Sandwich osteotomy for the reconstruction of deficient alveolar bone.

Alveolar bone deficiency is a very common problem encountered by the practitioner when planning dental implants. The severity of the deficiency is variable. Many practitioners perform augmentation using the method they feel comfortable with and do not necessarily use the most appropriate method. This is a retrospective study on 21 patients between the ages of 25 and 63 years exhibiting moderate vertical alveolar bone deficiency and treated by the sandwich technique. Mean vertical bone gain was 7.5mm. Sixty-one dental implants were inserted showing a survival rate of 96.7% with a median of 3.1 years follow-up. Main advantages of the method include minimal relapse, single operation and preservation of the native cortical bone in the occlusal surface. We believe the surgeon should maintain the capability of using different augmentation techniques and utilize them appropriately for different severities of deficiency. We wish to establish a paradigm for using different augmentation methods We recommend using the sandwich technique in the moderate deficient cases as described in this work, using alveolar distraction osteogenesis for the severe cases as described in our previous work, where lack of soft tissue for proper closure is a major limitation, and using guided bone regeneration for minor deficiencies.

Two-stage reconstruction of the severely deficient alveolar ridge: bone graft followed by alveolar distraction osteogenesis.

Distraction osteogenesis for the augmentation of severe alveolar bone deficiency has gained popularity during the past two decades. In cases where the vertical bone height is not sufficient to create a stable transport segment, performing alveolar distraction osteogenesis (ADO) is not possible. In these severe cases, a two-stage treatment protocol is suggested: onlay bone grafting followed by ADO. An iliac crest onlay bone graft followed by ADO was performed in 13 patients: seven in the mandible and six in the maxilla. Following ADO, endosseous implants and prosthetic restorations were placed. In all cases, the onlay bone graft resulted in inadequate height for implant placement, but allowed ADO to be performed. ADO was performed to a mean total vertical augmentation of 13.7mm. Fifty-two endosseous implants were placed. During a mean follow-up of 4.85 years, two implants failed, both during the first 6 months; the survival rate was 96.15%. In severe cases lacking the required bone for ADO, using an onlay bone graft as a first stage treatment increases the bone height thus allowing ADO to be performed. This article describes a safe and stable two-stage treatment modality for severely atrophic cases, resulting in sufficient bone for implant placement and correction of the inter-maxillary vertical relationship.

Internal mandibular distraction to relieve airway obstruction in children with severe micrognathia.

Congenital craniofacial malformations such as Pierre Robin sequence or Treacher Collins syndrome are associated with mandibular micrognathia, resulting in obstructive sleep apnea (OSA) due to a decreased pharyngeal airway; in severe cases this leads to tracheostomy dependence. We present a series of 18 patients in whom we performed mandibular lengthening using internal distraction devices to relieve airway obstruction. Seven were tracheostomy-dependent and 11 were respiratory distressed without tracheostomy. The mandible was distracted at a rate of 1mm per day. Following 3 months of consolidation for bony maturation, the distraction devices were removed. Results demonstrated forward mandibular elongation of a mean 22mm (range 20-25mm) and an increase in SNB angle and in pharyngeal airway. All patients with tracheostomies were decannulated, and there was an improved airway with resolution of signs and symptoms of OSA and elimination of oxygen requirement in all patients. We conclude that mandibular distraction using internal devices is a useful and comfortable method for younger children to expand the mandible forward and increase the pharyngeal airway.