Objectives: The objective was to assess the accuracy of orthognathic surgical planning using three-dimensional virtual planning compared with conventional two-dimensional planning.

Material and Methods: MEDLINE (PubMed), Embase and Cochrane Library search combined with hand-search of relevant journals was conducted to identify randomized controlled trials (RCTs) published in English through August 2^nd, 2022. Primary outcomes included postsurgical accuracy of hard and soft tissue. Secondary outcomes included treatment planning time, intraoperative time, intraoperative blood loss, complications, financial expenses, and patient-reported outcome measures (PROMs). Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool and GRADE system.

Results: Seven RCTs characterised by low, high, and unclear risk of bias fulfilled inclusion criteria. Included studies disclosed conflicting results regarding accuracy of hard and soft tissue as well as treatment planning time. The intraoperative time was shortened, and financial expenses were increased with three-dimensional virtual surgical planning (TVSP), while no planning-related complications were revealed. Comparable improvement in PROMs were reported with TVSP and two-dimensional planning.

Conclusions: Future orthognathic surgical planning will indisputable be performed by three-dimensional virtual planning. The financial expenses, treatment planning time, and intraoperative time will therefore probably decrease due to further development of three-dimensional virtual planning techniques. The hard and soft tissue accuracy between planned position and achieved surgical outcome seems to be improved by three-dimensional virtual planning compared with two-dimensional planning, although results are inconsistent. Further development of three-dimensional virtual planning involving cutting guides and patient-specific osteosynthesis plates are therefore needed to improve the accuracy of orthognathic surgical planning.

Objectives: The aims of this retrospective study were to objectively assess bone density values obtained by cone-beam computed tomography and to map the periapical and inter-radicular regions of the mandibular bone.

Material and Methods: In total, periapical bone regions of 6898 roots scanned by cone-beam computed tomography were evaluated retrospectively, and the results were recorded using Hounsfield units (HU).

Results: The correlation between periapical HU values of adjacent mandibular teeth were strongly positive (P ˂ 0.01). The anterior region of the mandible yielded highest mean HU value (633.55). The mean periapical HU value of the premolar region (470.58) was higher than that was measured for molar region (374.58). The difference between furcation HU values of the first and second molars was unnoticeable.

Conclusions: The results of this study have tried to evaluate the periapical regions of all mandibular teeth, which could ease to predict the bone radiodensity before implant surgery. Even though the Hounsfield units provide the average radio-bone density, a site-specific bone tissue evaluation of each case is essential for appropriate cone-beam computed tomography preoperative planning.

Objectives: The aim of this radiological study is to evaluate the lingual concavity dimensions and possible implant length in each posterior tooth region according to posterior crest type classification by using cone-beam computed tomography.

Material and Methods: According to inclusion criteria, 836 molar teeth regions from 209 cone-beam computed tomography images were evaluated. Posterior crest type (concave, parallel, or convex), possible implant length, lingual concavity angle, width, and depth were recorded.

Results: In each posterior tooth region, concave (U-type) crest was detected most frequently while convex (C-type) was the lowest. Possible implant length values were higher in second molar regions than first molars. Lingual concavity width and depth were decreasing from second molars to first molars for both sides. Additionally, lingual concavity angle showed higher values in second molar sites than first molars. In all molar teeth regions, lingual concavity width values were the highest in concave (U-type) crest type while they were the lowest in convex (C-type) crest type (P < 0.05). Lingual concavity angle values were recorded as the highest in concave (U-type) and the lowest in convex (C-type) crest type at the left first molar and right molars (P < 0.05).

Conclusions: The lingual concavity dimensions and possible implant length may vary according to crest type and edentulous tooth region. Due to this effect, the surgeons should examine crest type clinically and radiologically. All parameters in the present study are decreasing while moving from anterior to posterior as well as from concave (U-type) to convex (C-type) morphologies.

Background: Clinical examination revealed large periapical lesion. Patient was referred for endodontic treatment of right mandibular first and second molars before planed cystectomy. The aim of this case report is to present the clinical approach to preserve healthy pulp tissue by combining nonsurgical root canal treatment and vital pulp therapy for mature mandibular molar.

Methods: A minimally invasive endodontic therapy treatment with combination of nonsurgical root canal treatment and vital pulp therapy was performed. Osteotomies around wisdom teeth were performed, wisdom teeth extracted, and cyst was removed.

Results: At the 19 months follow-up appointment patient had no complaints, radiographically full regeneration of periapical bone was observed.

Conclusions: A minimally invasive endodontic therapy treatment with combination of nonsurgical root canal treatment and vital pulp therapy for mature mandibular molar before a planned cystectomy could be considered as a treatment option showing good long-term results.

Background: Congenital cystic swellings involving the floor of the mouth include various lesions such as developmental cysts (e.g., dermoid and epidermoid cysts), ranulas, vascular malformations etc. However, coexistence of such conditions, possibly with a cause-and-effect- relationship, is rare. The purpose of this case report is to present a rare case of a congenital epidermoid cyst associated with a mucous retention cyst in a newborn.

Methods: A 6-month-old female infant was referred to an Oral Medicine Clinic in Athens, Greece on October 2019 for evaluation of a swelling at the floor of the mouth, first noticed by her paediatrician just after birth. Clinically, a yellowish “pearly” nodule in close association with the orifice of the left submandibular duct, posteriorly transitioning to a diffuse bluish cystic swelling of the left floor of the mouth was observed. With a provisional diagnosis of a dermoid cyst and/or ranula, a surgical excision was performed under general anaesthesia.

Results: Histopathologically, a well-defined, keratin-filled, cystic cavity lined by orthokeratinized stratified squamous epithelium was observed in the anterior aspect while posteriorly and in close proximity, a dilated salivary duct lined by cylindrical, cuboidal or pseudostratified epithelium was noted. A final diagnosis of an epidermoid cyst intimately associated with a mucus retention cyst (ranula) of the submandibular duct was rendered.

Conclusions: The coexistence of two cystic lesions in the floor of the mouth with features of epidermoid and mucous retention cyst, respectively, is rare and its pathogenesis intriguing, especially in a newborn.