4 placement strategy might enable successful 4-implant fixed denture support for immediate function.

Maxillary V-4: Four implant treatment for maxillary atrophy with dental implants fixed apically at the vomer-nasal crest, lateral pyriform rim, and zygoma for immediate function. Report on 44 patients followed from 1 to 3 years.

STATEMENT OF PROBLEM: The V-4 implant placement technique is important for restoring patients with maxillary atrophy, but little has been documented on the outcomes of these treatments. PURPOSE: The purpose of this study was to evaluate the outcome of immediate function after 1 year when implants were placed without vertical bone augmentation in Cawood-Howell Classes IV-VI maxillary atrophy (Class C-D by the "all-on-four" site classification) with the nasal crest, lateral pyriform rim, and sometimes the zygoma for apical implant fixation. MATERIAL AND METHODS: Function of implants that had been immediately loaded were studied retrospectively after 1 year in 44 patients from 2 different clinics. For each patient studied, 2 angled implants were placed in the midline in the nasal crest/vomer area, and typically, 2 implants were engaged apically in the lateral pyriform rim bilaterally. All 4 of the implants used were angled toward the midline in a V formation, termed "V-4" implant placement. Insertion torque, anterior-posterior spread, implant diameter, implant length, and posterior cantilever were recorded. Implant survival and bone stability were assessed after 1 year. When the lateral pyriform was highly deficient (Class D), zygomatic implants were used posteriorly. RESULTS: A total of 179 implants were placed in 44 patients followed for 1 to 3 years. Six implants were lost, all in 1 patient. Anterior-posterior spread averaged 16 mm, with an average cantilever of 7.5 mm. Except for the lost implant sites, bone levels were stable throughout treatment for all patients. CONCLUSIONS: The use of 4 implants angled toward the midline, including 2 implants placed into a V-shaped point at the nasal crest and 2 implants placed into an M-shaped point at the pyriform rim bilaterally, showed good stability after 1 year despite gross absence of bone mass as a result of severe maxillary atrophy. The V-4 placement pattern is important for patients with deficient bone mass between the sinus and nasal cavities. In Class D situations where lateral nasal rim bone mass is nearly absent, zygomatic implants can be used.

Anterior sinus grafts for angled implant placement for severe maxillary atrophy as an alternative to zygomatic implants for full arch fixed restoration: technique and report of 5 cases.

We report on 5 cases, 4 to demonstrate the anterior sinus graft technique for angled implant placement and 1 comparison zygomatic case, all for immediate function implant restoration despite severe maxillary atrophy. The sinus graft was low volume, with less than 5 mL of bone morphogenetic protein-2/absorbable collagen sponge allograft in a 50% mixture placed against the lateral nasal wall, often in conjunction with implant placement. The importance of the technique is to simplify treatment of severe maxillary atrophy for immediate function to avoid the need for zygomatic implant placement in the vast majority of severely atrophic maxillas.

Secondary stabilization of maxillary m-4 treatment with unstable implants for immediate function: biomechanical considerations and report of 10 cases after 1 year in function.

PURPOSE: Primary stability of dental implants, particularly when they are placed into immediate function in the maxilla, has been thought to be required. An alternative to primary stability is secondary stabilization, which can be obtained by a four-implant distribution pattern using 30-degree angulations for all four implants in the so-called "M-4" treatment scheme in combination with cross-arch stabilization from a prosthesis. If successful, the use of these two measures brings into question whether or not primary stability is required for immediate function in the maxilla. MATERIALS AND METHODS: Patients were treated with the M-4 implant scheme with immediate function, despite the instability of at least one of the four implants. Instability was defined as less than 15 Ncm of insertion torque and palpable mobility, and an average anteroposterior spread of 15 mm between each implant was sought. The patients were followed for 1 year. RESULTS: Ten patients were treated with a total of 40 implants. Composite insertion torque of the four implants was less than 100 Ncm in half of the patients; the average anteroposterior spread was 15.6 mm. After 1 year, no implants had been lost, and bone levels around all implants were at or near operative levels. There were no failures of provisional or definitive prostheses. CONCLUSIONS: M-4 distribution of implants with an average of 15 mm of anteroposterior spread and cross-arch stabilization did not require that all four implants had high insertion torque; in fact, all mobile implants stabilized and osseointegrated under these conditions.

Paranasal bone: the prime factor affecting the decision to use transsinus vs zygomatic implants for biomechanical support for immediate function in maxillary dental implant reconstruction.

Paranasal bone affects the decision-making process for placement of implants for immediate function in the highly resorbed maxilla. The most important bone for apical fixation of implants in this setting is the lateral nasal bone mass. Maximum available bone mass found at the pyriform above the nasal fossa, designated M point, can most often engage two implants placed at 30-degree angles. The second most important area of paranasal bone mass is the subnasal bone of the premaxilla, which is required to engage an angled implant at the alveolar crest. However, only 4 to 5 mm in height is needed when implants are angled posterior to engage M point. The third most important paranasal bone site for implant fixation is the midline nasal crest extending upward to the vomer. This site, which is usually type 1/2 bone, can engage implants apically and provide enough fixation for immediate function even if implants are short. These anatomical bone sites enable placement of implants to obtain a 12- to 15-mm anterior-posterior spread, which is favorable for immediate function.

Angled dental implant placement into the vomer/nasal crest of atrophic maxillae for All-on-Four immediate function: a 2-year clinical study of 100 consecutive patients.

PURPOSE: To report on the use of angled implants placed into the vomer/nasal crest to support a complete-arch maxillary prosthesis. MATERIALS AND METHODS: Consecutive patients were treated with the All-on-Four concept to restore the maxillary dentition. When bone volume in the subnasal region was inadequate, angled implants were placed into the vomer/nasal crest area to support the restoration. All implants were loaded immediately. RESULTS: One hundred consecutive maxillary All-on-Four patients were treated over a period of 2 years. Four hundred six implants were placed; 12 were inserted into the vomer/nasal crest area. One year later, at definitive restoration, the 12 vomer implants were found to be osseointegrated without bone loss or instability. CONCLUSIONS: Midline maxillary bone volume at the nasal crest appeared to be a viable alternative to the lateral nasal rim when subnasal bone was deficient. Vomer implants allowed for immediate function or were sometimes used as a rescue implant when an anterior implant failed.

BMP-2/ACS/allograft for combined maxillary alveolar split/sinus floor grafting with and without simultaneous dental implant placement: report of 21 implants placed into 7 alveolar split sites followed for up to 3 years.

This report presents seven patients who were treated with combined alveolar split/sinus grafting technique and dental implants and followed for 1 to 3 years. The grafting material included bone morphogenetic protein-2 in an absorbable collagen sponge plus allograft. The procedure was successful in all patients, who received implants either simultaneously with grafting or 4 to 6 months after grafting.

The all on 4 shelf: mandible.

The use of full arch alveolar reduction as an aide to doing All on 4 implant restoration in the mandible is presented. The osteoplasty is described as a flat "shelf" on which to place the restoration. The shelf approach is used to establish optimal implant position and angulation as well as to define anatomy to maximize implant fixation for immediate load prosthetics.

The All-on-4 shelf: maxilla.

All-on-4 treatment is facilitated by bone reduction to create prosthetic restorative space, establish maximum anterior posterior spread of implants, and to avoid pneumatized sites. Unlike a reduction alveloplasty for denture placement, the All-on-4 shelf enables optimal surgical prosthetic management of implant placement for the fixed hybrid prosthesis.

The maxillary M-4: a technical and biomechanical note for all-on-4 management of severe maxillary atrophy--report of 3 cases.

We present a technical note and 3 case reports of all-on-4 treatment of highly resorbed maxillas. The use of 4 angled implants, placed at as much as 30 degrees off axis, that engage the lateral nasal wall bone provide high torque fixation for immediate temporization. The technique is proposed as an alternative to sinus grafting and for use with multiple implants or zygomatic implants.

All-on-4 treatment of highly atrophic mandible with mandibular V-4: report of 2 cases.

This report contains a technical note and 2 case reports of the "all-on-4" treatment of the highly resorbed mandible. The use of 4 angled implants directed toward the midline of the mandible at 30 degrees angles provides the advantage of increased implant length and adequate insertion torque for immediate temporization. The technique engages or perforates the inferior border with implants placed in a spaced distribution to avoid fracture of the mandible. The technique is proposed as an alternative to bone graft reconstruction.

Dental implants--isn't it about time?

Long-term studies indicate that dental implants are the most successful restorations fabricated and placed by dentists; however, only 30 percent of the dentists in this country restore implants on a regular basis. This article provides a six-step process for adding implant restoration to the regular services general practitioners provide for patients.